阅读说明：本技术 交流马达驱动器中电流测量偏移误差的闭环补偿 (Closed loop compensation for current measurement offset errors in AC motor drives ) 是由 P·普拉莫德 张喆 K·纳姆布利 I·O·罗维 A·萨哈 于 2020-11-30 设计创作，主要内容包括：本申请公开了交流马达驱动器中电流测量偏移误差的闭环补偿。公开了用于补偿永磁同步马达(PMSM)驱动器中的电流测量偏移误差的系统和方法。该系统和方法包括：读取输出电压命令信号；从输出电压命令信号中提取电流测量偏移误差的特征；以及基于特征使用反馈路径补偿闭环中的电流测量偏移误差。(Closed loop compensation of current measurement offset errors in an AC motor drive is disclosed. Systems and methods for compensating for current measurement offset errors in a Permanent Magnet Synchronous Motor (PMSM) drive are disclosed. The system and method include: reading an output voltage command signal; extracting a characteristic of a current measurement offset error from the output voltage command signal; and compensating for current measurement offset error in the closed loop using the feedback path based on the characteristic.)

1. A system for compensating for current measurement offset errors in an Alternating Current (AC) motor drive, the system comprising:

a processor; and

a memory comprising instructions that, when executed by the processor, cause the processor to:

reading an output voltage command signal;

extracting a characteristic of a current measurement offset error from the output voltage command signal; and

compensating for current measurement offset error in a closed loop using a feedback path based on the characteristic.

2. The system of claim 1, wherein to compensate for current measurement offset error in a closed loop using a feedback path based on the characteristic, the instructions further cause the processor to:

generating a correction term that compensates for the current measurement offset error;

applying the correction term to the estimated current to output a compensated estimated current to a current regulator; and

verifying that a subsequent output voltage command signal received from a current regulator via the feedback path does not include the current measurement offset error.

3. The system of claim 1, wherein the compensation for the current measurement offset error occurs in real time as the AC motor drive operates an AC motor.

4. The system of claim 1, wherein to extract the characteristic of the current measurement offset error from the output voltage command signal, the instructions further cause the processor to: sinusoidal components at a synchronous frequency are extracted from the output voltage command signal.

5. The system of claim 4, wherein to compensate for the current measurement offset error based on the characteristic, the instructions further cause the processor to: the features are input into an adaptive resonator to output a correction term.

6. The system of claim 5, wherein the instructions further cause the processor to: compensating for current measurement offset errors in the synchronous reference frame by transforming the correction term and adding the transformed correction term to the estimated synchronous frame current.

7. The system of claim 1, wherein to extract a characteristic of a current measurement offset error from the output voltage command signal, the instructions further cause the processor to: the feature is converted to a DC signal.

8. The system of claim 7, wherein to compensate for current measurement offset error based on the characteristic, the instructions further cause the processor to: the DC signal is input into a conventional integrator to output a DC correction term.

9. The system of claim 8, wherein the instructions further cause the processor to: applying the DC correction term to the current estimated in the synchronous reference frame to directly compensate for current measurement offset errors in the synchronous reference frame.

10. A method for compensating for current measurement offset error in an Alternating Current (AC) motor drive, the method comprising:

reading an output voltage command signal;

extracting a characteristic of a current measurement offset error from the output voltage command signal; and

compensating for current measurement offset error in a closed loop using a feedback path based on the characteristic.

11. The method of claim 10, wherein to compensate for current measurement offset error in a closed loop using a feedback path based on the characteristic, the method further comprises:

generating a correction term command to compensate for the current measurement offset error;

applying the correction term to the estimated current to output a compensated estimated current to a current regulator; and

verifying that a subsequent output voltage command signal received from a current regulator via the feedback path does not include the current measurement offset error.

12. The method of claim 10, further comprising: compensating for the current measurement offset error occurs in real time as the AC motor drive operates an AC motor.

13. The method of claim 10, wherein to extract the characteristics of the current measurement offset error from the output voltage command signal, the method further comprises: sinusoidal components at a synchronous frequency are extracted from the output voltage command signal.

14. The method of claim 13, wherein to compensate for current measurement offset error based on the characteristic, the method further comprises: the features are input into an adaptive resonator to output a correction term.

15. The method of claim 14, further comprising: current measurement offset errors in the stationary reference frame are directly compensated for by transforming the correction term and adding the transformed correction term to the estimated synchronous frame current.

16. The method of claim 10, wherein to extract the characteristics of the current measurement offset error from the output voltage command signal, the method further comprises: the feature is converted to a DC signal.

17. The method of claim 16, wherein to compensate for the current measurement offset error based on the characteristic, the method further comprises: the DC signal is input into a conventional integrator to output a DC correction term.

18. The method of claim 17, further comprising: applying the DC correction term to the current estimated in the synchronous reference frame to directly compensate for current measurement offset errors in the synchronous reference frame.

19. An electronic device, comprising:

a processor; and

a memory comprising instructions that, when executed by the processor, cause the processor to:

reading an output voltage command signal;

extracting a characteristic of a current measurement offset error from the output voltage command signal; and

compensating for current measurement offset error in a closed loop using a feedback path based on the characteristic.

20. The electronic device of claim 18, wherein:

to extract a characteristic of a current measurement offset error from the output voltage command signal, the instructions further cause the processor to: the characteristic is converted into a direct current signal.

To compensate for the current measurement offset error based on the characteristic, the instructions further cause the processor to: inputting the DC signal into a conventional integrator to output a DC correction term; and

the instructions further cause the processor to: applying the DC correction term to the current estimated in the synchronous reference frame to directly compensate for current measurement offset errors in the synchronous reference frame.

Technical Field

The present disclosure relates to current measurement offset error, and more particularly to systems and methods for closed loop compensation of current measurement offset error in permanent magnet synchronous motor drives.

Background

Vehicles such as automobiles, trucks, sport utility vehicles, cross-over vehicles, minivans, or other suitable vehicles may include an Electric Power Steering (EPS) system. Such EPS systems typically include an electric motor for providing steering assist during operation of the vehicle. In order to provide such steering assist, the EPS system may drive the electric motor according to a method of torque control. The electric motor may comprise a Permanent Magnet Synchronous Motor (PMSM) drive. When using PMSM drivers, EPS systems may utilize Field Oriented Control (FOC). The FOC converts Alternating Current (AC) phase motor voltage and current signals in a stationary reference frame to a synchronously rotating reference frame (commonly referred to as a d/q-axis reference frame), where the motor voltage and current become Direct Current (DC) quantities. FOC torque control is typically achieved by a closed-loop current control method that employs a current regulator to minimize the error between the commanded current and the measured current, thereby achieving perfect current tracking. Therefore, current control requires measuring the motor current, which can be achieved by measuring the phase current of the PMSM driver, which is then transformed into the synchronous coordinate system via park transform (park transform) to perform control in the synchronous reference coordinate system.

When an offset error of a certain magnitude occurs in the phase current measurements, a closed loop current controller operating in a synchronous reference frame adjusts the motor voltage to match the measurement of the motor current to the commanded current. The current controller may cause the actual motor current to become incorrect due to incorrect measurements. Such failure modes can result in motor torque and current errors related to motor position, which may be seen as large torque ripple on the motor shaft, and may be larger than the rated motor current (of the hardware design). When the torque ripple caused by the phase current measurement offset error exceeds a certain threshold, the offset error may produce a motor torque in the opposite direction to the motor torque command. When used in an EPS system, a failure to generate torque in the opposite direction to the desired motor torque command results in the following: steering assistance cannot be provided to the driver and the driver ultimately needs to apply more force than if the vehicle were operating in a manual steering mode (i.e., without an active EPS system).

Disclosure of Invention

The present disclosure relates generally to detection of current measurement offset errors.

An aspect of the disclosed embodiments includes a system for compensating for current measurement offset errors in an Alternating Current (AC) motor drive. The system includes a processor and a memory. The memory includes instructions that, when executed by the processor, cause the processor to: the method includes reading an output voltage signal, extracting a signature of a current measurement offset error from the output voltage signal, and compensating for the current measurement offset error in a closed loop using a feedback path based on the signature.

Another aspect of the disclosed embodiments includes a method for compensating for current measurement offset errors in an Alternating Current (AC) motor drive. The method comprises the following steps: the method includes reading an output voltage signal, extracting a characteristic of a current measurement offset error from the output voltage signal, and compensating for the current measurement offset error in a closed loop using a feedback path based on the characteristic.

Another aspect of the disclosed embodiments includes an electronic device. The electronic device includes a processor and a memory. The memory includes instructions that, when executed by the processor, cause the processor to: the method includes reading an output voltage signal, extracting a characteristic of a current measurement offset error from the output voltage signal, and compensating for the current measurement offset error in a closed loop using a feedback path based on the characteristic.

These and other aspects of the disclosure are disclosed in the following detailed description of the embodiments, the appended claims and the accompanying drawings.

Drawings

The present disclosure is best understood from the following detailed description when read with the accompanying drawing figures. It is emphasized that, according to common practice, the various features of the drawings are not to scale. On the contrary, the dimensions of the various features are arbitrarily expanded or reduced for clarity.

Fig. 1A-1C generally illustrate an Alternating Current (AC) motor drive system with closed loop current measurement offset error compensation in accordance with the principles of the present disclosure.

Fig. 2 generally illustrates a controller system according to the principles of the present disclosure.

Fig. 3 is a flow chart generally illustrating a method for closed loop compensation of current measurement offset error in an AC motor drive according to the principles of the present disclosure.

Detailed Description

The following discussion is directed to various embodiments of the disclosure. Although one or more of these embodiments may be preferred, the embodiments disclosed should not be interpreted, or otherwise used, as limiting the scope of the disclosure, including the claims. In addition, one skilled in the art will understand that the following description has broad application, and the discussion of any embodiment is meant only to be exemplary of that embodiment, and not intended to intimate that the scope of the disclosure, including the claims, is limited to that embodiment.

Some machines (e.g., vehicles, boats, airplanes, drones, power plants, yard equipment, pumps, compressors, etc.) may include an Alternating Current (AC) motor drive that controls an AC motor in a closed loop. A current measurement system may be included in the closed loop to measure the current output of the synchronous motor. Machines using current measurement systems may be subject to current measurement offset errors.

The current measurement offset error is generated based on imperfections or faults in the current measurement. The current measurement offset error may be caused by the current estimator incorrectly measuring the current output from the AC motor. In a closed loop system using a current regulator, the current regulator generates the required output voltage signal so that the measured current becomes equal to the commanded current. In this case, when the measured current is different from the commanded current, the output voltage signal will be incorrect (e.g., different from the expected output voltage signal based on the commanded current) because the current regulator is attempting to match the measured current (e.g., which is different from the commanded current) to the commanded current.

Gradual changes in the measurement circuit (e.g., operational amplifiers (op-amps), offset drift, etc.) may result in smaller current measurement offset errors. Failure of the measurement circuit may result in a larger current measurement offset error. As discussed, if left undetected and/or unrelieved, the failure mode will result in motor torque and current errors related to motor position, which may be considered large torque fluctuations at the motor shaft, and may be greater than the rated motor current (of the hardware design). When the torque ripple caused by the phase current measurement offset error exceeds a certain threshold, the offset error may produce a motor torque in the opposite direction to the motor torque command. When used in an EPS system, a failure to generate torque in the opposite direction to the required motor torque command results in the following: steering assistance cannot be provided to the driver and the driver ultimately needs to apply more force than if the vehicle were operating in a manual steering mode (i.e., without an active EPS system).

Accordingly, systems and methods such as those described herein may be configured to address the above-described problems by providing techniques for electronically compensating for current measurement offset errors in any AC motor drive and current measurement system. In some embodiments, the systems and methods described herein are capable of detecting, learning, and compensating for the effects on an AC motor drive caused by current measurement offset errors. For example, using closed loop compensation control, the effect of current measurement offset error may be at least partially compensated.

In some embodiments, the systems and methods described herein may be configured to provide techniques for detecting phase-to-phase current measurement offset errors in AC motor drives and current measurement systems in real time. The systems and methods described herein may be configured to extract characteristics of current measurement offset errors using various mathematical models, compensate for current measurement offset errors using a closed loop compensator, and correct for current measurement offset errors.

In some embodiments, the systems and methods described herein may be configured to vary the measured current in real time to adjust the operation of the AC motor drive to control the AC motor in a more desirable manner. The systems and methods described herein may result in enhanced AC motor performance, extended AC motor life, steering, and enhanced customer experience using machines that include AC motors.

The disclosed technique is applicable to any electric motor drive with an Alternating Current (AC) machine and any current measurement architecture (current measurement architecture involving both in-line and low side). A low-side current measurement system may refer to placing a current sensor in series with a load between the load and ground. In-line current measurement systems may refer to placing a current sensor in series with a circuit such that current flowing through the circuit also flows through the current sensor. Further, the disclosed embodiments may be implemented by a processor to detect, identify, and/or correct in real time while the AC motor is running. The disclosed embodiments may also be implemented by a processor at the end of line (EOL) of a manufacturing facility.

Fig. 1A generally illustrates an Alternating Current (AC) motor drive system 100 (referred to herein as a "system") according to the principles of the present disclosure. The system 100 may include a current command generator 102, a current regulator 104, a current measurement offset error compensation controller 106, a pulse width modulator 108, an inverter 110, an AC motor 112, a current sensor 114, and a current estimator 116. In some embodiments, the current regulator 104, the pulse width modulator 108, the inverter 110, the AC motor 112, the current sensor 114, and the current estimator 116 form a closed-loop current control system. The depicted AC motor drive system 100 also includes another closed loop within the current control system. For example, the current regulator 104, the current measurement offset error compensation controller 106, the current sensor 114, and the current estimator 116 form a closed-loop current measurement offset error compensation system. It should be noted that fewer or more components may be included in the system 10 as needed to perform the techniques disclosed herein, and the depicted components are for illustrative purposes.

In some embodiments, the closed loop current measurement offset error compensation system may function as follows. The current regulator 104 receives a command or reference current and outputs a corresponding output voltage command signal. The current measurement offset error compensation controller 106 receives the output voltage signal. The current measurement offset error compensation controller 106 includes a current measurement offset error compensator 106A and a summing block 106B.

FIG. 1B illustrates a detailed block diagram of the current measurement offset error compensation controller 106 in accordance with the principles of the present disclosure. The offset error feature extraction module 118 extracts features of the current measurement offset error. The error is subtracted from the zero command, i.e., the negative (negative) of the error is calculated and sent to the closed loop compensator 120, which closed loop compensator 120 generates a base current offset correction signal. The coordinate system transformation module 122 transforms the pre-transformed current offset correction signal to generate a final current offset correction signal. The final current offset correction signal is added to the current estimate at the summing block 106B to determine the measured current input to the current regulator 104, thereby closing the loop.

With the foregoing description, additional details and operation of AC motor drive system 100 will now be discussed. The AC motor 112 may generate a rotational force or a linear force for powering a machine (e.g., those machines described herein). The AC motor 112 may include a constant speed motor or other suitable motor. AC motor drive system 100 may selectively control the power provided to AC motor 112. AC motor drive system 100 may provide electrical energy to AC motor 112 at varying amounts and varying frequencies to indirectly control the speed and torque of AC motor 112.

The current measurement system 170 may include a current sensor 114 and a current estimator 116. The current sensor 114 may include any suitable current sensor configured to sense or measure current in a circuit. The current sensor may provide a signal indicative of the current to the current estimator 116. The current sensor may be configured to receive a signal indicative of the current and measure the amount of current output by the AC motor 112 (e.g., based on the current indicated by the signal). The current estimator 116 may be configured to transmit the stationary frame current of the AC motor 112 or to transform the measured current into a synchronous reference frame using a position estimate of the AC motor 112.

Current command generator 102 may receive a torque commandCurrent command generator 102 may generate a commanded current I based on a torque command^*. The current command may consist of a direct-axis (d-axis) current componentAnd quadrature-axis (q-axis) current componentAnd (4) forming. The current regulator 104 receives the commanded current and outputs a voltage command signal V^*To the pulse width modulator 108. The voltage command may be represented by a d-axis componentAnd q-axis componentAnd (4) forming. The pulse width modulator 108 may control the proportion of time that the output voltage signal is high over a constant period of time compared to the time that the output voltage signal is low, which may control the direction of the AC motor 112. The inverter 110 may include a voltage source inverter or other suitable inverter and may be configured to vary the frequency of the supplied electrical energy provided to the AC motor 112 to control the speed of the AC motor 112. The AC motor 112 may receive the output voltage signal V as an input. The AC motor 112 may use the input to generate as an output an amount of current I that may be equal to or different from the commanded current (e.g., when there is a current measurement offset error).

The current I output from the AC motor 112 may be sensed by a current sensor 114 to determine a measured currentThe current estimator 116 may receive the measured currentAnd determining an estimated currentThe current estimator 116 of the current measurement system 170 estimates the currentOutput to the current regulator 104. Thus, as depicted, the system 100 uses a closed loop. However, as discussed, in some cases, the measured current may be incorrect due to circuit degradation, drift, and the like.

The current regulator 104 may receive the estimated current and compare it to the commanded current. If there is any change, the current regulator 104 may send an output voltage command signal V^*Which will result in an estimated currentClosely matching the commanded current I^*. Thus, due to the commanded current I^*Is constant (or slowly varying), and the estimated currentEqual to the commanded current I^*So estimated currentIs also constant. When there is an offset error in the current measurement system, the current regulator 104 may include a ripple component in the output voltage command signal V^*In (1).

The current measurement offset error compensation controller 106 reads the output voltage command signal from the current regulator 104. The current measurement offset error compensation controller 106 may include a current measurement offset error compensator 106A including an offset error feature extraction module 118, a closed loop compensator 120, and a coordinate system transformation module 122. As will be described, the offset error feature extraction module 118 may use a mathematical model to extract a feature of the current measurement offset error from the output voltage command signal. The offset error characterization module 118 may characterize the current measurement offset error as a ripple frequency of a first electrical order (electrical order) in the output voltage command signal. In some embodiments, the offset error feature extraction module 118 may use an adaptive band-pass filter to extract features, as shown in fig. 1C. The adaptive band-pass filter may be configured to perform pre-filtering in the synchronous frame before transformation, or to use an adaptive low-pass filter in a (adaptively) tuned pseudo-stationary frame, depending on the ripple frequency (i.e. the ripple frequency of the first electrical order) being equal to the synchronous frequency. In some embodiments, the offset error feature extraction module 118 may perform direct sinusoidal error extraction on the output voltage command signal. In some embodiments, the offset error feature extraction 118 may perform demodulation to convert the sinusoidal portion of the output voltage command signal to a DC signal, and then perform low pass filtering.

As will be described, the closed-loop compensator 120 may receive the signature and generate a base current offset correction using an adaptive resonator for sinusoidal signatures, or a conventional integrator for DC signatures. As depicted in fig. 1C, the resonant controller may be used to generate a basic offset correction in the case of a sinusoidal characteristic of the current measurement offset error extracted from the output voltage command signal. The resonant controller receives a dummy command input Δ V equal to zero_c ^*With a filtered sinusoidal voltage component Δ V_cAnd generates a basic current offset correction signalThe resonant controller is adaptive in nature, i.e. designed to eliminate any error at its input at its critical frequency, which in this case is equal to the estimated synchronous frequencyThe coordinate system transformation module 122 utilizes the estimated electrical position by applyingPosition dependent transformation of a reference coordinate system ofConverting the basic current offset correction signal into a final current offset correction signalThe summing block 106B sums the resulting current offset error correction signalWith estimated currentAdding to compensate for current measurement offset error and generating a compensated estimated currentThe compensated estimated currentIs sent to the current regulator 104 in real time to mitigate any effects of current measurement offset errors.

The following discussion relates to mathematical models used by the systems and methods described herein. The measured current with offset error in the stationary reference frame can be mathematically represented as:

wherein, Delta I_αAnd Δ I_βIs an offset error in a stationary reference frame and represents the measured current, respectivelyAndwith the actual current I_αAnd I_βThe deviation of (2).

When using the transformation of the reference coordinate systemD/q current to be estimatedAndestimated d/q current when transformed into a synchronous reference frameAndthe following steps are changed:

wherein, Delta I_dAnd Δ I_qIs the current measurement error in the synchronous reference frame, I_dAnd I_qIs the actual current, andand

note that the transformation matrix is

Wherein X may represent a voltage or a current.

Assuming that the high performance current regulator has a sufficiently high bandwidth, the estimated current may be assumed to be approximately equal to the commanded current, thereby distorting the actual current. The actual current can be expressed as

The ripple component of the voltage command can then be calculated as:

wherein the content of the first and second substances,and ω_e,R,L_d,L_qSynchronous frequency (electric motor speed), motor resistance, d-axis inductance, and q-axis inductance, respectively. Thus, tuning at the synchronous frequency may be used when there is a current measurement offset errorAn adaptive band pass filter to filter the output voltage command for extraction in the offset error feature extraction module 118Pulsating component Δ V_cAs shown in fig. 1C. Please note that Δ V_cEqual to Δ V given in equation 5^*. The resonant controller 120 then operates on the error signature and outputs a base offset error correction termThe basic offset error correction termTransformed into a final offset error correction term by the reference frame transformation module 122And is summed with the estimated current at summing block 106BAdding to obtain the final estimated current in the synchronous reference coordinate systemThe final estimated currentIs input to the current regulator 104. The closed loop system forces the current measurement offset error to zero, mitigating ripple in the output current due to offset error in the measured current.

Fig. 2 generally illustrates a controller system 200 according to the principles of the present disclosure. The controller system 200 includes a current measurement offset error compensation controller 106 communicatively coupled to a memory 202. The current measurement offset error compensation controller 106 may include a processor. The processor may comprise any suitable processor, such as those described herein. The memory 202 may store instructions that, when executed by the current measurement offset error compensation controller 106, cause the current measurement offset error compensation controller 106 to perform at least the techniques disclosed herein. In particular, the computer instructions, when executed by the current measurement offset error compensation controller 106, may cause the current measurement offset error compensation controller 106 to perform the operations of the method 300, as further described below with reference to fig. 3.

Fig. 3 is a flow chart generally illustrating a method 300 for electronically compensating for current measurement offset errors in an AC motor drive, in accordance with the principles of the present disclosure. At 302, the method 300 reads the output voltage command signal. For example, the current regulator 104 may generate an output voltage command signal. At 304, the method 300 extracts a characteristic of the current measurement offset error from the output voltage command signal. In some embodiments, the output voltage command signal may include only a constant portion, and in some embodiments, the output voltage command signal may include both a constant portion and a sinusoidal portion. If the output voltage command signal includes only a constant portion, there may be no current measurement offset error because the sinusoidal portion of the output voltage signal represents a ripple that includes a characteristic of the current measurement offset error. Thus, when the output voltage signal includes a constant portion and a sinusoidal portion, the sinusoidal portion is extracted as a feature of the current measurement offset error when the feature has a frequency of the first electrical order (i.e., at the synchronization frequency). The sinusoidal portion may correspond to a pulsating portion of the output voltage signal and may be caused by the current regulator 104 causing the estimated current output from the current estimator 116 to become equal to the commanded current.

In some embodiments, to extract a characteristic of the current measurement offset error from the output voltage command signal, the method 300 further includes extracting a sinusoidal error directly from the output voltage command signal. In some embodiments, to extract a characteristic of the current measurement offset error from the output voltage command signal, the method 300 further includes transforming the output voltage command signal to transform the sinusoidal portion to a Direct Current (DC) characteristic and filtering the DC characteristic.

At 306, the method 300 compensates for current measurement offset error in the closed loop using the feedback path based on the characteristic. In some embodiments, the method 300 compensates for current measurement offset errors in real time (e.g., less than 2 seconds) as the AC motor drive operates the AC motor 112. In some embodiments, the method 300 compensates for current measurement offset error in the closed loop using a feedback path based on the characteristic by: generate a correction term to compensate for the current measurement offset error, apply the correction term to the estimated current to output a compensated estimated current to the current regulator 104, and verify that a subsequent output voltage signal received from the current regulator 104 via the feedback path does not include the current measurement offset error.

In some embodiments, when the method 300 directly extracts sinusoidal errors as features, the method 300 may also compensate current measurement offset errors by inputting the features into the adaptive resonator to output a correction term based on the features. The correction term may correct for current measurement offset errors. The adaptive resonator is capable of handling ac signals of any frequency. In some embodiments, the method 300 calculates a correction term for the current measurement offset error in the stationary reference frame and adds the transformed final correction term to the current estimated in the synchronous frame.

In some embodiments, when the method 300 transforms the output voltage command signal to convert the sinusoidal portion to a DC signature and filters the DC signature, the method 300 may also compensate for the current measurement offset error by inputting the DC signature into a conventional integrator to output a DC correction term based on the DC signature. The DC correction term can directly correct current measurement offset errors in the synchronous reference frame.

In any embodiment, the compensated estimated current may be sent to the current regulator 104 to cause the current regulator 104 to provide an output voltage command signal that lacks characteristics of a current measurement offset error.

In some embodiments, a system for compensating for current measurement offset errors in an Alternating Current (AC) motor drive includes a processor and a memory including instructions. The instructions, when executed, cause the processor to: the method includes reading an output voltage command signal, extracting a characteristic of a current measurement offset error from the output voltage command signal, and compensating for the current measurement offset error in a closed loop using a feedback path based on the characteristic.

In some embodiments, to compensate for current measurement offset error in the closed loop using the feedback path based on the characteristic, the instructions further cause the processor to: the method includes generating a correction term that compensates for a current measurement offset error, applying the correction term to the estimated current to output the compensated estimated current to the current regulator, and verifying that a subsequent output voltage command signal received from the current regulator via the feedback path does not include the current measurement offset error. In some embodiments, compensation for current measurement offset errors is performed in real time as the AC motor drive operates the AC motor. In some embodiments, to extract a characteristic of the current measurement offset error from the output voltage command signal, the instructions further cause the processor to: the sinusoidal error is extracted directly from the output voltage command signal. In some embodiments, to compensate the current measurement offset error based on the characteristic, the instructions further cause the processor to: the features are input into the adaptive resonator to output a correction term. In some embodiments, the instructions further cause the processor to: compensating for current measurement offset errors in the stationary reference frame by adding the transformed correction term to the estimated current of the synchronous frame. In some embodiments, to extract a characteristic of the current measurement offset error from the output voltage command signal, the instructions further cause the processor to: the signature is converted to a DC signal. In some embodiments, to compensate the current measurement offset error based on the characteristic, the instructions further cause the processor to: the DC signal is input into a conventional integrator to output a DC correction term. In some embodiments, the instructions further cause the processor to: the DC correction term is directly added to the estimated current of the synchronous coordinate system.

In some embodiments, a method for compensating for current measurement offset errors in an Alternating Current (AC) motor drive comprises: the method includes reading an output voltage command signal, extracting a characteristic of a current measurement offset error from the output voltage command signal, and compensating for the current measurement offset error in a closed loop using a feedback path based on the characteristic.

In some embodiments, to compensate for current measurement offset error in the closed loop using the feedback path based on the characteristic, the method further comprises: the method includes generating a correction term that compensates for a current measurement offset error, applying the correction term to the estimated current to output the compensated estimated current to the current regulator, and verifying that a subsequent output voltage command signal received from the current regulator via the feedback path does not include a current measurement offset error signature. In some embodiments, the method further comprises: compensation for current measurement offset errors is performed in real time as the AC motor drive operates the AC motor. In some embodiments, to extract a characteristic of the current measurement offset error from the output voltage command signal, the method further comprises: a sinusoidal component is extracted from the output voltage command signal. In some embodiments, to compensate current measurement offset error based on the characteristic, the method further comprises: the characteristic is input into the adaptive resonator to output a correction term. In some embodiments, the method further comprises: compensating for current measurement offset errors by: the correction term in the stationary reference frame is transformed and added to the estimated current of the synchronous frame. In some embodiments, to extract a characteristic of the current measurement offset error from the output voltage command signal, the method further comprises: the signature is converted to a DC signal. In some embodiments, to compensate current measurement offset error based on the characteristic, the method further comprises: the DC signal is input into a conventional integrator to output a DC correction term. In some embodiments, the method further comprises: the DC correction is added to the estimated current of the synchronous frame and the current measurement offset error is directly compensated in the synchronous reference frame.

In some embodiments, an electronic device includes a processor and a memory storing instructions. The instructions, when executed, cause the processor to: the method includes reading an output voltage command signal, extracting a characteristic of a current measurement offset error from the output voltage command signal, and compensating for the current measurement offset error in a closed loop using a feedback path based on the characteristic.

In some embodiments, to extract a characteristic of the current measurement offset error from the output voltage command signal, the instructions further cause the processor to: a sinusoidal component is extracted from the output voltage command signal. In some embodiments, to compensate the current measurement offset error based on the characteristic, the instructions further cause the processor to: the features are input into the adaptive resonator to output a correction term. In some embodiments, the instructions further cause the processor to: current measurement offset errors are compensated by transforming the correction term in the stationary reference frame and adding it to the estimated synchronous frame current. In some embodiments, to extract a characteristic of the current measurement offset error from the output voltage command signal, the instructions further cause the processor to: the signature is converted to a DC signal. In some embodiments, to compensate the current measurement offset error based on the characteristic, the instructions further cause the processor to: the DC signal is input into a conventional integrator to output a DC zero command. In some embodiments, the instructions further cause the processor to: converting the DC zero command to a sinusoidal zero command, and compensating for current measurement offset errors in the stationary reference frame by applying the sinusoidal zero command to the d/q measured current.

The above discussion is meant to be illustrative of the principles and various embodiments of the present invention. Numerous variations and modifications will become apparent to those skilled in the art once the above disclosure is fully appreciated. It is intended that the following claims be interpreted to embrace all such variations and modifications.

The word "example" is used herein to mean serving as an example, instance, or illustration. Any aspect or design described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other aspects or designs. Rather, use of the word "example" is intended to present concepts in a concrete fashion. As used in this application, the term "or" is intended to mean an inclusive "or" rather than an exclusive "or". That is, unless specified otherwise, or clear from context, "X comprises a or B" is intended to mean any of the natural inclusive permutations. That is, if X contains A; x comprises B; or X includes both A and B, then "X includes A or B" is satisfied under any of the foregoing circumstances. In addition, the articles "a" and "an" as used in this application and the appended claims should generally be construed to mean "one or more" unless specified otherwise or clear from context to be directed to a singular form. Furthermore, unless described as such, the use of the term "embodiment" or "one embodiment" throughout is not intended to refer to the same embodiment or implementation.

Implementations of the systems, algorithms, methods, instructions, etc. described herein may be implemented in hardware, software, or any combination thereof. The hardware may include, for example, a computer, an Intellectual Property (IP) core, an Application Specific Integrated Circuit (ASIC), a programmable logic array, an optical processor, a programmable logic controller, microcode, a microcontroller, a server, a microprocessor, a digital signal processor, or any other suitable circuitry. In the claims, the term "processor" should be understood to include any of the foregoing hardware, alone or in combination. The terms "signal" and "data" are used interchangeably.

As used herein, the term module may 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), a processing circuit configured to perform a specific function, and self-contained hardware or software components interfaced with a larger system. For example, a module may include, or be a combination of, an Application Specific Integrated Circuit (ASIC), a Field Programmable Gate Array (FPGA), a circuit, digital logic, analog circuitry, a combination of discrete circuits, gates, and other types of hardware. In other embodiments, a module may include a memory that stores instructions executable by a controller to implement features of the module.

Further, in an aspect, for example, the systems described herein may be implemented using a general purpose computer or a general purpose processor with a computer program that, when executed, performs any of the respective methods, algorithms, and/or instructions described herein. Additionally or alternatively, for example, a special purpose computer/processor may be utilized which may contain other hardware for carrying out any of the methods, algorithms, or instructions described herein.

Furthermore, all or a portion of an implementation of the present 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 apparatus that can tangibly contain, store, communicate, or transport the 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.

The above-described embodiments, embodiments and aspects have been described to allow easy understanding of the present invention and do not limit the present invention. On the contrary, the invention is intended to cover various modifications and equivalent arrangements included within the scope of the appended claims, which scope is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures as is permitted under the law.