CN114826039A - Control method suitable for electric vehicle motor - Google Patents

Abstract

The application discloses a control method suitable for an electric vehicle motor, which comprises the following steps: collecting a first type rotor angle signal of a first type position sensor; collecting a second type rotor angle signal of a second type position sensor; and judging whether the rotating speed of the electronic rotor meets a speed interval limited by a first switching threshold value or/and a second switching threshold value or/and according to the first-class rotor angle signal or/and the second-class rotor angle signal, and if the rotating speed meets the speed interval limited by the first switching threshold value or/and the second switching threshold value, switching between the first driving mode and the second driving mode is realized in a hysteresis switching mode. The beneficial effect of this application lies in providing one kind and can effectively realize the motor accurate under different rotational speeds the driven control method who is applicable to the electric motor car motor.

Description

Control method suitable for electric vehicle motor

Technical Field

The application relates to the field of motor control, in particular to a control method applicable to a motor of an electric vehicle.

Background

With the continuous development of economy, the requirement on travel is higher and higher; the electric moped is more and more popular due to the characteristics of small size, light weight, environmental protection, economy and the like; as one of the core components of the electric moped, the performance of the driving motor determines whether the power, driving comfort, endurance and the like of the whole vehicle meet the use requirements; most of driving motors applied to the market at present are SPMSM (surface-mounted permanent magnet synchronous motors), and the control modes are FOC (magnetic field orientation) control; the field orientation control needs to acquire the current three-phase current and rotor position signals of the motor in real time;

in a control mode of a driving motor of the electric moped, a traditional rotor angle obtaining position mode is obtained through a Hall position sensor, but the Hall position sensor cannot meet the requirement of the motor on position precision in a high-speed operation process due to the fact that the number of return pulses of the motor is small and sampling noise is large in the motor operation process; the non-inductive sensor is an angle acquisition mode for designing a counter electromotive force observer based on a fundamental voltage equation and further extracting a rotor position signal of a motor from the counter electromotive force signal, but the counter electromotive force signal is small when the motor runs at a low speed, and an effective rotor position signal cannot be extracted from the counter electromotive force signal, so the non-inductive observer is generally applied to occasions where the motor runs at a medium and high speed, the low speed generally runs in a voltage open-loop forced dragging mode, and in the mode, the running current of the motor is overlarge, and the non-synchronous state is easy to enter.

Disclosure of Invention

This summary is provided to introduce a selection of concepts in a simplified form that are further described below in the detailed description. This summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter.

Some embodiments of the present application provide a control method for an electric vehicle motor, which is performed by a motor control system, the motor control system including:

a first-type position sensor for detecting a rotor position of the motor based on a Hall effect to output a first-type rotor angle signal;

a second type position sensor for detecting a rotor position of the motor based on a back electromotive force of the motor to output a second type rotor angle signal;

the controller is used for outputting a driving signal for driving the motor according to the first type of rotor angle signal or/and the second type of rotor angle signal;

the control method comprises the following steps:

the controller collects first-class rotor angle signals of the first-class position sensors;

the controller collects a second type of rotor angle signal of the second type of position sensor;

judging whether the rotating speed of the electronic rotor meets a speed interval defined by the first switching threshold value or/and the second switching threshold value or not according to the first type of rotor angle signal or/and the second type of rotor angle signal, and if the rotating speed meets the speed interval defined by the first switching threshold value or/and the second switching threshold value, switching between a first driving mode and a second driving mode is achieved in a hysteresis switching mode;

when in the first driving mode, the controller outputs the driving signal according to the first type of rotor angle signal; and when in the second driving mode, the controller outputs the driving signal according to the second type of rotor angle signal.

Further wherein the first type of position sensor comprises three hall position sensors; the step of acquiring the first-class rotor angle signals of the first-class position sensors by the controller specifically comprises the following steps of:

and S1, the Hall position sensor processes the obtained three Hall levels to obtain a motor rotor angle signal under each switching period.

Further, wherein the motor is a surface permanent magnet synchronous motor, and the second type of position sensor comprises a non-inductive observer;

the step of acquiring the second type of rotor angle signals of the second type of position sensors by the controller specifically comprises the following steps:

s2, based on the alfa and beta axis fundamental wave voltage equation of the surface permanent magnet synchronous motor, the input quantities U _ alfa, i _ alfa, U _ beta and i _ beta are calculated, and the output angle signal of the non-inductive observer is obtained.

Further, the determining, according to the first-type rotor angle signal or/and the second-type rotor angle signal, whether the rotation speed of the electronic rotor satisfies a speed interval defined by the first switching threshold or/and the second switching threshold, and if the rotation speed satisfies the speed interval defined by the first switching threshold or/and the second switching threshold, implementing switching between the first driving mode and the second driving mode by using a hysteresis loop switching method specifically includes:

and S3, setting a rotating speed threshold hysteresis switching mode, including a first switching threshold and a second switching threshold, and realizing smooth switching of two angle acquisition modes of the non-inductive observer and the Hall position sensor.

Further, the determining, according to the first-type rotor angle signal or/and the second-type rotor angle signal, whether the rotation speed of the electronic rotor satisfies a speed interval defined by the first switching threshold or/and the second switching threshold, and if the rotation speed satisfies the speed interval defined by the first switching threshold or/and the second switching threshold, implementing switching between the first driving mode and the second driving mode by using a hysteresis loop switching method specifically further includes:

and S4, monitoring the health state of the Hall position sensor on line at the full-time operation stage of the motor, and if a fault occurs, switching to a non-inductive mode to operate, so as to realize redundant control under the Hall fault of the motor.

Further, the step S1 specifically includes the following steps:

s11, setting the initial calculation signal of the Hall three-level angle to be 0;

s12, determining the current sector of the rotor position signal according to the current state of the Hall three-level, and setting the rotor angle as the central angle of the current sector in order to approach the current actual angle of the rotor to the maximum extent;

s13, according to the rotor angle determined in the previous step, three-phase currents of the motor are obtained at the same time, clark conversion is carried out, components i _ alfa and i _ beta of stator winding currents on alfa and beta axes are obtained, components of the stator winding currents on dq axes are obtained, d-axis currents and q-axis currents are controlled respectively, d-axis voltages and q-axis voltages are obtained, and reverse park conversion is carried out by taking the dq-axis voltages and the current angle of the rotor as input quantities to obtain components U _ alfa and U _ beta of inverter output voltages on alfa and beta axes;

s14, updating the current angle in real time; taking the time difference of two sector changes as delta _ t, wherein the delta _ t = t1-t 2; wherein t1 is the time node of the last sector change, and t2 is the time node of the current sector change; the angular difference of the two sector changes is delta _ theta = pi/3, and the angular speed w = delta _ theta/delta _ t of the motor is obtained based on the derivation; performing equivalent operation on the angular speed w to obtain a change value w _ dpp of the angular signal in a switching period;

and S15, updating the current angle signal in real time in each switching cycle, wherein theta _ hall = theta _ hall + w _ dpp.

Further, the step S2 specifically includes the following steps:

s21, after the theta _ hall is processed by sine and cosine, original sin (theta _ est) and cos (theta _ est) in the back electromotive force observer are replaced by substitute signals, and the convergence speed of the back electromotive force observer for the back electromotive force observation is accelerated; wherein theta _ est is an angle estimation value of the observer;

and S22, substituting the theta _ hall signal obtained by calculation in the step S15 into the estimation angle calculation integral feedback module, and accelerating the convergence speed of the estimation angle of the whole PLL module.

Further, the step S3 specifically includes the following steps:

s31, in the running process of the motor, comparing an output signal of the Hall position sensor signal processing module with an output angle signal of the non-inductive observer, setting a rotating speed point speed1 after the output signal of the non-inductive observer is stable as a first switching threshold value, and adding a fixed rotating speed delta _ speed to speed1 to obtain a second switching threshold speed 2; wherein delta _ speed = speed/3;

s32, taking the angle signal w _ dpp obtained after Hall processing as an input signal, and judging the magnitude of theta _ hall _ dpp and speed 1;

s33, if the current motor running mode is a sensing driving mode1 which drives according to the output signal of the Hall position sensor, when w _ dpp is less than or equal to speed2, the current running mode of the motor is still mode1, otherwise, the running mode is switched to mode 2;

s34, if the current motor running mode is a non-inductive driving mode2 which drives according to the output signal of the non-inductive observer, when w _ dpp is less than or equal to speed1, the current running mode of the motor is switched to mode2, otherwise, the current running mode is kept to mode 2.

Further, the step S4 specifically includes the following steps:

and S41, judging the Hall three-level signals collected in real time, if the three levels are all high levels or all low levels, executing a Hall fault processing step by the controller, writing a Hall fault flag bit into a memory, and switching the motor operation mode to mode 2.

Further, the step S4 specifically includes the following steps: .

And S42, detecting the Hall level signals, if the Hall three level signals do not have high level or are all low level in n continuous judgment periods, clearing the Hall fault flag in the memory, removing the Hall fault state by the controller, and switching to the motor running mode according to the step S32 or S33.

The beneficial effect of this application lies in: the control method suitable for the motor of the electric vehicle can effectively realize accurate driving of the motor at different rotating speeds.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this application, serve to provide a further understanding of the application and to enable other features, objects, and advantages of the application to be more apparent. The drawings and their description illustrate the embodiments of the invention and do not limit it.

Further, throughout the drawings, the same or similar reference numerals denote the same or similar elements. It should be understood that the drawings are schematic and that elements and elements are not necessarily drawn to scale.

In the drawings:

FIG. 1 is a schematic diagram of the main steps of a control method for an electric vehicle motor according to an embodiment of the present application;

FIG. 2 is a schematic diagram of a portion of specific steps of a control method for an electric vehicle motor according to an embodiment of the present application;

fig. 3 is a schematic diagram of a part of specific steps of step S1 in the control method for the electric vehicle motor according to an embodiment of the present application;

fig. 4 is a schematic diagram of a part of specific steps of step S2 in the control method for the electric vehicle motor according to an embodiment of the present application;

fig. 5 is a schematic diagram of a part of specific steps of step S3 in the control method for the electric vehicle motor according to an embodiment of the present application;

fig. 6 is a schematic diagram of a part of specific steps of step S4 in the control method for the electric vehicle motor according to an embodiment of the present application;

FIG. 7 is a schematic diagram illustrating a specific logic determination process in a control method for an electric vehicle motor according to an embodiment of the present application;

fig. 8 is a schematic diagram of another specific logic determination process in a control method for an electric vehicle motor according to an embodiment of the application.

Detailed Description

Embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. While certain embodiments of the present disclosure are shown in the drawings, it is to be understood that the disclosure may be embodied in various forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided for a more thorough and complete understanding of the present disclosure. It should be understood that the drawings and embodiments of the disclosure are for illustration purposes only and are not intended to limit the scope of the disclosure.

It should be noted that, for convenience of description, only the portions related to the related invention are shown in the drawings. The embodiments and features of the embodiments in the present disclosure may be combined with each other without conflict.

It should be noted that the terms "first", "second", and the like in the present disclosure are only used for distinguishing different devices, modules or units, and are not used for limiting the order or interdependence of the functions performed by the devices, modules or units.

It is noted that references to "a" or "an" in this disclosure are intended to be illustrative rather than limiting, and that those skilled in the art will appreciate that references to "one or more" are intended to be exemplary and not limiting unless the context clearly indicates otherwise.

The names of messages or information exchanged between devices in the embodiments of the present disclosure are for illustrative purposes only, and are not intended to limit the scope of the messages or information.

The present disclosure will be described in detail below with reference to the accompanying drawings in conjunction with embodiments.

Referring to fig. 1 to 8, the control method for the electric vehicle motor according to the present application is executed by a motor control system, which includes: a first-class position sensor for detecting a rotor position of the motor based on a Hall effect to output a first-class rotor angle signal; a second type position sensor for detecting a rotor position of the motor based on a back electromotive force of the motor to output a second type rotor angle signal; and the controller is used for outputting a driving signal for driving the motor according to the first type of rotor angle signal or/and the second type of rotor angle signal.

As a more schematic scheme, the control system may specifically include: the device comprises a Hall position sensor signal processing module, a dq-abc conversion module, an SVM module, an IGBT switch module, a current sampling circuit, an abc-dq conversion module, a non-sensing observer module and the like.

As a specific scheme, the control method of the woolen cloth comprises the following steps: the controller collects first-class rotor angle signals of the first-class position sensors; the controller collects a second type rotor angle signal of a second type position sensor; judging whether the rotating speed of the electronic rotor meets a speed interval limited by a first switching threshold value or/and a second switching threshold value or/and according to the first-class rotor angle signal or/and the second-class rotor angle signal, and if the rotating speed meets the speed interval limited by the first switching threshold value or/and the second switching threshold value, switching between a first driving mode and a second driving mode is achieved in a hysteresis switching mode; when in a first driving mode, the controller outputs a driving signal according to the first type of rotor angle signal; and when in the second driving mode, the controller outputs a driving signal according to the second type of rotor angle signal.

Specifically, the first position sensor comprises three Hall position sensors; the method for acquiring the first-class rotor angle signals of the first-class position sensor by the controller specifically comprises the following steps of:

and S1, the Hall position sensor processes the obtained three Hall levels to obtain a motor rotor angle signal under each switching period.

Specifically, the motor is a surface permanent magnet synchronous motor, and the second type of position sensor includes a non-inductive observer. The method for acquiring the second type rotor angle signals of the second type position sensor by the controller specifically comprises the following steps:

s2, based on the alfa and beta axis fundamental wave voltage equation of the surface permanent magnet synchronous motor, the input quantities U _ alfa, i _ alfa, U _ beta and i _ beta are calculated, and the output angle signal of the non-inductive observer is obtained.

Specifically, the determining, according to the first-type rotor angle signal or/and the second-type rotor angle signal, whether the rotation speed of the electronic rotor satisfies a speed interval defined by a first switching threshold or/and a second switching threshold, and if the rotation speed satisfies the speed interval defined by the first switching threshold or/and the second switching threshold, implementing switching between the first driving mode and the second driving mode by using hysteresis switching specifically includes:

and S3, setting a rotating speed threshold hysteresis switching mode, including a first switching threshold and a second switching threshold, and realizing smooth switching of two angle acquisition modes of the non-inductive observer and the Hall position sensor.

Specifically, the determining, according to the first-type rotor angle signal or/and the second-type rotor angle signal, whether the rotation speed of the electronic rotor satisfies a speed interval defined by a first switching threshold or/and a second switching threshold, and if the rotation speed satisfies the speed interval defined by the first switching threshold or/and the second switching threshold, implementing switching between the first driving mode and the second driving mode by using hysteresis switching specifically further includes:

and S4, monitoring the health state of the Hall position sensor on line at the full-time operation stage of the motor, and if a fault occurs, switching to a non-inductive mode to operate, so as to realize redundant control under the Hall fault of the motor.

Specifically, step S1 specifically includes the following steps:

and S11, setting the initial angle calculation signal of the Hall three levels to be 0.

S12, determining the current sector of the rotor position signal according to the current state of the Hall three-level, and setting the rotor angle as the central angle of the current sector for approaching the current actual angle of the rotor to the maximum extent.

S13, according to the rotor angle determined in the previous step, three-phase currents of the motor are acquired at the same time, clark conversion is performed, components i _ alfa and i _ beta of stator winding currents on alfa and beta axes are obtained, components of the stator winding currents on dq axes are obtained, d-axis currents and q-axis currents are controlled respectively, d-axis voltages and q-axis voltages are obtained, and reverse park conversion is performed by taking the dq-axis voltages and the current angle of the rotor as input quantities to obtain components U _ alfa and U _ beta of inverter output voltages on alfa and beta axes.

S14, respectively controlling the components of the stator winding current on the dq axis, namely FOC control in the prior art; the motor is slowly accelerated from zero speed; and acquiring the real-time state quantity of the current Hall three-level signal changing along with the rotor angle. And updating the current angle in real time. The difference in sector change time is taken twice as delta _ t, delta _ t = t1-t 2. Wherein t1 is the time node of the last sector change, and t2 is the time node of the current sector change. The angular difference of the two sector changes is delta _ theta = pi/3, and the angular velocity w = delta _ theta/delta _ t of the motor is derived based on the above derivation. And performing equivalent operation on the angular speed w to obtain a change value w _ dpp of the angular signal in a switching period.

And S15, updating the current angle signal in real time in each switching cycle, wherein theta _ hall = theta _ hall + w _ dpp.

Specifically, step S2 specifically includes the following steps:

s21, after the theta _ hall is processed by sine and cosine, original sin (theta _ est) and cos (theta _ est) in the back electromotive force observer are replaced by the substitution signals, and the convergence speed of the back electromotive force observer for the back electromotive force observation is increased. Wherein, theta _ est is the angle estimation value of the observer.

The non-inductive observer consists of two parts, namely a back electromotive force observer part and a phase-locked loop (PLL) part; the phase-locked loop module also comprises an angle error calculation module, a PI regulator module and an estimation angle calculation integral feedback module. Preferably, the PLL comprises a PI module including two parameter variables Kp and Ki, a first multiplier M1, a first integrator S2, and a first adder, where Kp is a proportional gain and Ki is an integral gain.

And S22, substituting the theta _ hall signal obtained by calculation in the step S15 into the estimation angle calculation integral feedback module, and accelerating the convergence speed of the estimation angle of the whole PLL module.

Specifically, step S3 specifically includes the following steps:

s31, in the running process of the motor, comparing the output signal of the Hall position sensor signal processing module with the output angle signal of the non-inductive observer, setting a rotating speed point speed1 with the stable output signal of the non-inductive observer as a first switching threshold value, and adding a fixed rotating speed delta _ speed to speed1 to obtain a second switching threshold value speed 2. Wherein delta _ speed = speed/3.

S32, the angle signal w _ dpp obtained after Hall processing is used as an input signal, and the magnitude of theta _ hall _ dpp and speed1 is judged.

S33, if the current motor running mode is a sensing driving mode1 which drives according to the output signal of the Hall position sensor, when w _ dpp is less than or equal to speed2, the current running mode of the motor is still mode1, otherwise, the running mode is switched to mode 2.

S34, if the current motor running mode is a non-inductive driving mode2 which drives according to the output signal of the non-inductive observer, when w _ dpp is less than or equal to speed1, the current running mode of the motor is switched to mode2, otherwise, the current running mode is kept to mode 2.

Specifically, step S4 specifically includes the following steps:

and S41, judging the Hall three-level signals collected in real time, if the three levels are all high levels or all low levels, executing a Hall fault processing step by the controller, writing a Hall fault flag bit into a memory, and switching the motor operation mode to mode 2.

Specifically, step S4 further includes the following steps:

and S42, detecting the Hall level signals, if the Hall three level signals do not have high level or are all low level in n continuous judging periods, clearing the Hall fault flag in the memory, removing the Hall fault state by the controller, and switching to the motor running mode according to the step S32 or S33.

The application discloses a switching strategy of a Hall position sensor and a non-inductive observer; the algorithm controls the three-phase voltage of the IPMSM so as to control the three-phase current of the motor; at a low speed, a position signal of a motor rotor is obtained based on a Hall position sensor; when the device is operated at a medium and high speed, the device is switched to a mode in which a non-inductive observer acquires a position signal; the optimal acquisition of a rotor position signal is realized through a permanent magnet synchronous motor rotor position detection switching system; meanwhile, after the Hall fault is detected to occur, the controller writes the fault state into a flash memory of the controller chip for permanent storage, and meanwhile, the subsequent running state is switched to the non-inductive observer until the Hall position sensor is restored to be normal after being maintained.

By adopting the scheme, the riding noise at medium and high speed is reduced, and the riding comfort of a rider is improved; the functional safety level of the software is improved, the normal riding of the vehicle can be still maintained after the Hall fails, and the redundant control of parts is realized; the output angle of the Hall processing module is used as an initial set value of the non-inductive observer, so that the convergence speed and the convergence precision of the non-inductive observer are improved; the switching control algorithm disclosed by the invention can realize the balance of the stability and the reaction speed of the vehicle, and has comfortable riding experience.

The foregoing description is only exemplary of the preferred embodiments of the disclosure and is illustrative of the principles of the technology employed. It will be appreciated by those skilled in the art that the scope of the invention in the embodiments of the present disclosure is not limited to the specific combination of the above-mentioned features, but also encompasses other embodiments in which any combination of the above-mentioned features or their equivalents is made without departing from the inventive concept as defined above. For example, the above features and (but not limited to) technical features with similar functions disclosed in the embodiments of the present disclosure are mutually replaced to form the technical solution.

Claims (10)

1. A control method suitable for an electric vehicle motor is characterized in that:

the control method suitable for the motor of the electric vehicle is executed by a motor control system, and the motor control system comprises the following steps:

a first-type position sensor for detecting a rotor position of the motor based on a Hall effect to output a first-type rotor angle signal;

a second type position sensor for detecting a rotor position of the motor based on a back electromotive force of the motor to output a second type rotor angle signal;

the controller is used for outputting a driving signal for driving the motor according to the first type of rotor angle signal or/and the second type of rotor angle signal;

the control method comprises the following steps:

the controller collects first-class rotor angle signals of the first-class position sensors;

the controller collects a second type of rotor angle signal of the second type of position sensor;

judging whether the rotating speed of the electronic rotor meets a speed interval defined by the first switching threshold value or/and the second switching threshold value or not according to the first type of rotor angle signal or/and the second type of rotor angle signal, and if the rotating speed meets the speed interval defined by the first switching threshold value or/and the second switching threshold value, switching between a first driving mode and a second driving mode is achieved in a hysteresis switching mode;

when in the first driving mode, the controller outputs the driving signal according to the first type of rotor angle signal; and when in the second driving mode, the controller outputs the driving signal according to the second type of rotor angle signal.

2. The control method for the motor of the electric vehicle according to claim 1, wherein:

wherein the first type of position sensor comprises three Hall position sensors;

the step of acquiring the first type of rotor angle signals of the first type of position sensor by the controller specifically comprises the following steps:

and S1, the Hall position sensor processes the obtained three Hall levels to obtain a motor rotor angle signal under each switching period.

3. The control method for the motor of the electric vehicle according to claim 2, wherein:

the motor is a surface permanent magnet synchronous motor, and the second type of position sensor comprises a non-inductive observer;

the step of acquiring the second type of rotor angle signals of the second type of position sensors by the controller specifically comprises the following steps:

s2, based on the alfa and beta axis fundamental wave voltage equation of the surface permanent magnet synchronous motor, the input quantities U _ alfa, i _ alfa, U _ beta and i _ beta are calculated, and the output angle signal of the non-inductive observer is obtained.

4. The control method for the motor of the electric vehicle according to claim 3, wherein:

wherein, judging whether the rotation speed of the electronic rotor meets the speed interval defined by the first switching threshold value or/and the second switching threshold value according to the first type of rotor angle signal or/and the second type of rotor angle signal, and if the rotation speed meets the speed interval defined by the first switching threshold value or/and the second switching threshold value, implementing switching between the first driving mode and the second driving mode by adopting a hysteresis switching mode specifically comprises:

and S3, setting a rotating speed threshold hysteresis switching mode, including a first switching threshold and a second switching threshold, and realizing smooth switching of two angle acquisition modes of the non-inductive observer and the Hall position sensor.

5. The control method for the motor of the electric vehicle according to claim 4, wherein:

wherein, judging whether the rotation speed of the electronic rotor meets the speed interval defined by the first switching threshold value or/and the second switching threshold value according to the first type of rotor angle signal or/and the second type of rotor angle signal, and if the rotation speed meets the speed interval defined by the first switching threshold value or/and the second switching threshold value, implementing switching between the first driving mode and the second driving mode in a hysteresis switching manner further specifically comprises:

and S4, monitoring the health state of the Hall position sensor on line at the full-time operation stage of the motor, and if a fault occurs, switching to a non-inductive mode to operate, so as to realize redundant control under the Hall fault of the motor.

6. The control method for the motor of the electric vehicle according to claim 5, wherein:

the step S1 specifically includes the following steps:

s11, setting the initial calculation signal of the Hall three-level angle to be 0;

s12, determining the current sector of the rotor position signal according to the current state of the Hall three-level, and setting the rotor angle as the central angle of the current sector in order to approach the current actual angle of the rotor to the maximum extent;

s13, according to the rotor angle determined in the previous step, three-phase currents of the motor are obtained at the same time, clark conversion is carried out, components i _ alfa and i _ beta of stator winding currents on alfa and beta axes are obtained, components of the stator winding currents on dq axes are obtained, d-axis currents and q-axis currents are controlled respectively, d-axis voltages and q-axis voltages are obtained, and reverse park conversion is carried out by taking the dq-axis voltages and the current angle of the rotor as input quantities to obtain components U _ alfa and U _ beta of inverter output voltages on alfa and beta axes;

s14, updating the current angle in real time; taking the time difference of two sector changes as delta _ t, wherein the delta _ t = t1-t 2; wherein t1 is the time node of the last sector change, and t2 is the time node of the current sector change; the angular difference of the two sector changes is delta _ theta = pi/3, and the angular speed w = delta _ theta/delta _ t of the motor is obtained based on the derivation; performing equivalent operation on the angular speed w to obtain a change value w _ dpp of the angular signal in a switching period;

and S15, updating the current angle signal in real time in each switching cycle, wherein theta _ hall = theta _ hall + w _ dpp.

7. The control method for the motor of the electric vehicle according to claim 6, wherein:

the step S2 specifically includes the following steps:

s21, after the theta _ hall is processed by sine and cosine, original sin (theta _ est) and cos (theta _ est) in the back electromotive force observer are replaced by substitute signals, and the convergence speed of the back electromotive force observer for the back electromotive force observation is accelerated; wherein theta _ est is an angle estimation value of the observer;

and S22, substituting the theta _ hall signal obtained by calculation in the step S15 into the estimation angle calculation integral feedback module, and accelerating the convergence speed of the estimation angle of the whole PLL module.

8. The control method for the motor of the electric vehicle according to claim 7, wherein:

the step S3 specifically includes the following steps:

s31, in the running process of the motor, comparing an output signal of the Hall position sensor signal processing module with an output angle signal of the non-inductive observer, setting a rotating speed point speed1 with a stable output signal of the non-inductive observer as a first switching threshold value, and adding a fixed rotating speed delta _ speed to speed1 to obtain a second switching threshold value speed 2; wherein delta _ speed = speed/3;

s32, taking the angle signal w _ dpp obtained after Hall processing as an input signal, and judging the magnitude of theta _ hall _ dpp and speed 1;

s33, if the current motor running mode is a sensing driving mode1 which drives according to the output signal of the Hall position sensor, when w _ dpp is less than or equal to speed2, the current running mode of the motor is still mode1, otherwise, the running mode is switched to mode 2;

s34, if the current motor running mode is a non-inductive driving mode2 which drives according to the output signal of the non-inductive observer, when w _ dpp is less than or equal to speed1, the current running mode of the motor is switched to mode2, otherwise, the current running mode is kept to mode 2.

9. The control method for the motor of the electric vehicle according to claim 8, wherein:

the step S4 specifically includes the following steps:

and S41, judging the Hall three-level signals collected in real time, if the three levels are all high levels or all low levels, executing a Hall fault processing step by the controller, writing a Hall fault flag bit into a memory, and switching the motor operation mode to mode 2.

10. The control method for the motor of the electric vehicle according to claim 9, wherein:

the step S4 further includes the following steps:

and S42, detecting the Hall level signals, if the Hall three level signals do not have high level or are all low level in n continuous judgment periods, clearing the Hall fault flag in the memory, removing the Hall fault state by the controller, and switching to the motor running mode according to the step S32 or S33.

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