Claims:
1. An arc less switching device comprising:
a solid state device (1);
a controller; and
an electromechanical contactor (2) that is positioned in parallel with any or both of the solid state device and the controller, wherein the controller is placed centrally in communication with the electromechanical contactor (2) and the solid state device (1) such that the arc less switching device utilizes the solid state device (1) to make and break DC electrical circuit without any arc and carry current with less voltage drop and low power loss.
2. The arc less switching device as claimed in claim 1, wherein the solid state device comprises an insulated housing (3), a cover (4), and a PCB assembly (5), wherein the PCB assembly (5) is adapted to fit in at least one rectangular slot (6) of the insulated housing (3).
3. The arc less switching device as claimed in claim 2, wherein the insulated housing (3) comprises:
a base portion (7) having a first surface and a second surface, wherein the first surface and the second surface having at least one of a closed horizontal slot (9) and an open vertical slot (8) for mounting the solid state device;
one or more tool entry slots (11) allowing an entry for a tool to connect/operate the PCB assembly (5);
one or more heat dissipation slots (12) for adequate heat dissipation;
one or more wire entry slots (13, 14) allowing entry and/or exit for one or more power and control wires;
one or more tool entry slots (15) for entry of a toggle switch so as to switch ON/OFF a control/power supply.
4. The arc less switching device as claimed in claim 1, wherein the PCB assembly (5) comprises at least any or combination of one or more active components, one or more passive components, one or more insulated terminal connectors for connection of control and power supply, one or more load contacts, and one or more power contacts.
5. The arc less switching device as claimed in claim 1, wherein the solid state device (1) is electrically connected to an electromagnetic coil.
6. The arc less switching device as claimed in claim 1, wherein a source terminal and a drain terminal of the solid state device 1 is in parallel to a line terminal and a load terminal of the electromechanical contactor (2).
7. The arc less switching device as claimed in claim 1, wherein the electromechanical contactor (2) comprises a set of main contacts which provide a first current path, and the solid state device (1) provides a second parallel current path which diverts current away from the main contacts when the main contacts are being opened or closed, and the first current path and second current path provide a path for direct current.
8. The arc less switching device as claimed in claim 1, wherein the solid state device (1) further comprises a gate drive, wherein the gate drive is connected to the solid state switch and is operable to turn the solid state switch OFF or ON.
9. A method for enabling arc less switching, said method comprising the steps of:
providing a solid state device (1), a controller, and an electromechanical contactor (2) that is positioned in parallel with any or both of the solid state device and the controller, and the controller is placed centrally in communication with the electromechanical contactor (2) and the solid state device (1), wherein the solid state device (1) is placed in parallel with a set of main contacts associated with the electromechanical contactor (2); and
making and breaking, by utilizing the solid state device (1), DC electrical circuit without any arc and carry current with less voltage drop and low power losses.
10. The method as claimed in claim 1, said method further comprising the step of: moving the main contacts to either open or close positions, and there while passing the DC current through said solid state device (1) to achieve making and breaking without any arc and carry current with less voltage drop and low power losses.
, Description:
TECHNICAL FIELD
[0001] The present disclosure generally relates to hybrid direct current (DC) contactors and, more particularly to, but not by way of limitation, solid state circuit arrangement for dc hybrid contactor, and a system and method for controlling operation of a hybrid DC contactor that improves performance of the hybrid contactor.

BACKGROUND
[0002] Background description includes information that may be useful in understanding the present invention. It is not an admission that any of the information provided herein is prior art or relevant to the presently claimed invention, or that any publication specifically or implicitly referenced is prior art.
[0003] Electro-mechanical contactors are used in a variety of environments for turning on and off a power source to a load electrically. The contactors include movable contacts and fixed contacts. The movable contacts are connected to an electromagnet and are controlled to selectively turn on or off power from the source to the load. The contacts are typically maintained in an open position by way of a spring and are caused to translate to a closed position when power to the electromagnet's coil is applied.
[0004] When electro-mechanical contactors are used for interrupting AC currents, it is recognized that there is always a time when the current becomes zero. Electro-mechanical contactors can thus interrupt current at the zero current and when the contacts separated. However, when electro-mechanical contactors are used in a DC voltage system, an electric arc may form in the space between contacts during transition of the movable contacts between the closed and open positions. Without intervention, this arc will continue until the separation between the contacts is too large to sustain the arc. When interrupting DC current, the separation between the fixed and moving contacts has to be large (in air, under standard pressure conditions). Thus, it is known to experts in the field that, for interrupting DC currents, special magnets are required in DC contactors.
[0005] To address the issue of not being able to interrupt the current caused by arcing, hybrid DC contactors have been developed that incorporate a solid state device that is connected in parallel with the mechanical main contacts. The solid state device may, for example, include an IGBT switch, a snubber capacitor, and a snubber resistor. In operation, when changing the mechanical main contact from the closed state to the open state, the solid state device that is connected in parallel to the mechanical main contact is turned on first. The current flowing through the mechanical main contact is thus caused to flow through the solid state device. Next, the mechanical main contact is allowed to open by removing the voltage applied to the electromagnet coil that controls positioning of the mechanical main contact. By turning on the solid state device prior to opening the mechanical main contact, the voltage on both ends of the turned-on solid state device and the mechanical main contact can be opened with only a minimal voltage not sufficient to form an arc.
[0006] While existing hybrid DC contactors do function to provide a bypass path to the mechanical contacts, there are drawbacks to the design and control of such hybrid DC contactors. One such drawback to existing hybrid DC contactors is that, when bypassing the main contacts, the separation between the moving and fixed contacts cannot be determined. Not knowing the separation, the sold state device is left closed for a fixed but long enough delay to ensure interruption of the current. As such, the full current value needs to flow through the solid state switch for several milliseconds, necessitating that the solid state switch be oversized to handle several milliseconds of current. This oversizing of the IGBT switch increases the production cost of existing hybrid DC contactors.
[0007] Another drawback to existing drawback hybrid DC contactors is that the switching time of the contactor is prolonged enough that the contacts may still be exposed to an undesirable “restrike” of arcing. That is, when interrupting DC currents due to the inductance in the circuit, the voltage across the main contacts rapidly rises, and this rapid rise in voltage can cause a breakdown of the air gap between the fixed and moving contacts called “restrike.” The fixed and moving contacts have to be separated by a sufficient gap to prevent such a restrike (that is based on contactor design and other conditions). Still another drawback of the prior art hybrid DC contactors is that, if there is restrike of the arc, there is no capability to know the condition and this could result in the burning out of the contactor. Still another drawback to existing drawback hybrid DC contactors is that they do not provide galvanic isolation, which is desirable in some implementations of hybrid DC contactors.
[0008] Further to this, most of the DC air-break switching involves standing arcing between its cathode and anode, which leads to heavy erosion of the contact material and burning of the adjacent insulation supporting the current carrying parts. The intensity of the arc is normally reduced by means of forcibly dragging the standing arc towards the arc quenching unit, due to self-magnetic field developed by the arc and external magnetic field developed by a blowout coil or permanent magnets. Apart from this a simplest way to improve the arc voltage is to connect all the poles of an existing ac contactor in series so as to have multiple air break contacts. Yet another method is to break the electromechanical contacts with shorted resistors in parallel with it. This way while breaking the DC arc, is diverted towards the resistive path so as to limit the arc current. There are few other concepts adopted such as capacitors with discharge resistors are connected in parallel with the series connected pole of the contactor. One of the poles is utilized to break the negative or neutral/earth conductor so as to provide mechanical isolation between the line and load terminal. In certain case the electromechanical contacts are connected in parallel with “L-C” circuit, which superimpose a high frequency resonant AC component with the DC current so as to provide natural zero crossing at every half cycle. This helps to reduce the intensity of arcing as the arc is self-quenched at every zero crossover. Further work has been explored towards a roller contact instead of butt contact for DC current switching, which aids in improving the contact profile due to wiping action across its peripheral surface. The above technologies revealed, though reduce the intensity and duration of the arc, but could not be able to completely eliminate the arc. In order to avoid arcing between the anode and cathode contacts, the alternate technology, which has been widely adopted for manually and automatically operated device such as circuit breaker and contactor, is towards a solid state hybrid switching.
[0009] Also, at present air-break electromechanical contactors meant for switching DC electrical circuit, is subjected to standing arcing between its cathode and anode electrode. This leads to heavy erosion of the contacts and burning of adjacent insulation, which reduces the overall electrical life of the contactor and in extreme case, fails it at premature stage. Several arc quenching techniques deployed so as to reduce the intensity of the arcing by means of controlling the arc duration, current limiting and hence the arc energy. However with all this effort arcing between the contacts cannot be avoided. Solid state contactor or relay to some extent make and break the DC circuit without any arcing but owing to high voltage drop across the source and drain and hence high power loss, demand bulkier size heat sink, which increases the overall panel area and volume. Moreover it’s not an economical solution as the rating of the device increases. On contrast to the above said DC switching technology, a hybrid contactor would make and break the DC electrical circuit without any arc and carry continuous current with very less voltage drop and per pole power loss. In addition to this it is never subjected to contact repulsion due to holms and Lorentz force.
[0010] The aforementioned limitations of the existing prior-art are recognized by the inventors hereof and some or all of these limitations have been addressed by various embodiments of the present invention. The inventors of this applications recognized that it would be advantageous to provide a solid state circuit arrangement for an electromechanical contactor, which has better response time, positive electrical isolation between the control and power circuit, eliminate electromagnetic transformer, programmed microcontroller for logical sequence of operation between contactor and solid state device.
[0011] All publications herein are incorporated by reference to the same extent as if each individual publication or patent application were specifically and individually indicated to be incorporated by reference. Where a definition or use of a term in an incorporated reference is inconsistent or contrary to the definition of that term provided herein, the definition of that term provided herein applies and the definition of that term in the reference does not apply.
[0012] In some embodiments, the numbers expressing quantities of ingredients, properties such as concentration, reaction conditions, and so forth, used to describe and claim certain embodiments of the invention are to be understood as being modified in some instances by the term “about.” Accordingly, in some embodiments, the numerical parameters set forth in the written description and attached claims are approximations that can vary depending upon the desired properties sought to be obtained by a particular embodiment. In some embodiments, the numerical parameters should be construed in light of the number of reported significant digits and by applying ordinary rounding techniques. Notwithstanding that the numerical ranges and parameters setting forth the broad scope of some embodiments of the invention are approximations, the numerical values set forth in the specific examples are reported as precisely as practicable. The numerical values presented in some embodiments of the invention may contain certain errors necessarily resulting from the standard deviation found in their respective testing measurements.
[0013] As used in the description herein and throughout the claims that follow, the meaning of “a,” “an,” and “the” includes plural reference unless the context clearly dictates otherwise. Also, as used in the description herein, the meaning of “in” includes “in” and “on” unless the context clearly dictates otherwise.
[0014] The recitation of ranges of values herein is merely intended to serve as a shorthand method of referring individually to each separate value falling within the range. Unless otherwise indicated herein, each individual value is incorporated into the specification as if it were individually recited herein. All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g. “such as”) provided with respect to certain embodiments herein is intended merely to better illuminate the invention and does not pose a limitation on the scope of the invention otherwise claimed. No language in the specification should be construed as indicating any non-claimed element essential to the practice of the invention.
[0015] Groupings of alternative elements or embodiments of the invention disclosed herein are not to be construed as limitations. Each group member can be referred to and claimed individually or in any combination with other members of the group or other elements found herein. One or more members of a group can be included in, or deleted from, a group for reasons of convenience and/or patentability. When any such inclusion or deletion occurs, the specification is herein deemed to contain the group as modified thus fulfilling the written description in accordance with the appended claims.

SUMMARY
[0016] The aforementioned limitations of the existing arc less switching techniques are recognized by the inventors hereof and some or all of these limitations have been addressed by providing a DC hybrid contactor so as to overcome all the arcing issues that is prevailing with an electromechanical contactor. It makes and breaks the electrical circuit without any arcing and carries the current with less voltage drop and power loss. Thus do not demand a bulkier size heat sink as compared to solid state contactor or relay and can be developed with nearly the same size to that of an electromechanical contactor.
[0017] Accordingly, the present invention provides a new, efficient, technically advanced, system and method which provide a solid state circuit arrangement for an electromechanical contactor, which has better response time, positive electrical isolation between the control and power circuit, eliminate electromagnetic transformer, programmed microcontroller for logical sequence of operation between contactor and solid state device.
[0018] The present disclosure generally relates to hybrid direct current (DC) contactors and, more particularly to, but not by way of limitation, solid state circuit arrangement for dc hybrid contactor, and a system and method for controlling operation of a hybrid DC contactor that improves performance of the hybrid contactor.
[0019] An object of the present disclosure is to provide a solid state circuit arrangement for an electromechanical contactor, which has better response time, positive electrical isolation between the control and power circuit, eliminate electromagnetic transformer, programmed microcontroller for logical sequence of operation between contactor and solid state device.
[0020] An aspect of the present disclosure provides an arc less switching device. The an arc less switching device includes a solid state device, a controller, and an electromechanical contactor that is positioned in parallel with any or both of the solid state device and the controller. The controller is placed centrally in communication with the electromechanical contactor and the solid state device such that the arc less switching device utilizes the solid state device to make and break DC electrical circuit without any arc and carry current with less voltage drop and low power loss.
[0021] In an aspect, the solid state device comprises an insulated housing, a cover, and a PCB assembly. In another aspect, the PCB assembly is adapted to fit in at least one rectangular slot of the insulated housing.
[0022] In an aspect, the insulated housing can include a base portion having a first surface and a second surface. The first surface and the second surface having at least one of a closed horizontal slot and an open vertical slot for mounting the solid state device. In another aspect, the insulated housing can include one or more tool entry slots allowing an entry for a tool to connect/operate the PCB assembly. In yet another aspect, the insulated housing can include one or more heat dissipation slots for adequate heat dissipation. In yet another aspect, the insulated housing can include one or more wire entry slots allowing entry and/or exit for one or more power and control wires. In still another aspect, the insulated housing include one or more tool entry slots for entry of a toggle switch so as to switch ON/OFF a control/power supply.
[0023] In an aspect, the PCB assembly can include at least any or combination of one or more active components, one or more passive components, one or more insulated terminal connectors for connection of control and power supply, one or more load contacts, and one or more power contacts.
[0024] In an aspect, the solid state device can be electrically connected to an electromagnetic coil.
[0025] In an aspect, a source terminal and a drain terminal of the solid state device can be in parallel to a line terminal and a load terminal of the electromechanical contactor.
[0026] In an aspect, the electromechanical contactor can include a set of main contacts which provide a first current path, and the solid state device provides a second parallel current path which diverts current away from the main contacts when the main contacts are being opened or closed, and the first current path and second current path provide a path for direct current.
[0027] In an aspect, the solid state device can include a gate drive, wherein the gate drive is connected to the solid state switch and is operable to turn the solid state switch OFF or ON.
[0028] An aspect of the present disclosure provides a method for enabling arc less switching. The method can include the steps of providing a solid state device, a controller, and an electromechanical contactor that is positioned in parallel with any or both of the solid state device and the controller, and the controller is placed centrally in communication with the electromechanical contactor and the solid state device, and making and breaking, by utilizing the solid state device, DC electrical circuit without any arc and carry current with less voltage drop and low power losses. In an aspect, the solid state device is placed in parallel with the set of main contacts associated with the electromechanical contactor.
[0029] In an aspect, the method can further include the steps of moving the main contacts to either open or close positions, and there while passing the DC current through said solid state device to achieve making and breaking without any arc and carry current with less voltage drop and low power losses.
[0030] In contrast to the existing techniques of arc less switching, the present invention provides provide a solid state circuit arrangement for an electromechanical contactor, which has better response time, positive electrical isolation between the control and power circuit, eliminate electromagnetic transformer, programmed microcontroller for logical sequence of operation between contactor and solid state device.
[0031] Also, in contrast to the existing arc less switching techniques, the present invention provides The DC hybrid contactor essentially consists of an electromechanical contactor, whose series connected poles line and load terminal is connected in parallel with source and drain of the MOSFET. Both the electromagnet of the contactor and that of MOSFET driver circuit is driven by a common DC control supply. The prime purpose of the present invention is towards make and breaks the DC electrical circuit without any arc by means of switching ON and OFF the MOSFET. Whereas the continuous current is carried by the electromechanical contacts. By doing so the overall power loss per pole is reduced as compared to a dedicated solid state contactor, which consumes a power of 1watt per ampere. Presently the invention has been practiced for a power rating of 63A, 48 V DC. Major benefit of the invention is towards low response time, less power consumption of control circuit, power MOSFET is with better process technology so that the switching loss is less, isolation between power and control circuit, elimination of transformer thus occupy less space and size. High dv/dt withstanding capability and operating temperature etc.
[0032] Furthermore, the present invention discloses a solid state circuit arrangement for DC hybrid contactor, which has better response time, positive electrical isolation between the control and power circuit, eliminate electromagnetic transformer, programmed microcontroller for logical sequence of operation between contactor and solid state device. The microcontroller used is with lower wake up time and power consumption, is suitable for actuation and sensing purpose. The per pole watt loss of the solid state device is very low owing to lower thermal resistance, ON state resistance of the power MOSFET, whose drain to source is connected in parallel with the line and load terminal of the electromechanical contactor. It has higher operating temperature withstand. These characteristics of the solid state component utilized in the DC hybrid contactor, makes it superior to other type of DC solid state switching device, as disclosed in the closest known method. Presently the technology has been practiced for a lower rating of 63A, 48 V DC so as to meet the ELVDC requirement and can be developed for LVDC requirement.
[0033] Various objects, features, aspects and advantages of the inventive subject matter will become more apparent from the following detailed description of preferred embodiments, along with the accompanying drawing figures in which like numerals represent like components

BRIEF DESCRIPTION OF THE DRAWINGS
[0034] The accompanying drawings are included to provide a further understanding of the present disclosure, and are incorporated in and constitute a part of this specification. The drawings illustrate exemplary embodiments of the present disclosure and, together with the description, serve to explain the principles of the present disclosure.
[0035] FIG. 1 illustrates an exemplary assembly of a proposed DC hybrid contactor, in accordance with an embodiment of the present disclosure.
[0036] FIG. 2 illustrates an exemplary solid state contactor, in accordance with an embodiment of the present disclosure.
[0037] FIG. 3 illustrates an exemplary enclosure of the solid state circuit, in accordance with an embodiment of the present disclosure.
[0038] FIG. 4 illustrates a side cover of the exemplary enclosure, in accordance with an exemplary embodiment of the present disclosure.
[0039] FIG. 5 illustrates an exemplary PCB assembly, in accordance with an embodiment of the present disclosure.
[0040] FIG. 6 illustrates the power and control circuit, in accordance with an embodiment of the present disclosure.
[0041] FIG. 7 illustrates the maximum ripple current range that is allowable, in accordance with an embodiment of the present disclosure.
[0042] FIG. 8 illustrates an exemplary means of selection of inductance for known current and voltage of buck converter, in accordance with an exemplary embodiment of the present disclosure.
[0043] FIG. 9 illustrates a typical block diagram of the voltage regulator, in accordance with an embodiment of the present disclosure.
[0044] FIG. 10 illustrates exemplary output characteristics of the voltage regulator, in accordance with an embodiment of the present disclosure.
[0045] FIG. 11 illustrates a block diagram of the voltage regulator U3, in accordance with an embodiment of the present disclosure.
[0046] FIG. 12 illustrates a block diagram of optocoupler U5, in accordance with an exemplary embodiment of the present disclosure.
[0047] FIG. 13 illustrates an exemplary hysteresis effect of high speed transistor optocoupler, in accordance with an embodiment of the present disclosure.
[0048] FIG. 14 illustrates a typical test diagram of optocoupler, in accordance with an embodiment of the present disclosure.
[0049] FIG. 15 illustrates a detailed block diagram of the inverted MOSFET driver circuit, in accordance with an embodiment of the present disclosure.
[0050] FIG. 16 illustrates the inverted state of the input signal along with hysteresis effect, in accordance with an embodiment of the present disclosure.
[0051] FIG. 17 illustrates a making sequence of operation of DC hybrid contactor, in accordance with an exemplary embodiment of the present disclosure.
[0052] FIG. 18 illustrates a breaking sequence of operation of DC hybrid contactor, in accordance with an embodiment of the present disclosure.

DETAILED DESCRIPTION
[0053] The following is a detailed description of embodiments of the disclosure illustrated in the accompanying drawings. The embodiments are in such detail as to clearly communicate the disclosure. However, the amount of detail offered is not intended to limit the anticipated variations of embodiments; on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the present disclosure as defined by the appended claims.
[0054] In the following description, numerous specific details are set forth in order to provide a thorough understanding of embodiments of the present invention. It will be apparent to one skilled in the art that embodiments of the present invention may be practiced without some of these specific details.
[0055] Embodiments of the present invention include various steps, which will be described below. The steps may be performed by hardware components or may be embodied in machine-executable instructions, which may be used to cause a general-purpose or special-purpose processor programmed with the instructions to perform the steps. Alternatively, steps may be performed by a combination of hardware, software, and firmware and/or by human operators.
[0056] Various methods described herein may be practiced by combining one or more machine-readable storage media containing the code according to the present invention with appropriate standard computer hardware to execute the code contained therein. An apparatus for practicing various embodiments of the present invention may involve one or more computers (or one or more processors within a single computer) and storage systems containing or having network access to computer program(s) coded in accordance with various methods described herein, and the method steps of the invention could be accomplished by modules, routines, subroutines, or subparts of a computer program product.
[0057] If the specification states a component or feature “may”, “can”, “could”, or “might” be included or have a characteristic, that particular component or feature is not required to be included or have the characteristic.
[0058] As used in the description herein and throughout the claims that follow, the meaning of “a,” “an,” and “the” includes plural reference unless the context clearly dictates otherwise. Also, as used in the description herein, the meaning of “in” includes “in” and “on” unless the context clearly dictates otherwise.
[0059] Exemplary embodiments will now be described more fully hereinafter with reference to the accompanying drawings, in which exemplary embodiments are shown. These exemplary embodiments are provided only for illustrative purposes and so that this disclosure will be thorough and complete and will fully convey the scope of the invention to those of ordinary skill in the art. The invention disclosed may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Various modifications will be readily apparent to persons skilled in the art. The general principles defined herein may be applied to other embodiments and applications without departing from the spirit and scope of the invention. Moreover, all statements herein reciting embodiments of the invention, as well as specific examples thereof, are intended to encompass both structural and functional equivalents thereof. Additionally, it is intended that such equivalents include both currently known equivalents as well as equivalents developed in the future (i.e., any elements developed that perform the same function, regardless of structure). Also, the terminology and phraseology used is for the purpose of describing exemplary embodiments and should not be considered limiting. Thus, the present invention is to be accorded the widest scope encompassing numerous alternatives, modifications and equivalents consistent with the principles and features disclosed. For purpose of clarity, details relating to technical material that is known in the technical fields related to the invention have not been described in detail so as not to unnecessarily obscure the present invention.
[0060] Thus, for example, it will be appreciated by those of ordinary skill in the art that the diagrams, schematics, illustrations, and the like represent conceptual views or processes illustrating systems and methods embodying this invention. The functions of the various elements shown in the figures may be provided through the use of dedicated hardware as well as hardware capable of executing associated software. Similarly, any switches shown in the figures are conceptual only. Their function may be carried out through the operation of program logic, through dedicated logic, through the interaction of program control and dedicated logic, or even manually, the particular technique being selectable by the entity implementing this invention. Those of ordinary skill in the art further understand that the exemplary hardware, software, processes, methods, and/or operating systems described herein are for illustrative purposes and, thus, are not intended to be limited to any particular named element.
[0061] Each of the appended claims defines a separate invention, which for infringement purposes is recognized as including equivalents to the various elements or limitations specified in the claims. Depending on the context, all references below to the "invention" may in some cases refer to certain specific embodiments only. In other cases it will be recognized that references to the "invention" will refer to subject matter recited in one or more, but not necessarily all, of the claims.
[0062] All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g., “such as”) provided with respect to certain embodiments herein is intended merely to better illuminate the invention and does not pose a limitation on the scope of the invention otherwise claimed. No language in the specification should be construed as indicating any non-claimed element essential to the practice of the invention.
[0063] Various terms as used herein are shown below. To the extent a term used in a claim is not defined below, it should be given the broadest definition persons in the pertinent art have given that term as reflected in printed publications and issued patents at the time of filing.
[0064] The aforementioned limitations (recited in background section) of the existing arc less switching techniques are recognized by the inventors hereof and some or all of these limitations have been addressed by providing a DC hybrid contactor so as to overcome all the arcing issues that is prevailing with an electromechanical contactor. It makes and breaks the electrical circuit without any arcing and carries the current with less voltage drop and power loss. Thus do not demand a bulkier size heat sink as compared to solid state contactor or relay and can be developed with nearly the same size to that of an electromechanical contactor.
[0065] Accordingly, the present invention provides a new, efficient, technically advanced, system and method which provide a solid state circuit arrangement for an electromechanical contactor, which has better response time, positive electrical isolation between the control and power circuit, eliminate electromagnetic transformer, programmed microcontroller for logical sequence of operation between contactor and solid state device.
[0066] The present disclosure generally relates to hybrid direct current (DC) contactors and, more particularly to, but not by way of limitation, solid state circuit arrangement for dc hybrid contactor, and a system and method for controlling operation of a hybrid DC contactor that improves performance of the hybrid contactor..
[0067] An object of the present disclosure is to provide a solid state circuit arrangement for an electromechanical contactor, which has better response time, positive electrical isolation between the control and power circuit, eliminate electromagnetic transformer, programmed microcontroller for logical sequence of operation between contactor and solid state device.
[0068] An aspect of the present disclosure provides an arc less switching device. The an arc less switching device includes a solid state device, a controller, and an electromechanical contactor that is positioned in parallel with any or both of the solid state device and the controller. The controller is placed centrally in communication with the electromechanical contactor and the solid state device such that the arc less switching device utilizes the solid state device to make and break DC electrical circuit without any arc and carry current with less voltage drop and low power loss.
[0069] In an aspect, the solid state device comprises an insulated housing, a cover, and a PCB assembly. In another aspect, the PCB assembly is adapted to fit in at least one rectangular slot of the insulated housing.
[0070] In an aspect, the insulated housing can include a base portion having a first surface and a second surface. The first surface and the second surface having at least one of a closed horizontal slot and an open vertical slot for mounting the solid state device. In another aspect, the insulated housing can include one or more tool entry slots allowing an entry for a tool to connect/operate the PCB assembly. In yet another aspect, the insulated housing can include one or more heat dissipation slots for adequate heat dissipation. In yet another aspect, the insulated housing can include one or more wire entry slots allowing entry and/or exit for one or more power and control wires. In still another aspect, the insulated housing includes one or more tool entry slots for entry of a toggle switch so as to switch ON/OFF a control/power supply.
[0071] In an aspect, the PCB assembly can include at least any or combination of one or more active components, one or more passive components, one or more insulated terminal connectors for connection of control and power supply, one or more load contacts, and one or more power contacts.
[0072] In an aspect, the solid state device can be electrically connected to an electromagnetic coil.
[0073] In an aspect, a source terminal and a drain terminal of the solid state device can be in parallel to a line terminal and a load terminal of the electromechanical contactor.
[0074] In an aspect, the electromechanical contactor can include a set of main contacts which provide a first current path, and the solid state device provides a second parallel current path which diverts current away from the main contacts when the main contacts are being opened or closed, and the first current path and second current path provide a path for direct current.
[0075] In an aspect, the solid state device can include a gate drive, wherein the gate drive is connected to the solid state switch and is operable to turn the solid state switch OFF or ON.
[0076] An aspect of the present disclosure provides a method for enabling arc less switching. The method can include the steps of providing a solid state device, a controller, and an electromechanical contactor that is positioned in parallel with any or both of the solid state device and the controller, and the controller is placed centrally in communication with the electromechanical contactor and the solid state device, and making and breaking, by utilizing the solid state device, DC electrical circuit without any arc and carry current with less voltage drop and low power losses. In an aspect, the solid state device is placed in parallel with the set of main contacts associated with the electromechanical contactor.
[0077] In an aspect, the method can further include the steps of moving the main contacts to either open or close positions, and there while passing the DC current through said solid state device to achieve making and breaking without any arc and carry current with less voltage drop and low power losses.
[0078] In contrast to the existing techniques of arc less switching, the present invention provides provide a solid state circuit arrangement for an electromechanical contactor, which has better response time, positive electrical isolation between the control and power circuit, eliminate electromagnetic transformer, programmed microcontroller for logical sequence of operation between contactor and solid state device.
[0079] Also, in contrast to the existing arc less switching techniques, the present invention provides The DC hybrid contactor essentially consists of an electromechanical contactor, whose series connected poles line and load terminal is connected in parallel with source and drain of the MOSFET. Both the electromagnet of the contactor and that of MOSFET driver circuit is driven by a common DC control supply. The prime purpose of the present invention is towards make and breaks the DC electrical circuit without any arc by means of switching ON and OFF the MOSFET. Whereas the continuous current is carried by the electromechanical contacts. By doing so the overall power loss per pole is reduced as compared to a dedicated solid state contactor, which consumes a power of 1watt per ampere. Presently the invention has been practiced for a power rating of 63A, 48 V DC. Major benefit of the invention is towards low response time, less power consumption of control circuit, power MOSFET is with better process technology so that the switching loss is less, isolation between power and control circuit, elimination of transformer thus occupy less space and size. High dv/dt withstanding capability and operating temperature etc.
[0080] Furthermore, the present invention discloses a solid state circuit arrangement for DC hybrid contactor, which has better response time, positive electrical isolation between the control and power circuit, eliminate electromagnetic transformer, programmed microcontroller for logical sequence of operation between contactor and solid state device. The microcontroller used is with lower wake up time and power consumption, is suitable for actuation and sensing purpose. The per pole watt loss of the solid state device is very low owing to lower thermal resistance, ON state resistance of the power MOSFET, whose drain to source is connected in parallel with the line and load terminal of the electromechanical contactor. It has higher operating temperature withstand. These characteristics of the solid state component utilized in the DC hybrid contactor, makes it superior to other type of DC solid state switching device, as disclosed in the closest known method. Presently the technology has been practiced for a lower rating of 63A, 48 V DC so as to meet the ELVDC requirement and can be developed for LVDC requirement.
[0081] In an embodiment, the present invention provides a solid state circuit arrangement with an electromechanical contactor so as to make and break the DC electrical circuit without any arc.
[0082] FIG. 1 illustrates an exemplary assembly of a proposed DC hybrid contactor, in accordance with an embodiment of the present disclosure.
[0083] FIG. 2 illustrates an exemplary solid state contactor, in accordance with an embodiment of the present disclosure.
[0084] FIG. 3 illustrates an exemplary enclosure of the solid state circuit, in accordance with an embodiment of the present disclosure.
[0085] FIG. 4 illustrates a side cover of the exemplary enclosure, in accordance with an exemplary embodiment of the present disclosure.
[0086] FIG. 5 illustrates an exemplary PCB assembly, in accordance with an embodiment of the present disclosure.
[0087] FIG. 6 illustrates the power and control circuit, in accordance with an embodiment of the present disclosure.
[0088] FIG. 7 illustrates the maximum ripple current range that is allowable, in accordance with an embodiment of the present disclosure.
[0089] FIG. 8 illustrates an exemplary means of selection of inductance for known current and voltage of buck converter, in accordance with an exemplary embodiment of the present disclosure.
[0090] FIG. 9 illustrates a typical block diagram of the voltage regulator, in accordance with an embodiment of the present disclosure.
[0091] FIG. 10 illustrates exemplary output characteristics of the voltage regulator, in accordance with an embodiment of the present disclosure.
[0092] FIG. 11 illustrates a block diagram of the voltage regulator U3, in accordance with an embodiment of the present disclosure.
[0093] FIG. 12 illustrates a block diagram of optocoupler U5, in accordance with an exemplary embodiment of the present disclosure.
[0094] FIG. 13 illustrates an exemplary hysteresis effect of high speed transistor optocoupler, in accordance with an embodiment of the present disclosure.
[0095] FIG. 14 illustrates a typical test diagram of optocoupler, in accordance with an embodiment of the present disclosure.
[0096] FIG. 15 illustrates a detailed block diagram of the inverted MOSFET driver circuit, in accordance with an embodiment of the present disclosure.
[0097] FIG. 16 illustrates the inverted state of the input signal along with hysteresis effect, in accordance with an embodiment of the present disclosure.
[0098] FIG. 17 illustrates a making sequence of operation of DC hybrid contactor, in accordance with an exemplary embodiment of the present disclosure.
[0099] FIG. 18 illustrates a breaking sequence of operation of DC hybrid contactor, in accordance with an embodiment of the present disclosure.
[00100] As shown in FIG. 1, the assembly consists of a solid state device (1) and electromechanical air break contactor (2). FIG. 2 and FIG. 3 show the solid state device which constitutes an insulated housing (3), cover (4) and PCB assembly (5). The insulated housing consists of a rectangular slot (6), to accommodate the PCB assembly (5). At the top and bottom surface of the base (7), closed horizontal (9) and open vertical (8) oblong hole has been provided for ease of mounting of the device as per the standard. The oblong holes aids in adjusting the mounting position. Suitable insulated ribs provided along the oblong hole to improve the mechanical strength of the housing. At its four corners, protrusion is provided along with symmetrical hole (10) for screw fitment of the cover with the housing. Circular holes (11) has been provided in the rectangular opening (6) for ease of tool entry to the terminal box (5). Oblong thin openings (12) are provided in the rectangular slot (6), for adequate heat dissipation. Suitable small and large rectangular openings (13 and 14) are provided for entry of power and control wire into the respective terminal box. A rectangular opening (15) has been provided for entry of a toggle switch so as to switch ON/OFF the control supply. The insulated cover (4) as shown in FIG. 4 consists of circular hole (16) for screw fitment with the housing. Apart from the above electromechanical components discussed above, one of the critical assemblies of the hybrid contactor is the PCB assembly. The PCB assembly as shown in FIG. 5 constitutes active and passive components, four insulated terminal connectors for connection of control (39) and power (40) supply, load (37) and power contacts (36).
[00101] FIG. 6 shows the detailed power and control circuit diagram of solid state hybrid contactor. Presently the common control circuit is shown for a 48V ELVDC system. For a LVDC system, it can be used with a DC-DC converter or similar means. The control circuit can be protected against short circuit by means of incorporating a fusible resistor and overvoltage protection using varistor or snubber circuit. Capacitor C1 (17) is connected at the incoming end of the DC control supply to bypass any ripple content and reject high frequency noise. Suitable buck converter U1 (18) along with diode D1 (19), L1 (20) and C2 (21) is used to produce constant 12 V DC for a variable input voltage between 15 to 63V DC. Based upon the control circuit current and that of output voltage level, the inductance of L1 (20) is decided and then the capacitance C2 (21) is computed with known inductance, input and output voltage. FIG. 8 shows the relation between maximum input voltages and load current with respect to selection of inductance.
[00102] In an exemplary embedment, it’s a normal practice to operate the inductor in continuous mode of operation, so as to have better load regulation, lower peak switching, low inductor and diode current, low output ripple voltage etc. When the buck regulator operates in continuous mode, the inductor current changes from a saw tooth to triangular wave. For a given input and output voltage, the inductor current is maintained constant. During switching OFF condition, when the load current gets reduced below zero, then the regulator goes to discontinuous mode of operation. The higher the capacitance value, lower is the ripple content. Further rejection of high frequency signal can be obtained using a suitable filter circuit. The maximum ripple current range that is allowable is shown in FIG. 7.
[00103] In an exemplary embodiment, for a stable operation of the buck converter, the ON/OFF pin shall be properly grounded and never left open. D1 (19), acts as a freewheeling catch diode to carry the inductor current when the control supply is switched OFF. Because of its fast switching speed, low forward voltage drop, provides high efficiency. Due to abrupt switching off action, may lead to EMI and other instability, which can be recovered using such fast recovery diodes. Feedback signal of the output waveform is fed back to the FB terminal of U1 (18). The 12V DC signal which is derived from the buck converter is further reduced to 5V by means of using a constant voltage regulator U2 (22). FIG. 9 shows the typical block diagram of the voltage regulator, which reveals about the internal thermal and overload protection of the device. Its output voltage remains almost constant with respect to change in the operating temperature from -25ºC towards 125ºC. Within a differential voltage of 5 – 10 V DC between the input and output voltage of the regulator, the output current remains constant, as shown in FIG. 10.
[00104] In another exemplary embodiment, similarly the 12 V DC signal is step down to 3.5 V DC by means of using voltage regulator U3 (24). This regulator has very low line and load regulation of the order 0.01% and 0.1%. It has internal current limiting and thermal overload protection. The bypass adjust terminal, rejects ripple and has high ripple rejection ratios. It can operate with low voltage with 3V differential voltage between input and output. The overload protection is achieved by means of switching the Darlington circuit as shown in FIG. 11. Once the fault gets cleared, the circuit gets reset. Darlington circuit aids in amplification of the output signal obtained from the non-inverted op-amp. The input signal is compared with the threshold voltage as set by the Zener diode and next the operational amplifier operates considering an offset voltage. R1 and R2 resistors in FIG. 6 can be adjusted to obtain the desired constant output voltage. C4 (25) provides desired transient response of the voltage regulator. In some case branch circuit consisting of a capacitor and diode, is connected in parallel to C4 (25), which aids in further reducing the ripple content. To overcome high frequency noise during switching ON and OFF, capacitor C3 (23) is used after U2.
[00105] In an exemplary embodiment, each of the ELVDC voltage derived from the control circuit was utilized to power up the microcontroller unit, dual input and output optocoupler with negative logic, inverted MOSFET driver circuit to operate the electromechanical contactor and power MOSFET. The microcontroller do not get powered up till the toggle switch S1 (26) is not turned ON. The response time of microcontroller is very low as its wake up time is in µs and it can operate at various low power modes. This reduces the power consumption to few µA. As the low power mode increased from 0 to 5, the power consumption reduces. This is due to disable state of certain clocks, CPU and digital crystal oscillator. The brown out reset feature and reset pin aids in resetting the microcontroller once the programme is executed. Normally the microcontroller operates between 1.8 to 3.6V DC. However the data is retained till the input voltage is 1.6 V DC and above. With reduced input voltage, the default internal low clock frequency varies. It offers few ADC input channel for sensing and actuation purpose. Special clock configuration both internal and external, aids in adjusting the sampling and ADC conversion time. The sampling threshold value is decided by the NADC selected. Upon powering up, the microcontroller is programmed in such a way that it produce two output, which are at high state and is fed to the dual photodiode of optocoupler U5 (28), as shown in FIG. 12. One of the analogue outputs, which is meant for operating the power MOSFET first goes to high state thereby turns it ON to carry the making current. Next the second analogue output goes to high state to operate the electromechanical contactor. Owing to its higher response time, the electromechanical contactor picks up after few ms. Till then the power MOSFET is hold at its ON state. The first output then goes to low state so that the power MOSFET is turned off with electromechanical contactor in picked up state. This sequence of operation while making the electrical circuit ensures that the making current is carried by the power MOSFET and that of continuous load current is carried by the electromechanical contacts. While breaking the electrical circuit, the micro controller is programmed in such a way that it sense the input signal and when it goes below its threshold value, the first output goes to high state, thereby turns ON the power MOSFET. The turn ON resistance (Rds) of the MOSFET being very less as compared to that of the opening contact resistance, the breaking current gets diverted towards the power MOSFET. Next the second output goes to low state so as to drop the electromechanical contactor. The microcontroller programme along with the discharge capacitor ensures that the first output remains at high state for few ms and goes to low state after the electromechanical contactor fully drops down. Due to this sequence of operation, the breaking current is carried by the power MOSFET. Both the photodiode of U5, have a common ground, which turns on when the input signal is more than their respective forward voltage. The photodiode produce burst of photons as shown in broken arrow mark, which optically gets coupled with the phototransistor. When the phototransistor turns ON, it produces a low state output signal, which lags behind the input signal due to hysteresis effect. This effect shows the negative logic of the optocoupler. FIG. 13 shows such a behavior of the high speed transistor optocoupler, which aids in rejection of any high frequency signal. A typical test diagram of the optocoupler is shown in FIG. 14 for further reference.
[00106] In an exemplary embodiment, both the low state output signal obtained from the dual channel high speed transistor based optocoupler is fed to individual MOSFET driver, which are with inverting configuration and suitable for high speed operation. The first driver U7 (29) is meant to provide gate trigger signal to control MOSFET, which is responsible to energize the coil and thereby operate the electromechanical contactor. The second driver U6 (34) is meant to provide gate trigger signal to power MOSFET so as to carry the making and breaking current of the DC electrical circuit. When the driver circuit is powered up, will produce positive high state gate triggering signal. Due to their CMOS configuration, consume less power with high efficiency as compared to dual MOSFET driver. The best part of these devices is that it is virtually latch-up proof. They replace three or more discrete components, saving PCB area, parts and improving overall system reliability. FIG. 15 shows the detailed block diagram of the driver IC. Since the threshold voltage at which its Zener diode operates, is 4.7V DC, a 5V input signal obtained from the high speed phototransistor based optocoupler, is sufficient to turn it ON. This further triggers the gate drive of the internal MOSFET of IC U7 (29), U6 (34) and when they turns ON, provides a constant low state output to the Schmitt trigger so as to reject any high frequency noise or spurious signal. This state of the input signal is reversed due to inverting NOT gate as shown in the block diagram. The output of this signal, which is at high state, triggers the gate of two MOSFET. Typical inverting action of the U7 (29) and that of U6 (34) is shown in FIG. 16.
[00107] WORKING OF THE INVENTION: In an embodiment, a solid state circuit arrangement for a DC Hybrid Contactor is disclosed. The circuit can be utilized with an existing DC controlled contactor to operate it without any arcing. As explained above it essentially has two circuit viz. control and power circuit, which operates with DC power supply of 10 to 63A, 48V. The electromagnetic coil has to be connected to the solid state device via dc supply. The source and drain of the power MOSFET is connected in parallel to the line and load terminal of the electromechanical contactor. The band of control voltage at which it will pick up is 15 – 63 V DC. Drop out voltage of the device is less than 15 V DC. When DC supply is fed to the common control circuit, it power up the buck circuit so as to convert the high voltage to its equivalent low DC voltage so as to drive the microcontroller, optocoupler, MOSFET driver circuit and the power MOSFET etc. The L and C parameter along with the incoming capacitor is tuned to overcome the ripple effect and regulate the DC voltage as per intended requirement. The constant voltage obtained from the buck regulator is fed to a voltage regulator to further reduce it from 12 V – 5V – 3.5V DC. The microcontroller is powered up using a toggle switch. It is programmed in such a way that two analogue output is produced from the set pins at high state, which is then fed to the negative logic optocoupler, which produce two inverted output with low state. Here due to hysteresis effect, any high frequency switching noise is rejected. One of the inverted output (First output) is fed to a MOSFET driver, which produce a high state signal owing to inverting action of the internal NOT gate. This output signal from the MOSFET driver is fed to trigger the gate circuit of the power MOSFET, which turns ON to carry the making current of the DC circuit. Next the second analogue output from the common optocoupler is fed to a second inverted MOSFET driver circuit, which produces a high state signal. This is fed to trigger the gate circuit of the control MOSFET, which turns ON to energize the coil of DC electromagnet. Upon energizing, the DC contactor immediately picks up and when its contacts get fully closed, it offers a low resistance path in parallel to the high RDS of the power MOSFET. The DC circuit current flows through the electromechanical contacts and after a brief period, the power MOSFET is turned OFF as the first analogue output from microcontroller goes to low state. Next when the control supply is cutoff, due to the presence of capacitance, control supply is restored for a brief period as a backup power. The microcontroller is programmed in such a way that when its power is reduced, its first output goes to high state thereby turning ON the power MOSFET. During the same instant second output being at low state, drops down the electromechanical contactor. After few ms, the first and second output being at low state turns off both the power MOSFET and electro-mechanical contactor, there by breaking the DC electrical circuit without any arc.
[00108] To re-iterate the technical advancement, conventionally available air-break electromechanical contactors are meant for switching DC electrical circuit, is subjected to standing arcing between its cathode and anode electrode. This leads to heavy erosion of the contacts and burning of adjacent insulation, which reduces the overall electrical life of the contactor and in extreme cases it fails at premature stage. Several arc quenching techniques deployed so as to reduce the intensity of the arcing by means of controlling the arc duration, current limiting and hence the arc energy. However with all this effort arcing between the contacts cannot be avoided. Solid state contactor or relay to some extent make & break the DC circuit without any arcing but owing to high voltage drop across the source and drain and hence high power loss, demand bulkier size heat sink, which increases the overall panel area and volume. Moreover it’s not an economical solution as the rating of the device increases. On contrast to the above said DC switching technology, a hybrid contactor would make & break the DC electrical circuit without any arc and carry continuous current with very less voltage drop and per pole power loss. In addition to this it is never subjected to contact repulsion due to holms and Lorentz force.
[00109] In order to solve the above recited and other issue discussed throughout this disclosure, the present invention provides a DC hybrid contactor so as to overcome all the arcing issues that is prevailing with an electromechanical contactor. It makes and breaks the electrical circuit without any arcing and carries the current with less voltage drop and power loss. Thus do not demand a bulkier size heat sink as compared to solid state contactor or relay and can be developed with nearly the same size to that of an electromechanical contactor.
[00110] In an exemplary embodiment, the a solid state circuit arrangement for a DC Hybrid Contactor can include below recited few exemplary features:
1. Wide band of DC control supply – 15 to 63 V DC
2. Optional provision for positive delay between operation of electromechanical and solid state device
3. Constant buck type voltage regulator for control supply
4. Low voltage and power consumption control circuit
5. Positive isolation between the control & power circuit
6. High dv/dt protection, low response time, high operating temperature. Low switching loss
7. Elimination of pulse transformer
8. Short circuit protection for control & power circuit using semiconducting fuse (extended feature)
9. No separate control supply for electromagnet coil
10. No arcing across the contacts during making & breaking of the electrical circuit
11. No special cooling means such as heat sink is required
12. Ease of mounting with the mechanical switching device
13. Ease of termination of the power and control circuit
14. Ease of contact and coil replacement
15. Negative logic to avoid duplication and spurious market
[00111] EXPERIMENTAL ANALYSIS:
Specification:
i. Operating voltage: 48 V DC
ii. Rated current: 10 - 63 A for resistive and slightly inductive load
iii. Control supply: 15 - 63 V DC
iv. Coil supply: 48 V DC
Performance: The solid state circuit along with electromechanical contactor is mounted as under normal condition and then operation and operating limit is checked at the band of control supply mentioned. The making and breaking sequence of operation between the electromechanical and solid state contactor, is shown in the FIG. 17 and FIG. 18 respectively.
[00112] The various illustrative logical blocks, modules and circuits and algorithm steps described herein may be implemented or performed as electronic hardware, software, or combinations of both. To clearly illustrate this interchangeability of hardware and software, various illustrative components, blocks, modules, circuits, and steps have been described above generally in terms of their functionality. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the overall system. It is noted that the configurations may be described as a process that is depicted as a flowchart, a flow diagram, a structure diagram, or a block diagram. Although a flowchart may describe the operations as a sequential process, many of the operations can be performed in parallel or concurrently. In addition, the order of the operations may be re-arranged. A process is terminated when its operations are completed. A process may correspond to a method, a function, a procedure, a subroutine, a subprogram, etc. When a process corresponds to a function, its termination corresponds to a return of the function to the calling function or the main function.
[00113] When implemented in hardware, various examples may employ a general purpose processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array signal (FPGA) or other programmable logic device, discrete gate or transistor logic, discrete hardware components or any combination thereof designed to perform the functions described herein. A general purpose processor may be a microprocessor, but in the alternative, the processor may be any conventional processor, controller, microcontroller or state machine. A processor may also be implemented as a combination of computing devices, e.g., a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core or any other such configuration.
[00114] When implemented in software, various examples may employ firmware, middleware or microcode. The program code or code segments to perform the necessary tasks may be stored in a computer-readable medium or processor-readable medium such as a storage medium or other storage(s). A processor may perform the necessary tasks. A code segment may represent a procedure, a function, a subprogram, a program, a routine, a subroutine, a module, a software package, a class, or any combination of instructions, data structures, or program statements. A code segment may be coupled to another code segment or a hardware circuit by passing and/or receiving information, data, arguments, parameters, or memory contents. Information, arguments, parameters, data, etc. may be passed, forwarded, or transmitted via any suitable means including memory sharing, message passing, token passing, network transmission, etc.
[00115] As used in this application, the terms "component," "module," "system," and the like are intended to refer to a computer-related entity, either hardware, firmware, a combination of hardware and software, software, or software in execution. For example, a component may be, but is not limited to being, a process running on a processor, a processor, an object, an executable, a thread of execution, a program, and/or a computer. By way of illustration, both an application running on a computing device and the computing device can be a component. One or more components can reside within a process and/or thread of execution and a component may be localized on one computer and/or distributed between two or more computers. In addition, these components can execute from various computer readable media having various data structures stored thereon. The components may communicate by way of local and/or remote processes such as in accordance with a signal having one or more data packets (e.g., data from one component interacting with another component in a local system, distributed system, and/or across a network such as the Internet with other systems by way of the signal).
[00116] In one or more examples herein, the functions described may be implemented in hardware, software, firmware, or any combination thereof. If implemented in software, the functions may be stored on or transmitted over as one or more instructions or code on a computer-readable medium or processor-readable medium. A processor- readable media and/or computer-readable media include both computer storage media and communication media including any medium that facilitates transfer of a computer program from one place to another. A storage media may be any available media that can be accessed by a computer. By way of example, and not limitation, such computer- readable media can comprise RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to carry or store desired program code in the form of instructions or data structures and that can be accessed by a computer. Also, any connection is properly termed a computer-readable medium or processor-readable medium. For example, if the software is transmitted from a website, server, or other remote source using a coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL), or wireless technologies such as infrared, radio, and microwave, then the coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwave are included in the definition of medium. Disk and disc, as used herein, includes compact disc (CD), laser disc, optical disc, digital versatile disc (DVD), floppy disk and blue-ray disc where disks usually reproduce data magnetically, while discs reproduce data optically with lasers. Combinations of the above should also be included within the scope of computer-readable media. Software may comprise a single instruction, or many instructions, and may be distributed over several different code segments, among different programs and across multiple storage media. An exemplary storage medium may be coupled to a processor such that the processor can read information from, and write information to, the storage medium. In the alternative, the storage medium may be integral to the processor.
[00117] One or more of the components, steps, and/or functions illustrated in the Figures may be rearranged and/or combined into a single component, step, or function or embodied in several components, steps, or functions. Additional elements, components, steps, and/or functions may also be added without departing from the invention. The novel algorithms described herein may be efficiently implemented in software and/or embedded hardware.
[00118] Those of skill in the art would further appreciate that the various illustrative logical blocks, modules, circuits, and algorithm steps described in connection with the embodiments disclosed herein may be implemented as electronic hardware, computer software, or combinations of both. To clearly illustrate this interchangeability of hardware and software, various illustrative components, blocks, modules, circuits, and steps have been described above generally in terms of their functionality. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the overall system.
[00119] As used herein, and unless the context dictates otherwise, the term “coupled to” is intended to include both direct coupling (in which two elements that are coupled to each other or in contact each other) and indirect coupling (in which at least one additional element is located between the two elements). Therefore, the terms “coupled to” and “coupled with” are used synonymously. Within the context of this document terms “coupled to” and “coupled with” are also used euphemistically to mean “communicatively coupled with” over a network, where two or more devices are able to exchange data with each other over the network, possibly via one or more intermediary device.

ADVANTAGES OF THE PRESENT INVENTION:
[00120] The present disclosure provides a solid state circuit arrangement for dc hybrid contactor that enables to achieve a voltage drop across contact is in mV range.
[00121] The present disclosure provides a solid state circuit arrangement for dc hybrid contactor that enables to achieve very low power consumption across the contacts in few watts.
[00122] The present disclosure provides a solid state circuit arrangement for dc hybrid contactor that enables to achieve low temperature rise of the device.
[00123] The present disclosure provides a solid state circuit arrangement for dc hybrid contactor that is suitable for resistive and slightly inductive load.
[00124] The present disclosure provides a solid state circuit arrangement for dc hybrid contactor that enables to provide no burning of insulation or melting of contacts.
[00125] The present disclosure provides a solid state circuit arrangement for dc hybrid contactor that enables to provide no deposition of carbon or forming tracks across the insulation.
[00126] The present disclosure provides a solid state circuit arrangement for dc hybrid contactor that enables to provide no flash over across poles of the device.
[00127] The present disclosure provides a solid state circuit arrangement for dc hybrid contactor that is an improvement to an existing product such as air-break DC electromechanical contactor. When the solid state circuit is integrated with the electro-mechanical contactor would turn it as an arc less switching device
[00128] The present disclosure provides a solid state circuit arrangement for dc hybrid contactor that enables to achieve making and breaking of the electrical circuit without any arcing and carry the current with less voltage drop and power loss.
[00129] The present disclosure provides a solid state circuit arrangement for dc hybrid contactor that do not demand a bulkier size heat sink as compared to solid state contactor or relay and can be developed with nearly the same size to that of an electromechanical contactor.