Description:TECHNICAL FIELD
[0001] The invention relates to the technical field of electric motors. More specifically, the invention relates to a device for converting permanent magnet motors into permanent magnet free motors.

BACKGROUND
[0002] A permanent magnet motor is a type of electric motor that uses permanent magnets for the field excitation and a wound armature. The permanent magnets can either be stationary or rotating; interior or exterior to the armature for a radial flux machine or layered with the armature for an axial flux topology. The schematic shows a permanent magnet motor with stationary magnets outside of a brushed armature (a type commonly used on toy slot-cars).
[0003] Permanent magnets increase the power density and performance of various types of motors such as but not limited to direct current (DC)-Motors, permanent magnet, alternating current (PMAC) motors, permanent magnet synchronous motor (PMSM) motors, interior permanent magnet (IPM) motors, stepper motors, brushless direct current motor (BLDC) motors. However, permanent magnets are expensive, temperature sensitive, fragile and ridden with supply chain related problems. Electromagnets have been used as an alternative to provide the armature field but since the armature is rotating, power transmission to the field winding is mainly provided through slip rings and frequency induction which are prone to wear and friction losses.
[0004] Inductive power transmission (IPT) for field winding excitation removes the problems associated with slip rings. Inductive power transfer (IPT) is a technology that transfers power and data without mechanical or electrical contact. It's based on Faraday's law of magnetic induction and was first reported in 1914 by Tesla. IPT works by transferring energy between two coupled coils. The transmitter coil generates a varying magnetic field that induces a voltage across the receiver coil. This enables the power from an alternating current in one circuit to be coupled from one circuit into another. Inductively exciting the field windings has been attempted in the past, however these designs have not been implemented due to practical constraints.

SUMMARY
[0005] An object of the present invention is to provide a device for inductively exciting the field windings thus removing the need for using permanent magnets from various types of permanent magnet-based motors.
[0006] The invention relates to the technical field of electric motors. More specifically, the invention relates to a device for converting permanent magnet motors into permanent magnet free motors.
[0007] Accordingly, an aspect of the present invention relates to a device for inductively exciting the field windings thus removing the need for using permanent magnets from various types of permanent magnet-based motors. The disclosed device provides an efficient, practical and low-cost solution for making such motors permanent magnet free. The device moreover adds better control features in a motor making the its suitable various applications like high temperature environments.
[0008] As the main power transfer component is the specially designed rotating ferrite core transformer which performs the contact free power transfer at high frequency. The present invention uses high frequency power transfer which as an overall efficiency > 98% and due to high frequency switched mode the size of the device is very small. This makes the device low cost and easy to install in existing designs.
[0009] Examples of the invention may be implemented in hardware (such as FGPAs or ASICs or other hardware), or in software, middleware, firmware or any combination thereof. Embodiments of the invention comprise computer program products comprising program instructions to program a processor to perform one or more of the methods described herein, such products may be provided on computer readable storage media or in the form of a computer readable signal for transmission over a network. Embodiments of the invention provide computer readable storage media and computer readable signals carrying data structures, media data files or databases according to any of those described herein.
[00010] Any of one or more features of any of the embodiments described herein, whether defined in the body of the description or in the claims may be independently combined with any of the other embodiments described herein.

BRIEF DESCRIPTION OF DRAWINGS
[00011] 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.
[00012] The diagrams are for illustration only, which thus is not a limitation of the present disclosure, and wherein:
[00013] FIG. 1 illustrates a device for inductively exciting field windings of a motor, in accordance with an embodiment of the present invention.
[00014] FIG. 2A illustrates an exemplary motor incorporated with the device for inductively exciting field windings of a motor, in accordance with an embodiment of the present invention.
[00015] FIG. 2B illustrates a sectional view of an exemplary motor incorporated with the device for inductively exciting field windings of a motor, in accordance with an embodiment of the present invention.
[00016] FIG. 2C illustrates an exploded view of an exemplary motor incorporated with the device for inductively exciting field windings of a motor, in accordance with an embodiment of the present invention.
[00017] FIG. 3 shows a method for inductively exciting field windings of a motor, in accordance with an embodiment of the present invention.

DETAILED DESCRIPTION OF DRAWINGS
[00018] The present disclosure will now be described in detail with reference to one or more embodiments, examples of which are illustrated in the accompanying drawings. The examples and embodiments are provided by way of explanation and are not to be taken as limiting to the scope of the disclosure. Furthermore, features illustrated or described as part of one embodiment may be used by themselves to provide other embodiments and features illustrated or described as part of one embodiment may be used with one or more other embodiments to provide a further embodiment. It will be understood that the present disclosure will cover these variations and embodiments as well as other variations and/or modifications. It is also to be understood that one or more features of one embodiment may be combinable with one or more features of the other embodiments. In addition, a single feature or combination of features in certain embodiments may constitute additional embodiments.
[00019] The features disclosed in this specification (including accompanying claims, abstract, and drawings) may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise. Thus, unless expressly stated otherwise, each feature disclosed is one example of a generic series of equivalent or similar features.
[00020] The subject headings used in the detailed description are included only for the ease of reference of the reader and should not be used to limit the subject matter found throughout the disclosure or the claims. The subject headings should not be used in construing the scope of the claims or the claim limitations.
[00021] Certain embodiments are directed to electrical motors that are smaller and/or lighter than similar competing electric motors in the same class and yet have sufficient power output to replace the combustion motor that would otherwise be used to power the machine. Because of its small size and sufficient power to weight ratio, the electric motors disclosed herein allow the same or a similar machine to be powered at the same, similar or substantial the same performance characteristics.
[00022] Certain embodiments consist of a stator and a rotor which may be contained in an enclosure. The rotor creates a magnetic field in the vicinity of the stator; the stator creates a disturbance in the magnetic field forcing the rotor to move to a position that minimizes the disturbance in the magnetic field. The rotor may consist of a series of permanent magnets attached to a differential. The stator may consist of a series of coils, attached to an enclosure. The enclosure may house bearings to ensure that the rotor can rotate to minimize the disturbance in the magnetic field. Certain embodiments are directed to an electrical machine comprising: at least one rotor, a plurality of magnets used in, or in contact with, the rotor, at least one stator and a plurality of coils used in, or in contact with, the stator, wherein the configuration is contain, partially contained within and a enclosure; and a control electronics provides individual control over each coil and/or cluster of coils generating the disturbances. In certain embodiments, the control electronics provides individual control over one or more coils and/or one or more cluster of coils generating the disturbances.
[00023] Certain embodiments are directed to an electrical machine that provides significant size, weight reduction, price reduction, or combinations thereof, while increasing the electrical machine's power output, efficiency, reliability, maintainability or combinations thereof. Also disclosed are methods of using the electrical machine, methods of manufacturing the electrical machine and/or systems that incorporate the electrical machine.
[00024] Certain embodiments are directed to adaptive magnetic flux arrays wherein the device, methods, and/or systems permit real time, or substantially real time, software reconfigurable electrical motor/generator. The disclosed devices, methods and/or systems may be used as both a motor and a generator may also be referred to as an electrical machine. One advantage of certain embodiments is the ability of those embodiments to reconfigure itself in real time, or substantially real time, this permits the machine, method and/or system to find its optimal settings across very wide operating speeds and/or loads. Such flexibility results in energy savings across a plethora of industries. Other advantages of certain embodiments disclosed herein are: reduce cost by reducing the amount of copper in the windings; the amount of electrical steel; the size of the package required to house it or combinations thereof.
[00025] For example, the weight of the copper windings in an electrical machine is proportional to the size of current, greater the current the heavier the wire. This relationship is quadratic, not linear. Certain embodiments effectively divide and conquer this relationship. In certain embodiments each (or one or more) independent coil handles relatively small amounts of current. By using numerous small coils, the overall current through each coil (or one or more) remains low, but the total current for the whole system scales linearly, along with the quantity of material and/or the cost of the electrical machine. By overcoming this quadratic relationship much larger electrical machines may be built at more affordable prices.
[00026] Certain embodiments of the present disclosure may accommodate magnets of various shapes. For example, the shape may be a cylinder, cuboid, segmented, trapezoidal or other suitable shapes.
[00027] An object of the present invention is to provide a device for inductively exciting the field windings thus removing the need for using permanent magnets from various types of permanent magnet-based motors.
[00028] The invention relates to the technical field of electric motors. More specifically, the invention relates to a device for converting permanent magnet motors into permanent magnet free motors.
[00029] Accordingly, an aspect of the present invention relates to a device for inductively exciting the field windings thus removing the need for using permanent magnets from various types of permanent magnet-based motors. The disclosed device provides an efficient, practical and low-cost solution for making such motors permanent magnet free. The device moreover adds better control features in a motor making the its suitable various applications like high temperature environments.
[00030] As the main power transfer component is the specially designed rotating ferrite core transformer which performs the contact free power transfer at high frequency. The present invention uses high frequency power transfer which as an overall efficiency > 98% and due to high frequency switched mode the size of the device is very small. This makes the device low cost and easy to install in existing designs.
[00031] The invention will now be best explained with the figures included in the drawings:
[00032] FIG. 1 illustrates a device for inductively exciting field windings of a motor, in accordance with an embodiment of the present invention. As shown in FIG. 1, the device delivers the field excitation power at a very high frequency inductively. This makes the power transfer without any physical contact thus removing any friction or wear related problems. The inductive power transfer is performed using a compact device comprising of a voltage source (102), an oscillator (102), Rotating Ferrite Core Transformer [A-B] having a stationary RFCT-Fixed Side Winding (106), a rotating RFCT-Rotor Side Winding (108), a rectifier (110) and field winding (112) as depicted in FIG. 1.
[00033] The voltage source (102) provides electric power to the oscillator (104) which converts the DC voltage to a high frequency and feeds the stationary RFCT-Fixed Side Winding (106). The RFCT-Fixed Side Winding (106) inductively transfers this energy to the rotating RFCT-Rotor Side Winding (108) which is then rectified by the rectifier (110) and fed to the field winding (112).
[00034] The present invention provides a device for inductively exciting the field windings of motors which use electromagnets for generation of magnetic field.
[00035] FIG. 2A illustrates an exemplary motor incorporated with the device for inductively exciting field windings of a motor, in accordance with an embodiment of the present invention. FIG. 2A shows a configuration comprising of an externally excited synchronous motor using the disclosed device. Similarly, other type of motor such stepper motors, reluctance motors, AC motors, BLDC motors and DC motors can be externally excited using the disclosed device. The motor/generator described in FIG. 2A comprises of a shaft [1] bearing the rotor [13]. The rotor [13] has salient poles with rotor winding [12]. The combination of rotor [13] and rotor winding [12] make an electromagnet with fixed magnetic polarity. In a permanent magnet-based motor this would have been accomplished by permanent magnets. The excitation current/power for this rotor electromagnet is provided by the device as show and discussed in FIG. 1 (above) in a non-contact manner. The voltage source (102) provides electric power to the oscillator (104) which converts the DC voltage to a high frequency and feeds the stationary RFCT-fixed side winding (106). The RFCT-Fixed Side Winding (106) inductively transfers this energy to the rotating RFCT-rotor side winding (108) which is then rectified by the rectifier (110) and fed to the field winding (112).
[00036] FIG. 2B illustrates a sectional view of an exemplary motor incorporated with the device for inductively exciting field windings of a motor, in accordance with an embodiment of the present invention.
[00037] FIG. 2C illustrates an exploded view of an exemplary motor incorporated with the device for inductively exciting field windings of a motor, in accordance with an embodiment of the present invention.
[00038] It may be appreciated that while the FIGs. 2A-2C shows various components of the motor with numerals, however, the only components that are essential for understanding the invention are explained above.
[00039] Following are the components as shown in FIGs. 2A and 2B but are not explained herein this draft to maintain brevity of this document, however, a person skilled in the art would be able to appreciate the functioning of these components:
1- Shaft
2- Front end bell
3- Stator winding
4- Stator
A- RFCT Fixed Side
B- RFCT Rotor Side
7- Bearing
8- Back end bell
106- RCFT fixed side winding
108-RCFT rotor side winding
110- Rectifier
12- Rotor winding
13- Rotor
14- Enclosure
[00040] Following are the components as shown in FIG. 2C but are not explained herein this draft to maintain brevity of this document, however, a person skilled in the art would be able to appreciate the functioning of these components:
1- Stator
2- Shaft
3- Rotor
4- Converter
5- End bell
6- Bearing
A- RFCT Fixed Side
106- RCFT fixed side winding
B- RFCT Rotor Side
108-RCFT rotor side winding
11- Rotor side winding
12- stator side winding
[00041] In an embodiment, the present invention provides a device for inductively exciting field windings of a motor. The device includes a voltage source (102), an oscillator (104), a first transformer (A) connected to the oscillator (104), a second transformer (B) connected to a rectifier (110), and the rectifier (110) having a field winding (112).
[00042] The first transformer (106) having a stationary rotating ferrite core transformer (RFCT)-fixed side winding (106).
[00043] The second transformer having a rotating RFCT-rotor side winding (108).
[00044] In working mode, the voltage source (102) is adapted to provide a direct current (DC) voltage to the oscillator (104) that converts the DC voltage to a high frequency to be feed to the stationary RFCT-fixed side winding (106) such that the stationary RFCT-fixed side winding (106) inductively transfers the high frequency to the rotating RFCT-rotor side winding for rectifying the high frequency by the rectifier (110) to feed the rectified high frequency to the field winding (112) of the motor.
[00045] In an exemplary embodiment, the first transformer (A) and the second transformer (B) are a rotating ferrite core transformer (RFCT).
[00046] In an exemplary embodiment, the first transformer (A) is a stator.
[00047] In an exemplary embodiment, the second transformer (B) is a rotor.
[00048] It may be appreciated that, ferrite core transformers are non-conductive, ferromagnetic compounds that are used for high-frequency applications. They are made from ferrite cores with windings made from ferrites. The cores are made from a combination of iron oxides, zinc, nickel, and manganese compounds. Ferrite core transformers are used for transmitting signals and power to rotating systems. They are used in electronics for their high magnetic permeability and low electrical conductivity.
[00049] In another embodiment, a motor is disclosed. The motor includes a voltage source (102), an oscillator (104), a first transformer (A) connected to the oscillator (104), a second transformer (B) connected to a rectifier (110), and the rectifier (110) having a field winding (112).
[00050] The first transformer (106) having a stationary rotating ferrite core transformer (RFCT)-fixed side winding (106).
[00051] The second transformer having a rotating RFCT-rotor side winding (108).
[00052] In working mode, the voltage source (102) is adapted to provide a direct current (DC) voltage to the oscillator (104) that converts the DC voltage to a high frequency to be feed to the stationary RFCT-fixed side winding (106) such that the stationary RFCT-fixed side winding (106) inductively transfers the high frequency to the rotating RFCT-rotor side winding for rectifying the high frequency by the rectifier (110) to feed the rectified high frequency to the field winding (112) of the motor.
[00053] In an exemplary embodiment, the first transformer (A) and the second transformer (B) are a rotating ferrite core transformer (RFCT).
[00054] In an exemplary embodiment, the first transformer (A) is a stator.
[00055] In an exemplary embodiment, the second transformer (B) is a rotor.
[00056] FIG. 3 shows a method for inductively exciting field windings of a motor, in accordance with an embodiment of the present invention.
[00057] At step 302, a first transformer (A) is connected to an oscillator (104). The first transformer (106) has a stationary rotating ferrite core transformer (RFCT)-fixed side winding (106). The first transformer is a rotating ferrite core transformer (RFCT).
[00058] At step 304, a second transformer (B) is connected to a rectifier (110). The second transformer having a rotating RFCT-rotor side winding (108). The rectifier (110) has a field winding (112), and the second transformer is a rotating ferrite core transformer (RFCT).
[00059] In a working mode, a voltage source (102) is adapted to provide a direct current (DC) voltage to the oscillator (104) that converts the DC voltage to a high frequency to be feed to the stationary RFCT-fixed side winding (106) such that the stationary RFCT-fixed side winding (106) inductively transfers the high frequency to the rotating RFCT-rotor side winding for rectifying the high frequency by the rectifier (110) to feed the rectified high frequency to the field winding (112) of the motor.
[00060] 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.
[00061] All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of 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.
, C , Claims:CLAIMS:
WE CLAIM:

1. A device for inductively exciting field windings of a motor, the device comprising:
a voltage source (102);
an oscillator (104);
a first transformer (A) connected to the oscillator (104), the first transformer (106) having a stationary rotating ferrite core transformer (RFCT)-fixed side winding (106);
a second transformer (B) connected to a rectifier (110), the second transformer having a rotating RFCT-rotor side winding (108), and the rectifier (110) having a field winding (112);
wherein the voltage source (102) is adapted to provide a direct current (DC) voltage to the oscillator (104) that converts the DC voltage to a high frequency to be feed to the stationary RFCT-fixed side winding (106) such that the stationary RFCT-fixed side winding (106) inductively transfers the high frequency to the rotating RFCT-rotor side winding for rectifying the high frequency by the rectifier (110) to feed the rectified high frequency to the field winding (112) of the motor.

2. The device as claimed in claims 1, wherein the first transformer (A) and the second transformer (B) are a rotating ferrite core transformer (RFCT).

3. The device as claimed in claims 1, wherein the first transformer (A) is a stator.

4. The device as claimed in claims 1, wherein the second transformer (B) is a rotor.

5. A motor comprising:
a voltage source (102);
an oscillator (104);
a first transformer (A) connected to the oscillator (104), the first transformer (106) having a stationary rotating ferrite core transformer (RFCT)-fixed side winding (106);
a second transformer (B) connected to a rectifier (110), the second transformer having a rotating RFCT-rotor side winding (108), and the rectifier (110) having a field winding (112);
wherein the voltage source (102) is adapted to provide a direct current (DC) voltage to the oscillator (104) that converts the DC voltage to a high frequency to be feed to the stationary RFCT-fixed side winding (106) such that the stationary RFCT-fixed side winding (106) inductively transfers the high frequency to the rotating RFCT-rotor side winding for rectifying the high frequency by the rectifier (110) to feed the rectified high frequency to the field winding (112) of the motor.

6. The motor as claimed in claims 5, wherein the first transformer (A) and the second transformer (B) are a rotating ferrite core transformer (RFCT).

7. The motor as claimed in claims 5, wherein the first transformer (A) is a stator.

8. The motor as claimed in claims 5, wherein the second transformer (B) is a rotor.

9. A method for inductively exciting field windings of a motor, the method comprising:
connecting (302) a first transformer (A) to an oscillator (104), the first transformer (106) having a stationary rotating ferrite core transformer (RFCT)-fixed side winding (106), and the first transformer is a rotating ferrite core transformer (RFCT);
connecting (304) a second transformer (B) to a rectifier (110), the second transformer having a rotating RFCT-rotor side winding (108), and the rectifier (110) having a field winding (112), and the second transformer is a rotating ferrite core transformer (RFCT);
wherein a voltage source (102) is adapted to provide a direct current (DC) voltage to the oscillator (104) that converts the DC voltage to a high frequency to be feed to the stationary RFCT-fixed side winding (106) such that the stationary RFCT-fixed side winding (106) inductively transfers the high frequency to the rotating RFCT-rotor side winding for rectifying the high frequency by the rectifier (110) to feed the rectified high frequency to the field winding (112) of the motor.