A method and system for motor field weakening control based on current error-free prediction for vehicle

Abstract

The application discloses a kind of weak magnetic control method and system of motor for vehicle based on no difference current prediction, obtain motor torque instruction, determine d-axis reference current based on torque instruction;Adopt voltage closed loop negative id control mode to determine d-axis field weakening current;According to d-axis reference current and d-axis field weakening current, determine d-axis given current, determine q-axis given current based on d-axis given current;According to motor parameter, determine motor rotor speed, according to motor rotor speed, determine d-axis and q-axis reference voltage using no difference current prediction control mode or determine d-axis and q-axis reference voltage using current closed loop control mode;D-axis and q-axis reference voltage are obtained after park, clark inverse transformation three-phase voltage, based on three-phase voltage using SVPWM modulation mode, calculate PWM pulse duty ratio, control the on-off of inverter IGBT signal, realize control motor operation.The application has high torque accuracy in weak magnetic area steady state and better dynamic response capability in dynamic state.

Description

Technical Field

[0001] This invention belongs to the field of automotive motor control technology, specifically relating to a field weakening control method and system for automotive motors based on deadbeat current prediction. Background Technology

[0002] In the powertrain systems of new energy vehicles, the motor control system is one of the most important components, and its performance directly affects the driving experience. Automotive motors are generally permanent magnet synchronous motors with salient polarity, high field weakening ratios, and operate at relatively low speeds below the base speed. In most cases, the motor operates in the field weakening region; therefore, the steady-state and dynamic performance of the motor are crucial during field weakening control.

[0003] Existing field weakening control technology 1: Conventional dual-current closed-loop mode combined with field weakening control algorithms. These algorithms include feedforward open-loop field weakening, lookup table method field weakening, voltage closed-loop feedback field weakening, single-current regulation field weakening, and gradient descent field weakening. Each of these algorithms only satisfies one of the advantages of good robustness, ease of current trajectory planning, high torque accuracy, and improved field weakening depth; good dynamic performance and high steady-state torque accuracy cannot be simultaneously achieved.

[0004] Existing field weakening control technology 2: In recent years, scholars from various countries have begun to pay attention to the dynamic response capability of motors during field weakening operation and have proposed some solutions, such as: (1) a voltage feedback field weakening control strategy with negative q-axis current compensation has been proposed, which solves the problems of large torque oscillation and easy saturation of current regulator during deep field weakening; (2) a dynamic overmodulation strategy based on dynamic voltage correction has been proposed, which effectively improves the dynamic performance of the control system during sudden changes in operating conditions at high speed by improving the utilization rate of DC bus voltage. The above measures only focus on the dynamic adjustment capability during deep field weakening, and the performance effect is generally average. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the above-mentioned background technology and provide a field weakening control method and system for automotive motors based on deadbeat current prediction, which has high torque accuracy in steady state and good dynamic response capability in dynamic state when the motor enters the field weakening region.

[0006] The technical solution adopted in this invention is: a field weakening control method for automotive motors based on deadbeat current prediction, comprising the following steps:

[0007] Obtain the motor torque command and determine the d-axis reference current based on the torque command;

[0008] The d-axis magnetic weakening current is determined using a voltage closed-loop negative id control method.

[0009] The d-axis reference current and the d-axis field weakening current are used to determine the q-axis reference current, and the q-axis reference current is determined based on the d-axis reference current.

[0010] The motor rotor speed is determined based on the motor parameters. Based on the motor rotor speed, the reference voltages for the d-axis and q-axis are determined using either a deadbeat current predictive control method or a current closed-loop control method.

[0011] The d-axis and q-axis reference voltages are inversely transformed by Park and Clark to obtain the three-phase voltages. Based on the three-phase voltages, SVPWM modulation is used to calculate the PWM pulse duty cycle and control the on / off state of the inverter IGBT signal to control the motor operation.

[0012] Furthermore, the rotor angle is collected, the rotor angle is differentiated, and the real-time speed of the motor is calculated based on the differentiated rotor angle and the number of rotor pole pairs. The real-time speed of the motor is then subjected to a first-order low-pass filter to obtain the motor rotor speed.

[0013] Furthermore, the motor rotor speed is compared with the motor rotor base speed. If the motor rotor speed is less than or equal to the motor rotor base speed, a current closed-loop control method is used to determine the d-axis and q-axis reference voltages; if the motor rotor speed is greater than the motor rotor base speed, a deadbeat current predictive control method is used to determine the d-axis and q-axis reference voltages.

[0014] Furthermore, the process of determining the d-axis and q-axis reference voltages using deadbeat current predictive control is as follows:

[0015]

[0016]

[0017] Among them, u d (k), u q (k) represents the d-axis and q-axis voltages for period k, respectively; i * d i * q The currents are given for the d-axis and q-axis, respectively; i d (k), i q (k) represents the d-axis and q-axis currents for period k, respectively; T is the calculation period; R is the stator phase resistance of the motor; L d L q These are the d-axis and q-axis inductances of the motor, respectively; w e (k) is the electric angular velocity of period k.

[0018] Furthermore, within adjacent cycles, when switching from the current closed-loop control mode to the deadbeat-free current prediction control mode, the d-axis and q-axis reference voltages during the switching process are determined by the following formulas:

[0019] u * d =m*(u dpre -u dpi )

[0020] u * q =m*(u qpre -u qpi )

[0021] Among them, u * d u * q These are the reference voltages for the d-axis and q-axis, respectively; m is the slope of change; u dpi u qpi These are the d-axis and q-axis closed-loop voltages determined by current closed-loop control before the switching; u dpre u qpre These are the deadbeat voltages of the d-axis and q-axis determined by the deadbeat current prediction control method after switching.

[0022] Furthermore, within adjacent cycles, when switching from deadbeat current prediction control to current closed-loop control, the d-axis and q-axis reference voltages during the switching process are determined by the following formulas:

[0023] u * d =m*(u dpi -u dpre )

[0024] u * q =m*(u qpi -u qpre )

[0025] Among them, u * d u * q These are the reference voltages for the d-axis and q-axis, respectively; m is the slope of change; u dpi u qpi These are the d-axis and q-axis closed-loop voltages determined by current closed-loop control after switching; u dpre u qpre These are the deadbeat voltages of the d-axis and q-axis, determined by deadbeat current prediction control before switching.

[0026] Furthermore, before determining the d-axis given current, the d-axis current is first obtained based on the d-axis reference current and the d-axis weak magnetic current. The d-axis given current is then obtained after performing MTPV trajectory boundary processing on the d-axis current.

[0027] Furthermore, the q-axis given current is determined using the following formula.

[0028]

[0029] Among them, P, ψ f These represent the number of pole pairs of the motor and the flux linkage of the permanent magnet, respectively; T e * For motor torque command; i * d i * q These are the d-axis and q-axis current references, respectively; L d L q These are the d-axis inductance and the q-axis inductance, respectively.

[0030] A field weakening control system for automotive motors based on deadbeat current prediction, including

[0031] The field weakening control module is used to determine the d-axis field weakening current using a voltage closed-loop negative id control method.

[0032] The d-axis setpoint current calculation module is used to acquire motor torque commands, determine the d-axis reference current based on the torque commands, and determine the d-axis setpoint current based on the d-axis reference current and the d-axis field weakening current.

[0033] The q-axis given current calculation module is used to determine the q-axis given current based on the d-axis given current.

[0034] The mode determination module determines the motor rotor speed based on the motor parameters, and determines the voltage control method (determined current prediction control or closed-loop current control) based on the motor rotor speed.

[0035] The reference voltage control module is used to determine the d-axis and q-axis reference voltages using either a deadbeat current prediction control method or a current closed-loop control method.

[0036] The motor control module is used to obtain the three-phase voltage by performing Park and Clark inverse transformations on the d-axis and q-axis reference voltages. Based on the three-phase voltage, SVPWM modulation is used to calculate the PWM pulse duty cycle and control the on / off state of the inverter IGBT signal to control the motor operation.

[0037] Furthermore, the motor rotor speed is compared with the motor rotor base speed. If the motor rotor speed is less than or equal to the motor rotor base speed, a current closed-loop control method is adopted; if the motor rotor speed is greater than the motor rotor base speed, a deadbeat current predictive control method is adopted.

[0038] The beneficial effects of this invention are:

[0039] This invention divides the entire speed range of the motor into two parts. Below the base speed, current closed-loop control is used to ensure the control of phase current during startup and low speed. Above the base speed, the motor will enter the field weakening region under most operating conditions. Compared with conventional PI regulators, deadbeat current prediction control has advantages such as fast dynamic response, high bandwidth, small current fluctuation, and ease of implementation. The deadbeat current prediction field weakening control of this invention has high torque accuracy in steady state in the field weakening region and good dynamic response capability in dynamic state. Attached Figure Description

[0040] Figure 1 This is a schematic diagram of the main process of the motor control method of the present invention.

[0041] Figure 2 This is a schematic diagram of the magnetic field weakening control of the present invention.

[0042] Figure 3 This is a schematic diagram of the current closed-loop circuit of the present invention.

[0043] Figure 4 This is a diagram illustrating the process of determining the FWflag flag in this invention.

[0044] Figure 5 The output torque of the motor controlled by the current loop pi control of this invention is shown in the MATLAB simulation curve.

[0045] Figure 6 The output torque of the motor in the deadbeat current prediction control of this invention is shown in the MATLAB simulation curve.

[0046] Figure 7 This is a magnified curve of the motor output torque in MATLAB simulation of the current loop pi control of the present invention.

[0047] Figure 8 The figure shows a magnified portion of the output torque curve of the motor under the deadbeat current prediction control of this invention, obtained from a MATLAB simulation.

[0048] Figure 9 The graph shows the speed comparison curves of the two control methods of this invention simulated in MATLAB.

[0049] Figure 10 The graph shows a comparison of the q-axis current curves in MATLAB simulations of the two control methods of this invention. Detailed Implementation

[0050] The specific embodiments of the present invention will be further described below with reference to the accompanying drawings. It should be noted that these descriptions are for the purpose of aiding understanding the present invention, but do not constitute a limitation thereof. Furthermore, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0051] like Figure 1 As shown, this invention provides a field weakening control method for automotive motors based on deadbeat current prediction, comprising the following steps:

[0052] In step S101, the motor controller MCU receives the torque command T from the vehicle controller VCU via CAN communication. e * Then, the current reference value id is obtained by looking up the current map table. * T The current map table was determined during motor calibration.

[0053] Step S102: When the motor is running in the high-speed region, it will enter the field weakening control mode. The conventional voltage closed-loop negative id control method is adopted. After calculation through the field weakening loop, the negative d-axis field weakening current i is obtained. dfw .

[0054] Step S103: Obtain the current reference value id from the lookup table obtained in the above steps. * T With weak magnetic current i dfw Add them together to find the new d-axis current i. * dlim The d-axis current i * dlim The given d-axis current i needs to be obtained through MTPV trajectory boundary processing. * d That is, at the current rotational speed, the minimum limit value of the d-axis is obtained by looking up the table, i * d The current boundary limit of this invention is to ensure that the motor has the maximum torque output at the specified speed when it is operating in the field weakening zone II.

[0055] Step S104, the d-axis given current i obtained through the above steps * d The q-axis given current i is calculated using the torque formula. * q The torque formula is shown below.

[0056]

[0057] Wherein P, ψ f These represent the number of pole pairs of the motor and the flux linkage of the permanent magnet, respectively; L d L q These are the d-axis inductance and the q-axis inductance, respectively.

[0058] Step S105: Collect the three-phase current i of the motor in each FOC calculation cycle. a i b ic After coordinate transformation, the d-axis and q-axis feedback currents i are obtained. dfk i qfk The coordinate transformation formula is as follows:

[0059]

[0060]

[0061] i dfk =i α cosθ+i β sinθ

[0062] i qfk =-i α sinθ+i β cosθ,

[0063] Where i α i β Let be the current in the αβ coordinate system.

[0064] Step S106: Based on the rotational speed, determine whether the motor is currently operating within or above the base speed, indicated by the flag variable FWflag. The flag variable FWflag determines whether to use a current closed-loop control method or a deadbeat-free current predictive control method. Regardless of the control method used, the final output will be the reference voltage u for the d-axis and q-axis. * d u * q .

[0065] Step S107, d-axis and q-axis reference voltage u * d u * q After inverse Park and Clark transformations, the three-phase voltage u is obtained. a u b u c The voltage transformation formula used is as follows.

[0066] u α =u * d cosθ-u * q sinθ

[0067] u β =u * d sinθ+u * q cosθ,

[0068] Wherein u α uβ Let θ be the voltage in the stator αβ coordinate system, and θ be the electrical angle of the motor rotor.

[0069] Step S108: Using SVPWM modulation, the duty cycle of the PWM pulse is calculated to control the on / off state of the inverter IGBT signal, thereby controlling the motor operation.

[0070] Combined with appendix Figure 2 The method of step S102 above will be explained in detail below:

[0071] Step S201 employs a conventional voltage closed-loop field weakening control method. This step calculates the reference voltage amplitude using the following formula:

[0072] The maximum fundamental voltage amplitude of SVPWM modulation is Subtract the two to get the difference.

[0073] In step S202, the above difference is used as the input of the pi regulator, and the magnetic weakening current i is obtained after pi calculation. dfw .

[0074] Combined with appendix Figure 3 The method of current closed-loop control in step S106 above will be explained in detail:

[0075] The current closed-loop method uses a conventional approach, acquiring the three-phase current of the motor in each FOC calculation cycle, and then calculating the dq-axis feedback current i after coordinate transformation. dfk i qfk The coordinate transformation formula is as follows:

[0076]

[0077]

[0078] i dfk =i α cosθ+i β sinθ

[0079] i qfk =-i α sinθ+i β cosθ, where i α i β Let be the current in the αβ coordinate system.

[0080] For the d-axis current loop, a pi regulator is used, with the d-axis setpoint current i * d and feedback current i dfk As the input to the pi regulator, the output d-axis closed-loop voltage u dpi Similarly, the q-axis current loop outputs the q-axis closed-loop voltage u.qpi .

[0081] Finally, the reference voltage u was calculated. * d u * q The calculation formula is:

[0082] u * d =u dpi

[0083] u * q =u qpi

[0084] Combined with appendix Figure 4 The method for predictive control of deadbeat current in step S106 above will be explained in detail:

[0085] In step S301, the motor is equipped with a rotary transformer. In each FOC calculation cycle, rotor angle information can be collected, the angle is differentiated, and the real-time speed of the motor is calculated using the angle and pole pair information.

[0086] Step S302: Filter the real-time speed to obtain the filtered motor rotor speed, Speed. lpf In this scheme, a first-order low-pass filter is sufficient; higher filter orders result in larger phase shifts.

[0087] Step S303: Read the preset reference speed value. After the motor design is completed, the motor parameters are determined, and the reference speed value is also determined; it is a fixed value.

[0088] Step S304, compare Speed lpf and Speed st size.

[0089] Step S305: Assign a value to the flag variable FWflag, with the following judgment rules:

[0090]

[0091] When FWflag = 0, it indicates that the motor speed is below the base speed, and current closed-loop control is used; when FWflag = 1, it indicates that the motor speed is above the base speed, and deadbeat current predictive control is used. It is important to note that the voltage u will change during the switching between the two control modes. * d u * q The processing of voltage u * d u * qThe slope m of the change should be small, and the voltage transition formula is shown below.

[0092] Scenario 1: Transition from below the reference speed to above the reference speed

[0093] u * d =m*(u dpre -u dpi )

[0094] u * q =m*(u qpre -u qpi )

[0095] Scenario 2: Transition from above the reference speed to below the reference speed

[0096] u * d =m*(u dpi -u dpre )

[0097] u * q =m*(u qpi -u qpre )

[0098] The specific slope value shall be determined based on actual debugging.

[0099] The formulas for determining the d-axis and q-axis reference voltages in deadbeat current predictive control are derived as follows:

[0100] The voltage equation of the motor in the rotating coordinate system is:

[0101]

[0102]

[0103] Treating the current as a state variable in the voltage equation above, the rewritten current state equation is:

[0104]

[0105]

[0106] After performing micro-dispersion processing on the current, the current in the k-th period has the following formula:

[0107]

[0108]

[0109] Simplifying the above formula, we obtain the current formula for the current prediction model:

[0110]

[0111]

[0112] At time k+1, i d (k+1),i q The instantaneous current value of (k+1) is given by the current i along the dq axis. * d i * q The alternative voltage prediction formula without deadbeat current is:

[0113]

[0114]

[0115] In the formula, u d (k), u q (k) represents the d-axis and q-axis voltages for period k, respectively; i d (k), i q (k) represents the d-axis and q-axis currents for period k, respectively; T is the calculation period; R is the stator phase resistance of the motor; L d L q These are the d-axis and q-axis inductances of the motor, respectively; w e (k) is the electric angular velocity of period k.

[0116] Obtain the deadbeat voltage u along the d-axis and q-axis dpre u qpre value:

[0117] u dpre =u d (k)

[0118] u qpre =u q (k)

[0119] The L mentioned in the above formula d L q For d-axis and q-axis inductance, w e ω is the electric angular velocity.

[0120] Finally, the d-axis and q-axis reference voltages u were calculated. * d u * q The calculation formula is:

[0121] u * d =u dpre

[0122] u *q =u dpre

[0123] The advantage of this invention lies in dividing the entire speed range of the motor into two parts. Below the base speed, current closed-loop control is used to ensure the control of phase current during startup and low speed. Above the base speed, the motor will enter the field weakening region under most operating conditions. Compared with conventional PI regulators, deadbeat current prediction control has advantages such as fast dynamic response, high bandwidth, small current fluctuation, and ease of implementation. The deadbeat current prediction field weakening control of this invention has high torque accuracy in steady state in the field weakening region and good dynamic response capability in dynamic state.

[0124] A MATLAB model was built for further simulation verification of the invention. The theoretical base speed of the experimental motor was 3250 rpm. To ensure the motor operated in the field weakening region, the simulation conditions were set as follows: the motor ran in speed loop mode at 7000 rpm, the Mechanical input of the Simulink motor submodule was set to Torque Tm, the load torque was 0 within 0.5s, stepped to 100 Nm at 0.5s, and stepped to 50 Nm at 1s. The simulation duration was 1.5s. The curves of the current pi closed-loop control and the deadbeat current predictive control were compared.

[0125] Combined with appendix Figure 5-8 The method described in this invention will be specifically explained below;

[0126] During the simulation period from 0.5s to 1s, the motor ran stably at 7000rpm with a load of 100Nm. As can be seen from the magnified graph, the torque fluctuation of the current pi closed-loop control was a maximum of 107Nm and a minimum of 93Nm, while the torque fluctuation of the deadbeat current prediction control was a maximum of 105Nm and a minimum of no less than 96Nm. Through comparison, it is further verified that the field weakening control based on deadbeat current prediction of the present invention has small torque fluctuation and high torque accuracy in steady state.

[0127] Combined with appendix Figure 9 , Figure 10 The method described in this invention will be specifically explained below;

[0128] Figure 9 The results show that when the load jumps to 100Nm in 0.5s, the motor speed of the deadbeat current prediction control can quickly reach stability, which takes significantly less time than the current loop PI regulator control. When the load jumps to 50Nm in 1s, the speed curves are basically the same. Figure 10 The results show that, regardless of whether the load increases to 100 Nm or decreases to 50 Nm, the q-axis of the deadbeat current prediction control can quickly reach stability, while the current loop pi regulator control takes longer to reach stability. Simulations verify that the field weakening control based on deadbeat current prediction of this invention has better dynamic response capability.

[0129] The above are merely specific embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Contents not described in detail in this specification belong to prior art known to those skilled in the art.

Claims

1. A field weakening control method for automotive motors based on deadbeat current prediction, characterized in that, Includes the following steps: Obtain the motor torque command and determine the d-axis reference current based on the torque command; The d-axis magnetic weakening current is determined by calculating the magnetic weakening loop using a voltage closed-loop negative id control method. The d-axis reference current and the d-axis weakening magnetic current are used to determine the q-axis reference current, and the q-axis reference current is determined based on the d-axis reference current. The motor rotor speed is determined based on the motor parameters. Based on the motor rotor speed, the reference voltages for the d-axis and q-axis are determined using either a deadbeat current predictive control method or a current closed-loop control method. The d-axis and q-axis reference voltages are inversely transformed by Park and Clark to obtain the three-phase voltages. Based on the three-phase voltages, SVPWM modulation is used to calculate the duty cycle of the PWM pulses and control the on / off state of the inverter IGBT signals to control the motor operation. During adjacent cycles, when switching from current closed-loop control to deadbeat-free current prediction control, the d-axis and q-axis reference voltages during the switching process are determined by the following formulas: u * d = m*(u dpre -u dpi ) u * q = m*(u qpre -u qpi ) Among them, u * d u * q These are the reference voltages for the d-axis and q-axis, respectively; m is the slope of change; u dpi u qpi These are the d-axis and q-axis closed-loop voltages determined by current closed-loop control before the switching; u dpre u qpre These are the deadbeat voltages of the d-axis and q-axis determined by the deadbeat current prediction control method after switching.

2. The field weakening control method for automotive motors based on deadbeat current prediction according to claim 1, characterized in that: The rotor angle is collected, the rotor angle is differentiated, and the real-time speed of the motor is calculated based on the differentiated rotor angle and the number of rotor pole pairs. The real-time speed of the motor is then processed by a first-order low-pass filter to obtain the motor rotor speed.

3. The field weakening control method for automotive motors based on deadbeat current prediction according to claim 1, characterized in that: The motor rotor speed is compared with the motor rotor base speed. If the motor rotor speed is less than or equal to the motor rotor base speed, the current closed-loop control method is used to determine the d-axis and q-axis reference voltages. If the motor rotor speed is greater than the motor rotor base speed, the deadbeat current predictive control method is used to determine the d-axis and q-axis reference voltages.

4. The field weakening control method for automotive motors based on deadbeat current prediction according to claim 1, characterized in that: The process of determining the d-axis and q-axis voltages using deadbeat current predictive control is as follows: Among them, u d (k), u q (k) represents the d-axis and q-axis voltages for period k, respectively; i * d i * q The currents are given for the d-axis and q-axis, respectively; i d (k), i q (k) represents the d-axis and q-axis currents for period k, respectively; T is the calculation period; R is the stator phase resistance of the motor; L d L q These are the d-axis and q-axis inductances of the motor, respectively; w e (k) is the electric angular velocity of period k.

5. The field weakening control method for automotive motors based on deadbeat current prediction according to claim 1, characterized in that: During adjacent cycles, when switching from deadbeat current prediction control to current closed-loop control, the d-axis and q-axis reference voltages during the switching process are determined by the following formulas: u * d = m*(u dpi -u dpre ) u * q = m*(u qpi -u qpre ) Among them, u * d u * q These are the reference voltages for the d-axis and q-axis, respectively; m is the slope of change; u dpi u qpi These are the d-axis and q-axis closed-loop voltages determined by current closed-loop control after switching; u dpre u qpre These are the deadbeat voltages of the d-axis and q-axis, determined by deadbeat current prediction control before switching.

6. The field weakening control method for automotive motors based on deadbeat current prediction according to claim 1, characterized in that: Before determining the d-axis given current, the d-axis current is obtained based on the d-axis reference current and the d-axis weak magnetic current. The d-axis given current is obtained after performing MTPV trajectory boundary processing on the d-axis current.

7. The field weakening control method for automotive motors based on deadbeat current prediction according to claim 1, characterized in that: The q-axis current is determined using the following formula. Among them, P, ψ f These represent the number of pole pairs of the motor and the flux linkage of the permanent magnet, respectively; T e * For motor torque command; i * d i * q These are the d-axis and q-axis current references, respectively; L d L q These are the d-axis inductance and the q-axis inductance, respectively.

8. A field weakening control system for automotive motors based on deadbeat current prediction, characterized in that: include The field weakening control module is used to determine the d-axis field weakening current through field weakening loop calculation using a voltage closed-loop negative id control method. The d-axis setpoint current calculation module is used to acquire motor torque commands, determine the d-axis reference current based on the torque commands, and determine the d-axis setpoint current based on the d-axis reference current and the d-axis field weakening current. The q-axis given current calculation module is used to determine the q-axis given current based on the d-axis given current. The mode determination module determines the motor rotor speed based on the motor parameters, and determines the voltage control method (determined current prediction control or closed-loop current control) based on the motor rotor speed. The reference voltage control module is used to determine the d-axis and q-axis reference voltages using either a deadbeat current prediction control method or a current closed-loop control method. During adjacent cycles, when switching from current closed-loop control to deadbeat-free current predictive control, the d-axis and q-axis reference voltages during the switching process are determined by the following formulas: u * d = m*(u dpre -u dpi ) u * q = m*(u qpre -u qpi ) Among them, u * d u * q These are the reference voltages for the d-axis and q-axis, respectively; m is the slope of change; u dpi u qpi These are the d-axis and q-axis closed-loop voltages determined by current closed-loop control before the switching; u dpre u qpre These are the deadbeat voltages of the d-axis and q-axis determined by the deadbeat current prediction control method after switching; The motor control module is used to obtain the three-phase voltage by performing Park and Clark inverse transformations on the d-axis and q-axis reference voltages. Based on the three-phase voltage, SVPWM modulation is used to calculate the PWM pulse duty cycle and control the on / off state of the inverter IGBT signal to control the motor operation.

9. The field weakening control system for automotive motors based on deadbeat current prediction according to claim 8, characterized in that: The motor rotor speed is compared with the motor rotor base speed. If the motor rotor speed is less than or equal to the motor rotor base speed, a current closed-loop control method is used; if the motor rotor speed is greater than the motor rotor base speed, a deadbeat current predictive control method is used.

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