Claims:1. A motor controller architecture for a variable speed drive wherein the circuit boards comprising the motor controller are mounted on each other in such a fashion as to reduce size of the motor controller while maintaining isolation as well as electrical conduction requirement of signals between the boards, keeping the signals’ integrity intact, and providing heat dissipation.
2. The architecture of claim 1, wherein the mounting comprises any or a combination of an EMI/EMC board (102) mounted on a main power board (104) and a control board (106) mounted on the main power board (104), and wherein the main power board (104) carries means for heat dissipation.
3. The architecture of claim 2, wherein a display and user input board (108) is further mounted on the control board (106).
4. The architecture of claim 3 , wherein power is transmitted from the EMI/EMC board (102) to the main power board (104), the control board (106) and the display and user input board (108), in that order.
5. The architecture of claim 1, wherein the mounting provides for tool-less replacement of the boards.
, Description:
FIELD OF DISCLOSURE
[0001] The present disclosure relates to motor controllers. In particular it pertains to controllers for variable speed drives.

BACKGROUND OF THE DISCLOSURE
[0002] The 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] Many power applications such as motor controllers, power supplies etc. often use a number of circuit boards. Typically these boards include those for power modules, customer interface, display, control, direct current etc. Each of the circuit boards supports components and conducting paths for accomplishing various functions in the completed device. Some-such as those for power modules- generate large amount of heat and hence require coupling to appropriate heat sinks or other thermal management systems to prevent the circuit boards and parts therein from overheating. Heat sinks are typically metal components relatively large in size and can be secured to circuit boards or associated electrical devices to enhance heat dissipation there from.
[0004] For example, in the field of electronic motor controllers, it is commonplace to build a controller package as an assemblage of circuit boards, including a power substrate module or other heat dissipating medium. Such motor controllers generally include control logic circuitry and power components. The control logic circuitry, typically including programmable solid state circuits, such as a programmable logic controller mounted on a motherboard or a separate logic circuit module, monitors operating parameters of the motor and generates control signals for driving the motor in accordance with a preset control routine and various operator inputs. The power components typically include diode rectifying circuits for receiving AC power from a source and for converting it to DC power, and power transistors or similar solid state switching devices, such as, insulated gate bipolar transistors (IGBTs), for converting the DC power to controlled AC signals of varying frequency and/or voltage for driving the motor based upon the control signals produced by the control circuitry. Such signals can vary the speed of the motor and hence assemblies of motors with such controllers are also termed as variable speed drives. The power components are mounted on a circuit board optimized for heat dissipation while the logic circuitry is typically mounted on a customer interface or mother circuit board.
[0005] Switching of transistors /IGBTs in a motor controller as elaborated above leads to generation of electromagnetic energy which may cause unwanted effects such as electromagnetic interference (EMI) or even physical damage in operational equipment if not isolated properly. EMI noises generated are substantial and need careful consideration for their possible interference in other control signals. Electromagnetic Compatibility (EMC) seeks to ensure correct operation of various equipments in such an electromagnetic environment. Such isolation also increases size of the motor controller.
[0006] As elaborated above, considerations of heat dissipation and EMI/EMC factors lead to a bulky motor controller. Besides, it is not easy to quickly and easily replace faulty components in such controllers. For example, prior art US5930112 “Circuit board architecture for motor controller” discusses arrangement of circuit boards within a drive including fan assembly with various functionalities on single board. However, being a single circuit board, there is difficulty of isolation during service and it is not easy to quickly and easily replace faulty components. Another prior art US2008/0089042-A1 “Electronic circuit arrangement for control purposes” describes an electronic circuit arrangement comprising two or more circuit boards electrically connected. However this arrangement does not consider EMI/EMC and heat dissipation factors that are critically important, as elaborated above.
[0007] There is, therefore, a need in the art for motor controller architecture that considers power flow, EMI/EMC factors, heating of components and dissipation of such heat, and also compact size requirements keeping in mind costing of mechanical enclosures to house them.
[0008] 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.
[0009] In some embodiments, the numbers expressing quantities or dimensions of items, 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.
[00010] 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.
[00011] 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.
[00012] 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 of all Markush groups used in the appended claims.

OBJECTS OF THE INVENTION
[00013] Some of the objects of the present disclosure, which at least one embodiment herein satisfies are as listed herein below.
[00014] It is an object of the present disclosure to provide for a motor controller architecture for variable speed drive that enables a motor controller having compact size.
[00015] It is another object of the present disclosure to provide for a motor controller architecture as above as above that enables a motor controller having no electro-magnetic interference.
[00016] It is another object of the present disclosure to provide for a motor controller architecture as above as above that enables a motor controller having high heat dissipation
[00017] It is another object of the present disclosure to provide for a motor controller architecture as above that enables a motor controller to maintain isolation as well as electrical conduction requirement of signals between its various circuit boards and keep the signals’ integrity intact.

SUMMARY OF THE INVENTION
[00018] Present disclosure it pertains to controllers for variable speed drives. In particular it pertains to a motor controller architecture for a variable speed drive.
[00019] In an aspect, proposed invention discloses a motor controller architecture for a variable speed drive wherein the circuit boards comprising the motor controller can be mounted on each other in such a fashion as to reduce size of the motor controller while maintaining isolation as well as electrical conduction requirement of signals between the boards, keeping the signals’ integrity intact, and providing heat dissipation.
[00020] In another aspect, the mounting can include any or a combination of an EMI/EMC board mounted on a main power board and a control board mounted on the main power board, and wherein the main power board carries means for heat dissipation.
[00021] In yet another aspect, a display and user input board can be further mounted on the control board.
[00022] In an aspect, power can be transmitted from the EMI/EMC board to the main power board, the control board and the display and user input board, in that order.
[00023] In another aspect, the mounting can provide for tool-less replacement of the boards.
[00024] Various objects, features, aspects and advantages of the present disclosure will become more apparent from the following detailed description of preferred embodiments, along with the accompanying drawing figures in which like numerals represent like features.

BRIEF DESCRIPTION OF DRAWINGS
[00025] 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. The diagrams are for illustration only, which thus is not a limitation of the present disclosure, and wherein:
[00026] FIG. 1 illustrates various circuit boards of a motor controller and their interconnections, in accordance with an exemplary embodiment of the present disclosure.
[00027] FIG. 2 illustrates major sub-assemblies of various circuit boards of a motor controller along with various inputs and outputs as a single line diagram, in accordance with an exemplary embodiment of the present disclosure.
[00028] FIG. 3 illustrates a layout of various circuit boards of a motor controller, showing architecture proposed, in accordance with an exemplary embodiment of the present disclosure.

DETAILED DESCRIPTION
[00029] The following is a detailed description of embodiments of the disclosure depicted 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.
[00030] 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.
[00031] 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.
[00032] 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.
[00033] 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.
[00034] 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.
[00035] 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.
[00036] 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.
[00037] 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.
[00038] Present disclosure pertains to controllers for variable speed drives. In particular it pertains to motor controller architecture for a variable speed drive.
[00039] In an aspect, proposed invention discloses a motor controller architecture for a variable speed drive wherein the circuit boards (interchangeably termed as boards hereinafter) comprising the motor controller can be mounted on each other in such a fashion as to reduce size of the motor controller while maintaining isolation as well as electrical conduction requirement of signals between the boards, keeping the signals’ integrity intact, and providing heat dissipation.
[00040] In another aspect, the mounting can include any or a combination of an EMI/EMC board mounted on a main power board and a control board mounted on the main power board, and wherein the main power board carries means for heat dissipation.
[00041] In yet another aspect, a display and user input board can be further mounted on the control board.
[00042] In an aspect, power can be transmitted from the EMI/EMC board to the main power board, the control board and the display and user input board, in that order.
[00043] In another aspect, the mounting can provide for tool-less replacement of the boards.
[00044] Various objects, features, aspects and advantages of the present disclosure will become more apparent from the following detailed description of preferred embodiments, along with the accompanying drawing figures in which like numerals represent like features.
[00045] FIG. 1 illustrates various circuit boards of a motor controller and their interconnections, in accordance with an exemplary embodiment of the present disclosure.
[00046] In an aspect, as illustrated in FIG.1, proposed motor controller can include an EMI/EMC board 102 (to remove any EMI noise), a main power board 104, a control board 106 and a display and user input board 108.
[00047] In another aspect, power supply from an AC grid can flow from EMI/EMC board 102 to main power board 104. Main power board 104 can in turn provide power to control board 106. Control board 106 can in turn provide appropriate power to display and user input board 108. In an exemplary embodiment, main power board 104 can also take DC power from a PV ( photo voltaic) array as illustrated, in case of a dual power system.
[00048] In yet another aspect, main power board 104 can provide power of appropriate voltage and frequency to drive a motor 110 that can in turn be coupled to a suitable load, for example a submersible pump shown as 112. Control board 106 can receive various signals from display and user input board 108, main power board 104, motor 110 and pump 112, and accordingly provide control signals to main power board 104 according to which main power board 104 can vary voltage and frequency to motor 110 . In this fashion, proposed motor controller can control speed of motor 110.
[00049] FIG. 2 illustrates major sub-assemblies of various circuit boards of a motor controller along with various inputs and outputs as a single line diagram, in accordance with an exemplary embodiment of the present disclosure.
[00050] In an aspect, main power board 104 can include a semi-conductor module 202 (that can in turn include Inrush Control and IGBT Module as illustrated), switched mode power supply 204 and a gate controller 206. Switched mode power supply 204 can be used to supply power to control board 106 while semi-conductor module 202 can supply power to motor 110 as per signals received from gate controller 206.
[00051] In yet another aspect, gate controller 206 can receive appropriate control signals from control board 106. Control board 106 can in turn receive signals as per settings a user can set using display and user input board 108. In an exemplary embodiment, a user can, using display and user input board 108, set flow required from pump 112 at any time. Control signals can accordingly be sent from display and user input board 108 to control board 106. Control board 106 can in turn generate its own signals that it can provide to gate controller 206 and gate controller 206 can in turn use signals received to control semi-conductor module 202 to vary voltage and frequency as required to motor 110 that is coupled to pump 112. Accordingly, pump 112 can be controlled.
[00052] The circuit board layout of main power board 104 can be designed considering isolation of various digital, analog and gate driving signals (as being generated by gate controller 206 ) from each other.
[00053] In an aspect, proposed invention discloses an architecture wherein the circuit boards comprising the motor controller as elaborated above are mounted together as elaborated hereunder to maintain isolation as well as electrical conduction requirement of signals between various circuit boards and to keep the signals’ integrity intact.
[00054] In another aspect, main power board 104 can form a base board having a heat sink assembly underneath for quick dissipation of heat being generated by semi-conductor module 202 during operation. Main power board 104 can have mounted on it control board 106 and EMI/EMC board 102.These boards can be connected in such a fashion that power and control signals can flow among them as required. Control board 106 can consist of a main processor that can take feedback signals from various sensors and provide switching commands to semi-conductor module 202 using gate controller 206.
[00055] In yet another aspect, control board 106 can have mounted on it display and user input board 108 wherein power supply from main power board 104 can go to control board 106 and from control board 106 to display and user input board 108.
[00056] In an aspect, all boards can be so mounted and electrically connected as required using appropriate connectors in such a fashion that they can be easily replaced without any tools, leading to a modular construction.
[00057] As can be readily understood, all boards such as EMI/EMC board 102, main power board 104, control board 106 and display and user input board 108 are electrically connected to one another and are stacked as well as modular. Being modular, any board can easily and quickly be replaced in case of failure of any component thereon, reducing downtime, Besides, proposed motor controller architecture can be used for variety of different loads by making only minor changes. For example, to form a motor controller for a different pump load, only IGBT and power sensors on main power board 104 may need to be changed while rest of the boards can remain same.
[00058] As can be readily understood, proposed circuit board architecture may readily be applied to other applications such as medium voltage drives, power converter assemblies and other high power drives.
[00059] In this fashion, proposed invention discloses an architecture of circuit boards for variable speed drives that considers power flow, EMI/EMC factors, control signals for feedback, heating of components and dissipation of such heat. Using stackable and modular circuit boards, proposed architecture leads to a compact size thus lowering cost of mechanical enclosures to house a motor controller using such an arrangement
[00060] In an aspect, using proposed architecture, power can flow from EMI/EMC board 102 to main power board 104 and then from main power board 104 to motor 110 .Analog signals being generated by main power board 104 can be sent to control board 106 that can also receive signals from user input provided via display and user input board 108 as well as various sensors. Control board 106 can in turn provide signals to gate controller 206 that can in turn use such signals for switching of IGBT module of semi-conductor module 202 as required. Mounting of various boards as elaborated above can help in providing various power flows and signal integrity required.
[00061] In exemplary embodiments, EMI/EMC board 102 can include EMI/EMC components, protection components and snubbers, main power board 104 can include, power module, sensing circuit, switched mode power supply and gate drive circuit, control board 106 can include DSP processor, communication circuit and filtering circuits, and display and user input board 108 can include LCD display module and communication circuits.
[00062] As can be appreciated, novel architecture of circuit boards for a motor controller as elaborated above leads to easier assembly, easier and quicker service of individual cards with lesser downtime and a modular design with its consequent advantage of easy adaptability to higher / lower power ratings.
[00063] FIG. 3 illustrates a layout of various circuit boards of a motor controller, showing architecture as proposed, in accordance with an exemplary embodiment of the present disclosure.
[00064] As shown, EMI/EMC board 102 can be mounted on main power board 104. Control board 106 can also be mounted on main power board 104, while display and user input board 108 can be mounted on control board 106. Main power board 104 can have heat dissipation means (such as heat sinks) coupled to it for quick and easy dissipation of heat.
[00065] In an aspect, plug-in connectors 302 can be used to supply or extract power from the motor controller while other connectors shown as 304 can be use for transfer of control signals as appropriate. The various circuit boards can easily be disconnected and replaced. In this fashion, individual cards are easily serviceable, replaceable in case of fault and have modular design for high rating or for other applications or entire new product e.g. high power inverter modules, medium voltage drives etc.
[00066] In this fashion mounting together of circuit boards as elaborated above can maintain isolation as well as electrical conduction requirement of signals between various circuit boards and can keep the signals’ integrity intact.
[00067] It can be appreciated that while proposed disclosure has been elaborated as above with various circuit boards stacked vertically, any other mounting/coupling of the boards that achieves same purpose of compact size, high heat dissipation, maintenance of isolation as well as electrical conduction requirement of signals between various cards and keeping the signals’ integrity intact is fully within the present disclosure.
[00068] 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.
[00069] Moreover, in interpreting both the specification and the claims, all terms should be interpreted in the broadest possible manner consistent with the context. In particular, the terms “comprises” and “comprising” should be interpreted as referring to elements, components, or steps in a non-exclusive manner, indicating that the referenced elements, components, or steps may be present, or utilized, or combined with other elements, components, or steps that are not expressly referenced. Where the specification claims refers to at least one of something selected from the group consisting of A, B, C ….and N, the text should be interpreted as requiring only one element from the group, not A plus N, or B plus N, etc.
[00070] While some embodiments of the present disclosure have been illustrated and described, those are completely exemplary in nature. The disclosure is not limited to the embodiments as elaborated herein only and it would be apparent to those skilled in the art that numerous modifications besides those already described are possible without departing from the inventive concepts herein. All such modifications, changes, variations, substitutions, and equivalents are completely within the scope of the present disclosure. The inventive subject matter, therefore, is not to be restricted except in the spirit of the appended claims.

ADVANTAGES OF THE INVENTION
[00071] The present disclosure provides for a motor controller architecture for a variable speed drive that enables a motor controller having compact size.
[00072] The present disclosure provides for a motor controller architecture as above that enables a motor controller having no electro-magnetic interference.
[00073] The present disclosure provides for a motor controller architecture as above that enables a motor controller having high heat dissipation
[00074] The present disclosure provides for a motor controller architecture as above that enables a motor controller to maintain isolation as well as electrical conduction requirement of signals between its various circuit boards and keep the signals’ integrity intact.