A new energy electric drive rotor position estimation system, method, storage medium and computer program product

Abstract

The application provides a new energy electric drive rotor position estimation system, method, storage medium and computer program product; the system comprises a phase voltage reconstruction module, a counter electromotive force calculation module and a rotor position calculation module. The application estimates the rotor position by using the counter electromotive force calculation method, adopts the phase voltage reconstruction technology and the phase voltage and phase current alignment technology, improves the accuracy of the counter electromotive force calculation method for estimating the rotor position, can be used for actual rotor position monitoring, and improves the operation reliability and stability of the whole vehicle.

Description

Technical Field

[0001] This invention belongs to the field of new energy electric drive control technology, specifically relating to a new energy electric drive rotor position estimation system, method, storage medium, and computer program product. Background Technology

[0002] Permanent magnet synchronous motors and their control systems are the "heart" of new energy vehicles, directly determining the vehicle's acceleration performance, efficiency, driving range, smoothness, and noise level. Providing users with a better driving experience and more cost-effective new energy vehicles is currently the direction of the entire industry's development.

[0003] High-performance motor vector control requires precise, real-time knowledge of the rotor pole position and velocity. After prolonged operation, new energy vehicles may experience rotor position recognition failure due to poor manufacturing processes, vibrations, or other factors, causing the resolver to deviate from its initial fixed position. This can lead to unexpected torque output, and in severe cases, failure at high speeds, potentially threatening the driver's life. Therefore, monitoring and protecting the resolver position in new energy electric drives is an effective way to improve the driving experience and enhance the reliability and stability of the entire vehicle control system.

[0004] In the relevant technologies for rotor position estimation in new energy electric drive systems, the back EMF calculation method is often used for rotor position estimation at medium and high speeds. This method requires obtaining the three-phase voltage and three-phase current to derive the back EMF and thus obtain the rotor position information. However, the traditional estimation scheme directly uses the output voltage of the PI regulator as the source of the three-phase voltage. However, due to the influence of dead zone and voltage saturation characteristics, there is a large difference between the actual three-phase voltage and the regulator output voltage. In addition, there is a misalignment between the phase voltage and the phase current, which affects the estimation accuracy and restricts the improvement of the reliability and stability of the vehicle operation. Summary of the Invention

[0005] To improve the accuracy of rotor position estimation, this invention proposes a new energy electric drive rotor position estimation system, method, storage medium, and computer program product.

[0006] A new energy electric drive rotor position estimation system, which achieves one of the objectives of this invention, includes: The phase voltage reconstruction module is used to acquire the three-phase real-time current of a permanent magnet synchronous motor. I abc Obtain the output after the current is regulated by the current loop. d , q shaft voltage value U d and U q The rotor position calculated based on the previous sampling period Calculate the location compensation value According to the location compensation value Regarding the d , q shaft voltage value U d and U q Coordinate transformation is performed to obtain the α and β axis simulated stator voltages. and The duty cycle is calculated by generating the angle through PWM modulation. , , ; Calculate the duty cycle based on the angle. , , Substituting the values ​​into the preset voltage calculation formula, the corresponding reconstructed phase voltage is obtained. u AN , u BN , u CN The reconstructed phase voltage u AN , u BN , u CN Perform coordinate transformation to obtain the observed voltages along the α and β axes. u α and u β ; The back EMF calculation module is used to calculate the acquired stator three-phase real-time current. I abc By performing coordinate transformation, we obtain the α-axis and β-axis currents I. α and I β The observed voltages along the α and β axes u α and u β and α, β axis currents I α and I β Substituting the stator voltage equations into the α and β coordinate systems of the permanent magnet synchronous motor, the observed back electromotive force E along the α and β axes is calculated. α and E β ; Rotor position calculation module: used to observe the back electromotive force E based on the α and β axes. α and E β The rotor position of the current sampling period is calculated. .

[0007] The new energy electric drive described in this invention is a motor controller assembly that integrates a control unit and an inverter power unit.

[0008] Furthermore, the rotor position calculated based on the previous sampling period Methods for calculating position compensation values ​​include: In the formula, The location compensation value is... For the previous sampling period n -1 is the rotor position calculated; Current sampling period n The electric angular velocity of the motor.

[0009] Furthermore, the preset voltage calculation formula is: In the formula, u AN , u BN , u CN For the three-phase reconfigured phase voltage; u dc This is the bus voltage of the inverter; , , The duty cycle is calculated for the angle. The inverter described in this invention is a power conversion component installed inside the new energy electric drive and driven and controlled by the control unit, used to output AC power to the permanent magnet synchronous motor.

[0010] Furthermore, in the back EMF calculation module, before substituting the α and β axis currents into the stator voltage equation of the permanent magnet synchronous motor in the α and β coordinate system, the module also includes correcting the α and β axis currents based on the current change rate of the current in the current sampling period to eliminate the deviation caused by discretization.

[0011] Furthermore, methods for correcting the α-axis and β-axis currents based on the rate of change of current during the current sampling period include: and The corrected numbers are respectively the first. n The α and β axis currents at each running moment; T s The current carrier period; and The first n The α and β axis currents at each running moment; and The first n -1 α-axis currents at one running moment; and The first n -2 α-axis currents at different operating times.

[0012] Furthermore, the rotor position of the previous sampling period is a set value during the motor startup phase. The set value Based on the motor's electrical angular velocity when the motor is running at low speed Initial position and sampling period T s Calculated, i.e. The motor is running at low speed, which means the speed is less than 10% of the rated speed.

[0013] Furthermore, in the rotor position calculation module, the back electromotive force E is observed based on the α and β axes. α and E β Obtain the rotor position of the current sampling period The methods include: observing the back potential E along the α and β axes. α and E β The rotor position for the current sampling period is obtained by performing an arctangent operation.

[0014] Furthermore, it also includes an angle compensation module, used to calculate the rotor position based on the current sampling period obtained by the rotor position calculation module. Angle compensation is performed to obtain the wave transmission delay compensation angle. The waveform delay compensation angle is used to compensate for the angle error caused by the PWM waveform delay and the inverter drive delay, so that the voltage command is synchronized with the actual motor rotor position.

[0015] Furthermore, the preset correction formula is an angle compensation formula, and its specific expression includes: In the formula, The emission delay compensation angle; The current sampling period is calculated. n The rotor position; For compensation coefficient, Current sampling period n The electric angular velocity of the motor.

[0016] Furthermore, it also includes a motor drive module for adjusting the wave transmission delay compensation angle. For the d-axis and q-axis voltage values U d and U q Coordinate transformation is performed to obtain the voltages along the α and β axes. U α and U β ; for the α and β axis voltages U α and U βPWM modulation is used to obtain the current control duty cycle. D A , D B , D C The duty cycle is controlled according to the current. D A , D B , D C A PWM drive signal is generated to control the inverter to supply power to the permanent magnet synchronous motor. During the motor startup phase, the inverter outputs an initial excitation voltage to drive the motor from a standstill to the running state. During the steady-state operation phase, the inverter continues to output voltage to maintain motor operation.

[0017] Furthermore, during the motor startup phase, the three-phase real-time current of the permanent magnet synchronous motor... I abc The inverter outputs the initial excitation voltage, which causes the initial three-phase current generated in the stator winding of the permanent magnet synchronous motor; when the motor is in steady-state operation, it is the operating three-phase current generated by the continuous operation of the motor.

[0018] A method for estimating the position of a new energy electric drive rotor to achieve the second objective of this invention includes: Data acquisition of three-phase real-time current of permanent magnet synchronous motor I abc Obtain the output after the current is regulated by the current loop. d , q shaft voltage value U d and U q The rotor position calculated based on the previous sampling period Calculate the location compensation value According to the location compensation value Regarding the d , q shaft voltage value U d and U q Coordinate transformation is performed to obtain the α and β axis simulated stator voltages. and The duty cycle is calculated by generating the angle through PWM modulation. , , ; Calculate the duty cycle based on the angle. , , Substituting the values ​​into the preset voltage calculation formula, the corresponding reconstructed phase voltage is obtained. u AN , uBN , u CN The reconstructed phase voltage u AN , u BN , u CN Perform coordinate transformation to obtain the observed voltages along the α and β axes. u α and u β The preset voltage calculation formula is a stator terminal voltage observation formula based on motor parameters. The coordinate transformation in this step is the Clark transformation, which is used to convert the reconstructed phase voltage in the stator three-phase stationary coordinate system (abc axis) into the observed simulated stator voltage in the stator stationary coordinate system (α, β axis) to meet the requirements of subsequent substitution into the stator voltage equation in the α, β coordinate system of the permanent magnet synchronous motor and calculation of the observed back EMF of the α, β axis. Since the reconstructed phase voltage (abc axis) and the α, β axis voltages are both in the stator stationary coordinate system, their transformation depends only on the amplitude and phase relationship of the three-phase voltages.

[0019] The collected stator three-phase real-time current I abc By performing coordinate transformation, we obtain the α-axis and β-axis currents I. α and I β The process involves several steps: During startup, a preset initial current signal is acquired (when the motor is not running, the current can be zero or a preset initial current); during steady-state operation, a dynamic current signal is acquired to ensure that the current signal and the synchronously acquired voltage signal are in the same timing sequence, avoiding timing deviations that could affect the accuracy of rotor position estimation. The coordinate transformation in this step is a Clark transformation. Since the stator three-phase real-time current (a, b, c axes) and the α and β axis currents are all in the stator stationary coordinate system, the transformation process only needs to utilize the amplitude and phase relationship of the three-phase currents, without relying on the rotor position, to convert the acquired three-phase currents into two-phase quadrature currents; the α and β axis observed voltages are then... u α and u β and α, β axis currents I α and I β Substituting the stator voltage equations into the α and β coordinate systems of the permanent magnet synchronous motor, the observed back electromotive force E along the α and β axes is calculated. α and E β ; Based on the observed back electromotive force E along the α and β axes α and E β The rotor position of the current sampling period is calculated. .

[0020] Furthermore, the method also includes: calculating the rotor position of the current sampling period. Angle compensation is performed to obtain the wave transmission delay compensation angle. .

[0021] Furthermore, based on the aforementioned wave transmission delay compensation angle For the d-axis and q-axis voltage values U d and U q Coordinate transformation is performed to obtain the voltages along the α and β axes. U α and U β ; for the α and β axis voltages U α and U β PWM modulation is used to obtain the current control duty cycle. D A , D B , D C The duty cycle is controlled according to the current. D A , D B , D C Generate a PWM drive signal to control the inverter to supply power to the permanent magnet synchronous motor.

[0022] A non-transitory computer-readable storage medium for achieving the third objective of the present invention stores a computer program thereon, wherein the computer program, when executed by a processor, implements the steps of the new energy electric drive rotor position estimation method.

[0023] A computer program product for achieving the fourth objective of the present invention includes a computer program / instruction that, when executed by a processor, implements the steps of the new energy electric drive rotor position estimation method.

[0024] The beneficial effects of this invention include: This invention uses the back EMF calculation method to estimate the rotor position and employs phase voltage reconstruction technology and phase voltage and phase current alignment technology to improve the accuracy of the back EMF calculation method for estimating the rotor position. It can be used for actual rotor position monitoring, thereby improving the reliability and stability of the vehicle operation. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the system described in this invention; Figure 2 This is a topology diagram of a three-phase full-bridge inverter; Figure 3This is the timing diagram for sampling the PWM waveform current. Figure 4 This is a block diagram of the back EMF calculation method for estimating rotor position control. Detailed Implementation

[0026] The following detailed embodiments are provided to explain the technical solutions of the present invention, so that those skilled in the art can understand the present invention. The scope of protection of the present invention is not limited to the following specific embodiments. Any modifications or improvements made by those skilled in the art that incorporate the technical solutions of the present invention but differ from the following detailed embodiments are also within the scope of protection of the present invention.

[0027] First, we will briefly introduce the principle of the back EMF calculation method for estimating rotor position. The stator voltage equations of the permanent magnet synchronous motor in the α and β coordinate systems are as follows: (1) in: (2) in: u α , u β Motors α , β Voltage in a coordinate system; i α , i β Motors α , β Current in a coordinate system; L d , L q Motors d , q Inductance in a coordinate system; E α , E β Motors α , β Back potential in coordinate system; R s ω e These are the stator resistance and electric angular velocity of the motor, respectively. , θ e These are the motor rotor flux linkage, the motor rotor flux linkage, and the stator. α The included angle of the axis; From formula (2), it can be seen that the motor α ,β Back potential in coordinate system E α , E β Includes rotor position information θ e If we can get E α , E β ,Will E α , E β By calculating the arctangent, we can obtain the rotor flux linkage and stator flux linkage of the motor. α The included angle of the shaft, i.e., the rotor position information. θ e .

[0028] From formula (1), it can be seen that in order to obtain E α , E β It must be obtained u α , u β , i α , i β , L d , L q , R s ω e First consider u α , u β , i α , i β To obtain, i α , i β Three-phase current is typically obtained using phase current sampling technology. I abc It was then obtained through Clark transformation. u α , u β The output voltage of a PI regulator is usually used as the source of the phase voltage. However, due to the influence of dead zone and voltage saturation characteristics, there is a large difference between the actual three-phase voltage and the regulator output voltage. In addition, there is a misalignment between the phase voltage and the phase current, which affects the estimation accuracy.

[0029] According to formula (1), after discretization, we get: (3) in: T s The current carrier period or sampling period; superscript n For the first n The output value at each running time (or sampling period), superscript n -1 is the first n -1 output value at runtime, and so on; In the formula: (4) In order to obtain the n The rate of change of current at each running moment, but due to deviations in the discretization process, the calculated value is the current at the _th_ running moment. n and n The intermediate slope at time -1 leads to a loss of estimation accuracy. To address this, a correction scheme is proposed, as shown in equations (5) and (6) below, which are the corrected current calculation formulas to eliminate discretization bias and accurately obtain the current at time -1. n Rate of change of current at each running moment and .

[0030] (5) (6) The phase voltage reconstruction scheme is described as follows: like Figure 2 The diagram shows the topology of a three-phase full-bridge inverter. N is the center point of the three-phase motor lines, R is the three-phase motor resistance, L is the three-phase inductance, T1 to T6 are switching power devices, A, B, and C are the three-phase line lead-out points, and O is the virtual center point of the bus voltage. u dc This is the bus voltage.

[0031] Depend on Figure 2 We can obtain: (7) In the formula u OA , u OB , u OC Let be the voltages from point O to points A, B, and C, respectively. u AN , u BN , u CN Let A, B, and C be the voltages from points A, B, and C to the center point N. uNO Let N be the voltage from center point N to center point O.

[0032] (8) because: (9) get: (10) Substituting (10) into (7), we get: (11) And because: (12) (13) In equation (12) D A , D B , D C These are the actual duty cycles of the switching transistors in the three-phase full-bridge inverter, which are specifically composed of two parts from equation (13). The first part is the modulation output duty cycle. D A_SV , D B_SV , D C_SV The second part is the dead zone compensation duty cycle. D A_DC , D B_DC , D C_DC It can be determined based on the switching delay of the switching transistor and the bus voltage. u dc Calculated using conventional dead-zone compensation algorithms in this field; u dc The bus voltage; since it includes the modulation output duty cycle and the dead-time compensation duty cycle, it is calculated using equation (12). u AO , u BO , u CO The dead zone effect has been offset. Substituting equation (12) into equation (11) yields: (14) According to formula (14), the output three-phase AC voltage can be obtained. It can be seen that the output voltage is only related to the bus voltage. u dc The actual duty cycle of the switching transistors in a three-phase full-bridge inverter D A, D B , D C It is related, unaffected by dead time, and unaffected by modulation output nonlinearity.

[0033] The phase voltage and phase current alignment technique is described as follows: Taking one PWM cycle as an example, the PWM waveform current sampling timing diagram is as follows: Figure 3 As shown; Wherein, RP0 and RP1: RP0 represents the starting point of the counter cnt, and RP1 represents the carrier period. T s At the center moment, starting from RP0, the counter cnt begins to increment and continues until it reaches... T s After a certain time, cnt is reset to 0; CP0 and CP1: the entire carrier time. T s The counter compares the two flip points within the segment. Each time the counter reaches two points, the output PWM wave will flip once. T s The carrier period, the counter cnt starts from RP0 and increments until... T s Then reset back to RP0.

[0034] The phase current value is sampled at time RP0. I abc Phase current value I abc Output d-axis and q-axis voltages after current loop regulation U d and U q Meanwhile, the wave delay angle is calculated according to the following formula (15). ;Will U α and U β Combined with the compensated wave delay angle The duty cycle is calculated by generating an angle without dead-zone compensation through SVPWM modulation. This set of duty cycles is directly used to drive the inverter switching transistors T1-T6 to output AC voltage.

[0035] Due to the time delay of the complete control process of current sampling, current loop calculation, and PWM output, approximately 1.5 carrier cycles are involved. T s (1 calculation cycle + 0.5 PWM update cycles), the rotor will change with the electrical angular velocity ω during this delay time. e After rotating an additional certain angle, the angle at the sampling time is used directly. θ eThis can lead to phase deviation. To ensure that the PWM wave phase is accurately aligned with the real-time rotor position, the wave delay compensation angle needs to be calculated in advance according to the following formula: (15) In the formula, For the first n Periodic wave delay compensation angle; when n When not at the initial time, For the first n The period has been estimated using the rotor position angle described in this invention; when n At the initial moment, the rotor position angle is the set value. The set value Based on the motor's electrical angular velocity when the motor is running at low speed ,Location and period T s Calculated, i.e. The motor is running at low speed, meaning the speed is less than 10% of the rated speed. For the first n The motor's electrical angular velocity during the cycle; the rotor position angle estimated at the end of the current cycle will be used as historical data for compensation calculation in the next cycle, and the position estimation accuracy will converge through iterative updates. However, it is obvious that due to the discrete control principle, the modulation duty cycle calculated at this time... D A , D B , D C Ultimately, the effect occurs at RP1 of the next PWM, which causes the three-phase current sampling point (at RP0) and the voltage vector application point (at RP1) to be misaligned, resulting in a loss of estimation accuracy. Therefore, it is necessary to calculate another set of duty cycles aligned with the sampling current at RP0. The calculation method is as follows: d , q Voltage in coordinates U d and U q Combined with the rotor position electrical angle at time RP0 obtained through coordinate transformation α , β Voltage command value at time RP0 in the coordinate system U α , U β The output after PWM modulation is the same as the sampled current. I abc Calculate the duty cycle based on the alignment angle. The duty cycle of this group Substituting into equation (11), we obtain the reconstructed phase voltage synchronized with the sampling current: (16) Equation (16) is the formula for the reconstructed phase voltage in the continuous time domain. Since the control algorithm of this invention is based on a digital controller, it needs to be reconstructed according to the carrier period T. s Discretize to the th n After one operating cycle, the formula for the reconstructed phase voltage in the discrete domain (17) is obtained: (17) Transform to α , β The motor is obtained after the coordinate system is established. α , β The first coordinate system n Voltage per carrier cycle , .

[0036] The sampled phase current I abc Transform to α , β The motor is obtained after the coordinate system is established. α , β Phase current of the nth carrier cycle in the coordinate system , .

[0037] Will , and phase current , Substituting into equation (6), we can obtain the result. , Finally, the position of the electric drive rotor in the nth carrier cycle can be obtained. .

[0038] The control block diagram for estimating rotor position using the back EMF calculation method is shown below. Figure 4 As shown, the output from the current regulator d , q Voltage in coordinates U d , U q Substituting the position of the electric drive rotor in the previous carrier cycle into formula (15) yields the transmission delay compensation angle for the current transmission cycle. U d , U q The output is obtained after coordinate transformation based on the current cycle's wave delay compensation angle. U α , U β , Ud , U q The output is obtained by combining the position of the electric drive rotor from the previous carrier cycle with coordinate transformation. U α ’ , U β ’ ,in U α , U β Output after PWM modulation D A , D B , D C Used to control the inverter and output AC voltage. , Output after PWM modulation D A ’ , D B ’ , D C ’ After passing through equation (16), the output is a three-phase AC voltage. u AN , u BN , u CN The sampled three-phase current I abc After coordinate transformation, we obtain I α , I β Finally u AN , u BN , u CN and I α , I β The motor is obtained after formula (3). α , β The back electromotive force in the coordinate system is used to obtain the rotor position angle for the current period through the arctangent. θ e .

[0039] This invention effectively solves the technical problems of insufficient accuracy, large timing deviation, and poor adaptability of rotor position estimation in existing permanent magnet synchronous motors. By using the wave delay compensation angle formula shown in formula (15) to correct the rotor position, it can accurately compensate for the phase deviation caused by the time delay of current sampling, current loop calculation, and PWM output, and significantly improve the accuracy of rotor position estimation. By synchronously collecting the d-axis voltage values ​​and the stator three-phase real-time current and ensuring the consistency of their timing, combined with the synchronous execution of Clark transformation, inverse Park transformation and PWM carrier cycle, and the correction of the rate of change of α and β axis currents, the impact of discretization processing, high-frequency interference and zero-point drift on the back EMF calculation accuracy is further reduced, providing reliable data support for the preliminary estimation of rotor position. By using arctangent operation on the back EMF observed on the α and β axes to obtain the preliminary estimated value of rotor position, and constructing a closed-loop iterative mechanism, it combines the start-up stage and steady state. The differentiated rotor position design during operation enables dynamic convergence of rotor position estimation, adapting to the operating requirements of different motor speeds and ensuring motor stability. Simultaneously, a dead-zone compensation mechanism is introduced during phase voltage reconfiguration. By superimposing dead-zone compensation duty cycle correction angles to calculate the duty cycle, the impact of inverter dead-zone effect on the accuracy of reconfigured phase voltage is effectively offset, further ensuring the reliability of back EMF calculation and rotor position estimation. This invention requires no additional complex hardware structure; by optimizing control timing, improving correction mechanisms and iterative logic, accurate and stable rotor position estimation can be achieved on existing hardware. This not only reduces implementation costs but also improves the practicality and scalability of the solution, balancing estimation accuracy and operational stability. It better adapts to the actual application needs of new energy electric drive systems, solving potential estimation deviations and insufficient operating condition adaptation in the original technical solution, and improving the overall performance of motor drive control.

[0040] Based on the above principles, embodiments of the present invention provide a method for estimating the position of a new energy electric drive rotor, including: S1: Obtain the three-phase current I of the permanent magnet synchronous motor abc， Obtain the three-phase current I abc The PI regulator outputs d-axis and q-axis voltages. , ; S2: , Calculate the rotor position obtained from the previous sampling period Location compensation value Output after coordinate transformation , The duty cycle is calculated by outputting the angle after PWM modulation. , , ; S3: The output of step S2 , , Substituting into formula (16), the corresponding three-phase reconfiguration voltage is obtained. , , ; S4: Three-phase reconfiguration voltage , , Output the observed voltages along the α and β axes after coordinate transformation. , ; S5: After transforming the coordinates of the sampled three-phase currents Iabc, obtain the α and β axis currents. ; S6: The result will be , , Substituting the stator voltage equations of the permanent magnet synchronous motor in the α and β coordinate systems shown in formula (6), we obtain the observed back EMFs along the α and β axes. , ; S7: The result will be , After the reverse cut, the current rotor position information is obtained. That is, using the arctan2 function of the four quadrants with respect to the back potential along the α axis. β-axis back potential The calculations are performed to obtain the rotor position information within the complete electrical angle range; S8: The calculated result The wave compensation angle is obtained using formula (15). ; S9: , Using wave compensation angle Coordinate transformation output , After PWM modulation, the output current controls the duty cycle. , , Control the inverter output.

[0041] This invention also provides a new energy electric drive rotor position estimation system, such as... Figure 1 As shown, it includes: The phase voltage reconstruction module is used to acquire the three-phase real-time current of a permanent magnet synchronous motor. I abc Obtain the output after the current is regulated by the current loop. d , q shaft voltage value U d andU q The rotor position calculated based on the previous sampling period Calculate the location compensation value According to the location compensation value Regarding the d , q shaft voltage value U d and U q Coordinate transformation is performed to obtain the α and β axis simulated stator voltages. and The duty cycle is calculated by generating the angle through PWM modulation. , , ; Calculate the duty cycle based on the angle. , , Substituting the values ​​into the preset voltage calculation formula, the corresponding reconstructed phase voltage is obtained. u AN , u BN , u CN The reconstructed phase voltage u AN , u BN , u CN Perform coordinate transformation to obtain the observed voltages along the α and β axes. u α and u β ; The back EMF calculation module is used to calculate the acquired stator three-phase real-time current. I abc By performing coordinate transformation, we obtain the α-axis and β-axis currents I. α and I β The observed voltages along the α and β axes u α and u β and α, β axis currents I α and I β Substituting the stator voltage equations into the α and β coordinate systems of the permanent magnet synchronous motor, the observed back electromotive force E along the α and β axes is calculated. α and E β ; Rotor position calculation module: used to observe the back electromotive force E based on the α and β axes. α and E β The rotor position of the current sampling period is calculated. .

[0042] In one embodiment, the rotor position calculated based on the previous sampling period Methods for calculating position compensation values ​​include: In the formula, The location compensation value is... For the previous sampling period n -1 is the rotor position calculated; Current sampling period n The electric angular velocity of the motor.

[0043] In one embodiment, the stator voltage equation of the permanent magnet synchronous motor in the α and β coordinate systems is the equation shown in equation (1).

[0044] In one embodiment, the preset voltage calculation formula is: In the formula, u AN , u BN , u CN For the three-phase reconfigured phase voltage; u dc This is the bus voltage of the inverter; , , The duty cycle is calculated based on the angles of the inverter switching transistors.

[0045] In one embodiment, before substituting the α and β axis currents into the stator voltage equation of the α and β coordinate system of the permanent magnet synchronous motor, the α and β axis currents are further corrected according to the current change rate of the current in the current sampling period to eliminate the deviation caused by the discretization process.

[0046] In one embodiment, the method for correcting the α-axis and β-axis currents based on the rate of change of current in the current sampling period includes: and The corrected numbers are respectively the first. n The α and β axis currents at each running moment; T s The current carrier period; and The first n The α and β axis currents at each running moment; and The first n -1 α-axis currents at one running moment; and The first n-2 α-axis currents at different operating times.

[0047] In one embodiment, the rotor position of the previous sampling period is a set value during the motor startup phase, and the set value is based on the motor's electrical angular velocity when the motor is running at low speed. Initial position and period T s Calculated, i.e. The motor is running at low speed, which means the speed is less than 10% of the rated speed.

[0048] In one embodiment, the rotor position calculation module includes a method for obtaining the rotor position of the current sampling period based on the observed back EMFs of the α and β axes, which involves performing an arctangent operation on the observed back EMFs of the α and β axes to obtain the rotor position of the current sampling period.

[0049] In one embodiment, the system further includes an angle compensation module, used to process the rotor position calculated by the rotor position calculation module based on the current sampling period. Angle compensation is performed to obtain the wave transmission delay compensation angle. The waveform delay compensation angle is used to compensate for the angle error caused by the PWM waveform delay and the inverter drive delay, so that the voltage command is synchronized with the actual motor rotor position.

[0050] In one embodiment, the preset correction formula is an angle compensation formula, the specific expression of which includes: In the formula, The emission delay compensation angle; The current sampling period is calculated. n The rotor position; For compensation coefficient, Current sampling period n The electric angular velocity of the motor.

[0051] In one embodiment, a motor drive module is further included, used to adjust the wave transmission delay compensation angle according to the wave transmission delay compensation angle. For the d-axis and q-axis voltage values U d and U q Coordinate transformation is performed to obtain the voltages along the α and β axes. U α and U β ; for the α and β axis voltages U α and U β PWM modulation is used to obtain the current control duty cycle. D A ,D B , D C The duty cycle is controlled according to the current. D A , D B , D C A PWM drive signal is generated to control the inverter to supply power to the permanent magnet synchronous motor. During the motor startup phase, the inverter outputs an initial excitation voltage to drive the motor from a standstill to the running state. During the steady-state operation phase, the inverter continues to output voltage to maintain motor operation.

[0052] In one embodiment, during the motor startup phase, the three-phase real-time current of the permanent magnet synchronous motor is... I abc The inverter outputs the initial excitation voltage, which causes the initial three-phase current generated in the stator winding of the permanent magnet synchronous motor; when the motor is in steady-state operation, it is the operating three-phase current generated by the continuous operation of the motor.

[0053] This invention also provides a method for estimating the position of a new energy electric drive rotor, including: Data acquisition of three-phase real-time current of permanent magnet synchronous motor I abc Obtain the output after the current is regulated by the current loop. d , q shaft voltage value U d and U q The rotor position calculated based on the previous sampling period Calculate the location compensation value According to the location compensation value Regarding the d , q shaft voltage value U d and U q Coordinate transformation is performed to obtain the α and β axis simulated stator voltages. and The duty cycle is calculated by generating the angle through PWM modulation. , , ; Calculate the duty cycle based on the angle. , , Substituting the values ​​into the preset voltage calculation formula, the corresponding reconstructed phase voltage is obtained. u AN , u BN , u CNThe reconstructed phase voltage u AN , u BN , u CN Perform coordinate transformation to obtain the observed voltages along the α and β axes. u α and u β ; The collected stator three-phase real-time current I abc By performing coordinate transformation, we obtain the α-axis and β-axis currents I. α and I β The observed voltages along the α and β axes u α and u β and α, β axis currents I α and I β Substituting the stator voltage equations into the α and β coordinate systems of the permanent magnet synchronous motor, the observed back electromotive force E along the α and β axes is calculated. α and E β ; Based on the observed back electromotive force E along the α and β axes α and E β The rotor position of the current sampling period is calculated. .

[0054] In one embodiment, the method further includes: calculating the rotor position of the current sampling period. Angle compensation is performed to obtain the wave transmission delay compensation angle. .

[0055] In one embodiment, based on the wave transmission delay compensation angle For the d-axis and q-axis voltage values U d and U q Coordinate transformation is performed to obtain the voltages along the α and β axes. U α and U β ; for the α and β axis voltages U α and U β PWM modulation is used to obtain the current control duty cycle. D A , D B , D C The duty cycle is controlled according to the current. D A ,D B , D C Generate a PWM drive signal to control the inverter to supply power to the permanent magnet synchronous motor.

[0056] This invention also provides a computer program product, including a computer program / instructions that, when executed by a processor, implement the various steps of the method described in this invention.

[0057] This invention also provides a non-transitory computer-readable storage medium storing a computer program, which includes program instructions that, when executed by a processor, implement the various steps of the method described in this invention, which will not be elaborated further here.

[0058] The computer-readable storage medium can be the data transmission apparatus or the internal storage unit of a computer device provided in any of the foregoing embodiments, such as the hard disk or memory of the computer device. The computer-readable storage medium can also be the external storage device of the computer device, such as the plug-in hard disk, smart media card (SMC), secure digital (SD) card, flash card, etc. equipped on the computer device.

[0059] Furthermore, the computer-readable storage medium may include both internal storage units and external storage devices of the computer device. The computer-readable storage medium is used to store the computer program and other programs and data required by the computer device. The computer-readable storage medium may also be used to temporarily store data that is to be output or has already been output.

[0060] Those skilled in the art will understand that embodiments of the present invention can be provided as methods, systems, or computer program products. Therefore, the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention can take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0061] This invention is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart illustrations and / or block diagrams. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0062] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0063] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0064] The contents not described in detail in this specification are existing technologies known to those skilled in the art.

Claims

1. A new energy electric drive rotor position estimation system, characterized in that, include: The phase voltage reconstruction module is used to collect the three-phase real-time current of the permanent magnet synchronous motor, obtain the d and q axis voltage values ​​output after the current is regulated by the current loop, calculate the position compensation value based on the rotor position calculated in the previous sampling period, perform coordinate transformation on the collected d and q axis voltage values ​​based on the position compensation value to obtain the α and β axis simulated stator voltages, and generate multiple angles through PWM modulation to calculate the duty cycle. Substitute the duty cycle calculated from the multiple angles into the preset voltage calculation formula to obtain the corresponding reconstructed phase voltage; perform coordinate transformation on the reconstructed phase voltage to obtain the α and β axis observation voltages; The back EMF calculation module is used to perform coordinate transformation on the collected three-phase real-time current to obtain the α and β axis currents; and to substitute the α and β axis observed voltages and the α and β axis currents into the stator voltage equations of the permanent magnet synchronous motor in the α and β coordinate system to calculate the observed back EMFs of the α and β axes. The rotor position calculation module is used to calculate the rotor position of the current sampling period based on the observed back electromotive force of the α and β axes.

2. The new energy electric drive rotor position estimation system as described in claim 1, characterized in that, The preset voltage calculation formula is: In the formula, u AN , u BN , u CN These are the corresponding reconstructed phase voltages; u dc This is the bus voltage of the inverter; , , Calculate the duty cycle for each of the multiple angles.

3. The new energy electric drive rotor position estimation system as described in claim 1, characterized in that, In the back EMF calculation module, before substituting the α and β axis currents into the stator voltage equation of the permanent magnet synchronous motor in the α and β coordinate system, the module also includes correcting the α and β axis currents according to the current change rate of the current in the current sampling period to eliminate the deviation caused by discretization.

4. The new energy electric drive rotor position estimation system as described in claim 3, characterized in that, Methods for correcting the α-axis and β-axis currents based on the rate of change of current during the current sampling period include: and The corrected numbers are respectively the first. n The α and β axis currents at each running moment; T s This is the current sampling period; and The first n The α and β axis currents at each running moment; and The first n -1 α-axis currents at one running moment; and The first n -2 α-axis currents at different operating times.

5. The new energy electric drive rotor position estimation system as described in claim 1, characterized in that, It also includes an angle compensation module, which is used to perform angle compensation on the rotor position calculated by the rotor position calculation module for the current sampling period, so as to obtain the wave transmission delay compensation angle.

6. The new energy electric drive rotor position estimation system as described in claim 5, characterized in that, The rotor position for the current sampling period is compensated for using the following compensation formula: In the formula, The emission delay compensation angle; The calculated current sampling period n The rotor position; For compensation coefficient, Current sampling period n The electric angular velocity of the motor.

7. The new energy electric drive rotor position estimation system as described in claim 5 or 6, characterized in that, It also includes a motor drive module, which is used to perform coordinate transformation on the d and q axis voltage values ​​according to the wave delay compensation angle to obtain the α and β axis voltages, perform PWM modulation on the α and β axis voltages to obtain the current control duty cycle, generate a PWM drive signal according to the current control duty cycle, and control the inverter to supply power to the permanent magnet synchronous motor.

8. A method for estimating the position of a new energy electric drive rotor in the system described in claim 1, characterized in that, include: The three-phase real-time current of the permanent magnet synchronous motor is collected, and the d-axis and q-axis voltage values ​​output after the current is regulated by the current loop are obtained. The position compensation value is calculated based on the rotor position calculated in the previous sampling period. The collected d-axis and q-axis voltage values ​​are transformed by coordinate transformation based on the position compensation value to obtain the α-axis and β-axis simulated stator voltages. Multiple angles are generated by PWM modulation to calculate the duty cycle. Substitute the duty cycle calculated from the multiple angles into the preset voltage calculation formula to obtain the corresponding reconstructed phase voltage; The reconstructed phase voltage is subjected to coordinate transformation to obtain the observed voltages along the α and β axes.

9. A non-transitory computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the steps of the new energy electric drive rotor position estimation method as described in claim 8.

10. A computer program product comprising a computer program / instructions, characterized in that, When the computer program / instruction is executed by the processor, it implements the steps of the new energy electric drive rotor position estimation method as described in claim 8.

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