Open loop compensation of current harmonics caused by parameter imbalance

Abstract

A method for compensating for current harmonics caused by parameter imbalance in a synchronous motor drive is disclosed. The method includes receiving a command current signal corresponding to a generated command current. The method also includes receiving a position estimate signal indicative of an estimated position of the synchronous motor drive, and determining a voltage adjustment value using the command current signal and the position estimate signal in response to at least one current harmonic caused by parameter imbalance. The method also includes generating a voltage adjustment signal using at least the voltage adjustment value, the voltage adjustment signal being applied to the synchronous motor drive to compensate for the current harmonics caused by parameter imbalance.

Description

Technical Field

[0001] This disclosure relates to electric motors, and more particularly to systems and methods for open-loop (feedforward) compensation of current harmonics caused by parametric imbalance in synchronous motor drives. Background Technology

[0002] Vehicles such as cars, trucks, SUVs, crossovers, minivans, boats, aircraft, all-terrain vehicles, recreational vehicles, or other suitable vehicles may include electric power steering (EPS) systems. Such EPS systems typically include an electric motor for providing steering assistance during vehicle operation. To provide this steering assistance, the EPS system can drive the electric motor using a torque control method. Typically, electric motor drive applications utilizing synchronous motors may be susceptible to parameter imbalances during manufacturing and / or operation. During operation of a synchronous motor drive, such interphase parameter imbalances can lead to undesirable current and torque pulsations.

[0003] Typically, to reduce and / or minimize interphase parameter imbalances, such motors are designed and configured to meet minimum inter-part variations according to requirements and / or specifications. This is especially true for high-performance motion control applications sensitive to noise, vibration, and harshness (NVH), particularly those involving large-scale production, such as EPS. Specifying machines to meet the stringent requirements of minimum inter-part variations can be expensive. This necessitates the development of control techniques capable of mitigating current harmonics generated in response to parameter imbalances in synchronous motors. Summary of the Invention

[0004] This disclosure generally relates to feedforward compensation for current harmonics caused by parameter imbalances in synchronous motor drivers.

[0005] One aspect of the disclosed embodiments includes a system for compensating for current harmonics caused by parametric imbalance in an electric motor. The system includes a processor and a memory. The memory includes instructions that, when executed by the processor, cause the processor to: receive a command current signal corresponding to a generated command current; receive a position estimation signal indicating an estimated position of the electric motor; determine a voltage regulation value using the command current signal and the position estimation signal in response to at least one current harmonic caused by the parametric imbalance; and generate a voltage regulation signal, at least using the voltage regulation value, which is applied to the electric motor to compensate for the current harmonics caused by the parametric imbalance.

[0006] Another aspect of the disclosed embodiments includes a method for compensating for current harmonics caused by parametric imbalance in a synchronous motor driver. The method includes receiving a command current signal corresponding to a generated command current. The method further includes receiving a position estimation signal indicating an estimated position of the synchronous motor driver, and determining a voltage regulation value using the command current signal and the position estimation signal in response to at least one current harmonic caused by the parametric imbalance. The method also includes generating a voltage regulation signal using at least the voltage regulation value, the voltage regulation signal being applied to the synchronous motor driver to compensate for the current harmonics caused by the parametric imbalance.

[0007] Another aspect of the disclosed embodiments includes an apparatus. The apparatus includes a processor and a memory. The memory includes instructions that, when executed by the processor, cause the processor to: receive a command current signal corresponding to a generated command current; receive a position estimation signal indicating an estimated position of an electric motor; determine a voltage regulation value using the command current signal and the position estimation signal in response to at least one current harmonic caused by a parameter imbalance; and generate a voltage regulation signal using at least the voltage regulation value, the voltage regulation signal being applied to the electric motor to compensate for the current harmonic caused by the parameter imbalance.

[0008] These and other advantages and features will become more apparent from the following description taken in conjunction with the accompanying drawings. Attached Figure Description

[0009] The subject matter considered to be the invention is specifically pointed out and clearly stated in the claims at the end of the specification. The foregoing and other features and advantages of the invention will become apparent from the following detailed description taken in conjunction with the accompanying drawings, wherein:

[0010] Figure 1 The present invention generally illustrates a synchronous motor drive system with feedforward model-based compensation for current harmonics caused by parametric imbalance, in accordance with the principles of this disclosure.

[0011] Figures 2A-2C A block diagram of a mathematical model for detecting current harmonics caused by parametric imbalance, based on the principles of this disclosure, is shown in general.

[0012] Figure 3 A parametric imbalance compensator based on the principles of this disclosure is generally shown.

[0013] Figure 4 generally illustrates the controller system based on the principles of this disclosure.

[0014] Figure 5 A controller system based on the principles of this disclosure is shown in general.

[0015] Figure 6This is a flowchart generally illustrating a method for open-loop compensation of current harmonics caused by machine imbalance in a synchronous motor driver, based on the principles of this disclosure. Detailed Implementation

[0016] The following discussion pertains to various embodiments of the disclosed subject matter. While one or more of these embodiments may be preferred, the disclosed embodiments should not be construed as or otherwise used to limit the scope of this disclosure, including the claims. Furthermore, those skilled in the art will understand that the following description has broad application, and the discussion of any embodiment is intended only as an illustrative discussion of that embodiment and is not intended to imply that the scope of this disclosure, including the claims, is limited to that embodiment.

[0017] As described, vehicles such as automobiles, trucks, sport utility vehicles, crossovers, minivans, boats, aircraft, all-terrain vehicles, recreational vehicles, or other suitable vehicles may include electric power steering (EPS) systems. Such EPS systems typically include an electric motor for providing steering assistance during vehicle operation. To provide this steering assistance, the EPS system can drive the electric motor according to a torque control method. Typically, electric motor drive applications utilizing synchronous motors may be susceptible to parameter imbalances during manufacturing and / or operation. During operation of a synchronous motor drive, such interphase parameter imbalances can lead to undesirable current and torque pulsations.

[0018] To reduce and / or minimize interphase parameter imbalances, certain requirements and / or regulations stipulate that such motors must meet minimum inter-component variations. This is especially true for high-performance motion control applications sensitive to NVH (Noise, Vibration, and Harshness), particularly those involving large-scale production, such as EPS (Electric Power Suspension). Specifying that a machine meets the stringent requirement of minimum inter-component variations can be expensive. This necessitates the development of control techniques capable of mitigating current harmonics generated in response to parameter imbalances in synchronous motors.

[0019] As will be described, motion control applications utilizing synchronous motor drives (e.g., vehicles, ships, aircraft, drones, power equipment, site equipment, pumps, compressors, etc.) may be susceptible to parameter imbalances during manufacturing and / or operation. For example, motor drives, converters, and / or other circuits may experience parameter imbalances.

[0020] High-performance motion control system applications (especially those involving large-scale production, such as EPS) may be subject to stringent NVH requirements and may specify minimum inter-part variations. Uncorrected parameter imbalances (one or more) in such systems can lead to overall system performance degradation. However, enforcing strict tolerances for permissible parameter imbalances on the manufacturing and / or production sides of synchronous motors can be expensive. Furthermore, degradation of overall system performance may reduce the lifespan of the synchronous motor and / or reduce the likelihood of customers purchasing EPS systems that include synchronous motors. Therefore, it is desirable to compensate for or correct current harmonics generated in response to such parameter imbalances.

[0021] Certain nonlinear effects (such as temperature variations or failure modes) can cause significant changes in machine behavior. For example, motor winding involves placing the conductors of a synchronous motor within a coil closed around a coated flexible magnetic core. During the winding process (e.g., a phase winding process), attempts are made to wind the conductors such that the conductors corresponding to each respective phase (e.g., phase a, phase b, and phase c) are wound such that the resistance is equal.

[0022] However, temperature changes driven by heat generated during the phase winding process can lead to resistance imbalances in one or more phases. Therefore, the detection, identification, and / or correction of this nonlinear effect can be beneficial for improving the performance of synchronous motors utilizing synchronous motor drives. Furthermore, although systems composed of feedback control structures are inherently capable of mitigating these effects to some extent, they are typically not specifically designed or tuned for this purpose, thus failing to ensure compensation across the entire operating range. Therefore, a universal compensation technique specifically addressing this problem and compatible with any basic control structure is desired.

[0023] Therefore, systems and methods such as those described herein can be configured to address the aforementioned problems by providing techniques for open-loop or feedforward compensation of current harmonics caused by parameter imbalances in synchronous motor drivers. For example, systems and methods can be configured to receive a current command signal relating to a generated command current and a position estimation signal relating to an estimated position of the synchronous motor. The system and methods can be configured to determine a voltage regulation value based on the current command signal and the position estimation signal.

[0024] The system and method can be configured to generate a voltage regulation signal corresponding to a determined voltage regulation value. Furthermore, the voltage regulation signal can be applied to the motor to compensate for current harmonics caused by parameter imbalances. For example, the voltage regulation signal can be added to a basic command voltage signal (e.g., generated by a basic current controller) to form a final command voltage signal. This final command voltage signal can then be provided to the motor via a pulse width modulator and converter. This can result in a reduction and / or elimination of harmonics caused by interphase parameter imbalances in the current generated by the motor.

[0025] In some embodiments, the systems and methods described herein can be configured to provide techniques for real-time compensation of phase-to-phase parameter imbalances in synchronous motor drives.

[0026] The systems and methods described herein are configured to at least provide the benefit of detecting and identifying any type of parametric imbalance in a synchronous motor. The systems and methods described herein are applicable to various synchronous motor configurations (e.g., permanent magnet or wound-rotor synchronous motors, non-salient pole or salient pole motors, multiphase motors, etc.). Furthermore, the systems and methods described herein can be implemented by a processor to correct current harmonics caused by parametric imbalance in real time while the synchronous motor is running. Additionally, the systems and methods described herein compensate for current harmonics caused by parametric imbalance without necessarily being configured to rely on (e.g., receiving) a command voltage signal and / or an estimated (e.g., or measured) current as input to the system. In this way, the system and methods can efficiently and effectively compensate for parametric imbalance in an open-loop or feedforward manner without affecting the stability or performance of the base, and thus without affecting the overall motor current (and torque) control system.

[0027] Figure 1 A synchronous motor drive system 100 (referred to herein as system 100) with compensation for current harmonics caused by parametric imbalance is generally shown according to the principles of this disclosure. System 100 may include a motor 102 (e.g., a synchronous motor, etc.), an inverter 104, a pulse width modulator 106, a position estimator 116, a current sensing component 110, a current command generator 112, a current controller 114, a position estimator 116, a current estimator 118, and a parametric imbalance compensator 120. It should be understood that system 100 may include more or fewer components than those described herein.

[0028] In some embodiments, system 100 may include one or more parametric imbalance compensators 120. Parametric imbalance compensators 120 may include electronic control units (ECUs) and / or any other suitable controllers. Parametric imbalance compensators 120 may be configured to control, for example, aspects of the vehicle, such as aspects of system 100, aspects of the electric power steering (EPS) system, etc. The use of the term "compensation" in the context of parametric imbalance compensator 120 is not intended to limit the type of controller that can be implemented in any way. Rather, the term "compensation" is used to add clarity in distinguishing parametric imbalance compensator 120 from current controller 114.

[0029] In some embodiments, the parameter imbalance compensator 120 may include a processor 121 and a memory 122. The processor 121 may include any suitable processor, such as those described herein. Additionally or alternatively, the parameter imbalance compensator 120 may include any suitable number of processors other than or different from the processor 121. The memory 122 may include a single disk or multiple disks (e.g., a hard disk drive) and includes a storage management module for managing one or more partitions in the memory 122. In some embodiments, the memory 122 may include flash memory, semiconductor (solid-state) memory, etc. The memory 122 may include random access memory (RAM), read-only memory (ROM), or a combination thereof. The memory 122 may include instructions that, when executed by the processor 121, cause the processor 121 to control at least various functions of the system 100.

[0030] Motor 102 can generate rotational or linear force for powering a machine (e.g., those described herein). Motor 102 can be a synchronous motor or any other suitable type of motor. In some embodiments, various components of system 100 can be used as part of a synchronous motor driver (e.g., current controller 114, pulse width modulator 106, inverter 104, etc.). The synchronous motor driver can be an electronic device for controlling the electrical energy sent to motor 102. The synchronous motor driver can indirectly control the current and torque of motor 102 by supplying voltage to motor 102 in varying amounts and at varying frequencies.

[0031] In some embodiments, as will be described, one or more components of system 100 may perform open-loop or feedforward compensation for current harmonics caused by parametric imbalance.

[0032] In some embodiments, the current controller 114, the pulse width modulator 106, the inverter 104, and the motor 102 can form a feedforward current control system.

[0033] In some embodiments, the current controller 114, pulse width modulator 106, inverter 104, motor 102, current sensing component 110, and current estimator 118 form a feedback current control system.

[0034] Based on the preceding description, additional details and operation of system 100 will now be discussed. In some embodiments, the current command generator 112 can receive the electromagnetic torque of the command. As input, the electromagnetic torque of the command can be input by the user using a computing device, can be pre-programmed for motor 102, and / or can be received via another suitable method. The current command generator 112 can generate the command current based on the electromagnetic torque of the command. Current commands can be generated from the direct axis (d-axis) current component. Current components along the orthogonal axis (q-axis) Composition. In some embodiments, the current controller 114 can receive commanded current from the current command generator 112. In some embodiments, the current controller 114 may receive current commands input by a user using a computing device.

[0035] In some embodiments, the current controller 114 and the parameter imbalance compensator 120 respectively convert the basic command voltage signal and voltage regulation signal The signal is sent to summation box 124, which generates the final command voltage. And send it to pulse width modulator 106. As used herein, the final command voltage signal may refer to a voltage signal that system 100 assumes to be equal to or nearly equal to the actual input voltage applied to motor 102.

[0036] The pulse width modulator 106 can control the duration for which the inverter 104 is turned on and turned off within a given time period based on the final command voltage signal, so that the inverter generates the input voltage V. abc This voltage is then applied to motor 102. Inverter 104 can be a voltage source inverter that receives a constant or near-constant voltage from an external source such as a battery (not shown) and can change the amplitude, phase, and frequency of the voltage supplied to motor 102 to control the current and torque of motor 102. Motor 102 can use the input voltage V abc To generate a certain amount of current, which can be equal to the commanded current. Or it may be a different current than the command. (For example, when there is a parameter imbalance).

[0037] In some embodiments, the motor 102 can deliver current Iabc A current sensing component 110 is provided. The current sensing component 110 can be configured to detect and measure current in a circuit. The current sensing component 110 can provide an indication current I to the current estimator 118. abc signal The current estimator 118 can also receive a signal indicating the electrical (phase) position θ of the motor 102 from the position estimator 116. For example, the position sensing component 108 can sense or measure the instantaneous position of the motor 102 and can provide a signal indicating that position to the position estimator 116. The position estimator 116 can provide a signal indicating the phase θ to the current estimator 118. The current estimator 118 can estimate the amount of current output by the motor 102 in the synchronous (or dq) reference frame, and convert the estimated current into a voltage value. Send to basic current controller 114.

[0038] In some embodiments, such as when the basic current control scheme within system 100 is configured as a feedforward control architecture, the basic current controller 114 can be implemented as a feedforward current controller. In this case, the current estimator does not need to feed the estimated current. The command is sent to the current controller 114 (e.g., a basic current controller). Alternatively, the current controller 114 can receive the commanded current from the current command generator 112. And the current of the command can be used together. The inverse mathematical model of motor 102 uses estimated parameters to generate a basic command voltage signal. The basic command voltage signal This can be a constant or a slowly changing quantity. Additionally, the parameter imbalance compensator 120 can determine the regulating voltage signal. The regulating voltage signal This can be the amount of pulsation (i.e., depending on the estimated position of the motor). Therefore, the final command voltage signal is calculated by summation block 124. In addition to constant components, pulsating components can also be included.

[0039] In some embodiments, such as when the basic current control scheme within system 100 is configured as a feedback control architecture, the basic current controller 114 can be implemented as a current regulator. In this case, the current estimator 118 can provide the estimated current to the current controller 114 (e.g., the current regulator). The current controller 114 can estimate the current. Current with command A comparison is made. If the current regulator determines the estimated current... and the current of the command If there is a difference, the current controller 114 can send a basic command voltage signal. To make the estimated current Tracing the current of the command Thus, due to the current of the command It is constant (or slowly changing), and the estimated current... equal to the current of the command Therefore, the estimated current It is also constant. When the parameter imbalance compensator 120 is disabled, i.e., when the regulating voltage signal... When set to zero, the current regulator 114, by means of its feedback control structure, can generate pulsating components to minimize current harmonics caused by parametric imbalances in the motor 102. However, the level of compensation achieved by the feedback control system, and the range of effective operating conditions without the aid of the parametric imbalance compensator 120, is significantly limited and largely depends on the structure and tuning of the current regulator 114. Therefore, it is desirable to include the parametric imbalance compensator 120 to perform harmonic compensation, thereby reducing the burden on the current regulator and changing its task to tracking one of the basic current commands.

[0040] In some embodiments, the parameter imbalance compensator 120 can be triggered to determine a voltage regulation signal that can be used to compensate for current harmonics caused by parameter imbalance. For example, the parameter imbalance compensator 120 can be triggered to determine the voltage regulation signal based on one or more operating conditions to be met, detection of parameter imbalance characteristics, receipt of one or more input signals (e.g., command current signal, position estimation signal, etc.).

[0041] In some embodiments, the parameter imbalance compensator 120 can determine the voltage regulation signal. For example, the compensator 120 can use a mathematical model representing the phase-to-phase parameter imbalance in the machine to determine the voltage regulation signal using one or more adjustable compensator parameter values. In this way, the compensator 120 compensates for current harmonics caused by parameter imbalance in an open-loop manner.

[0042] Figures 2A-2C It generally illustrates a mathematical model of the imbalance or mismatch of parameters between the various phases of the machine. Figure 2A Box 202 is depicted to represent resistance imbalance. Figure 2B Box 204 includes both self-inductance imbalance and mutual inductance imbalance. Figure 2C Containing box 206, which represents interphase imbalance in interphase permanent magnet (PM) flux linkage. Figures 2A-2CThe remaining boxes depict well-known basic (e.g., average) models of synchronous motors in the dq reference frame. Note that while mathematical models of imbalances in each motor parameter (i.e., resistance, inductance, and PM flux linkage) are shown separately, they can be combined to obtain a single block diagram that captures them simultaneously.

[0043] The following discussion concerns the derivation of the mathematical model of the machine that captures the phenomenon of interphase parameter imbalance and is subsequently used to perform the techniques described herein. The machine model in a stationary (or abc) reference frame can be represented as:

[0044]

[0045] Among them, V x I x R x L x , λ xm and λ x Let M represent the input voltage, current, resistance, inductance, PM flux linkage, and total flux linkage of phase x (where x equals a, b, or c), respectively. xy Let θ represent the mutual inductance between phase x and phase y (where x ≠ y), θ be the electrical position of the motor, and β be equal to 0. A constant in rad. Based on the assumption that each motor parameter in each phase is equal, the average synchronous coordinate system model (frame model) commonly used for synchronous motors is derived. However, this assumption may be invalid in practice, especially in real-time operation, because nonlinear effects including temperature variations and magnetic saturation cause the parameters to differ in one or more phases. Therefore, equation (1) can be modified using the reference frame transformation shown in equation (2) below to generate the synchronous reference frame machine model given in equation (3) that includes the effects of parameter imbalance:

[0046] h dq0 =H h abc (2)

[0047]

[0048]

[0049] Where h represents voltage, current, or flux linkage, H is the transformation matrix that converts a quantity in a stationary or abc coordinate system to a synchronous or dq reference system, and V d and V q It is the input motor voltage. and The term ΔV is a voltage term associated with an ideal or average synchronous coordinate system motor model. dR and ΔV qR Including resistance imbalance, ΔVdL and ΔV qL Combining self-inductance imbalance and mutual inductance imbalance, ΔV dλ and ΔV qλ This indicates that the PM flux linkage is unbalanced, while R, L, M, and λ m Let represent the nominal or average values ​​of resistance, self-inductance, mutual inductance, and PM flux linkage, respectively, and ω e It is the electric speed of the motor (also known as the synchronous frequency).

[0050] Please note that equation (3) can be written in matrix form as follows:

[0051]

[0052] Where s represents the derivative operator in the frequency domain.

[0053] Please note that the motor model consists of a transformation matrix that converts the input voltage into the current output. Therefore, the motor model can be written as:

[0054] I = P(VE - ΔV) (5)

[0055] The voltage term caused by resistor imbalance is represented as follows:

[0056] ΔV dR =K R (cos(2θ+φ R )I d +sin(2θ+φ R )I q )

[0057] ΔV dR =K R (sin(2θ+φ R )I d -cos(2θ+φ R )I q )

[0058]

[0059]

[0060]

[0061] Where, ΔR x This indicates the deviation of the resistance in phase x from the nominal value R, where R is the resistance of each phase. x The average value of the amplitude.

[0062] The modified motor model, incorporating the effects of resistance imbalance, can be written in the following form:

[0063] I = (P) -1 +M R ) -1 (VE) (8)

[0064] Similarly, voltage ripples in a synchronous reference frame due to inductance imbalance are represented as follows:

[0065]

[0066]

[0067]

[0068]

[0069] Where, ΔL x This represents the deviation of the self-inductance of phase x from the nominal value L, where L is the self-inductance of each phase. x The average value, ΔM xy This represents the deviation of the mutual inductance between phase x and phase y from the nominal value M, which is the mutual inductance M between the three phase groups. xy The average value of the amplitude.

[0070] The modified motor model, incorporating the effects of inductance imbalance, can be written in the following form:

[0071] I = (P) -1 +M L ) -1 (VE) (12)

[0072] The pulsating voltage term caused by the imbalance of the permanent magnet flux linkage in the synchronous reference frame is as follows:

[0073] ΔV dλ =ω e K λ sin(2θ+φ λ )

[0074] ΔV qλ =-ω e K λ cos(2θ+φ λ )

[0075]

[0076]

[0077]

[0078] Where, Δλ x This represents the amplitude of the PM flux linkage in phase x and its nominal value λ. mThe deviation, the nominal value λ m It is the PM flux linkage λ of each phase xm The average value of the amplitude.

[0079] The modified motor model, which includes the effects of PM flux linkage imbalance, can be written in the following form:

[0080] I = P -1 (VEM λ (15)

[0081] The three sets of equations concerning flux linkage imbalance, resistance, and inductance clearly show that the effects of these three imbalances dominate in different operating regions. The mathematical models reveal that resistance imbalance dominates at high current and low speed, flux linkage imbalance is significant at low current and high speed, while inductance imbalance becomes particularly pronounced when both current and speed are significant.

[0082] Figure 3 A parametric imbalance compensator 120 for compensating current harmonics caused by parametric imbalance, according to the principles of this disclosure, is generally shown. In some embodiments, the compensator 120 may use one or more mathematical models to compensate for current harmonics caused by parametric imbalance. As shown, the compensator 120 consists of three separate compensators, each corresponding to an imbalance in one parameter. and The symbolic resistance imbalance compensator 302, inductance imbalance compensator 304, and PM flux linkage imbalance compensator 306 each generate corresponding voltage regulation signal components. and These components are then summed together at summation box 308 to calculate the final voltage regulation signal ΔV. * It should be understood that although the subscript "dq" has been omitted from the symbols representing different signal vectors, each signal consists of a d-axis component and a q-axis component.

[0083] Figure 4 generally illustrates detailed implementations of various imbalance compensators according to the principles of this disclosure. Besides the estimated control parameters representing estimates of the corresponding terms in the machine model presented above, the resistive imbalance compensator... Using current commands Inductance imbalance compensator Using current commands and estimated location The PM flux imbalance compensator only utilizes the estimated position.

[0084] The resistor imbalance compensator 302 is configured as follows to reduce the voltage regulation signal component used to reduce current harmonics caused by resistor imbalance.

[0085]

[0086] in, and This represents the estimate of the corresponding quantity in the machine model specified in equation (7).

[0087] The inductor imbalance compensator 304 is designed to reduce the voltage regulation signal component used to reduce current harmonics caused by resistive imbalance.

[0088]

[0089] in, and This represents an estimate of the quantities corresponding to the self-inductance imbalance and mutual inductance imbalance specified in equations (11) and (12), respectively. This represents an approximation of the differential operation. The exact model of the derivative term (with respect to the true derivative operator s) that may be applicable to system-level analysis depends on the design chosen for the implementation in the microcontroller.

[0090] The PM flux linkage unbalance compensator 306 is defined as follows for reducing the voltage regulation signal component used to reduce current harmonics caused by PM flux linkage unbalance.

[0091]

[0092] in, and This represents the estimate of the corresponding quantity in the machine model specified in equation (14).

[0093] As described in equations (16), (17) and (18), the different parameter estimates utilized in the parameter imbalance compensator 120 can be obtained offline (e.g., at the end of the assembly line during manufacturing) or in real time using various learning algorithms and techniques.

[0094] In some embodiments, the parametric imbalance compensator 120 can access a machine model trained to determine a voltage regulation signal using estimated parametric imbalance values ​​and received input data. As will be described in detail below, the parametric imbalance compensator 120 can receive input data and can use the machine model (configured with estimated parametric imbalance values) to determine the voltage regulation signal. The parametric imbalance compensator 120 can then use the voltage regulation signal to compensate for current harmonics caused by the parametric imbalance.

[0095] In some embodiments, the current command generator 112 can generate a command current signal and provide it to the current controller 114 and the parameter imbalance compensator 120. The current controller 114 can use the command current signal to generate a command voltage signal including a sinusoidal component in the presence of current harmonics caused by parameter imbalance. As will be shown, the parameter imbalance compensator 120 can use a machine model to determine a voltage regulation value and generate a voltage regulation signal corresponding to the determined regulation value.

[0096] The machine model can be configured to convert current into voltage. Additionally or alternatively, the machine model can be configured with sets of estimated parameter imbalances and / or trained using sets of estimated parameter imbalances. Sets of estimated parameter imbalances can include, for example, estimates of inductance parameter imbalance, flux linkage parameter imbalance, resistance parameter imbalance, etc.

[0097] In some embodiments, the machine model can be trained to model the effects of interphase parameter imbalances. This is because the generated command current can vary depending on a specific phase (e.g., phases a, b, c, etc.). Alternatively, the machine model can be trained to model using one or more types of machine configurations. For example, the machine model may include PM configurations, wound configurations, salient or non-salient pole configurations, multiphase configurations, etc. Alternatively, the machine model can be trained to compensate for certain nonlinear effects. For example, the machine model may be trained to estimate parameter imbalances in a manner that takes into account the effects of saturation and / or temperature on motor 102. In some embodiments, the machine model can be trained to receive specific input values ​​and output a voltage regulation signal value that represents the inverse of the sinusoidal component of the command voltage signal. The inputs to the machine model may include the generated command current and a position estimation signal.

[0098] To determine the voltage regulation value, the parametric imbalance compensator 120 can use a machine model to process the command current signal and the position estimation signal. For example, the parametric imbalance compensator 120 can use the machine model to determine the inverse of the inductance imbalance estimate, the inverse of the flux linkage imbalance estimate, and the inverse of the resistance imbalance estimate. In some embodiments, the parametric imbalance compensator 120 can sum each corresponding estimate to determine the voltage regulation value. The voltage regulation value can represent the sum of the inverses of each corresponding parametric imbalance. Furthermore, the voltage regulation value corresponds to a voltage regulation signal that can be used to cancel the sinusoidal component of the command voltage signal.

[0099] In some embodiments, the parameter imbalance compensator 120 may generate a voltage regulation signal based on a determined voltage regulation value. In some embodiments, another device or component of the system 100 may generate the voltage regulation signal. For example, the voltage regulation signal may be generated by the current controller 114 or the pulse width modulator 106. In this case, the parameter imbalance compensator 120 may provide the voltage regulation value to the component or device that will generate the voltage regulation signal.

[0100] In some embodiments, the parameter imbalance compensator 120 can add or apply a voltage regulation signal to the command voltage signal. For example, the parameter imbalance compensator 120 can add or apply a voltage regulation signal to the command voltage signal to form a final command voltage. The final command voltage can be provided to a pulse width modulator 106, which can operate the inverter 104 of the system 100. Because the voltage regulation signal has been used to cancel the sinusoidal component of the command voltage signal, the final command voltage does not include current harmonics caused by parameter imbalance.

[0101] In some embodiments, the parameter imbalance compensator 120 can determine the voltage regulation value and / or generate the voltage regulation signal in real time or near real time. For example, the parameter imbalance compensator 120 can iteratively determine and / or modify parameters that can be used to determine the voltage regulation value (and / or generate the voltage regulation signal) over time. Additionally or alternatively, these parameters can be determined at the end-of-line (EOL) manufacturing plant and / or relevant location.

[0102] In this way, the current controller 114 compensates for the sinusoidal component of the command voltage signal, thereby eliminating current harmonics caused by parameter imbalance.

[0103] Figure 5 A controller system 500 based on the principles of this disclosure is generally illustrated. The controller system 500 includes a parametric imbalance compensator 120 communicatively coupled to a motor 102. In some embodiments, system 100 may include one or more parametric imbalance compensators 120. The parametric imbalance compensator 120 may include an electronic control unit (ECU) and / or any other suitable controller. The parametric imbalance compensator 120 may be configured to control, for example, aspects of the vehicle, such as aspects of system 100, aspects of an electric power steering (EPS) system, etc. The use of the term "compensator" in the context of the parametric imbalance compensator 120 is not intended to limit the type of controller that can be implemented in any way. Rather, the term "compensator" is used to add clarity in distinguishing the parametric imbalance compensator 120 from the current controller 114.

[0104] In some embodiments, the parameter imbalance compensator 120 may include a processor 121 and a memory 122. The processor 121 may include any suitable processor, such as those described herein. Additionally or alternatively, the parameter imbalance compensator 120 may include any suitable number of processors other than or different from the processor 121. The memory 122 may include a single disk or multiple disks (e.g., a hard disk drive) and includes a storage management module for managing one or more partitions in the memory 122. In some embodiments, the memory 122 may include flash memory, semiconductor (solid-state) memory, etc. The memory 122 may include random access memory (RAM), read-only memory (ROM), or a combination thereof. The memory 122 may include instructions that, when executed by the processor 121, cause the processor 121 to control at least various functions of the system 100.

[0105] In some embodiments, the parametric imbalance compensator 120 can be configured to perform closed-loop compensation for current harmonics caused by parametric imbalance. For example, the parametric imbalance compensator 120 can receive and read an output current signal. The current estimator 118 can generate an output current signal and transmit it to the current controller 114. The output voltage signal corresponding to the output current signal may include a constant portion having a negligible sinusoidal component, while the output current signal may include both a constant portion and a sinusoidal component.

[0106] The parameter imbalance compensator 120 can determine whether the output current signal includes both a constant and a sinusoidal component. If the parameter imbalance compensator 120 determines that the output current signal includes only a constant component, then there may be no parameter imbalance, because the sinusoidal component of the output current signal represents current harmonics, which are characteristic of parameter imbalance in a synchronous motor.

[0107] Conversely, if the parametric imbalance compensator 120 determines that the output current signal comprises both a constant and a sinusoidal component, then the parametric imbalance compensator 120 is able to identify the presence of current harmonics caused by parametric imbalance in system 100. The parametric imbalance compensator 120 can determine the voltage regulation signal, as described in detail herein, to compensate for the sinusoidal component of the command voltage signal (which represents the parametric imbalance).

[0108] In some embodiments, the parameter imbalance compensator 120 can use an open-loop path to compensate for current harmonics caused by parameter imbalance in the closed loop. In some embodiments, when the system 100 operates the motor 102, the parameter imbalance compensator 120 can compensate for parameter imbalance in real time (e.g., within less than 2 seconds).

[0109] The parameter imbalance compensator 120 can apply a voltage regulation signal to the basic command voltage to output the final command voltage to the pulse width modulator 106. The pulse width modulator 106 operates the inverter 104 such that the voltage applied to the motor 102 causes current harmonics caused by the parameter imbalance to be suppressed and / or eliminated from the output current signal.

[0110] In some embodiments, system 500 may perform the methods described herein. However, the methods described herein as being performed by system 500 are not intended to be limiting, and any type of software executing on a controller may perform the methods described herein without departing from the scope of this disclosure. For example, a controller such as a processor executing software within a computing device may perform the methods described herein.

[0111] Figure 6 This is a flowchart generally illustrating a method 600 for open-loop compensation of current harmonics caused by machine imbalance in a synchronous motor driver, according to the principles of this disclosure. At 602, method 600 receives a command signal current corresponding to a generated command current. For example, parametric imbalance compensator 120 receives a command signal current corresponding to the generated command current.

[0112] At 604, method 600 receives a position estimation signal indicating the estimated position of the synchronous motor. For example, parametric imbalance compensator 120 receives a position estimation signal indicating the estimated position of electric motor 102.

[0113] In response to at least one current harmonic caused by parametric imbalance, at 606, method 600 uses a command current signal and a position estimation signal to determine a voltage regulation value. For example, parametric imbalance compensator 120 uses a command current signal and a position estimation signal to determine a voltage regulation value.

[0114] At 608, method 600 uses at least a voltage regulation value to generate a voltage regulation signal, which is applied to the synchronous motor to compensate for current harmonics caused by parameter imbalance. For example, parameter imbalance compensator 120 uses at least a voltage regulation value to generate a voltage regulation signal, which is applied to the motor to compensate for current harmonics caused by parameter imbalance. In some embodiments, another component of the synchronous motor drive system (e.g., system 100) may generate the voltage regulation signal. For example, parameter imbalance compensator 120 may provide a voltage regulation value to another component of system 100 (e.g., current controller 114, pulse width modulator 106, or inverter 104), and said component may generate the voltage regulation signal based on the voltage regulation value. In some embodiments, the voltage regulation signal may be used to compensate for current harmonics caused by parameter imbalance by being added to or applied to a command voltage signal (e.g., generated by current controller 114). In some embodiments, adding or applying the voltage regulation signal to the command voltage signal may form a final command voltage that can be provided to pulse width modulator 106. The pulse width modulator 106 operates the inverter 104 so that the final command voltage can be applied to the motor 102, thereby suppressing or eliminating current harmonics caused by parameter imbalance from the output current signal generated by the motor 102.

[0115] In some embodiments, a system for compensating for current harmonics caused by parametric imbalance in an electric motor. The system includes a processor and a memory. The memory includes instructions that, when executed by the processor, cause the processor to: receive a command current signal corresponding to a generated command current; receive a position estimation signal indicating an estimated position of the electric motor; determine a voltage regulation value using the command current signal and the position estimation signal in response to at least one current harmonic caused by the parametric imbalance; and generate a voltage regulation signal, at least using the voltage regulation value, which is applied to the electric motor to compensate for the current harmonics caused by the parametric imbalance.

[0116] In some embodiments, the voltage regulation value is determined based on the inverse of one or more parameter imbalance values ​​representing the sinusoidal portion of the command voltage signal. In some embodiments, the voltage regulation signal is added to the command voltage signal before being applied to the electric motor, wherein adding the voltage regulation signal to the electric motor command voltage signal cancels out the sinusoidal portion of the command voltage signal. In some embodiments, the one or more parameter imbalance values ​​include parameter imbalance estimates, flux linkage parameter imbalance estimates, and resistance parameter imbalance estimates. In some embodiments, the voltage regulation signal applied to the electric motor is applied using an open-loop path. In some embodiments, the instructions further instruct the processor to: determine one or more parameter imbalance estimates using a machine model, determine the inverse of each corresponding parameter imbalance estimate, and determine the voltage regulation signal based on the inverses of the one or more parameter imbalance estimates. In some embodiments, the machine model is trained using at least one of one or more saturation estimates, one or more temperature estimates, and one or more phase change estimates related to the phase-to-phase variation of a particular parameter imbalance.

[0117] In some embodiments, a method for compensating for current harmonics caused by parametric imbalance in a synchronous motor driver includes receiving a command current signal corresponding to a generated command current. The method further includes receiving a position estimation signal indicating an estimated position of the synchronous motor driver, and determining a voltage regulation value using the command current signal and the position estimation signal in response to at least one current harmonic caused by the parametric imbalance. The method also includes generating a voltage regulation signal using at least the voltage regulation value, the voltage regulation signal being applied to the synchronous motor driver to compensate for the current harmonics caused by the parametric imbalance.

[0118] In some embodiments, determining the voltage regulation value includes determining the voltage regulation value based on the inverse of one or more parameter imbalance values ​​representing the sinusoidal portion of the command voltage signal. In some embodiments, the voltage regulation signal is added to the command voltage signal before being applied to the synchronous motor driver, wherein adding the voltage regulation signal to the command voltage signal cancels out the sinusoidal portion of the command voltage signal. In some embodiments, the one or more parameter imbalance values ​​include parameter imbalance estimates, flux linkage parameter imbalance estimates, and resistance parameter imbalance estimates. In some embodiments, the voltage regulation signal applied to the electric motor is applied using an open-loop path. In some embodiments, the method further includes: using a machine model to determine one or more parameter imbalance estimates, determining the inverse of each corresponding parameter imbalance estimate, and determining the voltage regulation signal based on the inverse of the one or more parameter imbalance estimates. In some embodiments, the machine model is trained using at least one of one or more saturation estimates, one or more temperature estimates, and one or more phase change estimates related to the phase-to-phase variation of a particular parameter imbalance.

[0119] In some embodiments, an apparatus includes a processor and a memory. The memory includes instructions that, when executed by the processor, cause the processor to: receive a command current signal corresponding to a generated command current; receive a position estimation signal indicating an estimated position of an electric motor; determine a voltage regulation value using the command current signal and the position estimation signal in response to at least one current harmonic caused by a parameter imbalance; and generate a voltage regulation signal using at least the voltage regulation value, the voltage regulation signal being applied to the electric motor to compensate for the current harmonic caused by the parameter imbalance.

[0120] In some embodiments, the voltage regulation value is determined based on the inverse of one or more parameter imbalance values ​​representing the sinusoidal portion of the command voltage signal. In some embodiments, the voltage regulation signal is added to the command voltage signal before being applied to the electric motor, wherein adding the voltage regulation signal to the command voltage signal cancels out the sinusoidal portion of the command voltage signal. In some embodiments, the voltage regulation signal applied to the electric motor is applied using an open-loop path. In some embodiments, the instructions further instruct the processor to: determine one or more parameter imbalance estimates using a machine model, determine the inverse of each corresponding parameter imbalance estimate, and determine the voltage regulation signal based on the inverse of the one or more parameter imbalance estimates. In some embodiments, the machine model is trained using at least one of one or more interphase variation estimates, one or more saturation estimates, and one or more temperature estimates related to the interphase variation of a particular parameter imbalance.

[0121] The foregoing discussion is intended to illustrate the principles and various embodiments of the invention. Once the foregoing disclosure is fully understood, many variations and modifications will become apparent to those skilled in the art. The following claims are intended to be construed as encompassing all such variations and modifications.

[0122] The word “example” is used herein to mean used as an example, illustration, or description. Any aspect or design described herein as an “example” is not necessarily to be construed as being more preferred or advantageous than other aspects or designs. Rather, the use of the word “example” is intended to present a concept in a specific manner. As used in this application, the term “or” is intended to mean an inclusive “or” rather than an exclusive “or.” That is, unless otherwise stated or clearly apparent from the context, “X comprises A or B” is intended to mean any natural inclusion. That is, if X comprises A; X comprises B; or X comprises both A and B, then “X comprises A or B” is satisfied in any of the foregoing cases. Additionally, the article “a / an” used in this application and the appended claims should generally be interpreted as meaning “one or more” unless otherwise stated or clearly apparent from the context to the singular form. Furthermore, unless so described, the use of the terms “implementation” or “an embodiment” throughout the document is not intended to refer to the same embodiment or implementation.

[0123] The systems, algorithms, methods, and instructions described herein can be implemented in hardware, software, or any combination thereof. Hardware may include, for example, a computer, intellectual property (IP) core, application-specific integrated circuit (ASIC), programmable logic array, optical processor, programmable logic controller, microcode, microcontroller, server, microprocessor, digital signal processor, or any other suitable circuit. In the claims, the term "processor" should be understood to include any of the foregoing hardware, individually or in combination. The terms "signal" and "data" are used interchangeably.

[0124] As used herein, the term "module" can include a packaged functional hardware unit designed for use with other components, a set of instructions executable by a controller (e.g., a processor executing software or firmware), processing circuitry configured to perform a specific function, and self-contained hardware or software components that interface with a larger system. For example, a module can include an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), circuitry, digital logic circuitry, analog circuitry, a combination of discrete circuitry, gate circuitry, and other types of hardware or combinations thereof. In other embodiments, a module can include a memory storing instructions executable by a controller to implement the features of the module.

[0125] Furthermore, in one respect, for example, the system described herein can be implemented using a general-purpose computer or general-purpose processor with a computer program that, when executed, performs any of the corresponding methods, algorithms, and / or instructions described herein. Additionally or alternatively, for example, a special-purpose computer / processor may be utilized, which may contain additional hardware for performing any of the methods, algorithms, or instructions described herein.

[0126] Furthermore, all or part of the embodiments of this disclosure may take the form of a computer program product accessible from, for example, a computer-usable or computer-readable medium. A computer-usable or computer-readable medium may be, for example, any means that can tangibly contain, store, communicate, or transmit a program for use by or in connection with any processor. The medium may be, for example, an electrical, magnetic, optical, electromagnetic, or semiconductor device. Other suitable media may also be used.

[0127] The above embodiments, implementations, and aspects have been described to allow for an easy understanding of the invention and do not limit the invention. Rather, the invention is intended to cover various modifications and equivalent arrangements included within the scope of the appended claims, which should be given the broadest interpretation to cover all such modifications and equivalent structures permitted by law.

Claims

1. A system for compensating for current harmonics caused by parameter imbalance in an electric motor, the system comprising: processor; as well as The memory includes instructions that, when executed by the processor, cause the processor to: Receive the command current signal corresponding to the generated command current; Receive a position estimation signal indicating the estimated position of the electric motor; In response to at least one current harmonic caused by parametric imbalance, a voltage regulation value is determined using the command current signal and the position estimation signal, wherein the voltage regulation value is determined based on the inverse of one or more parametric imbalance values ​​representing the sinusoidal portion of the command voltage signal; as well as At least the voltage regulation value is used to generate a voltage regulation signal, which is applied to the electric motor to compensate for current harmonics caused by the parameter imbalance.

2. The system according to claim 1, wherein, The inverse of one or more parameter imbalance values ​​corresponds to the inverse mathematical model of the electric motor.

3. The system according to claim 1, wherein, The voltage regulation signal is added to the command voltage signal before being applied to the electric motor, wherein adding the voltage regulation signal to the command voltage signal cancels out the sine component of the command voltage signal.

4. The system according to claim 1, wherein, The one or more parameter imbalance values ​​include inductance parameter imbalance estimates, flux linkage parameter imbalance estimates, and resistance parameter imbalance estimates.

5. The system according to claim 1, wherein, The voltage regulation signal applied to the electric motor is applied using an open-loop path.

6. The system according to claim 1, wherein, The instruction also causes the processor to: Use machine models to determine one or more parameter imbalance estimates; Determine the inverse of the imbalance estimate for each corresponding parameter; as well as The voltage regulation signal is determined based on the inverse of the one or more parameter imbalance estimates.

7. The system according to claim 6, wherein, The machine model is trained using one or more saturation estimates.

8. A method for compensating current harmonics caused by parameter imbalance in a synchronous motor driver, the method comprising: Receive the command current signal corresponding to the generated command current; Receive a position estimation signal indicating the estimated position of the synchronous motor driver; In response to at least one current harmonic caused by parametric imbalance, a voltage regulation value is determined using the command current signal and the position estimation signal, wherein determining the voltage regulation value includes: determining the voltage regulation value based on the inverse of one or more parametric imbalance values ​​representing the sinusoidal portion of the command voltage signal; and At least the voltage regulation value is used to generate a voltage regulation signal, which is applied to the synchronous motor driver to compensate for the at least one current harmonic caused by parameter imbalance.

9. The method according to claim 8, wherein, The voltage regulation signal is added to the command voltage signal before being applied to the synchronous motor driver, wherein adding the voltage regulation signal to the command voltage signal cancels out the sine component of the command voltage signal.

10. The method according to claim 8, wherein, The inverse of one or more parameter imbalance values ​​corresponds to the inverse mathematical model of the synchronous motor driver.

11. The method according to claim 8, wherein, The one or more parameter imbalance values ​​include inductance parameter imbalance estimates, flux linkage parameter imbalance estimates, and resistance parameter imbalance estimates.

12. The method according to claim 8, wherein, The voltage regulation signal applied to the synchronous motor driver is applied using an open-loop path.

13. The method of claim 8, further comprising: Use machine models to determine one or more parameter imbalance estimates; Determine the inverse of the imbalance estimate for each corresponding parameter; as well as The voltage regulation signal is determined based on the inverse of the one or more parameter imbalance estimates.

14. The method according to claim 13, wherein, The machine model is trained using one or more saturation estimates.

15. An apparatus comprising: processor; as well as The memory includes instructions that, when executed by the processor, cause the processor to: Receive the command current signal corresponding to the generated command current; Receive a position estimation signal indicating the estimated position of the electric motor; In response to at least one current harmonic caused by parametric imbalance, a voltage regulation value is determined using the command current signal and the position estimation signal, wherein the voltage regulation value is determined based on the inverse of one or more parametric imbalance values ​​representing the sinusoidal portion of the command voltage signal; as well as At least the voltage regulation value is used to generate a voltage regulation signal, which is applied to the electric motor to compensate for the at least one current harmonic caused by parameter imbalance.

16. The apparatus according to claim 15, wherein, The inverse of one or more parameter imbalance values ​​corresponds to the inverse mathematical model of the electric motor.

17. The apparatus according to claim 15, wherein, The voltage regulation signal is added to the command voltage signal before being applied to the electric motor, wherein adding the voltage regulation signal to the command voltage signal cancels out the sine component of the command voltage signal.

18. The apparatus according to claim 15, wherein, The voltage regulation signal applied to the electric motor is applied using an open-loop path.

19. The apparatus according to claim 15, wherein, The instruction also causes the processor to: Use machine models to determine one or more parameter imbalance estimates; Determine the inverse of the imbalance estimate for each corresponding parameter; as well as The voltage regulation signal is determined based on the inverse of the one or more parameter imbalance estimates.

20. The apparatus according to claim 19, wherein, The machine model is trained using one or more saturation estimates.

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