A four-bridge-arm driving permanent magnet synchronous motor parameter identification method based on d-axis current injection

Abstract

The application discloses a four-bridge-arm driving permanent magnet synchronous motor parameter identification method based on d-axis current injection, which comprises the following steps: obtaining a q-axis current reference value according to a rotating speed ring; calculating a d-axis current reference value, an electric frequency of a base frequency required by a resonance controller and a phase compensation value, calculating a current d-axis and 0-axis control cycle resonance controller output, and injecting a d-axis current by setting the d-axis current reference value; calculating a reference voltage by FOC and performing inverter nonlinear compensation; calculating a reference value of three-phase voltage relative to a neutral point voltage, and further obtaining a driving signal; identifying resistance, inductance and a base wave flux linkage in real time based on an FFRLS algorithm; calculating a term containing third harmonic flux linkage information through a low-pass filter; and finally obtaining the third harmonic flux linkage through the FFRLS algorithm. The parameter identification method has the advantages of low cost, simplicity and the like.

Description

Technical Field

[0001] This invention belongs to the field of motor drive and control technology, and specifically relates to a parameter identification method for a four-bridge arm driven permanent magnet synchronous motor based on d-axis current injection. Background Technology

[0002] In the control process of a permanent magnet synchronous motor (PMSM) drive system, the accuracy of motor parameters directly determines the effectiveness of the control strategy and is the core foundation for achieving high-precision speed regulation, torque control, and efficient energy conversion. Core parameters of the PMSM, such as stator resistance, dq-axis inductance, and fundamental flux linkage of the permanent magnet, are not only crucial for constructing the motor's mathematical model but also important input conditions for current loop regulation, flux linkage observation, and torque calculation in mainstream control algorithms such as field vector control (FOC) and direct torque control (DTC). Furthermore, in terms of fault-tolerant control, systems with zero-sequence current will exhibit poor fault tolerance due to the third harmonic flux linkage introduced during motor design. However, during actual motor operation, the stator resistance will experience temperature drift due to winding heating, leading to an increase in stator resistance value. The dq-axis inductance will dynamically change due to magnetic circuit saturation. The fundamental and third harmonic flux linkages of the permanent magnet will also irreversibly decay with permanent magnet aging or temperature increases. These dynamic changes in parameters can significantly deviate from the controller's preset values, resulting in decreased control accuracy, increased torque ripple, and even drive system stability issues. Currently, the parameter identification methods for surface-mounted permanent magnet synchronous motors can be roughly divided into the following three categories:

[0003] (1) A method for parameter identification of permanent magnet synchronous motor based on model reference adaptation.

[0004] This type of method constructs an actual motor model containing real motor parameters and compares it with a reference model based on preset parameters. The error between the two outputs is used as the input to an adaptive law, and adaptive algorithms such as gradient descent are used to correct the identification parameters in real time until the output error between the actual model and the reference model converges to an acceptable range. Its advantages include no need for additional excitation signals, the ability to complete identification during normal motor operation, real-time performance, practicality, and strong adaptability to various motor operating conditions. However, the identification accuracy of this method is highly dependent on the structural design of the reference model. When the motor operates at low speed or light load, the system output error signal is weak and easily affected by measurement noise, leading to slower convergence speed and even parameter drift. Importantly, the parameter tuning process of the adaptive law is complex, requiring a trade-off between convergence speed and identification stability.

[0005] (2) Parameter identification method for permanent magnet synchronous motor based on signal injection.

[0006] Signal injection methods can be categorized into current signal injection and position signal injection. Since the q-axis current affects the electromagnetic torque of surface-mounted motors, most current injection methods employ d-axis current injection to achieve rank enhancement. Position signal injection involves adding a bias to the angle information sampled from the encoder and fed back to the controller, thus displacing the traditionally calculated dq-axis current from the synchronous rotating coordinate system. In a sense, this can be considered equivalent to current signal injection. Its advantage lies in the ability to eliminate the influence of inverter nonlinearity by subtracting data from different time periods. Its disadvantage is that it is generally only used for flux linkage identification and requires data accumulation, not real-time accurate identification.

[0007] (3) Parameter identification method for permanent magnet synchronous motor based on intelligent algorithm.

[0008] These methods leverage the nonlinear mapping capabilities and global optimization characteristics of intelligent algorithms such as neural networks, particle swarm optimization, genetic algorithms, and fuzzy logic to transform the motor parameter identification problem into a multivariate optimization problem. By constructing an optimization model with the mapping relationship between motor input / output data and parameters as the objective function, intelligent algorithms iteratively optimize the objective function to obtain the optimal motor parameter estimates. However, compared to other methods, the computational load is too high, making it difficult to perfectly implement its function within each control cycle of a real-time digital controller. Summary of the Invention

[0009] Purpose of the invention: The purpose of this invention is to propose a parameter identification method for a four-bridge driven permanent magnet synchronous motor based on d-axis current injection, which is used to identify the parameters of the permanent magnet synchronous motor, including stator resistance, inductance, fundamental flux linkage and third harmonic flux linkage values.

[0010] Technical solution: The present invention provides a parameter identification method for a four-bridge driven permanent magnet synchronous motor based on d-axis current injection, comprising the following steps:

[0011] The three-phase current and DC bus voltage of the permanent magnet synchronous motor are sampled in real time. The three-phase current of the permanent magnet synchronous motor is transformed into the dq axis by ABC coordinate transformation to obtain the dq axis current. The reference value of the q axis current is calculated based on the speed loop.

[0012] The shaft current reference value is calculated by setting the bias, amplitude, harmonics and rotor position of the d-axis current, as well as the electrical frequency and phase compensation value of the fundamental frequency required by the resonant controller. The output of the resonant controller for the current control cycle of the d-axis and 0-axis is further calculated, and the d-axis current is injected by setting the d-axis current reference value.

[0013] The reference voltage is calculated using FOC and inverter nonlinearity compensation is performed as follows: First, based on the DC bus voltage, dead time, sampling period, active switch threshold voltage, freewheeling diode threshold voltage, and A-phase, B-phase, and C-phase currents of the permanent magnet synchronous motor, the A-phase voltage reference compensation value, B-phase voltage reference compensation value, and C-phase voltage reference compensation value are calculated. Then, the d-axis voltage reference compensation value, q-axis voltage reference compensation value, and 0-axis voltage reference compensation value are calculated. Finally, the d-axis voltage reference value, q-axis voltage reference value, and 0-axis voltage reference value are calculated.

[0014] Based on the d-axis voltage reference value, q-axis voltage reference value, 0-axis voltage reference value, and rotor position θ, the reference values ​​of the three-phase voltages relative to the neutral point voltage are calculated, namely the A-phase voltage reference value, B-phase voltage reference value, and C-phase voltage reference value; and the drive signal is further obtained.

[0015] Based on the d-axis current, q-axis current, d-axis voltage reference value, q-axis voltage reference value, electric angular velocity, and control period, the input matrix and output matrix of the FFRLS algorithm are formed to identify the resistance, inductance, and fundamental flux linkage in real time. Based on the 0-axis voltage reference value and rotor position, the term containing the third harmonic flux linkage information is calculated through a low-pass filter, and finally the third harmonic flux linkage is obtained through the FFRLS algorithm.

[0016] Furthermore, the three-phase current of the permanent magnet synchronous motor is converted to dq-axis to obtain the dq-axis current, and the reference value of the d-axis current is calculated based on the speed loop, including the following steps:

[0017] (1) Measure the a-phase current of the motor using a current sensor. b-phase current and c-phase current Measure DC bus voltage using a voltage sensor ;

[0018] (2) Based on the phase a current of the permanent magnet synchronous motor b-phase current c-phase current Given the rotor position θ, the d-axis current is calculated. q-axis current and 0-axis current :

[0019] ;

[0020] (3) Based on the target rotational speed Actual speed Speed ​​regulator proportional coefficient and speed regulator integral coefficient The q-axis current reference value was calculated. :

[0021] .

[0022] Furthermore, the calculation of the d-axis current reference value, as well as the fundamental frequency and phase compensation value required by the resonant controller, includes the following steps:

[0023] (1) The bias of the d-axis current is set as needed. ,amplitude frequency multiples and rotor position Calculate the reference value of the d-axis current. :

[0024] ;

[0025] (2) Based on the rotor position transmitted back to the controller from the permanent magnet synchronous motor Calculate the motor speed after speed filtering. Combined with sampling period and the number of pole pairs of the motor Calculate the electrical frequency of the fundamental frequency required by the resonant controller in a PIR proportional-integral resonant controller. and phase compensation value :

[0026] ;

[0027] (3) The frequency doubling factor of the current to be tracked. Sampling period The fundamental frequency of the electrical frequency Phase compensation value and the set resonant frequency Calculate the intermediate parameters required for the resonant controller , , , , , and :

[0028] .

[0029] Furthermore, the output of the resonant controller during the current control cycle of the d-axis is calculated using the following formula:

[0030] ;

[0031] in, The output of the resonant controller is the current control cycle output for the d-axis. The resonant gain of the PIR controller. The resonant frequency, , , , , , , To calculate the frequency multiplication factor required for the PIR controller Equal to the frequency multiple of the d-axis current Parameters at time, The error between the reference value and the actual value of the d-axis current during the current control cycle. For the first The error between the reference value and the actual value of the d-axis current in each control cycle For the first The error between the reference value and the actual value of the d-axis current in each control cycle For the first The output of the resonant controller in one control cycle For the first The output of the resonant controller for each control cycle.

[0032] Furthermore, the output of the resonant controller during the current control cycle of axis 0 is calculated using the following formula:

[0033] ;

[0034] in, The output of the resonant controller is for the current control cycle of axis 0. The resonant gain of the PIR controller. The resonant frequency, , , , , , , To calculate the frequency multiplication factor required for the PIR controller The parameter equal to the 3rd harmonic of the 0-axis current. The error between the reference value and the actual value of the 0-axis current in the current control cycle. For the first The error between the reference value and the actual value of the 0-axis current in each control cycle For the first The error between the reference value and the actual value of the 0-axis current in each control cycle For the first The output of the resonant controller in one control cycle For the first The output of the resonant controller for each control cycle.

[0035] Furthermore, the reference voltage is calculated using FOC and inverter nonlinearity compensation is performed, including the following steps:

[0036] (1) Based on the DC bus voltage of the inverter circuit used in the permanent magnet synchronous motor Dead time Sampling period Active switching threshold voltage in inverter circuit Threshold voltage of the freewheeling diode in the inverter circuit The a-phase current of a permanent magnet synchronous motor b-phase current and c-phase current The voltage reference value of the d-axis in the calculation controller that needs to compensate for the nonlinear voltage of the inverter circuit is calculated. q-axis voltage reference value Voltage reference value of the 0 axis :

[0037] ;

[0038] in, For neutral current, This is the compensation value for the phase a voltage reference value. This is the compensation value for the b-phase voltage reference value. This is the compensation value for the c-phase voltage reference value. It is a symbolic function;

[0039] ;

[0040] (2) Based on the d-axis current q-axis current 0-axis current d-axis current reference value q-axis current reference value 0-axis current reference value dq axis current PI regulator proportional coefficient and the integral coefficient of the current PI regulator 0-axis current PI regulator proportional coefficient and the integral coefficient of the current PI regulator d-axis resonant controller output 0-axis resonant controller output d-axis voltage reference value for compensating inverter nonlinear voltage q-axis voltage reference value Voltage reference value of the 0 axis The d-axis voltage reference value was calculated. q-axis voltage reference value and 0-axis voltage reference value :

[0041] (10).

[0042] Furthermore, based on the d-axis voltage reference value, q-axis voltage reference value, 0-axis voltage reference value, and rotor position, the reference values ​​of the three-phase voltages relative to the neutral point voltage are calculated, namely, the a-phase voltage reference value, b-phase voltage reference value, and c-phase voltage reference value; and the drive signal is further obtained; including the following steps:

[0043] (1) Based on the d-axis voltage reference value q-axis voltage reference value 0-axis voltage reference value Given the rotor position θ, the reference values ​​of the three-phase voltage relative to the neutral point voltage are calculated, i.e., the reference value of phase a voltage. b-phase voltage reference value and c-phase voltage reference value :

[0044] ;

[0045] (2) Based on the reference value of phase a voltage b-phase voltage reference value and c-phase voltage reference value The drive signal is obtained by inputting the 3D-SVPWM algorithm and then driving the motor through the inverter circuit.

[0046] Furthermore, real-time identification of resistance, inductance, fundamental flux linkage, and third harmonic flux linkage information includes the following steps:

[0047] (1) The dq-axis voltage equation can be written in the following form:

[0048] ;

[0049] in, This represents the output matrix of FFRLS. express The transpose of the matrix, This represents the input matrix of FFRLS. Represents the real-time parameter estimation matrix;

[0050] ;

[0051] ;

[0052] Where k represents the k-th control cycle, i.e., the current control cycle, and k-1 represents the (k-1)-th control cycle. (k) represents the estimated stator resistance value for the current control cycle. (k) represents the estimated stator inductance value for the current control cycle. (k) represents the estimated fundamental flux linkage for the current control cycle. For the first d-axis current value per control cycle For the first d-axis current value per control cycle For the first d-axis current value per control cycle For the first Electrical angular velocity value per control cycle For the first Electrical angular velocity value per control cycle For the first q-axis current value per control cycle For the first q-axis current value per control cycle For the first d-axis voltage value per control cycle For the first d-axis voltage value per control cycle For the first q-axis voltage value per control cycle;

[0053] (2) Iteratively calculate the estimated values ​​of stator resistance, stator inductance and fundamental flux linkage in each control cycle, that is, complete the online identification of stator resistance, stator inductance and fundamental flux linkage;

[0054] ;

[0055] Among them, among them, Forgetting factor; This is the gain matrix; It is the covariance matrix; It is the identity matrix; For the first The parameter estimation matrix for each control cycle. For the first The parameter estimation matrix for each control cycle. For the first Gain matrix for each control cycle, For the first The output matrix of each control cycle For the first The input matrix for each control cycle, For the first Transpose of the input matrix for each control cycle For the first The covariance matrix of each control cycle For the first The covariance matrix of each control cycle;

[0056] (3) Based on the 0-axis voltage reference value and rotor position Considering the initial phase of the third harmonic back electromotive force, the information carrying the third harmonic flux is calculated, i.e., the 0-axis voltage equation becomes as follows:

[0057] ;

[0058] ;

[0059] in, The voltage is the zero axis voltage. It is a zero-sequence inductance. For third harmonic flux linkage, P3 represents the initial phase of the third harmonic back electromotive force, and P3 is a term related to the 0-axis current. Electric angular velocity;

[0060] (4) Based on the calculated and The simplified term containing third harmonic flux linkage information is obtained by passing a low-pass filter, and the square root of the sum of squares of each term after the low-pass filter is taken to obtain the final simplified term containing third harmonic flux linkage information.

[0061] ;

[0062] ;

[0063] ;

[0064] in, This is a low-pass filter function;

[0065] (5) Consider it as the output matrix y of the FFRLS algorithm, and Treat as input matrix The third harmonic flux It can be regarded as a parameter estimation matrix; according to the FFRLS algorithm calculation method, the estimated value of the third harmonic flux is iteratively calculated in each control cycle, so as to realize the online identification of the third harmonic flux.

[0066] The present invention discloses a parameter identification system for a four-arm driven permanent magnet synchronous motor based on d-axis current injection, comprising:

[0067] The first calculation unit is used to convert the three-phase current of the permanent magnet synchronous motor into dq-axis current, obtain the dq-axis current, and calculate the reference value of the q-axis current based on the speed loop.

[0068] The second calculation unit is used to calculate the d-axis current reference value, as well as the electrical frequency and phase compensation value of the fundamental frequency required by the resonant controller, and further calculate the resonant controller output of the current control cycle of the d-axis and 0-axis.

[0069] The third calculation unit is used to calculate the reference voltage and perform inverter nonlinearity compensation through FOC. It includes: firstly, calculating the a-phase voltage reference compensation value, b-phase voltage reference compensation value and c-phase voltage reference compensation value based on the DC bus voltage, dead time, sampling period, active switch threshold voltage in the inverter circuit, freewheeling diode threshold voltage in the inverter circuit, a-phase current, b-phase current and c-phase current of the permanent magnet synchronous motor; then calculating the d-axis voltage reference compensation value, q-axis voltage reference compensation value and 0-axis voltage reference compensation value; and finally calculating the d-axis voltage reference value, q-axis voltage reference value and 0-axis voltage reference value.

[0070] The fourth calculation unit is used to calculate the reference values ​​of the three-phase voltages relative to the neutral point voltage, namely the reference values ​​of phase a, phase b, and phase c voltages, based on the reference values ​​of the d-axis voltage, q-axis voltage, 0-axis voltage, and rotor position; and further obtain the drive signal.

[0071] Parameter identification unit, used to identify parameters based on d shaft current, q shaft current, d Shaft voltage reference value q The shaft voltage reference value, electrical angular velocity, and control cycle form the input and output matrices of the FFRLS algorithm, which identify the resistance, inductance, and fundamental flux linkage in real time. Based on the 0-axis voltage reference value and rotor position, a term containing the third harmonic flux linkage information is calculated through a low-pass filter, and finally the third harmonic flux linkage is obtained through the FFRLS algorithm.

[0072] An electronic device according to the present invention includes:

[0073] Memory containing executable program code;

[0074] A processor coupled to the memory;

[0075] The processor calls the executable program code stored in the memory to execute the steps of the method.

[0076] Beneficial Effects: Compared with the prior art, the significant technical effect of this invention is as follows: This parameter identification method for a four-arm driven permanent magnet synchronous motor based on d-axis current injection calculates the dq-axis reference voltage using a field-oriented control method, samples the motor current and electrical angle, and combines this with data from known device datasheets. Through the derived nonlinear voltage compensation of the four-arm topology inverter, it achieves parameter identification of resistance, inductance, fundamental flux linkage, and third harmonic flux linkage, while considering the initial phase problem of the third harmonic back electromotive force in the identification of the third harmonic flux linkage. Specifically, the technical solution of this invention has the following advantages:

[0077] (1) Compared with the existing permanent magnet synchronous motor parameter identification method based on signal injection, the method of the present invention takes into account the case of more complex topology, in which the distortion voltage compensation is re-derived and the third harmonic flux identification with the initial phase of the third harmonic back electromotive force is considered, which can make the system with zero sequence current have higher control accuracy in fault-tolerant control.

[0078] (2) Compared with the existing model reference adaptive permanent magnet synchronous motor parameter identification method, the method of the present invention does not require a complicated adaptive rate tuning process and has high stability;

[0079] (3) Compared with the existing methods for identifying parameters of permanent magnet synchronous motors based on intelligent algorithms, the method of the present invention does not require a large amount of computation and can complete the calculation within each control cycle in the digital controller, which is simple and easy to implement. Attached Figure Description

[0080] Figure 1 This is a schematic diagram of a three-phase four-bridge arm permanent magnet synchronous motor drive system.

[0081] Figure 2 This is a flowchart of the parameter identification method described in this invention;

[0082] Figure 3 This is a schematic diagram showing the estimated and actual resistance values.

[0083] Figure 4 This is a schematic diagram showing the estimated and actual values ​​of the inductance.

[0084] Figure 5 A schematic diagram showing the estimated and actual values ​​of the fundamental flux linkage;

[0085] Figure 6 This is a schematic diagram showing the estimated and actual values ​​of the third harmonic flux linkage. Detailed Implementation

[0086] The embodiments of the present invention will now be described with reference to the accompanying drawings.

[0087] Example 1:

[0088] like Figure 1 As shown, the drive system of an embodiment of the present invention includes: a DC voltage source, an inverter circuit, a permanent magnet synchronous motor, a controller, and a current sampling circuit. The DC voltage source provides the DC bus voltage to the inverter circuit. The current sampling circuit measures the three-phase current of the motor and returns the measured current signal to the controller. The controller outputs a voltage reference value based on the error between the required current reference value and the measured current signal, and further generates a drive signal through 3D-SVPWM to drive the inverter circuit to generate voltage to drive the permanent magnet synchronous motor.

[0089] The controller includes a first PI regulator, a second PI regulator, a first PIR controller, a second PIR controller, a coordinate transformation module, and a 3D-SVPWM module. The first PI regulator is located in the speed loop and is a speed loop PI regulator. The target speed of the permanent magnet synchronous motor is... and actual speed The q-axis current reference value is obtained after passing through the speed loop PI regulator. q-axis current reference value and q-axis current After passing through the second PI regulator, the uncompensated q-axis voltage reference value and d-axis current reference value are obtained. and d-axis current The uncompensated d-axis voltage reference value and 0-axis current reference value are obtained after passing through the first PIR controller. and 0-axis current The uncompensated 0-axis voltage reference value is obtained after passing through the second PIR controller. The d-axis compensated voltage is calculated using inverter nonlinearity voltage compensation of a three-phase four-bridge-arm topology voltage source inverter. q-axis compensation voltage and 0-axis compensation voltage Then, it is added to the uncompensated d-axis voltage reference value, the uncompensated q-axis voltage reference value, and the uncompensated 0-axis voltage reference value respectively to obtain the d-axis voltage reference value. d-axis voltage reference value and d-axis voltage reference value d-axis voltage reference value d-axis voltage reference value and d-axis voltage reference value The reference value of phase A voltage is obtained through the coordinate transformation module. B-phase voltage reference value and C-phase voltage reference value Phase A voltage reference value B-phase voltage reference value and C-phase voltage reference value Eight drive signals are obtained through the 3D-SVPWM algorithm, and the voltage signal for driving the motor is obtained through a four-bridge topology inverter.

[0090] In this embodiment, the permanent magnet synchronous motor is a surface-mounted permanent magnet synchronous motor, and its parameters are: rated phase voltage. =220V, number of pole pairs Stator phase resistance =1.15Ω, direct-axis inductance =3mH, quadrature axis inductance =3mH, permanent magnet flux =0.137Wb. The specific experimental conditions were: bus voltage 160V, switching frequency 10kHz, and load torque 1.5Nm.

[0091] like Figure 1 As shown, the motor drive system uses the relatively mature Field Oriented Control (FOC) algorithm, and further employs the recursive least squares method with forgetting factor (FFRLS algorithm) and nonlinear compensation based on the voltage source inverter driven by the four-bridge arm to complete the online parameter identification of four parameters (resistance, inductance, fundamental flux linkage and third harmonic flux linkage) of the permanent magnet synchronous motor driven by the four-bridge arm.

[0092] Example 2:

[0093] A parameter identification method for a four-arm driven permanent magnet synchronous motor based on d-axis current injection is proposed. This method ensures the d-axis reference current is sinusoidal through d-axis current injection; calculates the dq0-axis reference voltage using a field-oriented control method; and obtains the required voltage reference value for dq0-axis compensation using a nonlinear voltage compensation strategy of a four-arm voltage source inverter. By applying current, voltage, electrical angular velocity, and electrical angle information through a recursive least squares method with a forgetting factor, the method identifies resistance, inductance, fundamental flux linkage, and third harmonic flux linkage information in real time. This method is applicable to surface-mounted permanent magnet synchronous motors, is simple and easy to implement, has low hardware requirements, and can identify parameters of resistance, inductance, fundamental flux linkage, and third harmonic flux linkage. Furthermore, it addresses the often-neglected third harmonic flux linkage information and initial phase issues in the third harmonic back electromotive force. Figure 2 As shown, the specific steps include:

[0094] S1. Real-time sampling of the three-phase current and DC bus voltage of the permanent magnet synchronous motor; performing coordinate transformation from ABC to dq axis to obtain the dq axis current; and calculating the reference value of the q axis current based on the speed loop; specifically including:

[0095] (1) Measure the phase a current of the permanent magnet synchronous motor using a current sensor. b-phase current and c-phase current Measure DC bus voltage using a voltage sensor ;

[0096] (2) Based on the phase a current of the permanent magnet synchronous motor b-phase current c-phase current and rotor position The d-axis current is calculated using equation (1). q-axis current and 0-axis current :

[0097] (1)

[0098] (3) Based on the target rotational speed Actual speed Speed ​​ring PI regulator (i.e. Figure 1 The first PI) proportional coefficient and the integral coefficient of the speed PI regulator The reference value of the q-axis current is obtained by calculating using equation (2). :

[0099] (2)

[0100] S2. Calculate the d-axis current reference value using the set d-axis current bias D, amplitude A, harmonic number W, and rotor position θ, as well as the fundamental frequency and phase compensation value required by the resonant controller. Further calculate the resonant controller output for the current d-axis and 0-axis control cycle, and inject the d-axis current by setting the d-axis current reference value. This step injects the d-axis current through the resonant controller, allowing the actual current to track the d-axis current reference value. Specifically, this includes:

[0101] (1) Based on the required bias D, amplitude A, frequency multiple W and rotor position θ of the d-axis current, calculate the reference value of the d-axis current using equation (3). :

[0102] (3)

[0103] (2) Calculate the motor speed after speed filtering based on the rotor position θ transmitted back to the controller from the permanent magnet synchronous motor. Combined with sampling period The number of pole pairs p of the motor is calculated according to equation (4). Figure 1 The fundamental electrical frequency required by the resonant (R) controller in the two proportional-integral-resonant (PIR) controllers. and phase compensation value :

[0104] (4)

[0105] (3) The frequency multiplication factor F and sampling period of the current to be tracked. The fundamental frequency of the electrical frequency Phase compensation value and the set resonant frequency The intermediate parameters required for the resonant controller are calculated using equation (5). , , , , , and :

[0106] (5)

[0107] (4) Based on the resonant gain of the set PIR controller Resonant frequency Calculate the parameters required for the PIR controller when the frequency multiplication factor F is equal to the frequency multiplication factor W of the d-axis current. , , , , , , Current control cycle (i.e., the current control cycle) Error between d-axis current reference value and actual value (per control cycle) , No. Error between reference and actual d-axis current values ​​for each control cycle , No. Error between reference and actual d-axis current values ​​for each control cycle , No. The resonant controller outputs a control cycle. and the The resonant controller outputs a control cycle. Calculated using equation (6) Figure 1 The current control cycle of the first PIR controller, the output of the d-axis resonant controller. :

[0108] (6)

[0109] (5) Based on the set resonant gain Resonant frequency The required frequency multiplication factor F for the PIR controller is equal to the parameter when the frequency multiplication factor of the 0-axis current is 3. , , , , , , Current control cycle (i.e., the current control cycle) Error between reference and actual values ​​of 0-axis current (each control cycle) , No. Error between reference and actual values ​​of 0-axis current per control cycle , No. Error between reference and actual values ​​of 0-axis current per control cycle , No. The resonant controller outputs a control cycle. and the The resonant controller outputs a control cycle. The output of the 0-axis resonant controller in the current control cycle is calculated using equation (7). :

[0110] (7)

[0111] S3. Calculate the reference voltage using FOC and perform inverter nonlinearity compensation: First, based on the DC bus voltage of the inverter circuit... Dead time Sampling period Active switching threshold voltage in inverter circuit Threshold voltage of the freewheeling diode in the inverter circuit Phase A current of permanent magnet synchronous motor Phase B current and C-phase current Calculate the compensation values ​​for the A-phase voltage reference value, B-phase voltage reference value, and C-phase voltage reference value, and then calculate the compensation value for the d-axis voltage reference value. q-axis voltage reference value compensation value Compensation value for voltage reference value on the 0 axis Finally, calculate the d-axis voltage reference value. q-axis voltage reference value and 0-axis voltage reference value This step performs nonlinear compensation for the four-arm driven voltage source inverter, compensating for discrepancies between the actual voltage and the voltage command value caused by dead-time effects and other factors; specifically including:

[0112] (1) Based on the DC bus voltage of the inverter circuit used in the permanent magnet synchronous motor Dead time Sampling period Active switching threshold voltage in inverter circuit Threshold voltage of the freewheeling diode in the inverter circuit Phase A current of permanent magnet synchronous motor Phase B current and C-phase current The reference voltage value of the d-axis in the controller that needs to compensate for the nonlinear voltage of the inverter circuit is calculated using equations (8) and (9). q-axis voltage reference value Voltage reference value of the 0 axis :

[0113] (8)

[0114] in, For neutral current, This is the compensation value for the A-phase voltage reference value. This is the compensation value for the B-phase voltage reference value. This is the compensation value for the C-phase voltage reference value. It is a symbolic function.

[0115] (9)

[0116] (2) Based on the d-axis current q-axis current 0-axis current d-axis current reference value q-axis current reference value 0-axis current reference value dq axis current PI regulator proportional coefficient and the integral coefficient of the current PI regulator 0-axis current PI regulator proportional coefficient and the integral coefficient of the current PI regulator d-axis resonant controller output 0-axis resonant controller output d-axis voltage reference value for compensating inverter nonlinear voltage q-axis voltage reference value Voltage reference value of the 0 axis The reference value of the d-axis voltage is obtained by formula (10). q-axis voltage reference value and 0-axis voltage reference value :

[0117] (10)

[0118] S4. Based on the d-axis voltage reference value q-axis voltage reference value 0-axis voltage reference value Based on the rotor position θ, the reference values ​​of the three-phase voltage relative to the neutral point voltage are calculated, i.e., the reference value of phase A voltage. B-phase voltage reference value and C-phase voltage reference value And further obtain the driving signal;

[0119] (1) Based on the d-axis voltage reference value q-axis voltage reference value 0-axis voltage reference value Given the rotor position θ, the reference values ​​of the three-phase voltage relative to the neutral point voltage are calculated using equation (11), i.e., the reference value of phase A voltage. B-phase voltage reference value and C-phase voltage reference value :

[0120] (11)

[0121] (2) Based on the reference value of phase A voltage B-phase voltage reference value and C-phase voltage reference value The drive signal is obtained by inputting the 3D-SVPWM algorithm and then driving the motor through the inverter circuit.

[0122] S5, based on d-axis current q-axis current d-axis voltage reference value q-axis voltage reference value Electric angular velocity and control cycle This forms the input and output matrices in the FFRLS algorithm, enabling real-time resistor identification. ,inductance and fundamental magnetic flux Based on the 0-axis voltage reference value and rotor position The term containing third harmonic flux linkage information is calculated using a low-pass filter, and the third harmonic flux linkage is finally obtained using the FFRLS algorithm. This step involves parameter identification of the four-arm driven permanent magnet synchronous motor through time delay, extraction of third harmonic flux linkage information, low-pass filtering, and the FFRLS algorithm. Specifically, it includes:

[0123] (1) The dq-axis voltage equation is written in the form of equation (12), as shown in equations (13) and (14). Based on equation (13), the fundamental flux linkage is further identified through the resistance and inductance identification values ​​to obtain equation (14). This facilitates the nesting of recursive least squares (FFRLS) with forgetting factor, where This represents the output matrix of FFRLS. This represents the input matrix of FFRLS. express The transpose of the matrix, Let represent the real-time parameter estimation matrix, k represent the k-th control cycle (i.e., the current control cycle), and k-1 represent the (k-1)-th control cycle. This is the estimated value of the stator resistance for the current control cycle. This is the estimated value of the stator inductance for the current control cycle. This is the estimated value of the fundamental flux linkage for the current control cycle.

[0124] (12)

[0125] (13)

[0126] (14)

[0127] in, For the first d-axis current value per control cycle For the first d-axis current value per control cycle For the first d-axis current value per control cycle For the first Electrical angular velocity value per control cycle For the first Electrical angular velocity value per control cycle For the first q-axis current value per control cycle For the first q-axis current value per control cycle For the first d-axis voltage value per control cycle For the first d-axis voltage value per control cycle For the first q-axis voltage value per control cycle.

[0128] (2) Based on the FFRLS algorithm calculation method of equation (15), the estimated values ​​of stator resistance, stator inductance, and fundamental flux linkage are iteratively calculated in each control cycle, thereby completing the online identification of stator resistance, stator inductance, and fundamental flux linkage. Wherein, The forgetting factor is typically selected between 0.98 and 1. This is the gain matrix; It is the covariance matrix; It is the identity matrix; For real-time parameter estimation matrix; Indicates the first One control cycle; Indicates the first One control cycle:

[0129] (15)

[0130] in, For the first The parameter estimation matrix for each control cycle. For the first The parameter estimation matrix for each control cycle. For the first Gain matrix for each control cycle, For the first The output matrix of each control cycle For the first The input matrix for each control cycle, For the first Transpose of the input matrix for each control cycle For the first The covariance matrix of each control cycle For the first The covariance matrix of each control cycle.

[0131] (3) Based on the 0-axis voltage reference value and rotor position Considering the initial phase of the third harmonic back electromotive force, the information carrying the third harmonic flux can be calculated using equations (16) and (17), i.e., the zero-axis voltage equation can be transformed into the form of equations (16) and (17):

[0132] (16)

[0133] (17)

[0134] in, The voltage is the zero axis voltage. It is a zero-sequence inductance. For third harmonic flux linkage, P3 represents the initial phase of the third harmonic back electromotive force, and P3 is a term related to the 0-axis current. It represents the electric angular velocity.

[0135] (4) In Figure 1 The low-pass filter and parameter identification algorithm are uniformly represented in the recursive least squares method with a forgetting factor. The values ​​calculated according to equations (16) and (17) are... and The simplified terms containing third harmonic flux linkage information are obtained by passing a low-pass filter, as shown in equations (18) and (19). The square root of the sum of squares of the terms after each low-pass filter is then taken to obtain the final simplified terms containing third harmonic flux linkage information, as shown in equation (20).

[0136] (18)

[0137] (19)

[0138] (20)

[0139] in, This is a low-pass filter function.

[0140] (5) Compare equation (20) with equation (12), and consider the terms on the left as the output matrix y of the FFRLS algorithm. Treat as input matrix The third harmonic flux It is regarded as a parameter estimation matrix. According to the FFRLS algorithm calculation method of Equation (15), the estimated value of the third harmonic flux is calculated iteratively in each control cycle, so as to realize the online identification of the third harmonic flux.

[0141] This invention injects d-axis current into... Figure 1 The parameter identification performed in the three-phase four-bridge arm motor drive system controlled by the FOC algorithm, as shown, can improve the control accuracy of control strategies requiring precise parameters. In this embodiment, the bus voltage is 160V, the reference speed is set to 1200 r / min, the identification start time is 0.1s, the injected d-axis current amplitude is 2A, the bias is -2.1A, and the frequency multiplication factor is 6. The results are as follows: Figure 3 , Figure 4 , Figure 5 and Figure 6 As shown, the results include the estimated and actual values ​​of resistance, inductance, fundamental flux linkage, and third harmonic flux linkage. The identification effect is good, and the parameter identification of a four-bridge-arm driven permanent magnet synchronous motor based on d-axis current injection is realized.

[0142] Example 3:

[0143] A parameter identification system for a four-bridge driven permanent magnet synchronous motor based on d-axis current injection includes:

[0144] The first calculation unit is used to convert the three-phase current of the permanent magnet synchronous motor into dq-axis current, obtain the dq-axis current, and calculate the reference value of the q-axis current based on the speed loop.

[0145] The second calculation unit is used to calculate the d-axis current reference value, as well as the electrical frequency and phase compensation value of the fundamental frequency required by the resonant controller, and further calculate the resonant controller output of the current control cycle of the d-axis and 0-axis.

[0146] The third calculation unit is used to calculate the reference voltage and perform inverter nonlinearity compensation through FOC. It includes: firstly, calculating the a-phase voltage reference compensation value, b-phase voltage reference compensation value and c-phase voltage reference compensation value based on the DC bus voltage, dead time, sampling period, active switch threshold voltage in the inverter circuit, freewheeling diode threshold voltage in the inverter circuit, a-phase current, b-phase current and c-phase current of the permanent magnet synchronous motor; then calculating the d-axis voltage reference compensation value, q-axis voltage reference compensation value and 0-axis voltage reference compensation value; and finally calculating the d-axis voltage reference value, q-axis voltage reference value and 0-axis voltage reference value.

[0147] The fourth calculation unit is used to calculate the reference values ​​of the three-phase voltages relative to the neutral point voltage, namely the reference values ​​of phase a, phase b, and phase c voltages, based on the reference values ​​of the d-axis voltage, q-axis voltage, 0-axis voltage, and rotor position; and further obtain the drive signal.

[0148] Parameter identification unit, used to identify parameters based on d shaft current, q shaft current, d Shaft voltage reference value q The shaft voltage reference value, electrical angular velocity, and control cycle form the input and output matrices of the FFRLS algorithm, which identify the resistance, inductance, and fundamental flux linkage in real time. Based on the 0-axis voltage reference value and rotor position, a term containing the third harmonic flux linkage information is calculated through a low-pass filter, and finally the third harmonic flux linkage is obtained through the FFRLS algorithm.

[0149] Example 4:

[0150] An electronic device, characterized in that the device comprises:

[0151] Memory containing executable program code;

[0152] A processor coupled to the memory;

[0153] The processor calls the executable program code stored in the memory to execute the steps of the method.

[0154] In summary, the technical solution of this invention first calculates the dq0-axis reference voltage using a field-oriented control method, samples the motor current and electrical angle, and combines this with data from known device datasheets. Through derivation of a four-arm topology inverter nonlinear voltage compensation, the actual dq0-axis voltage is obtained. By injecting sinusoidal current along the d-axis and using a PIR controller, the actual current can follow the given d-axis current. Voltage and current information are sampled, and the processed information, including the third harmonic flux linkage, is passed through a low-pass filter. The stator resistance, inductance, fundamental flux linkage, and third harmonic flux linkage identification values ​​are calculated using recursive least squares (FFRLS) with a forgetting factor. This achieves parameter identification of resistance, inductance, fundamental flux linkage, and third harmonic flux linkage, while considering the initial phase of the third harmonic back electromotive force in the third harmonic flux linkage identification. The parameter identification method of this invention has the advantages of low cost and ease of implementation.

[0155] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the specific embodiments described above. The specific embodiments and descriptions in the specification are merely for further illustrating the principles of the invention. Various changes and modifications can be made to the present invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of the present invention is defined by the claims and their equivalents.

Claims

1. A method for parameter identification of a four-bridge-arm driven permanent magnet synchronous motor based on d-axis current injection, characterized in that: Includes the following steps: The three-phase current and DC bus voltage of the permanent magnet synchronous motor are sampled in real time. The three-phase current of the permanent magnet synchronous motor is transformed into the dq axis by ABC coordinate transformation to obtain the dq axis current. The reference value of the q axis current is calculated based on the speed loop. The reference value of the d-axis current is calculated by setting the bias, amplitude, harmonics and rotor position of the d-axis current, as well as the electrical frequency and phase compensation value of the fundamental frequency required by the resonant controller. The output of the resonant controller for the current d-axis and 0-axis control cycle is further calculated, and the d-axis current is injected by setting the reference value of the d-axis current. The reference voltage is calculated using FOC and inverter nonlinearity compensation is performed as follows: First, based on the DC bus voltage, dead time, sampling period, active switch threshold voltage, freewheeling diode threshold voltage, and A-phase, B-phase, and C-phase currents of the permanent magnet synchronous motor, the A-phase voltage reference compensation value, B-phase voltage reference compensation value, and C-phase voltage reference compensation value are calculated. Then, the d-axis voltage reference compensation value, q-axis voltage reference compensation value, and 0-axis voltage reference compensation value are calculated. Finally, the d-axis voltage reference value, q-axis voltage reference value, and 0-axis voltage reference value are calculated. Based on the d-axis voltage reference value, q-axis voltage reference value, 0-axis voltage reference value, and rotor position θ, the reference values ​​of the three-phase voltages relative to the neutral point voltage are calculated, namely the A-phase voltage reference value, B-phase voltage reference value, and C-phase voltage reference value; and the drive signal is further obtained. Based on the d-axis current, q-axis current, d-axis voltage reference value, q-axis voltage reference value, electric angular velocity, and control period, the input matrix and output matrix of the FFRLS algorithm are formed to identify the resistance, inductance, and fundamental flux linkage in real time. Based on the 0-axis voltage reference value and rotor position, the term containing the third harmonic flux linkage information is calculated through a low-pass filter, and finally the third harmonic flux linkage is obtained through the FFRLS algorithm.

2. The parameter identification method for a four-bridge-arm driven permanent magnet synchronous motor based on d-axis current injection according to claim 1, characterized in that, The three-phase current of the permanent magnet synchronous motor is converted to dq-axis to obtain the dq-axis current, and the reference value of the d-axis current is calculated based on the speed loop. The process includes the following steps: (1) Measure the a-phase current of the motor using a current sensor. b-phase current and c-phase current Measure DC bus voltage using a voltage sensor ; (2) Based on the phase a current of the permanent magnet synchronous motor b-phase current c-phase current Given the rotor position θ, the d-axis current is calculated. q-axis current and 0-axis current : ； (3) Based on the target rotational speed Actual speed Speed ​​regulator proportional coefficient and speed regulator integral coefficient The q-axis current reference value was calculated. : 。 3. The parameter identification method for a four-bridge-arm driven permanent magnet synchronous motor based on d-axis current injection according to claim 1, characterized in that, Calculate the d-axis current reference value, as well as the fundamental frequency and phase compensation value required by the resonant controller, including the following steps: (1) The bias of the d-axis current is set as needed. ,amplitude frequency multiples and rotor position Calculate the reference value of the d-axis current. : ； (2) Based on the rotor position transmitted back to the controller from the permanent magnet synchronous motor Calculate the motor speed after speed filtering. Combined with sampling period and the number of pole pairs of the motor Calculate the electrical frequency of the fundamental frequency required by the resonant controller in a PIR proportional-integral resonant controller. and phase compensation value : ； (3) The frequency doubling factor of the current to be tracked. Sampling period The fundamental frequency of the electrical frequency Phase compensation value and the set resonant frequency Calculate the intermediate parameters required for the resonant controller , , , , , and : 。 4. The parameter identification method for a four-bridge driven permanent magnet synchronous motor based on d-axis current injection according to claim 3, characterized in that, The output of the resonant controller during the current control cycle of the d-axis is calculated using the following formula: ； in, The output of the resonant controller is the current control cycle of the d-axis. The resonant gain of the PIR controller. The resonant frequency, , , , , , , To calculate the frequency multiplication factor required for the PIR controller Equal to the frequency multiple of the d-axis current Parameters at time, The error between the reference value and the actual value of the d-axis current in the current control cycle. For the first The error between the reference value and the actual value of the d-axis current in each control cycle For the first The error between the reference value and the actual value of the d-axis current in each control cycle For the first The output of the resonant controller in one control cycle For the first The output of the resonant controller for each control cycle.

5. The parameter identification method for a four-bridge-arm driven permanent magnet synchronous motor based on d-axis current injection according to claim 3, characterized in that, The output of the resonant controller during the current control cycle of axis 0 is calculated using the following formula: ； in, The output of the resonant controller is for the current control cycle of axis 0. The resonant gain of the PIR controller. The resonant frequency, , , , , , , To calculate the frequency multiplication factor required for the PIR controller The parameter equal to the 3rd harmonic of the 0-axis current. The error between the reference value and the actual value of the 0-axis current in the current control cycle. For the first The error between the reference value and the actual value of the 0-axis current in each control cycle For the first The error between the reference value and the actual value of the 0-axis current in each control cycle For the first The output of the resonant controller in one control cycle For the first The output of the resonant controller for each control cycle.

6. The method for parameter identification of a four-bridge-arm driven permanent magnet synchronous motor based on d-axis current injection according to claim 1, characterized in that, The steps involved in calculating the reference voltage using FOC and performing inverter nonlinearity compensation are as follows: (1) Based on the DC bus voltage of the inverter circuit used in the permanent magnet synchronous motor Dead time Sampling period Active switching threshold voltage in inverter circuit Threshold voltage of the freewheeling diode in the inverter circuit The a-phase current of a permanent magnet synchronous motor b-phase current and c-phase current The voltage reference value of the d-axis in the calculation controller that needs to compensate for the nonlinear voltage of the inverter circuit is calculated. q-axis voltage reference value Voltage reference value of 0 axis : ； in, For neutral current, This is the compensation value for the phase a voltage reference value. This is the compensation value for the b-phase voltage reference value. This is the compensation value for the c-phase voltage reference value. It is a symbolic function; ； (2) Based on the d-axis current q-axis current 0-axis current d-axis current reference value q-axis current reference value 0-axis current reference value dq axis current PI regulator proportional coefficient and the integral coefficient of the current PI regulator 0-axis current PI regulator proportional coefficient and the integral coefficient of the current PI regulator d-axis resonant controller output 0-axis resonant controller output d-axis voltage reference value for compensating inverter nonlinear voltage q-axis voltage reference value Voltage reference value of 0 axis The d-axis voltage reference value was calculated. q-axis voltage reference value and 0-axis voltage reference value : （10）。 7. The parameter identification method for a four-bridge driven permanent magnet synchronous motor based on d-axis current injection according to claim 1, characterized in that, Based on the d-axis voltage reference value, q-axis voltage reference value, 0-axis voltage reference value and rotor position, the reference values ​​of the three-phase voltage relative to the neutral point voltage are calculated, namely the a-phase voltage reference value, b-phase voltage reference value and c-phase voltage reference value; And further obtain the driving signal; including the following steps: (1) Based on the d-axis voltage reference value q-axis voltage reference value 0-axis voltage reference value Given the rotor position θ, the reference values ​​of the three-phase voltages relative to the neutral point voltage are calculated, i.e., the reference value of phase a voltage. b-phase voltage reference value and c-phase voltage reference value : ； (2) Based on the reference value of phase a voltage b-phase voltage reference value and c-phase voltage reference value The drive signal is obtained by inputting the 3D-SVPWM algorithm and then driving the motor through the inverter circuit.

8. The parameter identification method for a four-bridge driven permanent magnet synchronous motor based on d-axis current injection according to claim 1, characterized in that, Real-time identification of resistance, inductance, fundamental flux linkage, and third harmonic flux linkage information; including the following steps: (1) The dq-axis voltage equation can be written in the following form: ； in, This represents the output matrix of FFRLS. express The transpose of the matrix, This represents the input matrix of FFRLS. Represents the real-time parameter estimation matrix; ； ； Where k represents the k-th control cycle, i.e., the current control cycle, and k-1 represents the (k-1)-th control cycle. (k) represents the estimated stator resistance value for the current control cycle. (k) represents the estimated stator inductance value for the current control cycle. (k) represents the estimated fundamental flux linkage for the current control cycle. For the first d-axis current value per control cycle For the first d-axis current value per control cycle For the first d-axis current value per control cycle For the first Electrical angular velocity value per control cycle For the first Electrical angular velocity value per control cycle For the first q-axis current value per control cycle For the first q-axis current value per control cycle For the first d-axis voltage value per control cycle For the first d-axis voltage value per control cycle For the first q-axis voltage value per control cycle; (2) Iteratively calculate the estimated values ​​of stator resistance, stator inductance and fundamental flux linkage in each control cycle, that is, complete the online identification of stator resistance, stator inductance and fundamental flux linkage; ； Among them, among them, Forgetting factor; This is the gain matrix; It is the covariance matrix; It is the identity matrix; For the first The parameter estimation matrix for each control cycle. For the first The parameter estimation matrix for each control cycle. For the first Gain matrix for each control cycle, For the first The output matrix of each control cycle For the first The input matrix for each control cycle, For the first Transpose of the input matrix for each control cycle For the first The covariance matrix of each control cycle For the first The covariance matrix of each control cycle; (3) Based on the 0-axis voltage reference value and rotor position Considering the initial phase of the third harmonic back electromotive force, the information carrying the third harmonic flux is calculated, i.e., the 0-axis voltage equation becomes as follows: ； ； in, The voltage is the zero axis voltage. It is a zero-sequence inductance. For third harmonic flux linkage, P3 represents the initial phase of the third harmonic back electromotive force, and P3 is a term related to the 0-axis current. Electric angular velocity; (4) Based on the calculated and The simplified term containing third harmonic flux linkage information is obtained by passing a low-pass filter, and the square root of the sum of squares of each term after the low-pass filter is taken to obtain the final simplified term containing third harmonic flux linkage information. ； ； ； in, This is a low-pass filter function; (5) Consider it as the output matrix y of the FFRLS algorithm, and Treat as input matrix The third harmonic flux It can be regarded as a parameter estimation matrix; according to the FFRLS algorithm calculation method, the estimated value of the third harmonic flux is iteratively calculated in each control cycle, so as to realize the online identification of the third harmonic flux.

9. A parameter identification system for a four-bridge-arm driven permanent magnet synchronous motor based on d-axis current injection, characterized in that, include: The first calculation unit is used to convert the three-phase current of the permanent magnet synchronous motor into dq-axis current, obtain the dq-axis current, and calculate the reference value of the q-axis current based on the speed loop. The second calculation unit is used to calculate the d-axis current reference value, as well as the electrical frequency and phase compensation value of the fundamental frequency required by the resonant controller, and further calculate the resonant controller output of the current control cycle of the d-axis and 0-axis. The third calculation unit is used to calculate the reference voltage and perform inverter nonlinearity compensation through FOC. It includes: firstly, calculating the a-phase voltage reference compensation value, b-phase voltage reference compensation value and c-phase voltage reference compensation value based on the DC bus voltage, dead time, sampling period, active switch threshold voltage in the inverter circuit, freewheeling diode threshold voltage in the inverter circuit, a-phase current, b-phase current and c-phase current of the permanent magnet synchronous motor; then calculating the d-axis voltage reference compensation value, q-axis voltage reference compensation value and 0-axis voltage reference compensation value; and finally calculating the d-axis voltage reference value, q-axis voltage reference value and 0-axis voltage reference value. The fourth calculation unit is used to calculate the reference values ​​of the three-phase voltages relative to the neutral point voltage, namely the reference values ​​of phase a, phase b, and phase c voltages, based on the reference values ​​of the d-axis voltage, q-axis voltage, 0-axis voltage, and rotor position; and further obtain the drive signal. Parameter identification unit, used to identify parameters based on d shaft current, q shaft current, d Shaft voltage reference value q The shaft voltage reference value, electrical angular velocity, and control cycle form the input and output matrices of the FFRLS algorithm, which identify the resistance, inductance, and fundamental flux linkage in real time. Based on the 0-axis voltage reference value and rotor position, a term containing the third harmonic flux linkage information is calculated through a low-pass filter, and finally the third harmonic flux linkage is obtained through the FFRLS algorithm.

10. An electronic device, characterized in that, The device includes: Memory containing executable program code; A processor coupled to the memory; The processor invokes the executable program code stored in the memory to perform the steps of the method according to any one of claims 1-8.

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