Permanent magnet synchronous motor output torque calculation method, device and computer program product

Abstract

The application relates to the technical field of vehicle control, and provides a permanent magnet synchronous motor output torque calculation method, device and computer program product. The method comprises the following steps: acquiring three-phase phase current signals, a high-voltage bus voltage signal and three-phase bridge arm drive duty cycle signals; based on the high-voltage bus voltage signal and the drive duty cycle signal, three-phase phase voltage signals are calculated; based on a pre-calibrated delay time mapping table, a delay parameter is determined; the three-phase phase current signals and the three-phase phase voltage signals are subjected to delay processing by using the delay parameter; based on the synchronized phase current signals and the phase voltage signals, the instantaneous electric power of the motor is calculated; based on a pre-calibrated efficiency mapping table, a corresponding motor efficiency value is determined; based on the instantaneous electric power, the motor efficiency value and the motor rotating speed, the output torque of the motor is calculated. The application compensates for calculation errors caused by signal transmission path differences and motor nonlinear characteristics, and improves the calculation accuracy of the output torque.

Description

Technical Field

[0001] This application relates to the field of vehicle control technology, specifically to a method, device, and computer program product for calculating the output torque of a permanent magnet synchronous motor. Background Technology

[0002] Currently, there are two methods for calculating the output torque of a motor. One is the current method, which calculates the motor output torque by taking the current and electrical angle and the electromagnetic parameters of the motor. The other is to calculate the electric power, calculate the motor mechanical power based on the motor efficiency, and then calculate the motor output torque based on the motor speed.

[0003] The second method also involves two approaches to calculating electrical power. One is to multiply the bus voltage by the bus current. The bus voltage can be directly measured, while the bus current needs to be calculated using the phase current and electrical angle, which relies on the resolver signal. This is consistent with the signal required for torque calculation using the current method and has no practical significance. The other approach is to multiply the three-phase voltage by the sum of the phase currents. The phase voltage can be calculated by sampling from the driver chip, while the phase current can be directly measured. Compared to the first method, the second method does not require electrical angle and is more suitable for use in functional safety development as a redundancy strategy for torque calculation. However, due to the synchronization problem of sampling and calculating the two independent sets of phase voltage and phase current signals, the calculated electrical power has a large deviation. Using the calculated motor torque as the monitoring torque can easily lead to false triggering of faults that violate the torque monitoring safety target. Summary of the Invention

[0004] In view of this, embodiments of this application provide a method, apparatus and computer program product for calculating the output torque of a permanent magnet synchronous motor. By introducing a pre-calibrated delay mapping table and efficiency mapping table, the calculation error caused by differences in signal transmission paths and nonlinear characteristics of the motor is effectively compensated, the calculation accuracy of the output torque is improved and the possibility of false triggering of torque monitoring target violation is reduced.

[0005] The first aspect of this application provides a method for calculating the output torque of a permanent magnet synchronous motor, including:

[0006] Acquire the three-phase phase current signal, high-voltage bus voltage signal, and three-phase bridge arm drive duty cycle signal;

[0007] Based on the high-voltage bus voltage signal and the drive duty cycle signal, the three-phase voltage signal is calculated.

[0008] Based on the motor speed and target torque, and using a pre-calibrated delay time mapping table, the delay parameters required for synchronizing the three-phase current signals and three-phase voltage signals are determined.

[0009] The three-phase current signal and the three-phase voltage signal are delayed using the delay parameter to obtain synchronized phase current signal and phase voltage signal;

[0010] Based on the synchronized phase current signal and phase voltage signal, the instantaneous electric power of the motor is calculated;

[0011] Based on the motor speed and target torque, and using a pre-calibrated efficiency mapping table, the corresponding motor efficiency value is determined.

[0012] The output torque of the motor is calculated based on the instantaneous electric power, the motor efficiency value, and the motor speed.

[0013] In one embodiment, acquiring the three-phase phase current signal, the high-voltage bus voltage signal, and the drive duty cycle signal of the three-phase bridge arm includes:

[0014] The system collects the raw signals from the three-phase current sensor, the raw signals from the high-voltage bus voltage, and the raw duty cycle signals fed back by the six-phase upper and lower bridge arm drive chips.

[0015] The raw signal from the three-phase current sensor is filtered and biased to convert it into a three-phase current signal with physical quantity values.

[0016] The original signals of the high-voltage bus voltage and duty cycle are filtered and converted into physical quantity values.

[0017] In one embodiment, the calculation of the three-phase voltage signal based on the high-voltage bus voltage signal and the drive duty cycle signal includes the following calculation formula:

[0018] U a =DutyU×V dc -1 / 3(DutyU + DutyV + DutyW) ×V dc ;

[0019] U b =DutyV×V dc -1 / 3(DutyU + DutyV + DutyW) ×V dc ;

[0020] U c =DutyW×V dc -1 / 3(DutyU + DutyV + DutyW) ×V dc ;

[0021] Among them, U a U b U cThese are the phase voltages of phases A, B, and C, respectively. DutyU, DutyV, and DutyW are the drive duty cycles of the three-phase upper bridge arms, respectively, and Vdc is the high-voltage bus voltage.

[0022] In one embodiment, determining the delay parameters required for synchronizing the three-phase current signals and three-phase voltage signals based on the motor speed and target torque, using a pre-calibrated delay time mapping table, includes:

[0023] The motor state is determined based on the electrical power value at the previous moment, wherein the motor state is either the driving state or the generating state.

[0024] Based on the motor state, a pre-calibrated delay mapping table is selected, and the delay parameters required for synchronizing the three-phase current signal and the three-phase voltage signal are determined by looking up the table. The pre-calibrated delay mapping table is either a delay mapping table corresponding to the driving condition or a pre-calibration and efficiency mapping table corresponding to the power generation condition.

[0025] The step of determining the corresponding motor efficiency value based on the motor speed and target torque, using a pre-calibrated efficiency mapping table, includes:

[0026] The motor state is determined based on the electrical power value at the previous moment, wherein the motor state is either the driving state or the generating state.

[0027] Based on the motor state, a pre-calibrated efficiency mapping table is selected, and the corresponding motor efficiency value is determined by looking up the table. The pre-calibrated efficiency mapping table is either an efficiency mapping table corresponding to the driving condition or a pre-calibrated and efficiency mapping table corresponding to the power generation condition.

[0028] In one embodiment, the instantaneous electrical power of the motor is calculated based on the synchronized phase current signal and phase voltage signal using the following formula:

[0029] Pe=U a1 ×I a1 + U b1 ×I b1 + U c1 ×I c1 ;

[0030] Where Pe is the instantaneous electrical power of the motor, and U a1 U b1 U c1 These are the synchronized phase voltage signals, I a1 I b1 I c1 These are the phase current signals after synchronization.

[0031] In one embodiment, calculating the motor output torque based on the instantaneous electrical power, the motor efficiency value, and the motor speed includes:

[0032] The mechanical power is calculated using the formula Pm=Pe×η, where Pm is the mechanical power, Pe is the instantaneous electrical power of the motor, and η is the motor efficiency value.

[0033] The output torque is calculated using the formula T=Pm / ω, where T is the output torque and ω is the angular velocity of the motor.

[0034] In one embodiment, the pre-calibrated delay mapping table is obtained through bench calibration, and the calibration process includes:

[0035] Select a motor speed from the motor's operating speed range;

[0036] At the specified motor speed, the motor output torque is adjusted in stages from the minimum to the maximum value;

[0037] For each torque step, adjust the delay parameter between the phase current signal and the phase voltage signal, monitor the calculated electric power value, and record the combination of delay parameters corresponding to the maximum electric power value.

[0038] After completing the calibration of all torque steps at the current speed, the speed is changed to another motor speed, and the process returns to the step of adjusting the motor output torque from the minimum to the maximum value at the motor speed until the entire operating speed range and torque range of the motor are covered to obtain the delay mapping table.

[0039] In one embodiment, the pre-calibrated efficiency mapping table is obtained through bench calibration, and the calibration process includes:

[0040] Select a motor speed from the motor's operating speed range;

[0041] At the specified motor speed, the output torque of the motor is controlled to be adjusted in stages from the minimum to the maximum value;

[0042] For each torque step, the mechanical power is calculated based on the actual output torque and speed measured on the test bench. The motor efficiency value at that operating point is calculated based on the mechanical power and electrical power, and then recorded.

[0043] After completing the calibration of all torque steps at the current speed, the speed is changed to another motor speed, and the process returns to the step of controlling the motor output torque to be adjusted in stages from the minimum to the maximum value at the motor speed, until the entire operating speed and torque range of the motor is covered, in order to obtain the efficiency mapping table.

[0044] A second aspect of this application provides a permanent magnet synchronous motor output torque calculation device, comprising:

[0045] The data acquisition module is used to acquire three-phase phase current signals, high-voltage bus voltage signals, and three-phase bridge arm drive duty cycle signals;

[0046] The three-phase voltage calculation module is used to calculate the three-phase voltage signal based on the high-voltage bus voltage signal and the drive duty cycle signal.

[0047] The delay parameter determination module is used to determine the delay parameters required for synchronizing the three-phase current signals and three-phase voltage signals based on the motor speed and target torque and a pre-calibrated delay time mapping table.

[0048] The delay processing module is used to perform delay processing on the three-phase current signal and the three-phase voltage signal using the delay parameters, so as to obtain synchronized phase current signal and phase voltage signal;

[0049] The electric power calculation module is used to calculate the instantaneous electric power of the motor based on the synchronized phase current signal and phase voltage signal;

[0050] The motor efficiency value determination module is used to determine the corresponding motor efficiency value based on the motor speed and target torque, and on a pre-calibrated efficiency mapping table.

[0051] The output torque calculation module is used to calculate the output torque of the motor based on the instantaneous electric power, the motor efficiency value, and the motor speed.

[0052] A third aspect of this application provides an electronic device including a processor, a memory, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, the electronic device implements the permanent magnet synchronous motor output torque calculation method provided in the first aspect of this application.

[0053] A fourth aspect of this application provides a computer program product including a computer program that, when run, causes the method described in the first aspect of this application to be performed.

[0054] The first aspect of this application provides a method for calculating the output torque of a permanent magnet synchronous motor. This method eliminates the reliance on rotor position sensors and utilizes the inherent signals of the drive system to estimate torque, thus reducing system cost and improving reliability. By introducing pre-calibrated delay and efficiency mapping tables, it effectively compensates for calculation errors caused by differences in signal transmission paths and the nonlinear characteristics of the motor, maintaining calculation accuracy across a wide speed range and under dynamic load variations. This method can serve as a redundant calculation method for output torque to monitor the safety targets of permanent magnet synchronous motors, improving the accuracy of output torque calculation and reducing the possibility of false triggering of torque monitoring targets.

[0055] It is understood that the beneficial effects of the second to fourth aspects mentioned above can be found in the relevant descriptions in the first aspect mentioned above, and will not be repeated here. Attached Figure Description

[0056] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0057] Figure 1 This is a schematic flowchart of a method for calculating the output torque of a permanent magnet synchronous motor according to an embodiment of this application;

[0058] Figure 2 This is a flowchart illustrating a method for calculating the output torque of a permanent magnet synchronous motor according to another embodiment of this application;

[0059] Figure 3 This is a flowchart illustrating a method for calculating the output torque of a permanent magnet synchronous motor according to another embodiment of this application;

[0060] Figure 4 This is a schematic diagram of a current delay processing flow provided in an embodiment of this application;

[0061] Figure 5 This is a schematic diagram of a voltage delay processing flow provided in an embodiment of this application;

[0062] Figure 6 This is a schematic diagram of the structure of the permanent magnet synchronous motor output torque calculation device provided in the embodiments of this application;

[0063] Figure 7 This is a schematic diagram of the structure of the electronic device provided in the embodiments of this application. Detailed Implementation

[0064] In the following description, specific details such as particular system architectures and techniques are set forth for illustrative purposes and not for limitation, in order to provide a thorough understanding of the embodiments of this application. However, those skilled in the art will understand that this application may also be implemented in other embodiments without these specific details. In other instances, detailed descriptions of well-known systems, apparatuses, circuits, and methods have been omitted so as not to obscure the description of this application with unnecessary detail.

[0065] It should be understood that, when used in this application specification and the appended claims, the term "comprising" indicates the presence of the described features, integrals, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components and / or a collection thereof.

[0066] It should also be understood that the term “and / or” as used in this application specification and the appended claims means any combination of one or more of the associated listed items and all possible combinations, and includes such combinations.

[0067] As used in this application specification and the appended claims, the term "if" may be interpreted, depending on the context, as "when," "once," "in response to determination," or "in response to detection." Similarly, the phrase "if determined" or "if detected [the described condition or event]" may be interpreted, depending on the context, as meaning "once determined," "in response to determination," "once detected [the described condition or event]," or "in response to detection [the described condition or event]."

[0068] Furthermore, in the description of this application and the appended claims, the terms "first," "second," "third," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0069] References to "one embodiment" or "some embodiments" as described in this specification mean that one or more embodiments of this application include a specific feature, structure, or characteristic described in connection with that embodiment. Therefore, the phrases "in one embodiment," "in some embodiments," "in other embodiments," "in still other embodiments," etc., appearing in different parts of this specification do not necessarily refer to the same embodiment, but rather mean "one or more, but not all, embodiments," unless otherwise specifically emphasized. The terms "comprising," "including," "having," and variations thereof mean "including but not limited to," unless otherwise specifically emphasized.

[0070] like Figure 1 , 2As shown, the method for calculating the output torque of a permanent magnet synchronous motor provided in this application includes the following steps S101 to S107:

[0071] Step S101: Acquire the three-phase phase current signal, the high-voltage bus voltage signal, and the drive duty cycle signal of the three-phase bridge arm;

[0072] Step S102: Based on the high-voltage bus voltage signal and the drive duty cycle signal, calculate the three-phase phase voltage signal;

[0073] Step S103: Based on the motor speed and target torque, and using a pre-calibrated delay time mapping table, determine the delay parameters required for synchronizing the three-phase current signals and three-phase voltage signals.

[0074] Step S104: Use the delay parameter to delay the three-phase current signal and the three-phase voltage signal to obtain synchronized phase current signal and phase voltage signal;

[0075] Step S105: Calculate the instantaneous electric power of the motor based on the synchronized phase current signal and phase voltage signal;

[0076] Step S106: Based on the motor speed and target torque, determine the corresponding motor efficiency value according to the pre-calibrated efficiency mapping table;

[0077] Step S107: Calculate the output torque of the motor based on the instantaneous electric power, the motor efficiency value, and the motor speed.

[0078] In practical applications, the implementation first involves synchronously acquiring the output voltage signals of the three-phase current sensors, the voltage divider signals of the high-voltage bus, and the pulse width modulation signals fed back by the power drive chip through the analog-to-digital conversion channel configured in the motor controller. Subsequently, a recursive averaging filtering algorithm is used to preprocess the original signals to eliminate high-frequency noise. During the voltage reconstruction stage, based on the space vector modulation principle, the six duty cycle signals are linearly combined with the bus voltage to generate equivalent instantaneous values ​​of the three-phase phase voltages.

[0079] To address timing discrepancies caused by differences in signal transmission paths, a two-dimensional delay parameter mapping table stored in non-volatile memory is consulted based on the motor's real-time operating speed and target torque. This mapping table uses speed as the x-axis and torque as the y-axis, and correlates the optimal current sampling delay time with the voltage calculation delay time. A configurable clock cycle delay is applied to the phase current signal through a first-in-first-out buffer within the digital signal processor, while an interpolation algorithm is used to perform phase compensation on the phase voltage sequence, ensuring precise alignment of the two sets of signals in the time domain.

[0080] The synchronized three-phase voltage and current instantaneous values ​​are then multiplied by phase and summed to obtain the instantaneous electrical power. To improve calculation stability, the power value is subjected to first-order inertial filtering. Finally, combined with the motor efficiency value obtained by looking up the efficiency mapping table, the electrical power is converted into mechanical power and divided by the motor angular velocity obtained by the resolver to output a high-precision torque estimate.

[0081] In applications, signal synchronization processing can be achieved using a hardware timer-triggered dual-buffer switching mechanism, while the calibration of the efficiency mapping table is obtained by comparing the deviation between the directly measured torque and the calculated torque at different operating points through bench testing.

[0082] This application eliminates the reliance on rotor position sensors and utilizes the inherent signals of the drive system to achieve torque estimation, thereby reducing system cost and improving reliability. By introducing pre-calibrated delay and efficiency mapping tables, calculation errors caused by differences in signal transmission paths and the nonlinear characteristics of the motor are effectively compensated, ensuring calculation accuracy over a wide speed range and under dynamic load variations. This method can serve as a redundant calculation method for output torque to monitor the safety targets of permanent magnet synchronous motors, improving the accuracy of output torque calculation and reducing the possibility of false triggering of torque monitoring targets.

[0083] In one embodiment, acquiring the three-phase phase current signal, the high-voltage bus voltage signal, and the drive duty cycle signal of the three-phase bridge arm includes the following steps S201 to S203:

[0084] Step S201: Collect the raw signals from the three-phase current sensor, the raw signals from the high-voltage bus voltage, and the raw duty cycle signals fed back by the six-phase upper and lower bridge arm drive chips.

[0085] Step S202: Filter and bias correct the original signal of the three-phase current sensor to convert it into a three-phase current signal of physical quantity.

[0086] Step S203: Filter the original signal of the high-voltage bus voltage and the original signal of the duty cycle, and convert them into physical quantity values.

[0087] In the application, redundant current sampling circuits are used to acquire three-phase current signals in parallel to improve reliability. A high-voltage isolation sampling module is integrated to obtain the bus voltage, and a digital isolator captures the drive pulse width of the power module. At the signal processing level, a Kalman filter-based fusion algorithm is used to eliminate crosstalk errors between sampling channels. Current signal processing includes an automatic bias voltage calibration stage, which obtains zero-point drift values ​​and performs digital compensation by periodically shorting the sampling resistor. For high-voltage signals, polynomial fitting is used to correct their nonlinear characteristics.

[0088] In applications, the three-phase current signal can be acquired using an integrated current sensor such as a Hall effect device. Its output signal is conditioned by an instrumentation amplifier and then sent to a differential input analog-to-digital converter. The duty cycle signal is acquired by the pulse width measurement function of the capture timer.

[0089] In applications, such as Figure 3 As shown, the sampling, reception, and processing of three-phase current signals can be achieved through the following steps:

[0090] a. The underlying configuration uses redundant sampling of three-phase current signals to convert voltage signals into digital signals;

[0091] b. Configure the underlying interface functions for the application layer to use and process;

[0092] c. The application layer receives the phase current-based sampling signal through the RTE interface;

[0093] d. The application layer uses SimLink to model and bias the received current signal, converting the digital signal into a physical signal;

[0094] More specifically, this can be achieved through the following steps:

[0095] a. Configure the redundant hardware pins of the main control chip's current sensor in MCa and determine the data type;

[0096] b. Configure three redundant phase current signal channels SwsGet_AI_U_CUR_CH2, SwsGet_AI_V_CUR_CH2, and SwsGet_AI_W_CUR_CH2 in the interface file;

[0097] c. Configure the RTE interface to connect the underlying layer and the application layer;

[0098] d. The application layer software filters the received lower-level signals, removes the bias, and converts them into physical signals to obtain the three-phase current signal I. a ,I b ,I c .

[0099] In applications, high-voltage sampling, duty cycle sampling, filtering, and phase voltage calculation by the driver chip can be achieved through the following steps:

[0100] a. The underlying configuration uses six-channel driver chip duty cycle sampling to output the physical signal of the closed duty cycle of the upper and lower bridges of the three-phase driver chip;

[0101] b. Low-level configuration for bus voltage signal sampling;

[0102] c. Configure the underlying interface functions for the application layer to use and process;

[0103] d. The application layer receives high-voltage bus signals through the RTE interface, uses the upper bridge drive signal as the phase voltage calculation input, and uses the lower bridge signal for signal confidence verification.

[0104] e. Calculate the phase voltage and perform phase voltage reconstruction calculations.

[0105] In applications, the acquisition of three-phase phase voltage signals can be achieved through the following steps:

[0106] a. Configure the duty cycle signal and high-voltage bus voltage signal received by the three-phase upper and lower bridge drive chips from the main control chip in MCa, and determine the data type.

[0107] b. Configure six duty cycle signal channels and high-voltage bus signal channels in the interface file:

[0108] SwsGet_DPI_UC_PWM_UH_FB;

[0109] SwsGet_DPI_UC_PWM_UL_FB;

[0110] SwsGet_DPI_UC_PWM_VH_FB;

[0111] SwsGet_DPI_UC_PWM_VL_FB;

[0112] SwsGet_DPI_UC_PWM_WH_FB;

[0113] SwsGet_DPI_UC_PWM_WL_FB;

[0114] SwsGet_AI_DC_A;

[0115] c. Configure the RTE interface to connect the underlying layer and the application layer;

[0116] d. The application layer software performs the following calculations on the received upper bridge duty cycle signals DutyU, DutyV, DutyW and bus voltage signal Vdc:

[0117] U a =DutyU×V dc -1 / 3(DutyU + DutyV + DutyW) ×V dc ;

[0118] U b =DutyV×V dc -1 / 3(DutyU + DutyV + DutyW) ×V dc ;

[0119] Uc =DutyW×V dc -1 / 3(DutyU + DutyV + DutyW) ×V dc ;

[0120] The redundant sampling channel design employed in this application not only improves the reliability of signal acquisition but also enables timely detection of sensor faults through a comparative verification mechanism. Filtering and bias correction of the raw signal effectively suppress measurement errors introduced by electromagnetic interference and zero-point drift, providing a clean data foundation for subsequent high-precision calculations.

[0121] In one embodiment, the calculation of the three-phase voltage signal based on the high-voltage bus voltage signal and the drive duty cycle signal includes the following calculation formula:

[0122] U a =DutyU×V dc -1 / 3(DutyU + DutyV + DutyW) ×V dc ;

[0123] U b =DutyV×V dc -1 / 3(DutyU + DutyV + DutyW) ×V dc ;

[0124] U c =DutyW×V dc -1 / 3(DutyU + DutyV + DutyW) ×V dc ;

[0125] Among them, U a U b U c These are the phase voltages of phases A, B, and C, respectively. DutyU, DutyV, and DutyW are the drive duty cycles of the three-phase upper bridge arms, respectively, and Vdc is the high-voltage bus voltage.

[0126] In the application, a voltage reconstruction model based on switching function theory is adopted to convert the complementary conduction states of the upper and lower bridge arms into phase voltage calculation coefficients. Specifically, the actual duty cycle signal of the three-phase upper bridge arm is monitored, and combined with the real-time value of the bus voltage, the three-phase voltage equations are solved using Cramer's rule. To suppress voltage distortion caused by dead time, a compensation term based on the switching frequency is introduced into the calculation formula.

[0127] In applications, the duty cycle signal can be obtained by measuring the time difference between the rising and falling edges of the pulse using a high-precision clock counter, while the bus voltage sampling uses a successive approximation analog-to-digital converter to ensure dynamic response speed.

[0128] The computational load of the linearized model in this application is significantly lower than that of traditional methods based on switching functions or coordinate transformations, making it highly suitable for embedded systems with extremely high real-time requirements. The common-mode component elimination mechanism implicit in the formula can effectively suppress common-mode noise caused by three-phase imbalance or neutral point drift, thereby improving the accuracy and anti-interference ability of phase voltage calculation. This calculation model ensures both accuracy and execution efficiency.

[0129] In one embodiment, determining the delay parameters required for synchronizing the three-phase current signals and three-phase voltage signals based on the motor speed and target torque, using a pre-calibrated delay time mapping table, includes the following steps S301 to S302:

[0130] Step S301: Determine the motor state based on the power value at the previous moment, wherein the motor state is either the driving state or the generating state.

[0131] Step S302: Select a pre-calibrated delay mapping table based on the motor state, and determine the delay parameters required for synchronizing the three-phase current signal and the three-phase voltage signal by looking up the table. The pre-calibrated delay mapping table is a delay mapping table corresponding to the driving condition or a pre-calibration and efficiency mapping table corresponding to the power generation condition.

[0132] The step of determining the corresponding motor efficiency value based on the motor speed and target torque, using a pre-calibrated efficiency mapping table, includes the following steps S401 to S402:

[0133] Step S401: Determine the motor state based on the power value at the previous moment, wherein the motor state is either the driving state or the generating state.

[0134] Step S401: Select a pre-calibrated efficiency mapping table based on the motor state, and determine the corresponding motor efficiency value by looking up the table. The pre-calibrated efficiency mapping table is either an efficiency mapping table corresponding to the driving condition or a pre-calibrated and efficiency mapping table corresponding to the power generation condition.

[0135] In applications, delay parameters include current delay parameters (such as...) Figure 4 (as shown) and voltage delay parameters (such as) Figure 5 As shown in the figure, the phase current and phase voltage after the delay are multiplied by each phase and then summed to obtain Pe.

[0136] In application, the direction of energy flow is determined by real-time monitoring of the power symbol. When a positive power value is detected, the system automatically switches to the drive condition delay mapping table, which stores the optimal lead compensation time between the voltage signal and the current signal under motoring conditions. When the power value is negative, the generator condition mapping table is activated, which contains the specific delay parameters required for the current signal under braking conditions. The switching logic of the efficiency mapping table is synchronized with this.

[0137] In application, an efficiency curve based on a copper loss and iron loss separation model can be used for the electric state, while a modified efficiency model that takes into account diode freewheeling losses is used for the power generation state. The operating condition can be determined by comparing the power values ​​of three consecutive sampling periods through symbol voting, and the addressing index of the mapping table uses a normalized combination key value of speed and torque.

[0138] The adaptive operating condition mechanism established in this application enables the system to intelligently identify and adapt to different energy conversion modes of the motor. By determining the power flow direction in real time and switching the corresponding mapping table, the modeling challenge caused by the significant differences in motor parameter characteristics between driving and generating states is solved. The dual-mode mapping table design allows the system to call the optimal compensation parameters under both electric acceleration and regenerative braking conditions, avoiding the problem of insufficient adaptability of a single model under complex operating conditions and significantly expanding the effective working range of the torque calculation method.

[0139] In one embodiment, the instantaneous electrical power of the motor is calculated based on the synchronized phase current signal and phase voltage signal using the following formula:

[0140] Pe=U a1 ×I a1 + U b1 ×I b1 + U c1 ×I c1 ;

[0141] Where Pe is the instantaneous electrical power of the motor, and U a1 U b1 U c1 These are the synchronized phase voltage signals, I a1 I b1 I c1 These are the phase current signals after synchronization.

[0142] In the application, the synchronized discrete sampled values ​​are multiplied and accumulated point by point. To eliminate harmonic errors caused by sampling non-idealities, the signal can be windowed using a Hanning window before the multiplication operation, and the calculation results are filtered using a moving average. The phase voltage signal U... a1 The phase current signal I can be obtained at a sampling rate of 20kHz using a 12-bit analog-to-digital converter. a1After being processed by a 50kHz bandwidth anti-aliasing filter, the sample is synchronously sampled. The multiplier is implemented using a 32-bit fixed-point digital signal processor hardware multiplication unit.

[0143] The instantaneous power calculation method defined in this application is based directly on the instantaneous values ​​of the synchronized phase voltage and phase current. This time-domain multiplication and accumulation calculation avoids the loss of phase information and calculation delay caused by frequency domain transformation, and can quickly respond to instantaneous changes in torque. The direct summation of three-phase power naturally eliminates the influence of zero-sequence components on the total power, making it particularly suitable for star-connected motor systems without a neutral wire. This method achieves a good balance between computational complexity and accuracy.

[0144] In one embodiment, calculating the motor output torque based on the instantaneous electrical power, the motor efficiency value, and the motor speed includes:

[0145] The mechanical power is calculated using the formula Pm=Pe×η, where Pm is the mechanical power, Pe is the instantaneous electrical power of the motor, and η is the motor efficiency value.

[0146] The output torque is calculated using the formula T=Pm / ω, where T is the output torque and ω is the angular velocity of the motor.

[0147] In applications, the efficiency coefficient η can be obtained in real time from the efficiency mapping table through a three-dimensional interpolation algorithm. The conversion between mechanical power Pm and output torque T needs to consider the consistency of the unit of angular velocity ω. When revolutions per minute is used as the unit of rotational speed, it needs to be multiplied by a conversion factor of 2π / 60. To reduce computational complexity, the efficiency mapping table can be pre-compiled into a lookup table based on piecewise linear approximation, where the angular velocity ω can be calculated from the pulse frequency output by the moiré fringe encoder.

[0148] The torque conversion process described in this application strictly adheres to the physical essence of electromechanical energy conversion. Converting electrical power to mechanical power through an efficiency mapping table essentially provides real-time compensation for internal iron losses, copper losses, and mechanical losses within the motor, making the calculation result closer to the actual shaft-end output torque. Using angular velocity as the basis for the final torque conversion conforms to the fundamental mechanical principles of rotary motion systems, ensuring the rigor of the conversion process from electrical signal to physical torque.

[0149] In one embodiment, the pre-calibrated delay mapping table is obtained through bench calibration, and the calibration process includes the following steps S401 to S404:

[0150] Step S401: Select a motor speed from the motor's operating speed range;

[0151] Step S402: At the motor speed, the motor output torque is adjusted in stages from the minimum value to the maximum value;

[0152] Step S403: For each torque step, adjust the delay parameter between the phase current signal and the phase voltage signal, monitor the calculated electric power value, and record the combination of delay parameters corresponding to the maximum electric power value.

[0153] Step S404: After completing the calibration of all torque steps at the current speed, change to another motor speed and return to the step of adjusting the motor output torque from the minimum to the maximum value at the motor speed until the entire operating speed range and torque range of the motor are covered to obtain the delay mapping table.

[0154] In the application, a reference torque value is obtained through a high-precision torque sensor during the calibration process. The binary search method is used to search for the combination of delay parameters that minimizes the deviation between the calculated power and the measured mechanical power at each operating point. To improve calibration efficiency, a multi-objective optimization technique based on a genetic algorithm can be used to adjust the three-phase delay parameters synchronously. The torque step adjustment adopts a closed-loop control strategy to ensure that the torque is stable within ±0.5% of the target value. The maximum power value is determined by collecting the power values ​​of 100 consecutive cycles, calculating their standard deviation, removing outliers, and then taking the average value for comparison.

[0155] In the application, the delay mapping table was calibrated for both the driving condition and the power generation condition. An example of the method is shown below:

[0156] a. Bench calibration preparation: The motor control software must be calibrated and the torque control accuracy must meet the requirements.

[0157] b. Drive condition calibration:

[0158] b1. The test bench rotates at 1000 rpm, and the control motor outputs 10 Nm. By adjusting the delay time of the phase current and phase voltage, the maximum power point is found, and the optimal delay data for this operating condition is determined. This process is repeated to determine 20 Nm, 30 Nm, and so on, until the motor reaches its maximum output torque.

[0159] b2. Increase the motor speed to 2000 rpm and repeat the previous step. Continue this process, increasing the motor speed to the maximum speed. Finally, determine the delay data map under the drive conditions.

[0160] c. Power generation operating condition calibration:

[0161] c1. With the test bench rotating at 1000 rpm and the control motor outputting -10 Nm, the maximum power point is found by adjusting the delay time of the phase current and phase voltage, thus determining the optimal delay data for this operating condition. This process is repeated to determine -20 Nm, -30 Nm, and so on, until the motor reaches its maximum output torque.

[0162] c2. Increase the motor speed to 2000 rpm and repeat the previous step. Continue this process, increasing the motor speed to the maximum speed. Finally, determine the delay data map under the generator operating condition.

[0163] Table 1 below shows an example of actual calibration data in the delay data map of an implementation case:

[0164] Table 1

[0165]

[0166] The delay mapping table calibration method described in this application employs a full-condition scanning strategy, which can systematically capture the optimal synchronization relationship between signals at different operating points. By finding the optimization target of the power maximum point at each torque step, it essentially transforms the time delay, which is difficult to measure directly, into an easily observable power index for indirect optimization. This bench-based calibration method can effectively extract the dynamic characteristics of the controlled object in actual operation, and the obtained delay parameters have high practicality and accuracy, providing offline data support for the accuracy of online calculations.

[0167] In one embodiment, the pre-calibrated efficiency mapping table is obtained through bench calibration, and the calibration process includes the following steps S501 to S504:

[0168] Step S501: Select a motor speed from the motor's operating speed range;

[0169] Step S502: At the motor speed, control the motor output torque to be adjusted in stages from the minimum value to the maximum value;

[0170] Step S503: For each torque step, calculate the mechanical power based on the actual output torque and speed measured on the test bench, calculate the motor efficiency value at that operating point based on the mechanical power and electrical power, and record it.

[0171] Step S504: After completing the calibration of all torque steps at the current speed, change to another motor speed and return to the step of controlling the motor output torque to be adjusted in stages from the minimum to the maximum value at the motor speed, until the entire operating speed and torque range of the motor are covered, so as to obtain the efficiency mapping table.

[0172] In the application, a calibration scheme combining direct measurement and indirect calculation methods is adopted. Each operating point can be continuously run for 30 seconds until thermal equilibrium is reached. The shaft torque, speed and system input electrical parameters output by the dynamometer are recorded simultaneously. The optimal efficiency value at that point is obtained by fitting the least squares method. To eliminate the influence of temperature, the calibration data needs to be compensated to the standard 25℃ reference condition. The mechanical power calculation needs to consider the inertia loss of the transmission system and adopts a dynamic torque compensation algorithm based on the differential of acceleration. The electrical power measurement uses a broadband power analyzer to obtain the true effective value.

[0173] In the application, the efficiency mapping table was calibrated for both the driving condition and the power generation condition. An example of the method is shown below:

[0174] a. Electric operating condition calibration:

[0175] a1. With the test bench rotating at 1000 rpm and the controlled motor output at 10 Nm, calculate the motor's mechanical power based on the motor output torque and speed indicated on the test bench. Then, based on the calculated electrical power, calculate the motor efficiency under the current operating condition using the formula η = Pm / Pe. Continue this process, calibrating to 20 Nm, 30 Nm, and so on, until the motor reaches its maximum output torque condition.

[0176] a2. Increase the motor speed to 2000 rpm and repeat the previous step. Continue this process, increasing the motor speed to the maximum speed. Finally, determine the motor efficiency map under the drive conditions.

[0177] b. Power generation operating condition calibration:

[0178] b1. The test bench rotates at 1000 rpm, and the control motor outputs -10 Nm. Based on the test bench's indication of the motor's output torque and speed, calculate the motor's mechanical power. Then, based on the calculated electrical power, calculate the motor efficiency under the current operating condition using the formula η=Pm / Pe. Continue this process, determining -20 Nm, -30 Nm, and so on, until the motor reaches its maximum output torque.

[0179] b2. Increase the motor speed to 2000 rpm and repeat the previous step. Continue this process, increasing the motor speed to the maximum speed. Finally, determine the motor efficiency map under generator operation.

[0180] Table 2 below shows an example of actual calibration data in the motor efficiency map of an implementation case:

[0181] Table 2

[0182]

[0183] This application's embodiments employ direct bench measurement of torque and speed to calculate mechanical power, avoiding errors caused by theoretical model simplification and ensuring the accuracy of efficiency values. The graded adjustment calibration strategy for torque and speed ensures that the mapping table covers the entire operating envelope of the motor, and the obtained efficiency data accurately reflects the motor's energy efficiency characteristics in actual operation, providing a reliable efficiency benchmark for online torque calculation.

[0184] like Figure 6 As shown, this method is used to collect real data in a vehicle environment.

[0185] In one embodiment, the calculation of the output torque is further verified, which includes the following steps:

[0186] a. Integrate calibration data and bench verify the calculated output torque.

[0187] b. Fix the motor output torque to 10 Nm, control the motor speed from 500 rpm to the maximum speed, and verify the consistency between the target torque and the calculated torque under the drive condition.

[0188] c. Fix the motor output torque to 20Nm, 30Nm, and so on up to the maximum torque, and verify the consistency between the target torque and the calculated torque.

[0189] d. Fix the motor output torque to -10Nm, control the motor speed from 500rpm to the maximum speed, and verify the consistency between the target torque and the calculated torque under power generation conditions.

[0190] e. Fix the motor output torque to -20Nm, -30Nm, and so on up to the maximum torque, and verify the consistency between the target torque and the calculated torque.

[0191] It should be understood that the sequence number of each step in the above embodiments does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application.

[0192] This application also provides a permanent magnet synchronous motor output torque calculation device for performing the steps in the above-described permanent magnet synchronous motor output torque calculation method embodiments. The permanent magnet synchronous motor output torque calculation device can be a virtual appliance within an electronic device, run by the electronic device's processor, or it can be the electronic device itself.

[0193] like Figure 6 As shown, the permanent magnet synchronous motor output torque calculation device 100 provided in this application embodiment includes:

[0194] The data acquisition module 101 is used to acquire the three-phase phase current signal, the high-voltage bus voltage signal, and the drive duty cycle signal of the three-phase bridge arm;

[0195] The three-phase voltage calculation module 102 is used to calculate the three-phase voltage signal based on the high-voltage bus voltage signal and the drive duty cycle signal.

[0196] The delay parameter determination module 103 is used to determine the delay parameters required for synchronizing the three-phase current signals and three-phase voltage signals based on the motor speed and target torque and a pre-calibrated delay time mapping table.

[0197] Delay processing module 104 is used to perform delay processing on the three-phase phase current signal and the three-phase phase voltage signal using the delay parameters to obtain synchronized phase current signal and phase voltage signal;

[0198] The electric power calculation module 105 is used to calculate the instantaneous electric power of the motor based on the synchronized phase current signal and phase voltage signal.

[0199] The motor efficiency value determination module 106 is used to determine the corresponding motor efficiency value based on the motor speed and target torque, and on a pre-calibrated efficiency mapping table.

[0200] The output torque calculation module 107 is used to calculate the output torque of the motor based on the instantaneous electric power, the motor efficiency value and the motor speed.

[0201] In applications, the modules in the permanent magnet synchronous motor output torque calculation device can be software program modules, or they can be implemented through different logic circuits integrated in the processor, or they can be implemented through multiple distributed processors.

[0202] like Figure 7 As shown, this application embodiment also provides an electronic device 200, including: at least one processor 201 ( Figure 7 The diagram shows only one processor, memory 202, and computer program 203 stored in memory 202 and executable on at least one processor 201. When processor 201 executes computer program 203, it implements the steps in the various method embodiments described above.

[0203] In applications, electronic devices may include, but are not limited to, processors and memory. Those skilled in the art will understand that... Figure 7 This is merely an example of an electronic device and does not constitute a limitation on the electronic device. It may include more or fewer components than shown, or a combination of certain components, or different components.

[0204] In applications, the processor can be a Central Processing Unit (CPU), but it can also be other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor can be a microprocessor or any conventional processor.

[0205] In applications, memory can be an internal storage unit of an electronic device in some embodiments, such as a hard drive or RAM. In other embodiments, memory can be an external storage device of the electronic device, such as a plug-in hard drive, Smart Media Card (SMC), Secure Digital (SD) card, or Flash Card. Furthermore, memory can include both internal and external storage units of the electronic device. Memory is used to store operating systems, applications, bootloaders, data, and other programs, such as program code for computer programs. Memory can also be used to temporarily store data that has been output or will be output.

[0206] It should be noted that the information interaction and execution process between the above-mentioned devices / units are based on the same concept as the method embodiments of this application. For details on their specific functions and technical effects, please refer to the method embodiments section, and they will not be repeated here.

[0207] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the above-described division of functional units and modules is merely an example. In practical applications, the above functions can be assigned to different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above. The functional units and modules in the embodiments can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit. Furthermore, the specific names of the functional units and modules are only for easy differentiation and are not intended to limit the scope of protection of this application. The specific working process of the units and modules in the above system can be referred to the corresponding process in the foregoing method embodiments, and will not be repeated here.

[0208] This application also provides a computer-readable storage medium storing a computer program, which, when executed by a processor, implements the steps described in the various method embodiments above.

[0209] This application provides a computer program product, including a computer program, which, when run on an electronic device, enables the electronic device to perform the steps described in the various method embodiments above.

[0210] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, all or part of the processes in the methods of the above embodiments of this application can be implemented by a computer program instructing related hardware. The computer program can be stored in a computer-readable storage medium, and when executed by a processor, it can implement the steps of the various method embodiments described above. The computer program includes computer program code, which can be in the form of source code, object code, executable files, or certain intermediate forms. A computer-readable medium can include at least: any entity or device capable of carrying computer program code to a device / electronic device, a recording medium, a computer memory, a read-only memory (ROM), a random access memory (RAM), an electrical carrier signal, a telecommunication signal, and a software distribution medium. Examples include USB flash drives, portable hard drives, magnetic disks, or optical disks. In some jurisdictions, according to legislation and patent practice, computer-readable media cannot be electrical carrier signals or telecommunication signals.

[0211] In the above embodiments, the descriptions of each embodiment have different focuses. For parts that are not described in detail or recorded in a certain embodiment, please refer to the relevant descriptions of other embodiments.

[0212] Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0213] In the embodiments provided in this application, it should be understood that the disclosed apparatus and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative. For instance, the division of modules or units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between apparatuses or units may be electrical, mechanical, or other forms.

[0214] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0215] The above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application, and should all be included within the protection scope of this application.

Claims

1. A method for calculating the output torque of a permanent magnet synchronous motor, characterized in that, include: Acquire the three-phase phase current signal, high-voltage bus voltage signal, and three-phase bridge arm drive duty cycle signal; Based on the high-voltage bus voltage signal and the drive duty cycle signal, the three-phase voltage signal is calculated. Based on the motor speed and target torque, and using a pre-calibrated delay time mapping table, the delay parameters required for synchronizing the three-phase current signals and three-phase voltage signals are determined. The three-phase current signal and the three-phase voltage signal are delayed using the delay parameter to obtain synchronized phase current signal and phase voltage signal; Based on the synchronized phase current signal and phase voltage signal, the instantaneous electric power of the motor is calculated; Based on the motor speed and target torque, and using a pre-calibrated efficiency mapping table, the corresponding motor efficiency value is determined. The output torque of the motor is calculated based on the instantaneous electric power, the motor efficiency value, and the motor speed. The step of determining the delay parameters required for synchronizing the three-phase current signals and three-phase voltage signals based on the motor speed and target torque, using a pre-calibrated delay time mapping table, includes: The motor state is determined based on the electrical power value at the previous moment, wherein the motor state is either the driving state or the generating state. Based on the motor state, a pre-calibrated delay mapping table is selected, and the delay parameters required for synchronizing the three-phase current signal and the three-phase voltage signal are determined by looking up the table. The pre-calibrated delay mapping table is either a delay mapping table corresponding to the driving condition or a pre-calibrated delay mapping table corresponding to the power generation condition. The step of determining the corresponding motor efficiency value based on the motor speed and target torque, using a pre-calibrated efficiency mapping table, includes: The motor state is determined based on the electrical power value at the previous moment, wherein the motor state is either the driving state or the generating state. Based on the motor state, a pre-calibrated efficiency mapping table is selected, and the corresponding motor efficiency value is determined by looking up the table. The pre-calibrated efficiency mapping table is either an efficiency mapping table corresponding to the driving condition or a pre-calibrated efficiency mapping table corresponding to the power generation condition. The pre-calibrated delay mapping table is obtained through bench calibration, and the calibration process includes: Select a motor speed from the motor's operating speed range; At the specified motor speed, the motor output torque is adjusted in stages from the minimum to the maximum value; For each torque step, adjust the delay parameter between the phase current signal and the phase voltage signal, monitor the calculated electric power value, and record the combination of delay parameters corresponding to the maximum electric power value. After completing the calibration of all torque steps at the current speed, the speed is changed to another motor speed, and the process returns to the step of adjusting the motor output torque from the minimum to the maximum value at the motor speed until the entire operating speed range and torque range of the motor are covered to obtain the delay mapping table.

2. The method for calculating the output torque of a permanent magnet synchronous motor as described in claim 1, characterized in that, The acquisition of the three-phase phase current signal, the high-voltage bus voltage signal, and the drive duty cycle signal of the three-phase bridge arm includes: The system collects the raw signals from the three-phase current sensor, the raw signals from the high-voltage bus voltage, and the raw duty cycle signals fed back by the six-phase upper and lower bridge arm drive chips. The raw signal from the three-phase current sensor is filtered and biased to convert it into a three-phase current signal with physical quantity values. The original signals of the high-voltage bus voltage and duty cycle are filtered and converted into physical quantity values.

3. The method for calculating the output torque of a permanent magnet synchronous motor as described in claim 1, characterized in that, The three-phase voltage signals are calculated based on the high-voltage bus voltage signal and the drive duty cycle signal, including the following formula: U a =DutyU×V dc -1 / 3(DutyU+DutyV+DutyW)×V dc ; U b =DutyV×V dc -1 / 3(DutyU+DutyV+DutyW)×V dc ; U c =DutyW×V dc -1 / 3(DutyU+DutyV+DutyW)×V dc ; Among them, U a U b U c These are the phase voltages of phases A, B, and C, respectively. DutyU, DutyV, and DutyW are the drive duty cycles of the three-phase upper bridge arms, respectively, and Vdc is the high-voltage bus voltage.

4. The method for calculating the output torque of a permanent magnet synchronous motor as described in claim 1, characterized in that, The instantaneous electrical power of the motor is calculated based on the synchronized phase current signal and phase voltage signal, using the following formula: Pe=U a1 ×I a1 +U b1 ×I b1 +U c1 ×I c1 ; Where Pe is the instantaneous electrical power of the motor, and U a1 U b1 U c1 These are the synchronized phase voltage signals, I and I. a1 I b1 I c1 These are the phase current signals after synchronization.

5. The method for calculating the output torque of a permanent magnet synchronous motor as described in claim 1, characterized in that, The calculation of the motor's output torque based on the instantaneous electrical power, the motor efficiency value, and the motor speed includes: The mechanical power is calculated using the formula Pm=Pe×η, where Pm is the mechanical power, Pe is the instantaneous electrical power of the motor, and η is the motor efficiency value. The output torque is calculated using the formula T=Pm / ω, where T is the output torque and ω is the angular velocity of the motor.

6. The method for calculating the output torque of a permanent magnet synchronous motor as described in claim 1, characterized in that, The pre-calibrated efficiency mapping table is obtained through bench calibration, and the calibration process includes: Select a motor speed from the motor's operating speed range; At the specified motor speed, the output torque of the motor is controlled to be adjusted in stages from the minimum to the maximum value; For each torque step, the mechanical power is calculated based on the actual output torque and speed measured on the test bench. The motor efficiency value at that operating point is calculated based on the mechanical power and electrical power, and then recorded. After completing the calibration of all torque steps at the current speed, the speed is changed to another motor speed, and the process returns to the step of controlling the motor output torque to be adjusted in stages from the minimum to the maximum value at the motor speed, until the entire operating speed and torque range of the motor is covered, in order to obtain the efficiency mapping table.

7. A device for calculating the output torque of a permanent magnet synchronous motor for implementing the method described in any one of claims 1 to 6, characterized in that, include: The data acquisition module is used to acquire three-phase phase current signals, high-voltage bus voltage signals, and three-phase bridge arm drive duty cycle signals; The three-phase voltage calculation module is used to calculate the three-phase voltage signal based on the high-voltage bus voltage signal and the drive duty cycle signal. The delay parameter determination module is used to determine the delay parameters required for synchronizing the three-phase current signals and three-phase voltage signals based on the motor speed and target torque and a pre-calibrated delay time mapping table. The delay processing module is used to perform delay processing on the three-phase current signal and the three-phase voltage signal using the delay parameters, so as to obtain synchronized phase current signal and phase voltage signal; The electric power calculation module is used to calculate the instantaneous electric power of the motor based on the synchronized phase current signal and phase voltage signal; The motor efficiency value determination module is used to determine the corresponding motor efficiency value based on the motor speed and target torque, and on a pre-calibrated efficiency mapping table. The output torque calculation module is used to calculate the output torque of the motor based on the instantaneous electric power, the motor efficiency value, and the motor speed.

8. A computer program product, characterized in that, Includes a computer program, which, when run, causes the method as described in any one of claims 1-6 to be performed.

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