Fixed-side-only compensation network

Abstract

Embodiments of the present disclosure provide an electric drive motor system including a stationary side and a rotating side. The fixed side includes a fixed side only (OSS) compensation network. A first OSS compensation element of the OSS compensation network is operable to provide a rotation side compensation function.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of the prior filing date of U.S. Provisional Application Serial No. 63 / 333,790, filed on April 22, 2022, the entire disclosure of which is incorporated herein by reference. Background Art

[0003] A wound-rotor synchronous machine (WRSM) is an electric motor with a rotor and a stator. The stator is the fixed part of the machine, and the rotor is the rotating part of the machine. The stator usually has a multi-phase winding, and the rotor is made with field windings instead of permanent magnets. The rotor rotates in a magnetic field, and the magnetic field can be generated by windings or field coils. The field coil is an electromagnet that is used to generate a magnetic field in an electromagnetic machine, typically a rotating electrical machine such as a motor or generator. It consists of a coil of wire through which an electric current flows. In the case of a machine with a field coil, an electric current must flow in the coil to generate a magnetic field, otherwise no power is transferred to or from the rotor. The process of generating a magnetic field with the help of an electric current is called excitation. The field coil produces the most flexible form of flux regulation and deregulation, but at the expense of the flow of electric current.

[0004] Conventionally, the rotor windings of a WRSM can be powered or excited using a slip ring and brush assembly system. However, the slip ring and brush assembly system has disadvantages, including low efficiency at high speeds, frequent maintenance requirements, and overall loss, especially at high speeds due to the high contact resistance between the brushes and the slip rings.

[0005] In order to avoid the shortcomings of the slip ring and brush assembly excitation methods, wireless (or contactless) excitation systems or wireless power transfer systems have been developed. In general, wireless power transfer can be implemented using various technologies to transfer energy by means of an electromagnetic field (EMF) without the need for a physical link. In a wireless power transfer system, a transmitter device driven by power from a power source generates a time-varying EMF, which transmits power to a receiver device via mutual inductance (M) across space. The receiver device extracts power from the EMF using M and supplies the extracted power to an electrical load. Wireless power transfer provides power to electrical devices / loads where interconnecting wires are inconvenient, dangerous or impossible. Wireless power technology is mainly divided into two categories, near field and far field. In near field technology, time-varying EMF is generated using various technologies, including resonant inductive coupling. Resonant inductive coupling is a near-field wireless transfer of electrical energy between magnetically coupled coils, which are part of a resonant circuit and are tuned to resonate at the same frequency as the driving frequency.

[0006] Rotary transformer (RT) is a wireless power transfer system that can be used for controlled wireless excitation of WRSM rotor windings. RT performs the same general function as a conventional transformer, in that both transfer electrical energy from one circuit to another at the same frequency but different voltages. Conventional transformers work according to the principle of electromagnetic induction, that is, an electromotive force is induced in a closed circuit due to a variable magnetic field around it. RT is different from conventional transformers in that the RT geometry is arranged so that the primary winding and the secondary winding can rotate relative to each other, with negligible changes in electrical characteristics. In a known configuration, RT can be constructed by winding the primary winding and the secondary winding into two separate halves of a cup-shaped core. The concentric halves face each other, with each half mounted on one of the parts that rotate relative to each other. The magnetic flux provides coupling from one half of the cup-shaped core across the air gap to the other half, providing M that transfers energy from the primary winding of the RT to its secondary winding.

[0007] Known methods of using an RT system to provide excitation to a WRSM may include providing the RT system with a resonant tuning network, also referred to as a compensation network. The resonant tuning network may include circuit components (e.g., various combinations of resistors (R), inductors (L), and / or capacitors (C)) that enable an associated transformer to store oscillating electrical energy similar to a resonant circuit and thus act as a bandpass filter, allowing frequencies close to their resonant frequency to pass from the primary winding to the secondary winding, but blocking other frequencies. The amount of M between the primary and secondary windings, together with the quality factor (Q factor) of the circuit, determines the shape of the frequency response curve. Resonant circuits are often referred to as LC or LRC circuits because of the inductance, resistance, and capacitance components used to form the resonant circuit. In materials science, each material has its own natural frequency. If an external vibration is equal to the natural frequency, resonance occurs. In electrical science, the impedance of an inductor and a capacitor depends on frequency. The impedance of a capacitor is inversely proportional to the frequency, while the impedance of an inductor is directly proportional to the frequency. At a specific frequency, the two cancel each other (or tune each other). Such a circuit is called a resonant circuit, and the specific frequency is the resonant frequency. Additionally, for an LC circuit, where the reactance of the L component is substantially the same as the reactance of the C component, the L and C components cancel each other, which means that the L and C components compensate or tune each other.

[0008] In conventional RT systems that provide resonant tuning or compensation (i.e., RT compensation systems), a resonant tuning network (or compensation network) is provided on both the stationary (or stator, or primary) side and the rotating (or rotational, or secondary) side of the WRSM. For the primary coil, the basic function of "compensation" is to minimize the input apparent power and / or minimize the voltage-ampere (VA) rating of the power supply. For the secondary coil, compensation cancels out the leakage inductance of the secondary coil in order to maximize the transfer capability.

[0009] RT compensation systems that provide resonant circuit components on both the stationary and rotating sides of a WRSM have disadvantages. For example, it is difficult to place a resonant tuning network or compensation network on the rotating side due to the very limited space and high temperature operating conditions of the rotating side, which exceeds the temperature ratings of commercially available resonant tuning components (such as capacitors). In addition, having a resonant tuning capacitor on the rotating side reduces the mechanical reliability of the rotating parts and increases the complexity, mechanical mass and inertia of the rotating parts, especially at high rotational speeds.

[0010]

[0006] Therefore, there is a need in the art to provide a compensation network for use in an RT system that provides the benefits of wireless power transfer without the difficulties associated with providing compensation components on the rotating side of an electric motor, such as a WFSM. Summary of the invention

[0011] Embodiments of the present disclosure provide an electric drive motor system including a stationary side and a rotating side. The stationary side includes an only-stationary-side (OSS) compensation network. A first OSS compensation element of the OSS compensation network is operable to provide a rotating side compensation function.

[0012] Embodiments of the present disclosure provide a method for manufacturing an electric drive motor system including a stationary side and a rotating side. The stationary side includes an OSS compensation network. A first OSS compensation element of the OSS compensation network is operable to provide a rotating side compensation function. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 is a simplified block diagram illustrating a non-limiting example of an electric drive motor system having a stationary-only compensation network according to aspects of the present disclosure;

[0014] Figure 2 The invention is a view showing an aspect of the present disclosure Figure 1 A simplified block diagram of a non-limiting example of how an electric motor drive system may be implemented is shown;

[0015] Figure 3 is a simplified flow chart illustrating a method according to aspects of the present disclosure;

[0016] Figure 4 is a simplified flow chart illustrating a method according to aspects of the present disclosure;

[0017] Figure 5 It is shown Figure 1 and Figure 2 A simplified block diagram of an equivalent circuit representation of the electric drive motor system shown in;

[0018] Figure 6 It is shown Figure 1 and Figure 2 A simplified block diagram of another equivalent circuit representation of the electric drive motor system shown in ;

[0019] Figure 7 It is shown Figure 1 and Figure 2 A simplified block diagram of another equivalent circuit representation of the electric drive motor system shown in ;

[0020] Figure 8 depicts various equations that may be used to design a fixed-side-only compensation network according to aspects of the present disclosure;

[0021] Fig. 9 depicts various equations that may be used to design a fixed-side-only compensation network according to aspects of the present disclosure;

[0022] Fig.10 depicts various equations that may be used to design a fixed-side-only compensation network according to aspects of the present disclosure;

[0023] Fig.11 depicts various equations that may be used to design a fixed-side-only compensation network according to aspects of the present disclosure;

[0024] Fig.12 depicts various equations that may be used to design a fixed-side-only compensation network according to aspects of the present disclosure;

[0025] Fig.13 depicts various equations that may be used to design a fixed-side-only compensation network according to aspects of the present disclosure;

[0026] Fig.14 depicts various equations that may be used to design a fixed-side-only compensation network according to aspects of the present disclosure; and

[0027] Fig.15 Various equations are depicted that may be used to design a fixed-side-only compensation network according to aspects of the present disclosure. DETAILED DESCRIPTION

[0028] Embodiments of the present disclosure provide an RT compensation system having a novel fixed-side-only compensation network. In various embodiments of the present disclosure, the novel fixed-side-only compensation network can be incorporated into an electric motor drive system having an electric motor (e.g., a WRSM) operable to include a fixed side and a rotating side. The novel fixed-side-only compensation network disclosed herein is provided by implementing the fixed-side-only compensation network as a fixed-side-only resonant LCC (inductor-capacitor-capacitor) network, which solves the previously described difficulties associated with placing a resonant tuning network or compensation circuit on the rotating / secondary side. The fixed-side-only resonant LCC (inductor-capacitor-capacitor) network is operable to provide tuning only on the fixed side (or primary side) without providing compensation elements (e.g., without one or more resonant tuning capacitor elements) for RT compensation system applications on the rotating side (or secondary side). In the embodiments described herein, the term "fixed side-only" is applied to a compensation network implemented in an electric drive motor system having a fixed side and a rotating side, meaning that no compensation components are provided on the rotating side. In embodiments of the present disclosure, the need for compensation elements on the rotating side is eliminated by configuring only the fixed-side LCC network to perform a rotating-side compensation function, wherein the rotating-side compensation is provided by one or more compensation elements of the only fixed-side LCC network. For example, in some embodiments of the present disclosure, the rotating-side compensation function includes determining one or more values ​​of one or more compensation elements of the only fixed-side LCC network, such that the one or more compensation elements on the fixed side provide the compensation function for the rotating side.

[0029] In aspects of the present disclosure, the previously described electric motor drive system includes a resonant inverter that is operable to convert direct current (DC) (e.g., from a vehicle battery) into high frequency (HF) AC and provide the HF AC to a fixed-side resonant LCC network only. The fixed-side resonant LCC network only is designed in such a way that the fixed-side resonant LCC network only can perform a rotating-side compensation function in addition to providing fixed-side compensation. The rotating-side compensation function includes a novel design method that includes calculating a "reflected" fixed-side coil impedance due to an impedance on the rotating-side coil of the electric motor. In general, the reflected impedance (or inductance) is a portion of the impedance of a circuit (e.g., circuit A) due to the influence of another coupled circuit (e.g., circuit B). The novel design method also includes selecting the location and component values ​​of the fixed-side resonant LCC network only so that the fixed-side resonant LCC network only tunes the "reflected" fixed-side coil impedance due to the impedance on the rotating-side coil outside the fixed-side resonant LCC network only. For example, with appropriate placement and dimensions of the capacitive components (e.g., capacitive elements in series with the primary winding / coil) of only the fixed side resonant LCC network, the capacitors of the LCC tuning network can be tuned by only fixing the capacitive components (e.g., Figure 2 The rotating side winding of the electric motor is tuned from the stationary side with proper location and size of the C1 capacitor (shown in FIG. 1 ). The LCC tuning on the primary side is configured and arranged so that constant current source behavior is achieved on the primary side coil, regardless of the load current or coupling coefficient. Therefore, the resonant inverter output current is directly related to the rectifier output current fed to the rotor winding on the secondary side. In the absence of compensation on the secondary side (e.g., without one or more resonant tuning capacitors), the tuning circuit on the secondary side is simplified, the need to identify and provide high temperature rotating side capacitors is eliminated, the costs associated with the secondary side tuning components are eliminated, and the overall reliability of the wireless motor excitation system is improved.

[0030] Turning now to a more detailed description of embodiments of the present disclosure, Figure 1 A system 100 embodying aspects of the present disclosure is depicted. The system 100 includes an energy source 110 electronically coupled to an electric motor drive system 102. The electric motor drive system 102 includes a resonant inverter 120, a DC excitation motor 130, and an inverter controller 150, configured and arranged as shown. According to aspects of the present disclosure, the DC excitation motor 130 includes a fixed-side-only compensation network 140. Although the resonant inverter 120, the DC excitation motor 130, the fixed-side-only compensation network 140, and the inverter controller 150 are depicted as separate components, it should be understood that the resonant inverter 120, the DC excitation motor 130, the fixed-side-only compensation network 140, and the inverter controller 150 can be configured and arranged in any suitable combination. For example, the inverter controller 150 may be incorporated into the resonant inverter 120 ; the resonant inverter 120 may be incorporated into the DC excitation motor 130 ; and / or the resonant inverter 120 and the inverter controller 150 may be incorporated into the DC excitation motor 130 .

[0031] The energy source 110 can be implemented in various forms (including, for example, as a battery). In some embodiments of the present disclosure, the battery can be a battery pack having a group of one or more individual battery cells connected in series or in parallel and operating under the control of one or more controllers (such as a battery control module (BCM) that monitors and controls the performance of the battery pack). For example, the BCM can monitor several battery pack level characteristics, such as the battery pack current, battery pack voltage, and battery pack temperature measured by a current sensor. The battery pack can be recharged by an external power source (not shown). The battery pack may include power conversion electronics that are operable to regulate power from an external power source to provide the battery pack with appropriate voltage and current levels. The individual battery cells within the battery pack may be composed of various chemical formulas. The battery pack chemical composition may include, but is not limited to, lead acid, nickel cadmium (NiCd), nickel metal hydride (NIMH), lithium ion, or lithium ion polymer.

[0032] The resonant inverter 120 is electrically coupled between the energy source 110 and the DC excitation motor 130 to transfer excitation energy from the energy source 110 to the DC excitation motor 130. More specifically, the resonant inverter 120 is operable to provide energy from the energy source 110 to the fixed-side compensation network 140 of the DC excitation motor 130 at a desired resonant frequency for the purpose of providing excitation to the DC excitation motor 130. In an embodiment of the present disclosure, the resonant inverter 120 is operable to convert the DC voltage from the energy source 110 into an AC current of a desired resonant frequency according to the requirements of the DC excitation motor 130 and the fixed-side compensation network 140 for motor excitation. In an embodiment of the present disclosure, the resonant inverter 120 may be a full-bridge resonant inverter having four switches organized into two "phase legs". Each phase leg may include two switches connected in series and connected between a positive DC rail and a negative DC rail. A phase node may be positioned between the two switches of each phase leg to provide a phase of an AC waveform output of a desired resonant frequency. In some embodiments of the present disclosure, the resonant inverter 120 generates HF AC. The inverter controller 150 is electrically coupled to the phase leg switches to control the on / off state of the switches, thereby controlling the frequency and phase of the AC waveform generated by the resonant inverter 120. The inverter controller 150 includes a computing device (with memory) including a computer, a microprocessor digital signal processor, and the like configured and operable to execute software commands and programs, and may include associated firmware so that the controller 150 is configured and operable to control the on / off switching operation of the resonant inverter 120.

[0033] The DC excitation motor 130 can be any compromise electric motor design suitable for the work to be performed by the motor. In conventional automotive-based motor applications, examples of work that can be done by the motor include operating or moving power windows; power seats; fans for heaters and radiators; windshield wipers; and / or the engine of a vehicle with a hybrid electric vehicle configuration. Regardless of the type of DC excitation motor 130, it relies on electromagnetic and flipping magnetic fields to generate mechanical power. Conventional implementations of DC excitation motors 130 include five basic parts, namely a stator; a rotor; a solid shaft; a coil; and a so-called "squirrel cage". The windings of a DC excitation motor stator are rings of electromagnets that are paired in sequence and energized, which produces a rotating magnetic field. The rotor in a DC excitation motor does not have any direct connection to the power supply and has no brushes. Instead, it often uses the squirrel cage described previously. The squirrel cage in a DC excitation motor is a set of rotor bars connected to two rings, one at each end. The squirrel cage rotor goes inside the stator. When the excitation power is sent through the stator, it generates EMF. The bars in the squirrel cage rotor are conductors, so they react to the flipping of the stator's magnetic poles, which causes the rotor to spin and create its own magnetic field. The key to an induction motor (where the rotor's magnetic field is induced by the stator's magnetic field) is that the rotor is always trying to catch up. It's always seeking static equilibrium, so it's spinning to find that stable state. However, the EMF generated by the stator is always a little faster than the rotor's magnetic field. The rotation of the rotor creates the torque needed to produce the mechanical power to turn the wheels of a car or the blades of a fan. Some DC-excited motors use a wound rotor (such as a WRSM), which is wrapped with wire instead of a squirrel cage. In either case, there is only one moving part in a DC-excited motor, which means there are fewer things to replace or maintain.

[0034] In some embodiments of the present disclosure, the DC excitation motor 130 may be a WRSM. A WRSM is a rotary electric motor having a rotor and a stator. The stator is the fixed part of the machine, and the rotor is the rotating part of the machine. The stator typically has a multi-phase winding, and the rotor is made with an excitation winding instead of a permanent magnet. The rotor rotates in a magnetic field, and the magnetic field may be generated by windings or excitation coils. In the case of a machine with an excitation coil, an excitation current must flow in the coil to generate a magnetic field, otherwise no power is transferred to or from the rotor. The excitation coil produces the most flexible form of flux regulation and deregulation, but at the expense of the flow of current. Conventionally, the rotor windings of a WRSM can be powered or excited with a slip ring and brush assembly. However, the slip ring and brush system has disadvantages, including low efficiency at high speeds, frequent maintenance requirements, and overall losses, especially at high speeds due to the high contact resistance between the brush and slip ring system.

[0035] In order to avoid the disadvantages of the slip ring and brush assembly excitation method, only the fixed side compensation network 140 is incorporated into the RT compensation system (not shown separately from the motor 130), which is operable to provide a wireless excitation or wireless power transfer from the stator side of the motor 130 to the rotor side of the motor 130. In an embodiment of the present disclosure, only the fixed side compensation network 140 can be implemented as part of a specially designed fixed side only RT compensation system. In general, RT is a circuit and method for wireless power transfer to the rotor winding of the WRSM for controlled excitation. RT is basically the same as a conventional transformer because it transfers electrical energy from one circuit to another at the same frequency but different voltages. In general, a conventional transformer works according to the principle of electromagnetic induction, that is, an electromotive force is induced in a closed circuit due to a variable magnetic field around it. RT differs from a conventional transformer in that the geometry of the RT is arranged so that the primary winding and the secondary winding can rotate relative to each other, with negligible changes in electrical characteristics. In a known configuration, the RT can be constructed by winding the primary winding and the secondary winding into separate halves of a cup-shaped core. The concentric halves face each other with each half mounted on one of the parts that rotate relative to each other. Magnetic flux provides coupling from one half of the cup core across the air gap to the other half, providing M that couples energy from the primary winding of the RT to its secondary winding.

[0036] In conventional RT designs that provide resonant tuning or compensation (i.e., RT compensation systems), the resonant tuning network (or compensation network) is provided on both the stationary (or primary) side and the rotating (or secondary) side of the WRSM. RT designs that have resonant circuit components on both the stationary and rotating sides of the WRSM are difficult to implement. For example, due to very limited rotor space and high temperature rotor operating conditions that exceed the temperature ratings of commercially available compact capacitors, it is difficult to place a resonant tuning network or compensation circuit on the secondary side in practice. In addition, having a resonant tuning capacitor on the secondary side increases the complexity of the rotating parts, increases mechanical mass, increases inertia, and reduces mechanical reliability, especially at high rotational speeds.

[0037] The fixed-side-only compensation network 140 solves the difficulties associated with going beyond on-paper design and computer simulation and actually implementing (i.e., building and using) conventional RT compensation system designs including fixed-side and rotating-side compensation networks by providing the benefits of compensated RT functionality without the difficulties associated with providing compensation circuitry on the rotating side of a DC-excited motor 130 (e.g., a WFSM). More specifically, the fixed-side-only compensation network 140 is operable to facilitate wireless delivery of rotor excitation current from the fixed side to the rotating rotor, thereby eliminating brush and slip ring maintenance issues, as well as the inefficiencies, manufacturing challenges, and design drawbacks associated with brush and slip ring systems.

[0038] In aspects of the present disclosure, the fixed-side-only compensation network 140 takes into account the absence of a resonant tuning capacitor on the secondary side by providing an additional resonant tuning capacitor on the primary side (i.e., one of the resonant tuning capacitors of the LCC network embodiment of the fixed-side-only compensation network 140) and adjusting the two primary-side resonant tuning capacitors so that the uncompensated secondary side does not impose inefficiencies or other disadvantages on the network 140. In an embodiment of the present disclosure, a fixed-side-only LCC design method is provided, the method including reflecting the impedance and / or inductance of the secondary side to the primary side, and the secondary coil (e.g., Figure 2 The leakage inductance of L2) shown in Figure 1 is tuned on the primary side. In general, reflected impedance (or inductance) is the portion of the impedance of a circuit (e.g., circuit A) that is caused by affecting another coupled circuit (e.g., circuit B). In an embodiment of the present disclosure, this can be achieved by deriving an equivalent circuit model of system 100 and an overall impedance model of system 100, which allows the calculation of the reflected impedance from the secondary to the primary. Further simplifications are applied to the derived equivalent circuit model so that the total impedance seen by the resonant inverter 120 can be calculated. In order to tune this total impedance to unity power factor, the tuning capacitor of the LCC design (e.g., Figure 2 Thus, the fixed side only compensation network 140 eliminates the need for capacitor tuning on the secondary side, as well as the need for one or more secondary side resonant tuning capacitors and their tuning, by providing additional primary side tuning components (e.g., one or more resonant tuning capacitors) and adjusting the values ​​of the tuning components on the primary side. Additional details of the fixed side only LCC design and its associated design methods according to aspects of the present disclosure are provided in Figures 3 to 15 is shown in and subsequently described herein.

[0039] Figure 2 A system 100A is depicted having a DC link capacitor (C dc ) is electronically coupled to a vehicle battery 110A of an electric motor drive system 102A. The system 100A is a system 100 ( Figure 1 ) is a non-limiting example embodiment; the vehicle battery 110A is the energy source 110 ( Figure 1 ) is a non-limiting example embodiment; and the electric motor drive system 102A is an electric motor drive system 102 ( Figure 1 1. The electric motor drive system 102A may be implemented as a resonant inverter 120A electronically coupled to an inverter controller 150 and a simplified representation of an electric machine 130A. The resonant inverter 120A is an inverter 120 ( Figure 1The motor 130A is a DC excitation motor 130 ( Figure 1 The motor 130A includes a novel fixed-side resonant LCC 140A, a rectifier 210, and a rotor inductor L rotor and rotor resistance R rotor The novel fixed-side-only resonant LCC 140A is a novel fixed-side-only wireless power transfer network 140 ( Figure 1 1 and 10. The system 100A includes a fixed side (e.g., a stator side) 220 and a rotating side (e.g., a rotor side) 230. In general, the fixed side 220 includes the stator winding L1 and circuit elements on its left side, and the rotating side 230 includes the stator winding L2 and circuit elements on its right side. Although the resonant inverter 120A, the motor 130A, and the inverter controller 150 are depicted as separate components, it should be understood that the resonant inverter 120A, the motor 130A, and the inverter controller 150 can be configured and arranged in any suitable combination of components. For example, the inverter controller 150 can be incorporated into the resonant inverter 120A; the resonant inverter 120A can be incorporated into the motor 130A; and / or the resonant inverter 120A and the inverter controller 150 can be incorporated into the motor 130A.

[0040] Still reference Figure 2 The fixed side 220 is configured to transfer power to the rotating side 230 using inductive power transfer, and the rotating side 230 is configured to receive power from the fixed side 220 via inductive power transfer. The fixed side 220 includes a DC vehicle battery 110A, a DC link capacitor C dc, resonant inverter 120A, only fixed side resonant LCC 140A and stator side coil L1. The resonant inverter 120A receives a DC input signal from a vehicle battery 110A and converts the DC input signal into an AC output signal of a desired resonant frequency. In some embodiments of the present disclosure, the resonant inverter 120A is a full-bridge inverter circuit, which is operable to include four power electronic switching devices T1, T2, T3, T4, configured and arranged as shown. The switching devices T1, T2, T3, T4 can be implemented in any suitable format, including but not limited to metal oxide semiconductor field effect transistors (metal oxide semiconductor field effect transistors, MOSFET), BJT, FET, IGBT, IGFET and the like. The inverter controller 150 is electrically coupled to each of the switching devices T1, T2, T3, T4 to control the switching operation of the resonant inverter 120A. The inverter controller 150 turns on and off the switching devices T1, T2, T3, T4 to generate an AC output signal V at a desired resonant frequency. inv_0 The inverter controller 150 comprises a computing device (with memory) including a computer, microprocessor, digital signal processor, and the like operable to execute software commands and programs, and may include associated firmware such that the controller 150 is configured and operable to control the on / off switching operation of the resonant inverter 120A.

[0041] Only the stationary-side resonant LCC 140A interconnects the resonant inverter 120A with the stator-side coil L1. Figure 2 In the non-limiting example embodiment of the present disclosure depicted in FIG. 1 , only the stationary-side resonant LCC 140A is configured to include a stator-side inductor L f1 , stator side series capacitor C1 (connected in series with stator side coil L1) and stator side parallel capacitor C f1 (with stator side inductor L f1 The stator-side series capacitor C1 is coupled in series to the positive terminal of the stator-side coil L1, and the stator-side parallel capacitor C f1 Coupled in parallel with the stator side coil L1.

[0042] The rotating side 230 includes a rotor side coil L2 electrically coupled to a rectifier 210. The rotor side coil L2 is close enough to the stator side coil L1 to be within the EMF generated by the stator side coil L1, so that M is between the stator side coil L1 and the rotor side coil L2. The rotor side coil L2 generates AC current using M, and the rectifier 210 converts the AC current into a DC current (I rotorIn some embodiments of the present disclosure, the rectifier 210 is a bridge rectifier circuit including four diodes D1, D2, D3, and D4. The DC current is provided to the rotor of the motor 130A. The rotor is Figure 2 is represented as a resistor R rotor The series inductor L rotor .

[0043] Energy is transferred between the stator side coil L1 and the rotor side coil L2 via M, and any L1 / L2 leakage inductance does not contribute directly to the active power transfer. Leakage inductance can also be undesirable because it causes the voltage to change with load. In a conventional method of reducing leakage inductance and increasing M, a rotor side compensation circuit (e.g., a rotor side capacitance circuit / element) is provided on the rotating side 230. However, for applications such as systems 100, 100A, where the rotor side rotates relative to the stator side, it is extremely difficult to manufacture a rotor with a rotor side compensation circuit. Embodiments of the present disclosure avoid the need for rotor side compensation circuits / elements by configuring and arranging a fixed side resonant LCC 140A only so that the compensation provided by the rotor side compensation circuit / element on the rotating side 230 in a conventional RT compensation design is provided instead by the design and component value setting of the fixed side resonant LCC 140A only. Additional details of the fixed side resonant LCC 140A only design and its associated design methods according to aspects of the present disclosure are described in detail in the accompanying drawings. Figures 3 to 15 is shown in and subsequently described herein.

[0044] Figure 3 Depicted is a diagram showing that a system 100, 100A ( Figure 1 and Figure 2 310A) is a flowchart of method 300 performed by a computer aided design (CAD) system running on a processor (e.g., having the same processor functionality as controller 150) in some embodiments of the present invention. The CAD system described previously may be implemented using a CAD software application that may be operable to optionally perform calculations, circuit modeling, and circuit simulation operations that may be used to select compensation component values ​​for only the fixed side resonant LCC 140A. According to aspects of the present disclosure, the CAD system described previously may be implemented using a CAD software application that may be operable to optionally perform Figures 4 to 15 Although the description of method 300 refers to components of system 100A, the description is equally applicable to one or more corresponding elements of system 100.

[0045] like Figure 3As shown, the method 300 begins at block 302 with generating AC. In an embodiment of the present disclosure, the AC may be HF AC generated by converting DC received from a vehicle battery 110A to HF AC using a resonant inverter 120A. At block 304, the HF AC is received at a novel fixed-side-only compensation / tuning network (e.g., fixed-side-only resonant LCC 140A) associated with the primary coil L1.

[0046] Blocks 312 and 314 are off-line operations that can be used to design only the fixed side tuning network (e.g., only the fixed side resonant LCC 140A) used at blocks 304, 306. At block 312, the "reflected" fixed side coil impedance due to the impedance on the rotating side coil is calculated. In some embodiments of the invention, the impedance associated with the rotating side or primary coil is reflected to the fixed side. In some embodiments of the invention, the impedance associated with the primary coil and the load (e.g., by Figure 2 L rotor and R rotor denoted) is reflected to the fixed side. At block 314, the location and component values ​​of the fixed side only tuning network are selected so that the fixed side only tuning network tunes the "reflected" fixed side coil impedance due to the impedance on the rotating side coil outside the fixed side only tuning network. For example, with appropriate location and size of the capacitive components (e.g., C1 capacitor) of the fixed side only tuning network, the rotating side winding (e.g., L2) can be tuned from the fixed side by appropriate location and size of the capacitive components (e.g., C1 capacitor) of the fixed side only tuning network. Additional details of how blocks 312 and 314 may be implemented are described in Figures 4 to 15 and described in more detail later herein.

[0047] After the operation at block 304, the method 300 moves to block 306. At block 306, only the fixed side tuning network design has compensation components (e.g., two capacitive elements C1, C f1 ) and calculated compensation component values ​​that enable the fixed-side only tuned network to act as a load and further act as an M-independent constant current source that is operable to generate an alternating current EMF using the AC received at block 304. Utilizing this property of the fixed-side only tuned network (e.g., the fixed-side only resonant LCC 140A), the fixed-side coil (e.g., L1) current does not depend on the rotor current (I rotor) or the relative positions of the stationary side coil (e.g., L1) and the rotating side coil (L2). As a result, the AC generated at block 302 (e.g., generated by the resonant inverter 120A) has an output current root mean square (RMS) value that is directly related to the output current of the stationary side tuning network alone (which will have both active and reactive components). The resulting high M value and large L rotor The inductor eliminates the need for a tuning network on the rotating side. The inductance of the rotating side inductor (L2) can be referenced or reflected to the fixed side and the capacitive components (e.g., C f1 With proper placement and sizing of the capacitors (e.g., Cf1 capacitors), the rotating side winding (e.g., L2) can be tuned from the fixed side (e.g., by proper placement and sizing of the capacitive components (e.g., Cf1 capacitors) of the fixed side tuning network only). The resulting system 100, 100A has a good tuning performance for L rotor Inductance is also not sensitive because the rotor winding inductance is on the DC side (i.e., from Figure 2 rectifier 210 shown), and the inductor in steady state operates as a short circuit at DC voltage and current. Therefore, L rotor The time constant is introduced only when the current changes from one value to another. In addition to introducing the time constant (inertia to current changes), L rotor It is not reflected to the input of the rectifier input 210 and the fixed side 220 .

[0048] After the operation at block 306, the method 300 moves to block 308. At block 308, the AC EMF generated in the rotating side coil (L2) generates M between L1 and L2, and the rotating side coil (L2) uses M to generate an AC charging current. At block 310, the AC charging current is converted to a DC current and provided to downstream motor components (e.g., the rotor, Figure 2 Indicated as L rotor and R rotor ).

[0049] Figures 4 to 15 A more detailed example of a design method for determining component values ​​for a stationary-side-only resonant LCC 140A of a system 100A that eliminates the need for compensation circuits and / or compensation components on the rotating side 230 is depicted. More specifically, Figure 4 Depicting a design method 400 according to an embodiment of the present disclosure; Figures 5 to 7 Depicting equivalent circuits and circuit models (systems 100B, 100C, 100D) used in one or more design methods according to embodiments of the present disclosure; and Figures 8 to 15 Various equations (Equations 1-43) used in one or more design methods according to embodiments of the present disclosure are depicted.

[0050] Go to Figure 4 , will refer to Figures 5 to 7 Some component element labels (e.g., L f1 , C1, C f1 , L1, L2, etc.) to describe method 400. Figure 4 As shown, method 400 is operable to start in parallel at blocks 402 and 412 and then move through multiple paths to generate outputs at blocks 432 (primary coil current, primary side shunt tuning capacitor current, and voltage across the primary tuning capacitor), 436 (output voltage and power), and 422 (primary compensation network design based on the value of the primary side series tuning capacitor (C1) value). At block 402, method 400 calculates the primary coil current, the primary side shunt tuning capacitor current, and the voltage across the primary tuning capacitor. At block 404, method 400 converts Z in Written as Z 12 and the primary side resonant tuning inductor (L f1 ) is the sum of the inductive reactances of the Z 12 Written as Z cf1 and Z1 in parallel. In the disclosed embodiment, Z1 is the total equivalent impedance seen by the inverter. At block 408, method 400 writes Z1 as Z L1 , Z c1 and Z ref sum ( Figure 8 =Equation 6 in (6), and then Z1 is provided to block 410. Substantially in parallel with the operations at blocks 402-408, block 412 calculates the secondary side (i.e., rotating side) reflected impedance Z ref , and substitutes it into the Z1 equation at block 410 ( Figure 8 =Equation-6 in the above table.

[0051] Block 412 also provides its output to block 414. At block 414, method 400 adds the reflected impedance of the secondary side to the impedance of the primary side coil inductance and the series tuning capacitor. At block 416, method 400 forms a T network equivalent impedance circuit, calculates the branch impedance and the total equivalent impedance seen by the inverter. At block 418, method 400 calculates the inverter output current. At block 420, method 400 designs the primary side series tuning capacitor value so that the inverter output reactive power is greatly eliminated. Alternatively, block 420 can tune off the imaginary part of the total equivalent impedance seen by the inverter. At block 422, method 422 designs the primary compensation network according to the value of the primary side series tuning capacitor (C1) value.

[0052] Returning to block 410, method 400 moves from block 410 to block 430 and calculates whether Z1 and Z in Parallel Z in The calculations performed in block 430 are provided to blocks 432 and 434. At block 432, the method 400 calculates the primary coil current, the primary side shunt tuning capacitor current, and the voltage across the primary tuning capacitor. At block 434, the method 400 calculates the secondary side current using the voltage induced on the secondary side along with the total equivalent impedance of the secondary side. The calculations performed at block 434 are provided to block 436, where the method 400 calculates the output voltage and power.

[0053] Now turn to Figures 5 to 7 The equivalent circuit and circuit model (systems 100B, 100C, 100D) depicted in Figures 8 to 15 A more detailed discussion of the various equations (Equations 1-43) depicted in Figure 5 The equivalent circuit of the system 100, 100A is depicted using the first harmonic approximation (FHA), and Figure 6 The mutually coupled circuit model of the system 100, 100A is depicted using the series equivalent internal resistance of the circuit components. Figure 6 In the example, the primary and secondary coil self-inductances are used, while the magnetizing branch uses a current-dependent voltage source to model the mutual coupling effect between the primary and secondary windings. In the absence of a resonant tuning circuit implemented on the secondary side, the equivalent impedance on the secondary side can be calculated using Equation-1 ( Figure 8 The input current of the primary side (which is the inverter output current) can be expressed by equation-2 ( Figure 8 ) represents the input impedance (Z in ) or the total impedance is given by Equation-3 ( Figure 8 The Z of equation 3 is shown in 12 The components are given by Equation-4 ( Figure 8 ). Because L f1 Using C f1 is tuned out, so this means that Equation -5 ( Figure 8 At the same time, the impedance of Z1 is given by Equation-6 ( Figure 8 ) is given by, where Z ref is the reflected impedance from the secondary side, and the impedance of Z1 can be written as Equation-7 ( Figure 8 ).

[0054] The primary coil current can be expressed by equation-8 ( Fig. 9 ) and the primary-side parallel tuning capacitor (C f1 ) is given by equation-9 ( Fig. 9 ), and the voltage is given by equation-10 ( Fig. 9 The secondary coil current will be a function of the voltage induced on the secondary side and the total equivalent impedance on the secondary side, which is given by Equation-11 ( Fig. 9 The voltage across the output is given by Equation-12 ( Fig. 9 is shown in the figure, and the power at the output can be calculated using equation -13 ( Fig. 9 ) is calculated.

[0055] For the purpose of designing the fixed-side-only resonant LCC 140A, the equivalent internal series resistance can be assumed to be zero, and the output load can be considered resistive since the rotor winding inductance is on the DC side (i.e., downstream from the rectifier 210) and has no effect on the steady-state operation of the system. Under these considerations, the total equivalent impedance on the secondary side is given by Equation-14 ( Fig.10 ), and the reflected impedance from the secondary side to the primary side is given by Equation-15A, Equation-15B and Equation-16 ( Fig.10 ) are given.

[0056] To design the parameters of the fixed-side resonant LCC 140A on the primary side, this reflected impedance from the secondary side should also be considered because the secondary coil inductance is not tuned out on the secondary side. Therefore, the T network of the fixed-side resonant LCC 140A with all equivalent impedances can be obtained by including the Z reflected from the secondary side. ref Therefore, the equivalent T circuit model of only the fixed-side resonant LCC 140A can be shown as Figure 7 For the system 100D, the impedance j Zb and j Za According to equation-17( Fig.11 ) and Equation-18 ( Fig.11 As a result, using equation 19 ( Fig.11 ) determines the input current i Lf1 , and using Equation-20( Fig.11 ) and Equation-21 ( Fig.11 ) to determine Z of Equation 19 12 As a result, only the input impedance of the fixed-side resonant LCC 140A (as seen by the inverter 120A) becomes Z in , as shown in Equation 22( Fig.11 As a result, the input current i Lf1 It can be obtained from equation-23( Fig.11 The primary coil current i1 is expressed as Equation-24 ( Fig.12), and the input current can be calculated using Equation 25 ( Fig.12 The primary compensation capacitor must eliminate reactive power, so that Equation 26 ( Fig.12 ), Equation-27( Fig.12 ), Equation-28( Fig.12 ) and Equation-29 ( Fig.13 ). Therefore, the value of the fixed-side tuning capacitor C1 is given by Equation 30 (shown in Figure 30). In addition, note that the value of C1 cannot be negative. Therefore, the expression for the C1 capacitor should satisfy Equation -31 ( Fig.13 ) set forth in the conditions and / or equation-32 ( Fig.13 Therefore, it can be based on the equation-33 ( Fig.13 The DC voltage gain given in Figure 2 is used to design the values ​​of the self-inductors L1 and L2. f1 The input inductor, first the output power can be calculated by equation-34 ( Fig.14 ), Equation-35( Fig.14 ) and Equation-36 ( Fig.14 For L f1 Solve Equation 36( Fig.14 ) can be used using equation -37 ( Fig.15 ) to Equation-42 ( Fig.15 ) to obtain Equation-43 ( Fig.15 ) to achieve this.

[0057] Therefore, it can be obtained from Figures 3 to 15 As can be seen from the foregoing description, only the fixed side resonant LCC 140A provides technical effects and technical benefits. Although C1 is on the fixed side 230, C1 performs a rotating side compensation function, which is operable to provide compensation for the L2 winding on the rotating side. This rotating side compensation function can be achieved by reflecting the L2 impedance to the fixed side 220 and then using Figures 8 to 15 The various calculations shown in FIG. 1 are implemented to use reflected impedance as part of the process to develop the value of C1. In some embodiments of the present invention, the primary coil L2 and the load (such as the one represented by Figure 2 L rotor and R rotor The impedance associated with L1 is reflected to the fixed side and used to develop the value of C1. In some embodiments of the present disclosure, in addition to compensating the L2 winding from the fixed side 220, C1 also jointly compensates a portion of L1 or L1 and L2. f1 Therefore, in some embodiments of the present disclosure, the value of C1 depends on L2, L1 and L f1 . C f1 Used to "tune out" Lf1 , which provides at least a portion of compensation for the L1 winding on the fixed side 220.

[0058] For ease of illustration and explanation, the various components / modules of the system shown herein are depicted separately. In embodiments of the present disclosure, the functions performed by the various components / modules / models may be distributed differently than shown without departing from the scope of the various embodiments of the present disclosure described herein, unless otherwise explicitly stated.

[0059] The terms used herein are for the purpose of describing specific embodiments only and are not intended to be limiting. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and / or "comprising", when used in this specification, specify the presence of stated features, integers, steps, operations, elements and / or parts, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements parts and / or groups thereof.

[0060] The figures described herein are illustrative. There may be many variations of the figures or the steps (or operations) described therein without departing from the spirit of the present disclosure. For example, actions may be performed in different orders, or actions may be added, deleted or modified. In addition, the term "coupling" describes having a signal path between two elements, and does not imply a direct connection between elements, without intermediate elements / connections therebetween. All of these variations are considered to be a part of the present disclosure.

[0061] The following definitions and abbreviations will be used in the interpretation of the claims and specification. As used herein, the terms "comprises," "comprising," "includes," "including," "has," "having," "contains," or "containing" or any other variation thereof are intended to cover a non-exclusive inclusion. For example, a composition, mixture, process, method, article, or apparatus that comprises a list of elements is not necessarily limited to only those elements but may include other elements not expressly listed or inherent to such composition, mixture, process, method, article, or apparatus.

[0062] Additionally, the term "exemplary" is used herein to mean "serving as an example, instance, or illustration." Any embodiment or design described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other embodiments or designs. The terms "at least one" and "one or more" are understood to include any integer greater than or equal to one, i.e., one, two, three, four, etc. The term "plurality" is understood to include any integer greater than or equal to two, i.e., two, three, four, five, etc. The term "connected" may include both indirect "connections" and direct "connections."

[0063] The terms "about," "substantially," "approximately," and variations thereof are intended to include the degree of error associated with measurement of a particular quantity based on the equipment available at the time the application was filed. For example, "about" may include a range of ±8% or 5% or 2% of a given value.

[0064] The flowcharts and block diagrams in the figures illustrate the architecture, functions and operations of possible implementations of the systems, methods and computer program products according to various embodiments of the present disclosure. In this regard, each block in the flowchart or block diagram may represent a module, segment or portion of an instruction, which includes one or more executable instructions for implementing one or more specified logical functions. In some alternative embodiments, the functions indicated in the blocks may appear outside the order indicated in the figure. For example, two blocks shown in succession may actually be executed substantially simultaneously, or the blocks may sometimes be executed in reverse order, depending on the functions involved. It will also be noted that each block illustrated in the block diagram and / or flowchart, and the combination of blocks in the block diagram and / or flowchart, can be implemented by a dedicated hardware-based system that performs a specified function or action or performs a combination of dedicated hardware and computer instructions.

[0065] Although the present disclosure has been described with reference to one or more exemplary embodiments, it will be appreciated by those skilled in the art that various changes may be made and equivalents may be substituted for its elements without departing from the scope of the present invention. In addition, many modifications may be made to adapt specific circumstances or materials to the teachings of the present disclosure without departing from its essential scope. Therefore, it is intended that the present invention is not limited to the specific embodiments disclosed as the best mode contemplated for carrying out the present invention, but that the present invention will include all embodiments falling within the scope of the claims.

Claims

1. An electric drive motor system, comprising: Fixed side; and Rotating side; wherein the fixed side includes a fixed side only (OSS) compensation network; and Therein, the first OSS compensation element of the OSS compensation network is operable to provide a rotating side compensation function.

2. The system according to claim 1, wherein: The value of the first OSS compensation element is selected such that the value of the first OSS compensation element contributes to the rotating-side compensation function.

3. The system according to claim 2, wherein: The second OSS compensation element of the OSS compensation network is operable to provide a fixed side compensation function.

4. The system according to claim 3, wherein: The value of the second OSS compensation element is selected such that the value of the second OSS compensation element contributes to the fixed-side compensation function.

5. The system according to claim 4, wherein: A third OSS compensation element of the OSS compensation network is operable to further contribute to the fixed side compensation function.

6. The system according to claim 5, wherein: The value of the third OSS compensation element is selected such that the value of the third OSS compensation element contributes to the fixed-side compensation function.

7. The system according to claim 2, wherein: The first OSS compensation element includes a first OSS capacitance compensation element.

8. The system of claim 4, wherein: The first OSS compensation element comprises a first OSS capacitance compensation element; and The second OSS compensation element includes a second OSS capacitance compensation element.

9. The system of claim 6, wherein: The first OSS compensation element comprises a first OSS capacitance compensation element; The second OSS compensation element comprises a second OSS capacitance compensation element; and The third OSS compensation element includes an OSS inductance compensation element.

10. The system of claim 1, wherein: The fixed side includes a stator having a fixed side winding; The rotating side includes a rotor having a rotating side winding; The stationary side winding is operable to wirelessly transmit an alternating current (AC) excitation signal to the rotating side winding; The OSS compensation network is operable to provide an excitation signal to the fixed side winding; The rotating side compensation function is applied to the wireless transmission of the AC excitation signal to the rotating side winding; The first OSS compensation element comprises a first OSS capacitance compensation element; The OSS compensation network further includes an inductive element coupled via a branch to a capacitive element and a node of the first OSS capacitive compensation element; and The first OSS capacitance compensation element is coupled in series to the stationary side winding.

11. A method of manufacturing an electric drive motor system, the method comprising: forming a fixed side; and forming a rotating side; wherein the fixed side includes a fixed side only (OSS) compensation network; and Therein, the first OSS compensation element of the OSS compensation network is operable to provide a rotating side compensation function.

12. The method according to claim 11, wherein: The value of the first OSS compensation element is selected such that the value of the first OSS compensation element contributes to the rotating-side compensation function.

13. The method according to claim 12, wherein: The second OSS compensation element of the OSS compensation network is operable to provide a fixed side compensation function.

14. The method according to claim 13, wherein: The value of the second OSS compensation element is selected such that the value of the second OSS compensation element contributes to the fixed-side compensation function.

15. The method according to claim 14, wherein: A third OSS compensation element of the OSS compensation network is operable to further contribute to the fixed side compensation function.

16. The method according to claim 15, wherein: The value of the third OSS compensation element is selected such that the value of the third OSS compensation element contributes to the fixed-side compensation function.

17. The method according to claim 12, wherein: The first OSS compensation element includes a first OSS capacitance compensation element.

18. The method of claim 14, wherein: The first OSS compensation element comprises a first OSS capacitance compensation element; and The second OSS compensation element includes a second OSS capacitance compensation element.

19. The method of claim 16, wherein: The first OSS compensation element comprises a first OSS capacitance compensation element; The second OSS compensation element comprises a second OSS capacitance compensation element; and The third OSS compensation element includes an OSS inductance compensation element.

20. The method of claim 11, wherein: The fixed side includes a stator having a fixed side winding; The rotating side includes a rotor having a rotating side winding; The stationary side winding is operable to wirelessly transmit an alternating current (AC) excitation signal to the rotating side winding; The OSS compensation network is operable to provide an excitation signal to the fixed side winding; The rotating side compensation function is applied to the wireless transmission of the AC excitation signal to the rotating side winding; The first OSS compensation element comprises a first OSS capacitance compensation element; The OSS compensation network further includes an inductive element coupled via a branch to a capacitive element and a node of the first OSS capacitive compensation element; and The first OSS capacitance compensation element is coupled in series to the stationary side winding.

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