Electric machine with reconfigurable rotor poles

Abstract

An electric machine having reconfigurable rotor poles. The electric machine may include a stator including a plurality of stator windings configured to generate a rotating magnetic field (RMF), and a rotor configured to rotate within the stator in accordance with torque induced by the RMF. The rotor may include a plurality of rotor windings wound around the plurality of circumferentially spaced rotor protrusions. The electric machine may include a rotor power transfer circuit operable to reconfigure electrical excitation of the rotor windings according to a plurality of excitation modes.

Description

Technical Field

[0001] The present disclosure relates to electric machines, such as, but not necessarily limited to, separately excited machines (SEMs) having reconfigurable rotor poles. Background Art

[0002] Some electric machines may be configured to utilize electrical power to perform work, such as by rotating a rotor in response to a rotating magnetic field (RMF) provided by a stator. The rotor of such an electric machine may include individually energizable rotor windings, wherein the rotor windings may be energized to generate their own magnetic fields via corresponding rotor poles. The configuration of rotor poles has historically been fixed because the electric machine lacks the ability to change or otherwise selectively control the number and / or polarity of rotor poles while the electric machine is in use. Summary of the invention

[0003] One non-limiting aspect of the present disclosure relates to an electric machine having reconfigurable rotor poles whereby the number and / or polarity of the rotor poles may be varied or otherwise selectively controlled while in use. The electric machine may be operable according to a plurality of excitation modes, wherein the excitation modes may be selectively used to effectuate corresponding changes to the number and / or polarity of the rotor poles according to operating conditions, such as to optimize performance according to the selectable number and / or polarity of the rotor poles.

[0004] One non-limiting aspect of the present disclosure relates to a separately excited electric machine (SEM) with reconfigurable rotor poles. The SEM may include a stator and a rotor, the stator including a plurality of stator windings configured to generate a rotating magnetic field (RMF), the rotor configured to rotate within the stator according to a torque induced by the RMF. The rotor may include a plurality of rotor windings wound around a plurality of circumferentially spaced rotor protrusions, the rotor windings providing a plurality of rotor poles when electrically excited. The SEM may also include a rotor power transfer circuit operable to reconfigure the electrical excitation of the rotor windings according to a plurality of excitation modes.

[0005] The excitation pattern may include a polar excitation pattern operable to reconfigure the magnetic polarity of one or more of the rotor poles from a north magnetic polarity to a south polarity.

[0006] The excitation mode may include an excitation mode operable to reconfigure the number of rotor poles from a first number to a second number.

[0007] The quantitative excitation mode can reconfigure the rotor poles from alternating magnetic polarity to paired magnetic polarity, which results in adjacent pairs of rotor poles having matching magnetic polarity.

[0008] Adjacent pairs of matching magnetic polarities may each respectively combine to form a plurality of equivalent rotor poles such that a first number corresponds to rotor poles having alternating magnetic polarities and a second number corresponds to rotor poles having paired magnetic polarities.

[0009] The quantity excitation mode can reconfigure the rotor poles from balanced excitation to unbalanced excitation, where unbalanced excitation causes one or more of the rotor windings to be unexcited relative to balanced excitation.

[0010] Balancing the excitation may include exciting each of the rotor windings such that a first number corresponds to each of the rotor poles that are excited and a second number corresponds to one or more of the rotor poles that are not excited.

[0011] The rotor power transmission circuit may include a controller, a plurality of winding circuits connected to the rotor windings, and a plurality of switches connected between one or more of the winding circuits and a source of direct current (DC) power. The controller may be operable to selectively control the switches between open and closed states to reconfigure the electrical excitation of the rotor windings associated therewith.

[0012] The winding circuits may include one or more non-reconfigurable winding circuits and one or more reconfigurable winding circuits, the non-reconfigurable winding circuits being directly connected to the source independent of the switches, and the reconfigurable winding circuits being connected to the source via one or more of the switches.

[0013] The switches of each of the winding circuits may be arranged according to an H-bridge configuration including an upper left switch, an upper right switch, a lower left switch, and a lower right switch.

[0014] Each winding circuit may include a first terminal and a second terminal, wherein the first terminals are each connected between an upper left switch and a lower left switch of an H-bridge configuration associated therewith, and the second terminals are each connected between an upper right switch and a lower right switch of an H-bridge configuration associated therewith.

[0015] The source can provide a DC output relative to a positive rail and a negative rail, wherein an upper left switch and an upper right switch are connected to the positive rail, a lower left switch and a lower right switch are connected to the negative rail, an upper left switch of each of the H-bridge configurations is connected to a lower left switch of the H-bridge configuration corresponding to the switch, and an upper right switch of each of the H-bridge configurations is connected to a lower right switch of the H-bridge configuration corresponding to the switch.

[0016] The switch may be included in an outer portion of the rotor power transfer circuit external to the shaft of the rotor.

[0017] The switch may be included within an internal portion of the rotor power transfer circuit within the shaft of the rotor.

[0018] The rotor projections may each comprise no more than one rotor winding, the rotor windings each being connected to a different one of the winding circuits such that each of the rotor poles corresponds to a separate one of the winding circuits.

[0019] The rotor power transfer circuit may include an electrical interface for each of the winding circuits, each electrical interface transferring electrical power between a switch and a winding circuit associated with the switch.

[0020] The electrical interface may be configured to provide mechanical transmission of electrical power using brushes and slip rings, inductive transmission of electrical power using transformers, and / or capacitive transmission of electrical power using capacitors.

[0021] A non-limiting aspect of the present disclosure relates to an electric machine with reconfigurable rotor poles. The electric machine may include a stator and a rotor, the stator including a plurality of stator windings configured to generate a rotating magnetic field (RMF), the rotor being configured to rotate within the stator according to a torque induced by the RMF. The rotor may include a plurality of rotor windings wound around a plurality of circumferentially spaced rotor protrusions, the rotor windings providing a plurality of rotor poles when electrically excited. The electric machine may include a rotor power transmission circuit including a plurality of winding circuits connected to the rotor windings, a plurality of switches connected between one or more of the winding circuits and a source of direct current (DC) power, and a controller operable to reconfigure the number and / or polarity of the rotor poles by changing the electrical excitation of the rotor windings.

[0022] The source may provide a DC output relative to a positive rail and a negative rail, the rotor projections may each include no more than one rotor winding, the rotor windings may each be connected to a different one of the winding circuits, the winding circuits may each include a first terminal and a second terminal, and the switches of each of the winding circuits may be arranged according to an H-bridge. The H-bridge configuration may include an upper left switch, an upper right switch, a lower left switch, and a lower right switch, optionally, the first terminal is each connected between the upper left switch and the lower left switch of the H-bridge configuration associated therewith, the second terminal is each connected between the upper right switch and the lower right switch of the H-bridge configuration associated therewith, the upper left switch and the upper right switch are connected to the positive rail, the lower left switch and the lower right switch are connected to the negative rail, the upper left switch of each of the H-bridge configurations is connected to the lower left switch of the H-bridge configuration corresponding thereto, and the upper right switch of each of the H-bridge configurations is connected to the lower right switch of the H-bridge configuration corresponding thereto. The machine may also include a controller operable to selectively control the switch between an open and a closed state to reconfigure the electrical excitation of the rotor winding associated with the switch.

[0023] A non-limiting aspect of the present disclosure relates to a vehicle. The vehicle may include an electric motor configured to convert electrical power into mechanical power to propel the vehicle. The electric motor may include a stator and a rotor, the stator including a plurality of stator windings configured to generate a rotating magnetic field (RMF), and the rotor configured to rotate within the stator according to a torque induced by the RMF. The rotor may include a plurality of rotor windings wound around a plurality of circumferentially spaced rotor protrusions, the rotor windings providing a plurality of rotor poles when electrically excited. The electric motor may also include a rotor power transmission circuit operable to reconfigure the number and / or polarity of rotor poles by changing the electrical excitation of the rotor windings according to a corresponding one of a plurality of excitation modes.

[0024] The present invention provides the following technical solutions.

[0025] Technical solution 1. A separately excited motor (SEM) with reconfigurable rotor poles, comprising:

[0026] a stator comprising a plurality of stator windings configured to generate a rotating magnetic field (RMF);

[0027] a rotor configured to rotate within the stator in response to a torque induced by the RMF, the rotor comprising a plurality of rotor windings wound around a plurality of circumferentially spaced rotor protrusions, the rotor windings providing a plurality of rotor poles when electrically excited; and

[0028] A rotor power transfer circuit is operable to reconfigure electrical excitation of the rotor windings according to a plurality of excitation modes.

[0029] Technical solution 2. The SEM according to technical solution 1, wherein:

[0030] The excitation pattern includes a polar excitation pattern operable to reconfigure the magnetic polarity of one or more of the rotor poles from a north magnetic polarity to a south polarity.

[0031] Technical solution 3. The SEM according to technical solution 1, wherein:

[0032] The excitation mode includes a number excitation mode operable to reconfigure the number of rotor poles from a first number to a second number.

[0033] Technical solution 4. The SEM according to technical solution 3, wherein:

[0034] The quantitative excitation pattern reconfigures the rotor poles from alternating magnetic polarity to paired magnetic polarity that results in adjacent pairs of the rotor poles having matching magnetic polarity.

[0035] Technical solution 5. The SEM according to technical solution 4, wherein:

[0036] The matching magnetic polarities of the adjacent pairs are each respectively combined to form a plurality of equivalent rotor poles such that the first number corresponds to the rotor poles having the alternating magnetic polarities and the second number corresponds to the rotor poles having the paired magnetic polarities.

[0037] Technical solution 6. The SEM according to technical solution 3, wherein:

[0038] The quantitative excitation mode reconfigures the rotor poles from balanced excitation to unbalanced excitation, wherein the unbalanced excitation causes one or more of the rotor windings to be unexcited relative to the balanced excitation.

[0039] Technical solution 7. The SEM according to technical solution 6, wherein:

[0040] The balanced excitation includes exciting each of the rotor windings such that the first number corresponds to each of the rotor poles that are excited and the second number corresponds to one or more of the rotor poles that are not excited.

[0041] Technical solution 8. The SEM according to technical solution 1, wherein:

[0042] The rotor power transmission circuit includes a controller, a plurality of winding circuits connected to the rotor windings, and a plurality of switches connected between one or more of the winding circuits and a source of direct current (DC) power, wherein the controller is operable to selectively control the switches between open and closed states to reconfigure the electrical excitation of the rotor windings associated with the switches.

[0043] Technical solution 9. The SEM according to technical solution 8, wherein:

[0044] The winding circuit includes one or more non-reconfigurable winding circuits and one or more reconfigurable winding circuits, wherein the non-reconfigurable winding circuits are directly connected to the source independently of the switches, and the reconfigurable winding circuits are connected to the source via one or more of the switches.

[0045] Technical solution 10. The SEM according to technical solution 8, wherein:

[0046] The switches of each of the winding circuits are arranged according to an H-bridge configuration including an upper left switch, an upper right switch, a lower left switch, and a lower right switch.

[0047] Technical solution 11. The SEM according to technical solution 10, wherein:

[0048] The winding circuits each include a first terminal and a second terminal; and

[0049] The first terminals are each connected between the upper left switch and the lower left switch of the H-bridge configuration associated with the first terminal; and

[0050] The second terminals are each connected between the upper right switch and the lower right switch of the H-bridge configuration associated with the second terminal.

[0051] Technical solution 12. The SEM according to technical solution 11, wherein:

[0052] said source providing said DC output relative to a positive rail and a negative rail;

[0053] The upper left switch and the upper right switch are connected to the positive rail;

[0054] The lower left switch and the lower right switch are connected to the negative rail;

[0055] The upper left switch of each of the H-bridge configurations is connected to the lower left switch of the H-bridge configuration corresponding to the upper left switch; and

[0056] The upper right switch of each of the H-bridge configurations is connected to the lower right switch of the H-bridge configuration corresponding to the upper right switch.

[0057] Technical solution 13. The SEM according to technical solution 12, wherein:

[0058] The switch is included in an outer portion of the rotor power transfer circuit external to a shaft of the rotor.

[0059] Technical solution 14. The SEM according to technical solution 12, wherein:

[0060] The switch is included within an interior portion of the rotor power transfer circuit within a shaft of the rotor.

[0061] Technical solution 15. The SEM according to technical solution 12, wherein:

[0062] said rotor protrusions each comprising no more than one said rotor winding; and

[0063] The rotor windings are each connected to a different one of the winding circuits such that each of the rotor poles corresponds to a separate one of the winding circuits.

[0064] Technical solution 16. The SEM according to technical solution 12, wherein:

[0065] The rotor power transfer circuit includes an electrical interface for each of the winding circuits, each electrical interface transferring electrical power between the switch and the winding circuit associated with the switch.

[0066] Technical solution 17. The SEM according to technical solution 16, wherein:

[0067] The electrical interface is configured to provide mechanical transmission of electric power using brushes and slip rings, to provide inductive transmission of electric power using transformers, and / or to provide capacitive transmission of electric power using capacitors.

[0068] Technical Solution 18. A motor with reconfigurable rotor poles, comprising:

[0069] a stator comprising a plurality of stator windings configured to generate a rotating magnetic field (RMF);

[0070] a rotor configured to rotate within the stator in response to a torque induced by the RMF, the rotor comprising a plurality of rotor windings wound around a plurality of circumferentially spaced rotor protrusions, the rotor windings providing a plurality of rotor poles when electrically excited; and

[0071] A rotor power transmission circuit comprising:

[0072] a plurality of winding circuits connected to the rotor windings;

[0073] a plurality of switches connected between one or more of the winding circuits and a source of direct current (DC) power; and

[0074] A controller is operable to reconfigure the number and / or polarity of the rotor poles by varying the electrical excitation of the rotor windings.

[0075] Technical Solution 19. The motor according to Technical Solution 18, wherein:

[0076] said source providing said DC output relative to a positive rail and a negative rail;

[0077] said rotor projections each comprising no more than one of said rotor windings;

[0078] The rotor windings are each connected to a different one of the winding circuits;

[0079] The winding circuits each include a first terminal and a second terminal;

[0080] The switches of each of the winding circuits are arranged according to an H-bridge configuration comprising an upper left switch, an upper right switch, a lower left switch and a lower right switch, wherein:

[0081] The first terminals are each connected between the upper left switch and the lower left switch of the H-bridge configuration associated with the first terminal;

[0082] The second terminals are each connected between the upper right switch and the lower right switch of the H-bridge configuration associated with the second terminal;

[0083] The upper left switch and the upper right switch are connected to the positive rail;

[0084] The lower left switch and the lower right switch are connected to the negative rail;

[0085] The upper left switch of each of the H-bridge configurations is connected to the lower left switch of the H-bridge configuration corresponding to the upper left switch; and

[0086] The upper right switch of each of the H-bridge configurations is connected to the lower right switch of the H-bridge configuration corresponding to the upper right switch; and

[0087] The controller is operable to selectively control the switch between open and closed states to reconfigure the electrical excitation of the rotor winding associated with the switch.

[0088] Technical Solution 20. A means of transport, comprising:

[0089] an electric motor configured to convert electrical power into mechanical power for propelling the vehicle; and

[0090] Wherein, the electric motor comprises:

[0091] a stator comprising a plurality of stator windings configured to generate a rotating magnetic field (RMF);

[0092] a rotor configured to rotate within the stator in response to a torque induced by the RMF, the rotor comprising a plurality of rotor windings wound around a plurality of circumferentially spaced rotor protrusions, the rotor windings providing a plurality of rotor poles when electrically excited; and

[0093] A rotor power transfer circuit is operable to reconfigure the number and / or polarity of the rotor poles by varying the electrical excitation of the rotor winding according to a corresponding one of a plurality of excitation modes.

[0094] These features and advantages and other features and advantages of the present teachings may be apparent from the following detailed description of the modes for carrying out the present teachings when combined with the accompanying drawings. It should be understood that even though the following drawings and embodiments may be described separately, their individual features may also be combined into additional embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0095] The accompanying drawings, which may be incorporated in and constitute a part of this specification, illustrate implementations of the present disclosure and, together with the description, serve to explain the principles of the present disclosure.

[0096] Figure 1 A schematic diagram of a reconfigurable electric machine according to one non-limiting aspect of the present disclosure is illustrated.

[0097] Figure 2 A schematic diagram of a vehicle having an electric machine according to one non-limiting aspect of the present disclosure is illustrated.

[0098] Figure 3 A schematic diagram of a transmission circuit according to one non-limiting aspect of the present disclosure is illustrated.

[0099] Figure 4 An alternating polarity excitation pattern is illustrated in accordance with one non-limiting aspect of the present disclosure.

[0100] Figure 5 An excitation pattern with paired magnetic polarity according to one non-limiting aspect of the present disclosure is illustrated.

[0101] Figure 6 An excitation mode with unbalanced excitation according to one non-limiting aspect of the present disclosure is illustrated.

[0102] Figure 7 A schematic diagram of another transmission circuit according to one non-limiting aspect of the present disclosure is illustrated.

[0103] Figure 8 A schematic diagram of a reconfigurable motor with a capacitive interface according to one non-limiting aspect of the present disclosure is illustrated.

[0104] Fig. 9 A schematic diagram of a capacitive interface according to one non-limiting aspect of the present disclosure is illustrated in more detail.

[0105] Fig.10 A schematic diagram of a reconfigurable motor with an inductive interface according to one non-limiting aspect of the present disclosure is illustrated. DETAILED DESCRIPTION

[0106] As desired, detailed embodiments of the present disclosure may be disclosed herein; however, it is understood that the disclosed embodiments may be merely examples of disclosures that may be implemented in various and alternative forms. The drawings may not necessarily be drawn to scale; some features may be exaggerated or minimized to show details of particular components. Therefore, the specific structural and functional details disclosed herein may not be interpreted as limiting, but merely as a representative basis for teaching those skilled in the art to use the present disclosure in various ways.

[0107] Figure 1A schematic diagram of a reconfigurable electric machine 10 according to one non-limiting aspect of the present disclosure is illustrated. The electric machine 10 may be of a type that employs a rotor 12 to apply mechanical force to a load in proportion to the electrical excitation of the rotor 12 and / or to generate electrical energy in response to the rotation of the rotor 12. At least in the illustrated configuration, the electric machine 10 may be referred to as an electric motor or separately excited electric machine (SEM) 10 that is operable for propulsion of a vehicle and / or regenerative braking. Figure 2 A schematic diagram of a vehicle 14 having an electric motor 10 is illustrated in accordance with one non-limiting aspect of the present disclosure. The electric motor 10 may be used within the vehicle 14 to facilitate applying mechanical force to a propulsion system, powertrain, or transmission system 16 operable to propel or otherwise drive the vehicle 14. The vehicle 14 is illustrated as a hybrid type, as the powertrain 12 optionally includes an internal combustion engine (ICE) 18. The powertrain 16 may include a transmission, drive shafts, differentials, axles, and / or other components to facilitate transferring rotational force from a rotor shaft 30 (see FIG. 1 ) coupled to the rotor 10. Figure 1 ) are transmitted to wheels 20, 22, 24, 26. The vehicle 14 is shown as including the power system 12 operable with the front wheels 20, 24 for non-limiting purposes, as the present disclosure fully contemplates its use and application in four-wheel drive vehicles and other non-automotive types of vehicles.

[0108] return Figure 1 , the electric motor 10 may include a housing 32 that is configured to support a rear end (not shown) of the rotor shaft 30 while allowing the rotor 10 to rotate relative to the stator 36 within the air gap 34. The stator 36 may be disposed annularly about the rotor 10 for the purpose of generating a rotating magnetic field (RMF), which, as will be appreciated by those skilled in the art, may be used to impart a rotational torque sufficient to rotate the rotor 10. Although not shown in detail, the stator 36 may include stator windings or other features that are capable of being electrically excited for the purpose of controlling the RMF and the resulting rotation of the rotor 10. The rotor 10 may include a plurality of rotor windings 38 wound around a plurality of circumferentially spaced rotor protrusions 42, which, when excited, may be used to induce a rotor magnetic field within a corresponding plurality of rotor poles 44 (see Figure 3 ). The rotor magnetic field may interact with the RMF to facilitate rotation of the rotor shaft 30 to propel the vehicle 14 and / or regenerative braking in response to rotation of the rotor shaft 30. The rotor 10 may be formed in a generally annular shape, optionally formed from a plurality of laminations stacked axially in a side-by-side facing relationship along the axis of rotation A. Although Figure 1As generally shown in FIG. 1 and described in more detail below, the present disclosure contemplates a rotor 12 having rotor projections 42 wound or otherwise configured with one or more individually energizable rotor windings 38 (i.e., having rotor projections 42 wound with distinct and independently energizable groups of rotor windings 38).

[0109] Figure 3 is a schematic diagram of a reconfigurable separately excited electric machine rotor according to one non-limiting aspect of the present disclosure. The electric motor may include a rotor transmission circuit 50, which is shown as being operable with a single set of rotor windings 38 wound around each protrusion 42, however, the present disclosure fully contemplates that the rotor transmission circuit 50 is operable with multiple sets of rotor windings 38. The rotor winding 38 may be electrically connected to one of a plurality of rotor winding circuits 54, 56, the illustrated configuration corresponding to a first portion of the rotor winding 38 being connected to the first winding circuit 54, and a second portion of the rotor winding 38 being connected to the second rotor winding circuit 56. The configuration of the rotor winding circuits 54, 56 and the connection of the rotor winding 38 thereto may be design parameters that may vary depending on operational considerations of the electric motor 10. Additional rotor winding circuits may be included and / or the rotor winding circuits 54, 56 may be connected to the rotor winding in a different order, pattern, and / or the connection points between the rotor winding 38 and the winding circuits 54, 56 may be changed, i.e., the ends of the rotor winding 38 may be switched or reversed relative to the corresponding winding circuits 54, 56 to provide different magnetic polarities.

[0110] The rotor transmission circuit 50 may be operable in the manner described herein to facilitate selectively exciting the rotor windings 38 via corresponding rotor winding circuits 54, 56. Excitation of the rotor windings 38 may generate corresponding magnetic fields relative to the rotor protrusions 42 associated therewith, which in the illustrated configuration may be used to produce an eight-pole configuration, i.e., when each of the rotor windings 38 is excited, the rotor winding excitation effectively produces eight rotor poles 44. This eight-pole configuration is presented as the present disclosure for non-limiting purposes, and the rotor transmission circuit may be operated with or included as part of a motor having more or fewer rotor protrusions 42, for example, to support six-pole, 12-pole, etc. configurations. The rotor transmission circuit 50 may be used in the manner described herein to reconfigure one or more of the rotor poles 44, such that the number and / or polarity of the rotor poles 44 may be changed or otherwise selectively controlled when in use. The number, polarity, and / or other characteristics of the rotor poles 44 may be reconfigurable accordingly according to a plurality of excitation modes. The excitation mode may be selectively employed to reconfigure the rotor poles 44 based on operating conditions, such as to optimize performance based on a selectable number and / or polarity of rotor poles 44 .

[0111] The rotor transmission circuit 50 may include a DC to DC (DC-DC) converter 60 operable to control DC power transmission using a DC power source 62. The source 62 may optionally correspond to a rechargeable energy storage system (RESS) operable to store and supply DC power, and optionally a DC link capacitor 64 is connected across a positive terminal 66 and a negative terminal 68 of the source 62 to facilitate filtering and smoothing the DC power. The rotor transmission circuit 50 may include a switching circuit 70 having a plurality of switches S1, S2, S3, S4 operable between an open or off state and a closed or on state. The switches S1, S2, S3, S4 may be semiconductor switches, transistors, etc. that are selectively controllable between an open and closed state. The switches S1, S2, S3, S4 are shown as being external to the rotor shaft 30, i.e., within an external portion of the rotor transmission circuit 50. However, the present disclosure contemplates integrating the switches S1, S2, S3, S4 within an internal portion of the rotor transmission circuit 50, such as within the rotor shaft 30. The rotor transmission circuit 50 may include a controller 74 configured to selectively control the switches S1, S2, S3, S4 between states. The controller 74 may include a plurality of non-transitory instructions stored on a computer-readable storage medium that, when executed with one or more processors, may operate to facilitate the operations, processes, and other activities contemplated herein. The controller 74 may be configured to facilitate reconfiguring the rotor poles 44 by selectively controlling the excitation of the rotor windings 38 associated therewith according to one or more of a plurality of excitation modes.

[0112] The excitation of the rotor winding 38 can be based on the transmission of electrical power through the switching circuit 70, such as between the DC output 76 provided from the DC-DC converter relative to the positive rail 78 and the negative rail 80. The rotor transmission circuit 50 can include an electrical interface 84, 86 configured to electrically connect the switching circuit 70 with the winding circuits 54, 56. The electrical interface 84, 86 is shown as a brush-slip ring configuration, where brushes and slip rings 92, 94, 96, 98, 100, 102, 104, 106 can be used to transfer electrical power between the switching circuit 70 and the winding circuits 54, 56. The electrical interface 84 can include, for example, brushes 92, 94 operable to exchange electrical power with slip rings 96, 98 connected to the first winding circuit 54 and brushes 100, 102 operable to exchange electrical power with slip rings 104, 106 connected to the second winding circuit 56. The positive and negative brushes 92, 94, 100, 102 may be correspondingly positioned to physically contact slip rings 96, 98, 104, 106 attached to the rotor shaft 30, the physical contact being operable to facilitate electrical power exchange therebetween when the rotor 12 is stationary and rotating. The present disclosure fully contemplates an electrical interface 94 having other configurations suitable for providing electrical energy to and / or receiving electrical energy from the rotor winding 38, such as via capacitive and / or inductive type couplings, whereby physical contact between the switching circuit 70 and the rotor winding circuit 54 may not be necessary.

[0113] The switching circuit 70 is shown with the first winding circuit 54 having a non-reconfigurable configuration and the second winding circuit 56 having a reconfigurable configuration, such that the first winding circuit 54 can be correspondingly characterized as a non-reconfigurable winding circuit and the second winding circuit 56 can be considered a reconfigurable winding circuit. The first winding circuit 54 can be considered non-reconfigurable because its first terminal 110 and second terminal 112 are fixedly or permanently connected to a respective one of the positive rail 78 and the negative rail 80. The second winding circuit 56 can be considered reconfigurable because its first terminal 114 and second terminal 116 can be selectively connected to a respective one of the positive rail 78 and the negative rail 80 depending on whether the intervening switches S1, S2, S3, S4 are controlled to an open and / or closed state. The switches S1, S2, S3, S4 can be arranged in the manner shown according to the H-bridge configuration 120. The H-bridge configuration 120 may be characterized in that the switches S1, S2, S3, S4 are arranged to include an upper left switch S1, an upper right switch S3, a lower left switch S2, and a lower right switch S4. With respect to the second circuit 56, the first terminal 114 may be connected between the upper left switch S1 and the lower left switch S2, and the second terminal 116 may be connected between the upper right switch S3 and the lower right switch S4. The upper left switch S1 and the upper right switch S3 may be connected to the positive rail 78, the lower left switch S2 and the lower right switch S4 may be connected to the negative rail 80, the upper left switch S1 may be connected to the lower left switch S2, and the upper right switch S3 may be connected to the lower right switch S4.

[0114] Figure 4 An alternating polarity excitation pattern according to one non-limiting aspect of the present disclosure is illustrated. The alternating polarity excitation pattern may correspond to the controller 74 controlling the DC-DC converter 60 to provide DC power and controlling the H-bridge configuration 120 such that the upper left switch S1 and the lower right switch S4 are in a closed state, and the lower left switch S2 and the upper right switch S3 are in an open state. With the first winding circuit 54 tethered to the positive rail 78 and the negative rail 80, the alternating polarity excitation may result in the first terminal 114 of the second circuit winding 56 being connected to the positive rail 78 and the second terminal 116 thereof being connected to the negative rail 80, which in turn results in the first rotor pole 44A having a first polarity or north pole, the second rotor pole 44B having a second polarity or south polarity, the third rotor pole 44C having a north pole, the fourth rotor pole 44D having a south polarity, the fifth rotor pole 44E having a north pole, the sixth rotor pole 44F having a south polarity, and the eighth rotor pole 44G having a north pole, and the corresponding current flows are shown by arrows.

[0115] Figure 5A number of excitation patterns with paired magnetic polarities according to one non-limiting aspect of the present disclosure are illustrated. The excitation pattern may correspond to the controller 74 controlling the DC-DC converter 60 to provide DC power and controlling the H-bridge configuration 120 such that the upper left switch S1 and the lower right switch S4 are in an open state, and the lower left switch S2 and the upper right switch S3 are in a closed state. With the first winding circuit 54 tethered to the positive rail 78 and the negative rail 80, excitation may result in the first terminal 114 of the second circuit winding 56 being connected to the negative rail 80 and the second terminal 116 thereof being connected to the positive rail 78, which in turn results in the first rotor pole 44A having a north polarity, the second rotor pole 44B having a north polarity, the third rotor pole 44C having a south polarity, the fourth rotor pole 44D having a south polarity, the fifth rotor pole 44E having a north polarity, the sixth rotor pole 44F having a north polarity, the seventh rotor pole 44G having a south polarity, and the eighth rotor pole 44H having a south polarity, and the corresponding current flows are shown with arrows. This implementation can be used to move rotor poles 44A, 44B, 44C, 44D, 44E, 44F, 44G, 44H from Figure 4 The alternating magnetic polarity shown in FIG. 4 is reconfigured into paired magnetic polarity, whereby adjacent pairs of rotor poles 44A, 44B, 44C, 44D, 44E, 44F, 44G, 44H have matching magnetic polarity. The matching magnetic polarity of adjacent pairs can cause these pairs to combine to form equivalent rotor poles 44I, 44J, 44K, 44L, so that relative to Figure 4 , the rotor poles 44 may be capable of being reconfigured from a first number to a second number, ie, from an eight-pole configuration to a four-pole configuration.

[0116] Figure 6 A quantitative excitation pattern with unbalanced excitation according to one non-limiting aspect of the present disclosure is illustrated. The excitation pattern may correspond to the controller 74 controlling the DC-DC converter 60 to provide DC power and controlling the H-bridge configuration 120 such that the upper left switch S1, the lower right switch S2, the lower left switch S3, and the upper right switch S4 are in an open state. With the first winding circuit 54 tethered to the positive rail 78 and the negative rail 80, the excitation may cause the first terminal 114 and the second terminal 116 of the second circuit winding 56 to be de-energized or disconnected, which in turn causes the first rotor pole 44A to have a north polarity, the second rotor pole 44B to be de-energized, the third rotor pole 44C to be de-energized, the fourth rotor pole 44D to have a south polarity, the fifth rotor pole 44E to have a north polarity, the sixth rotor pole 44F to be de-energized, the seventh rotor pole 44G to be de-energized, and the eighth rotor pole 44H to have a south polarity, and the corresponding current flows are shown as arrows. This implementation may be used to move the rotor poles 44 from Figure 4The alternating magnetic polarity or balanced polarity shown in (where each of the rotor poles 44 is excited) is reconfigured to unbalanced excitation (where one or more of the rotor poles 44 are not excited). The unexcited magnetic poles 44B, 44C, 44F, 44G can cause the rotor poles 44 to be reconfigured from a first number to a second number, that is, from an eight-pole configuration to a four-pole configuration. By deactivating some of the rotor windings 38 in this manner, lower resistance and inductance can be achieved in the rotor system, thereby improving efficiency, while the unexcited or inactive rotor poles 44B, 44C, 44F, 44G may not completely remain because they may still generate magnetic resistance.

[0117] Figure 7 1 is a schematic diagram of a reconfigurable electric machine 10 according to one non-limiting aspect of the present disclosure. Figure 3 Unlike in the embodiment of the present invention, the rotor transmission circuit 50 can be configured such that the switching circuit 70 includes a plurality of H-bridge configurations 120, which are shown as including one H-bridge 120A, 120B for each of the winding circuits 54, 56. For simplicity of representation, a first winding circuit 54 and a second winding circuit 56 are shown, however, additional winding circuits 54, 56 for each of the rotor poles 44 will be included. In other words, the electric motor can include eight winding circuits, each of which is individually and independently connected to one of the rotor windings 38, and the switches S1, S2, S3, S4, Sn-1, Sn-2, Sn-3, Sn-4 of the switching circuit 70 are arranged to provide eight H-bridge configurations 120 therefor. Additionally, unlike in the embodiment of the present invention, in which one of the winding circuits 54, 56 can be permanently tethered to the positive rail 78 and the negative rail 80, Figure 3Unlike, none of the winding circuits 54, 56 are so tethered. The current and direction of each winding circuit 54, 56 may be independently controlled for each rotor winding 38, depending on the manner in which the controller 74 may control the switches S1, S2, S3, S4, Sn-1, Sn-2, Sn-3, Sn-4 of the corresponding H-bridge configurations 120A, 120B. Thus, the controller 74 may individually control the switches S1, S2, S3, S4, Sn-1, Sn-2, Sn-3, Sn-4 to independently energize or de-energize the rotor poles 44, independently switch the polarity of each rotor pole 44, control multiple rotor poles 44 to provide equivalent poles, provide balanced and unbalanced configurations, etc. Separate winding circuits 54, 56 and H-bridge configurations 120A, 120B for each of the rotor poles 44 may be beneficial in maximizing the reconfigurability of the electric motor 10. However, the present disclosure fully contemplates other relationships, such as some of the winding circuits 54, 56 being connected to more or fewer rotor windings 38 than others of the winding circuits 54, 56, optionally with each such winding circuit 54, 56 including a dedicated H-bridge configuration 120A, 120B for managing current passing therethrough.

[0118] Figure 8 A schematic diagram of a reconfigurable motor 10 having electrical interfaces 84 , 86 configured as capacitive interfaces is illustrated in accordance with one non-limiting aspect of the present disclosure. Fig. 9 The schematic diagram of the electrical interface 84, 86 is shown in more detail. As shown, the capacitive interface 84, 86 may include an alternating concentric layer of insulating retaining material and a rotor magnetic field to use a diode on the rotor frame (see Figure 8 ) provides a wireless form of power transfer, converting AC current into DC current in a wireless power transfer box (rectifier). With capacitive plates acting in the radial direction, multiple rings can be placed on the same plane to allow multiple connection paths, allowing multi-pole configurations for SEMs. The ring carrier can be made using PCB and copper traces, and for higher speed applications, more robust materials and aluminum can be used. For higher power transfer, the plates can be stacked in the radial direction, or the diameter or ring carrier needs to be increased to allow for a larger surface area. Each path may require its own set of DC / AC / DC converters. Fig.10A schematic diagram of a reconfigurable motor 10 having electrical interfaces 84, 86 configured as an inductor-based interface in accordance with one non-limiting aspect of the present disclosure is illustrated. By using two sets of stacked rotary transformers, two separate excitation signals can be sent to two independent sets of rotor windings, which can be driven with two different pole configurations. Each pair of rotary transformers may need to be magnetically isolated from each other because both secondary rotating windings will be excited with two independent flux paths. The inductive power transfer of the pole configuration is not limited to the axial orientation, but can also be used in the radial direction for shaft embedded power transfer.

[0119] The terms "comprise", "include" and "have" are inclusive and therefore specify the presence of the features, steps, operations, elements and / or parts, but do not exclude the presence or addition of one or more other features, steps, operations, elements or parts. The order of steps, processes and operations can be changed when possible, and additional or alternative steps can be adopted. As used in this specification, the term "or" includes any one and all combinations of the associated enumerated items. The term "any of..." is understood to include any possible combination of the cited items, including "any of" the cited items. "One", "one", "the", "at least one" and "one or more" are used interchangeably to indicate that at least one of the items exists. There may be multiple such items, unless the context clearly indicates otherwise. Unless otherwise clearly or clearly indicated by the context, including the attached claims, all parameter values ​​(e.g., the value of quantity or condition) should be understood to be modified by the term "about" in all cases, regardless of whether "about" actually appears before the value. A component "configured to" perform a specified function is able to perform the specified function without change, rather than just having the potential to perform the specified function after further modification. In other words, when expressly configured to perform a specified function, the described hardware is specifically selected, created, implemented, utilized, programmed and / or designed for the purpose of performing the specified function.

[0120] Although various embodiments have been described, the description is intended to be exemplary, not restrictive, and it is obvious to those of ordinary skill in the art that more embodiments and implementations within the scope of the embodiments are possible. Unless specifically limited, any feature of any embodiment can be used in combination with any other feature or element in any other embodiment or be replaced by any other feature or element in any other embodiment. Therefore, the embodiments are not limited except according to the attached claims and their equivalents. In addition, various modifications and changes can be made within the scope of the attached claims. Although several modes for performing many aspects of this teaching have been described in detail, people familiar with the fields involved in these teachings will recognize various alternative aspects for practicing this teaching within the scope of the attached claims. It is intended that all content contained in the above description or shown in the accompanying drawings should be interpreted as an illustration and example of the overall scope of alternative embodiments that ordinary skill in the art will recognize, which are implied by the included content, structurally and / or functionally equivalent to the included content, or become obvious in other ways based on the included content, and are not limited to those embodiments that are clearly depicted and / or described.

Claims

1. A separately excited electric machine (SEM) with reconfigurable rotor poles, comprising: a stator comprising a plurality of stator windings configured to generate a rotating magnetic field (RMF); a rotor configured to rotate within the stator in response to a torque induced by the RMF, the rotor comprising a plurality of rotor windings wound around a plurality of circumferentially spaced rotor protrusions, the rotor windings providing a plurality of rotor poles when electrically excited; and A rotor power transfer circuit is operable to reconfigure electrical excitation of the rotor windings according to a plurality of excitation modes.

2. The SEM of claim 1, wherein: The excitation pattern includes a polar excitation pattern operable to reconfigure the magnetic polarity of one or more of the rotor poles from a north magnetic polarity to a south polarity.

3. The SEM of claim 1, wherein: The excitation mode includes a number excitation mode operable to reconfigure the number of rotor poles from a first number to a second number.

4. The SEM of claim 3, wherein: The quantitative excitation pattern reconfigures the rotor poles from alternating magnetic polarity to paired magnetic polarity that results in adjacent pairs of the rotor poles having matching magnetic polarity.

5. The SEM of claim 4, wherein: The matching magnetic polarities of the adjacent pairs are each respectively combined to form a plurality of equivalent rotor poles such that the first number corresponds to the rotor poles having the alternating magnetic polarities and the second number corresponds to the rotor poles having the paired magnetic polarities.

6. The SEM of claim 3, wherein: The quantitative excitation mode reconfigures the rotor poles from balanced excitation to unbalanced excitation, wherein the unbalanced excitation causes one or more of the rotor windings to be unexcited relative to the balanced excitation.

7. The SEM of claim 6, wherein: The balanced excitation includes exciting each of the rotor windings such that the first number corresponds to each of the rotor poles that are excited and the second number corresponds to one or more of the rotor poles that are not excited.

8. The SEM of claim 1, wherein: The rotor power transmission circuit includes a controller, a plurality of winding circuits connected to the rotor windings, and a plurality of switches connected between one or more of the winding circuits and a source of direct current (DC) power, wherein the controller is operable to selectively control the switches between open and closed states to reconfigure the electrical excitation of the rotor windings associated with the switches.

9. An electric machine with reconfigurable rotor poles, comprising: a stator comprising a plurality of stator windings configured to generate a rotating magnetic field (RMF); a rotor configured to rotate within the stator in response to a torque induced by the RMF, the rotor comprising a plurality of rotor windings wound around a plurality of circumferentially spaced rotor protrusions, the rotor windings providing a plurality of rotor poles when electrically excited; and A rotor power transmission circuit comprising: a plurality of winding circuits connected to the rotor windings; a plurality of switches connected between one or more of the winding circuits and a source of direct current (DC) power; and A controller is operable to reconfigure the number and / or polarity of the rotor poles by varying the electrical excitation of the rotor windings.

10. A means of transport, comprising: an electric motor configured to convert electrical power into mechanical power for propelling the vehicle; and Wherein, the electric motor comprises: a stator comprising a plurality of stator windings configured to generate a rotating magnetic field (RMF); a rotor configured to rotate within the stator in response to a torque induced by the RMF, the rotor comprising a plurality of rotor windings wound around a plurality of circumferentially spaced rotor protrusions, the rotor windings providing a plurality of rotor poles when electrically excited; and A rotor power transfer circuit is operable to reconfigure the number and / or polarity of the rotor poles by varying the electrical excitation of the rotor winding according to a corresponding one of a plurality of excitation modes.

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