CN112583307B

CN112583307B - Permanent magnet synchronous motor and soft decoding method and system of rotary transformer of permanent magnet synchronous motor

Info

Publication number: CN112583307B
Application number: CN202011482161.0A
Authority: CN
Inventors: 马彦; 陈娜娜; 张国花; 徐龙增; 郎学政; 张正阳; 李富民
Original assignee: Weichai Power Co Ltd
Current assignee: Weichai Power Co Ltd
Priority date: 2020-12-15
Filing date: 2020-12-15
Publication date: 2022-08-05
Anticipated expiration: 2040-12-15
Also published as: CN112583307A

Abstract

The invention discloses a soft decoding method and a soft decoding system for a permanent magnet synchronous motor and a rotary transformer thereof, wherein the soft decoding method comprises the following steps: the controller acquires a discrete envelope line of an orthogonal differential sine and cosine signal of a rotary transformer of the permanent magnet synchronous motor in a first period; performing arc tangent operation on the discrete envelope curve of the orthogonal differential sine and cosine signals to obtain a first rotor angle corresponding to the discrete envelope curve of the orthogonal differential sine and cosine signals; the third-order angle observer calculates a second rotor angle according to the first rotor angle and a third-order angle observation algorithm, wherein the first rotor angle is used as an initial value of a last integrator of the third-order angle observer; the controller controls the permanent magnet synchronous motor according to the second rotor angle. The technical scheme provided by the invention not only meets the safety level of ISO26262 ASIL D, but also can obtain accurate rotor position information, improves the smoothness of the motor during starting and has better dynamic response characteristic.

Description

Permanent magnet synchronous motor and soft decoding method and system of rotary transformer of permanent magnet synchronous motor

Technical Field

The embodiment of the invention relates to the technical field of motors, in particular to a permanent magnet synchronous motor and a soft decoding method and system of a rotary transformer of the permanent magnet synchronous motor.

Background

Currently, a dedicated spin-hardened part decoding chip is mostly adopted when a permanent magnet synchronous motor acquires a rotor position, the method cannot meet the requirement of an automobile Safety integrity Level D (ASIL D) in the ISO26262 standard, potential Safety hazards exist, and the Safety Level cannot be improved only through the same hardware redundancy; in addition, the existing soft decoding algorithm, namely the current angle observer algorithm ignores the hysteresis of integral, the accurate initial rotor position cannot be obtained at the first step of the system algorithm, the magnetic field orientation of the permanent magnet synchronous motor is influenced, and the stability of the motor during starting is reduced.

Disclosure of Invention

The invention provides a permanent magnet synchronous motor and a soft decoding method and system of a rotary transformer of the permanent magnet synchronous motor, which can not only meet the safety level of ISO26262 ASIL D, but also obtain accurate rotor position information, improve the smoothness of the motor during starting and have better dynamic response characteristics.

In a first aspect, an embodiment of the present invention provides a soft decoding method for a resolver of a permanent magnet synchronous motor, including the following steps:

the controller acquires a discrete envelope line of an orthogonal differential sine and cosine signal of the rotary transformer of the permanent magnet synchronous motor in a first period;

performing arc tangent operation on the discrete envelope curve of the orthogonal differential sine and cosine signal to obtain a first rotor angle corresponding to the discrete envelope curve of the orthogonal differential sine and cosine signal;

the third-order angle observer calculates a second rotor angle according to the first rotor angle and a third-order angle observation algorithm, wherein the first rotor angle is used as an initial value of a last integrator of the third-order angle observer;

and the controller controls the permanent magnet synchronous motor according to the second rotor angle.

Optionally, before the controller obtains the discrete envelope of the quadrature differential sine and cosine signal of the resolver of the permanent magnet synchronous motor at the first period, the method further includes:

and the DSADC module collects discrete envelope lines of orthogonal differential sine and cosine signals of the permanent magnet synchronous motor rotary transformer in a second period, wherein the second period is greater than the first period.

Optionally, after the controller obtains the first rotor angle corresponding to the discrete envelope of the orthogonal differential sine and cosine signal, the method further includes:

the controller obtains an angle compensation quantity of the first rotor angle;

and the third-order angle observer calculates a second rotor angle according to the first rotor angle, the angle compensation quantity and a third-order angle observation algorithm.

Optionally, the obtaining, by the controller, an angle compensation amount of the first rotor angle includes:

acquiring a time difference value between the end time of the Nth first period and the end time of the (N-1) th second period;

acquiring the angular velocity value output by the third-order angle observer at the moment when the (N-1) th first period ends;

and acquiring an angle compensation quantity of the first rotor angle corresponding to the moment when the Nth first period ends according to the time difference and the angular velocity value, wherein the time difference is greater than or equal to zero and smaller than the first period, N is greater than or equal to 3, and N is a positive integer.

Optionally, before the controller performs an arc tangent operation on the discrete envelope of the quadrature differential sine and cosine signal, the method further includes:

judging whether the sum of the square of the sine signal and the square of the cosine signal is within the range of 1 +/-delta;

if the sum of the square of the sine signal and the square of the cosine signal is within the range of 1 +/-delta, continuing to perform arc tangent operation on the discrete envelope curve of the orthogonal differential sine and cosine signal;

and if the sum of the square of the sine signal and the square of the cosine signal is not within the range of 1 +/-delta, returning to the step of acquiring the discrete envelope curve of the orthogonal differential sine and cosine signal of the permanent magnet synchronous motor resolver in a first period, wherein delta is a preset constant.

Optionally, the acquiring, by the DSADC module, a discrete envelope of an orthogonal differential sine and cosine signal of the resolver of the permanent magnet synchronous motor at a second period includes:

the DSADC module generates positive and negative PWM signals and sends the positive and negative PWM signals to the rotary transformer excitation circuit;

the positive and negative PWM signals are converted into sine and cosine excitation signals through the rotary transformer excitation circuit and are sent to a rotary transformer;

the sine and cosine excitation signals are converted into four paths of orthogonal differential sine and cosine signals through the rotary transformer and are sent to a rotary transformer return buffer circuit;

the four paths of orthogonal differential sine and cosine signals are subjected to offset adjustment and proportion adjustment through the rotary transformer return buffer circuit and then are sent to the DSADC module;

the four paths of orthogonal differential sine and cosine signals after offset adjustment and proportion adjustment are modulated, filtered, shaped and integrated by the DSADC, and discrete envelope lines of the two paths of orthogonal differential sine and cosine signals are acquired by the DSADC module.

Alternatively to this, the first and second parts may,

the DSADC module generates positive and negative PWM signals and synchronous signals at the same time, and sends the synchronous signals to a shaping unit of the DSADC module;

and a shaping unit of the DSADC module corrects the four paths of orthogonal differential sine and cosine signals according to the synchronous signals.

In a second aspect, an embodiment of the present invention further provides a soft decoding system for a rotating transformer of a permanent magnet synchronous motor, including:

the controller acquires a discrete envelope line of an orthogonal differential sine and cosine signal of the permanent magnet synchronous motor rotary transformer in a first period; performing arc tangent operation on the discrete envelope curve of the orthogonal differential sine and cosine signal to obtain a first rotor angle corresponding to the discrete envelope curve of the orthogonal differential sine and cosine signal;

the controller is also used for controlling the permanent magnet synchronous motor according to the second rotor angle.

Optionally, the soft decoding system of the resolver of the permanent magnet synchronous motor further includes:

the DSADC module collects discrete envelope lines of orthogonal differential sine and cosine signals of the permanent magnet synchronous motor rotary transformer in a second period, wherein the second period is larger than the first period.

In a third aspect, an embodiment of the present invention further provides a permanent magnet synchronous motor, including the soft decoding system of the resolver of the permanent magnet synchronous motor as described above.

In the embodiment of the invention, the discrete envelope curve of the orthogonal differential sine and cosine signal of the rotary transformer of the permanent magnet synchronous motor is obtained once every other first period by the controller, and the arc tangent operation is carried out on the discrete envelope curve of the orthogonal differential sine and cosine signal obtained each time to obtain the corresponding first rotor angle; the third-order angle observer adopts a third-order angle observation algorithm to calculate and obtain a second rotor angle according to the first rotor angle, wherein the first rotor angle is determined as an initial value of a last integrator of the third-order angle observer, the problem of hysteresis of neglecting an integration link in the existing soft decoding algorithm is solved, the problem of obtaining an accurate initial rotor position is realized, the smoothness of the motor during starting is improved while the safety level of ISO26262 ASIL D is met, and the dynamic response characteristic is better.

Drawings

Fig. 1 is a flowchart of a soft decoding method for a rotating transformer of a permanent magnet synchronous motor according to an embodiment of the present invention;

FIG. 2 is a schematic diagram of a relationship between the quadrature differential sine and cosine signal and a rotor position according to an embodiment of the present invention;

fig. 3 is a flowchart of a soft decoding method for a rotating transformer of a permanent magnet synchronous motor according to a second embodiment of the present invention;

fig. 4 is a flowchart of a DSADC module according to a second embodiment of the present invention acquiring discrete envelope curves of quadrature differential sine and cosine signals of a resolver of a permanent magnet synchronous motor at a second period;

fig. 5 is a flowchart illustrating the controller obtaining the angle compensation amount of the first rotor angle according to the second embodiment of the present invention;

FIG. 6 is a time axis of a first period and a second period provided in accordance with an embodiment of the present invention;

FIG. 7a is a partial software flowchart of a soft decoding algorithm provided in the second embodiment of the present invention;

FIG. 7b is another partial software flowchart of the soft decoding algorithm provided in the second embodiment of the present invention;

fig. 8 is a schematic structural diagram of a soft decoding system of a resolver of a permanent magnet synchronous motor according to a third embodiment of the present invention;

fig. 9 is a schematic structural diagram of a soft decoding system of a resolver of a permanent magnet synchronous motor according to another embodiment of the present invention;

fig. 10 is a block diagram of a permanent magnet synchronous motor according to a fourth embodiment of the present invention.

Detailed Description

The present invention will be described in further detail with reference to the drawings and examples. It is to be understood that the specific embodiments described herein are merely illustrative of the invention and are not limiting of the invention. It should be further noted that, for the convenience of description, only some of the structures related to the present invention are shown in the drawings, not all of the structures.

Example one

Fig. 1 is a flowchart of a soft decoding method for a resolver of a permanent magnet synchronous motor according to an embodiment of the present invention. As shown in fig. 1, the soft decoding method for the permanent magnet synchronous motor resolver includes the following steps:

s110, the controller acquires a discrete envelope curve of an orthogonal differential sine and cosine signal of the rotary transformer of the permanent magnet synchronous motor in a first period.

When the permanent magnet synchronous motor rotary transformer works, a sine winding of the permanent magnet synchronous motor rotary transformer can output a sine signal, other chord windings can output a cosine signal, the sine signal and the cosine signal are in orthogonal difference, fig. 2 is a schematic diagram of the relation between the orthogonal difference sine and cosine signals and the position of a rotor, which is provided by the first embodiment of the invention, and as shown in fig. 2, the position information of the rotor can be obtained by acquiring the discrete envelope curve of the orthogonal difference sine and cosine signals and combining an arctangent function. According to the soft decoding method of the permanent magnet synchronous motor rotary transformer, firstly, a discrete envelope curve of the orthogonal differential sine and cosine signal is obtained once every first period through a controller. It is understood that the first period, i.e. a time interval, corresponds to a certain frequency, and for example, the frequency of the first period may be 10 Khz.

And S120, performing arc tangent operation on the discrete envelope curve of the orthogonal differential sine and cosine signal to obtain a first rotor angle corresponding to the discrete envelope curve of the orthogonal differential sine and cosine signal.

After the discrete envelope curve of the orthogonal differential sine and cosine signal is obtained each time, the controller performs arc tangent operation on the discrete envelope curve of the sine and cosine signal by using a four-quadrant arc tangent function ATAN2, and the obtained angle is the first rotor angle.

S130, the third-order angle observer calculates a second rotor angle according to the first rotor angle and a third-order angle observation algorithm, wherein the first rotor angle is used as an initial value of a last integrator of the third-order angle observer.

The controller initially performs arc tangent operation on the discrete envelope curve of the sine and cosine signal by using a four-quadrant arc tangent function ATAN2, and the obtained angle is the first rotor angle.

And performing integral operation on the first rotor angle through a first integrator of the third-order angle observer to calculate angular acceleration, then calculating angular velocity through a second integrator according to the angular acceleration, and finally calculating a second rotor angle through a last integrator. The embodiment of the invention limits the first rotor angle to the initial value of the last integrator of the third-order angle observer, solves the problem of hysteresis existing in integration, enables the soft decoding system to obtain the initial absolute position of the rotor at the first step length, ensures the stability of the magnetic field orientation control system when the permanent magnet synchronous motor is started, and has stronger robustness.

And S140, controlling the permanent magnet synchronous motor by the controller according to the second rotor angle.

According to the second rotor angle obtained by the third-order angle observer, the controller can accurately and stably control the operation of the permanent magnet synchronous motor.

In the first embodiment of the invention, a discrete envelope curve of an orthogonal differential sine and cosine signal of a rotary transformer of a permanent magnet synchronous motor is obtained once every other first period through a controller, and arc tangent operation is carried out on the discrete envelope curve of the orthogonal differential sine and cosine signal obtained every time to obtain a corresponding first rotor angle; the third-order angle observer adopts a third-order angle observation algorithm to calculate and obtain a second rotor angle according to the first rotor angle, wherein the first rotor angle is determined as an initial value of a last integrator of the third-order angle observer, the problem of hysteresis of neglecting an integration link in the existing soft decoding algorithm is solved, the problem of obtaining an accurate initial rotor position is realized, the smoothness of the motor during starting is improved while the safety level of ISO26262 ASIL D is met, and the dynamic response characteristic is better.

Example two

On the basis of the first embodiment, a second embodiment of the present invention further provides another soft decoding method for a rotating transformer of a permanent magnet synchronous motor, and fig. 3 is a flowchart of the soft decoding method for the rotating transformer of the permanent magnet synchronous motor according to the second embodiment of the present invention. Referring to fig. 3, the soft decoding method for the resolver of the permanent magnet synchronous motor includes the steps of:

s210, a DSADC (Delta-Sigma Analog Digital Converter) module collects discrete envelope lines of orthogonal differential sine and cosine signals of the rotary transformer of the permanent magnet synchronous motor at a second period, wherein the second period is greater than the first period.

The DSADC module may be an Analog to Digital Converter (Delta-Sigma Analog Digital Converter). The DSADC module acquires discrete envelope lines of the orthogonal differential sine and cosine signals every second period. It is understood that the second period, i.e., a time interval, corresponds to a certain frequency, and the second period is greater than the first period, and the second period may correspond to a frequency of 9.7Khz, for example.

Fig. 4 is a flowchart of the DSADC module according to the second embodiment of the present invention acquiring discrete envelope curves of the quadrature differential sine and cosine signals of the resolver of the permanent magnet synchronous motor at the second period. Optionally, referring to fig. 4, S210 includes that the DSADC module acquires discrete envelope curves of the quadrature differential sine-cosine signals of the resolver of the permanent magnet synchronous motor at the second period, where the discrete envelope curves include:

s2101, DSADC module produce two way PWM signal of positive and negative, and send to and change the excitation circuit soon.

A carrier generation unit in the DSADC module can generate positive and negative high-frequency PWM signals and transmit the signals to the rotary transformer excitation circuit.

And S2102, the positive and negative PWM signals are changed into sine and cosine excitation signals through a rotary excitation circuit and are sent to the rotary transformer.

The rotary transformer excitation circuit converts the positive and negative PWM signals into sine excitation signals and cosine excitation signals and transmits the sine excitation signals and the cosine excitation signals to the rotary transformer.

And S2103, the sine and cosine excitation signals are converted into four paths of orthogonal differential sine and cosine signals through the rotary transformer and are sent to the rotary transformer return buffer circuit.

The rotary transformer converts the sine excitation signal and the cosine excitation signal into four paths of orthogonal differential sine and cosine signals, and transmits the four paths of orthogonal differential sine and cosine signals to the rotary transformer return buffer circuit.

And S2104, the four paths of orthogonal differential sine and cosine signals are subjected to offset adjustment and proportion adjustment through a rotary transformer return buffer circuit and then are sent to the DSADC module.

The rotary transformer return buffer circuit performs offset adjustment and proportion adjustment on the four paths of orthogonal differential sine and cosine signals, and the four paths of orthogonal differential sine and cosine signals are transmitted to a modulation unit of the DSADC module through a channel of the DSADC module.

S2105, after the four paths of orthogonal differential sine and cosine signals are subjected to bias adjustment and proportion adjustment, the four paths of orthogonal differential sine and cosine signals are subjected to DSADC modulation, filtering, shaping and integration, and the DSADC module acquires discrete envelope curves of the two paths of orthogonal differential sine and cosine signals.

The modulation unit of the DSADC module converts the four paths of orthogonal differential sine and cosine signals after offset adjustment and proportion adjustment into high-frequency 1-bit data stream signals and transmits the high-frequency 1-bit data stream signals to the filtering unit of the DSADC module. The filtering unit of the DSADC module converts the signal into a low-frequency and multi-bit digital result and transmits the digital result to the shaping unit of the DSADC module.

Optionally, the DSADC module may generate a synchronization signal while generating positive and negative PWM signals, and send the synchronization signal to the shaping unit of the DSADC module; and a shaping unit of the DSADC module corrects four paths of orthogonal differential sine and cosine signals according to the synchronous signals.

And the shaping unit of the DSADC module inverts the low-frequency and multi-bit digital result output by the filtering unit in a negative half cycle mode according to the synchronous signal, namely corrects the four paths of orthogonal differential sine and cosine signals, and then transmits the four paths of orthogonal differential sine and cosine signals to the integrating unit of the DSADC module. And finally, an integration unit of the DSADC module obtains discrete envelope lines of the two orthogonal differential sine and cosine signals through integration.

S220, the controller acquires a discrete envelope curve of an orthogonal differential sine and cosine signal of the rotary transformer of the permanent magnet synchronous motor in a first period.

And S230, performing arc tangent operation on the discrete envelope curve of the orthogonal differential sine and cosine signal to obtain a first rotor angle corresponding to the discrete envelope curve of the orthogonal differential sine and cosine signal.

Optionally, before S230, that is, before the controller performs an arctangent operation on the discrete envelope of the quadrature differential sine-cosine signal, the method may further include:

s2301, judging whether the sum of the square of the sine signal and the square of the cosine signal is within the range of 1 +/-delta, wherein delta is a preset constant; if yes, go to S230; if not, go to step S220.

The controller acquires a discrete envelope curve of an orthogonal differential sine and cosine signal of a permanent magnet synchronous motor rotary transformer in a first period, before performing arc tangent operation, the controller needs to perform inspection operation on the acquired orthogonal differential sine and cosine signal to judge whether the sine and cosine signal is correct, specifically, firstly, square sum operation is performed on the sine signal and the cosine signal to judge whether the sum of the square of the sine signal and the square of the cosine signal is equal to 1 or within the range of 1 +/-delta, delta is a preset constant of an evaluation error, and exemplarily, the value of delta can be 0.1, 0.01 or 0.001 and the like; if so, performing arc tangent operation on the discrete envelope line of the orthogonal differential sine and cosine signal; and if not, returning, and acquiring the discrete envelope curve of the orthogonal differential sine and cosine signals of the rotary transformer of the permanent magnet synchronous motor again in the first period.

S240, the controller obtains the angle compensation quantity of the first rotor angle.

The DSADC module has certain program delay when acquiring discrete envelope lines of sine and cosine signals, the angle compensation amount is used for calculating the time consumed by system sampling and calculation so as to compensate or calculate the lost rotor position, and the hardware basis of the step is a GTM TIM module in an Aurix singlechip.

Fig. 5 is a flowchart illustrating the method for acquiring the angle compensation amount of the first rotor angle by the controller according to the second embodiment of the present invention. Alternatively, referring to fig. 5, S240 includes that the controller obtains the angle compensation amount of the first rotor angle may include:

s2401, obtaining a time difference value between the end time of the Nth first period and the end time of the (N-1) th second period.

To more clearly explain the specific steps of the controller obtaining the angle compensation amount of the first rotor angle, the following explanation is made by way of example. The second period is greater than the first period, for example, the first period may be 100us, the second period may be 102us, and fig. 6 is a time axis of the first period and the second period according to a second embodiment of the present invention, as shown in fig. 6, after the rotation transformer of the permanent magnet synchronous motor is started, the DSADC module collects discrete envelope curves of the orthogonal differential sine and cosine signals of the rotation transformer of the permanent magnet synchronous motor in the second period, and the controller performs arc tangent calculation on the discrete envelope curves of the orthogonal differential sine and cosine signals in the first period, because the first period is smaller than the second period, after the rotation transformer of the permanent magnet synchronous motor is started, a time point of collecting the discrete envelope curves of the orthogonal differential sine and cosine signals of the rotation transformer of the permanent magnet synchronous motor lags behind a time point of the arc tangent calculation, and further, at a time point of the arc tangent calculation, the rotor of the permanent magnet synchronous motor has rotated by a certain angle, the angle that the rotor rotates corresponding to the time difference needs to be compensated. When the controller needs to acquire the 1 st orthogonal differential sine and cosine signal for operation at the time of the 1 st first cycle ending, because the time of the 1 st second cycle ending is not yet ended, the 1 st orthogonal differential sine and cosine signal is not acquired yet, so the controller can acquire the sine and cosine signal at the time of the 1 st second cycle ending only at the time of the 2 nd first cycle ending, as shown in fig. 6, the acquired time difference between the time of the 2 nd first cycle ending and the time of the 1 st second cycle ending is 100- (102-100) ═ 98us, and the difference gradually decreases with the increase of time.

S2402, acquiring angular velocity values output by a third-order angle observer at the end of the (N-1) th first period.

S2403, acquiring an angle compensation amount of the first rotor angle corresponding to the moment when the Nth first period ends according to the time difference and the angular velocity value, wherein the time difference is greater than or equal to zero and smaller than the first period, N is greater than or equal to 3, and N is a positive integer.

It should be noted that N is greater than or equal to 3, since the third-order angle observer outputs the angular velocity value only at the time when the second first cycle ends, the rotor of the permanent magnet synchronous motor rotates by a certain angle between the time when the second first cycle ends and the time when the first second cycle ends and cannot be calculated, the time difference between the rotor of the permanent magnet synchronous motor and the time when the second cycle ends is calculated only at the time when the third first cycle ends, the angular velocity value output by the third-order angle observer at the time when the second first cycle ends is obtained, and the angular velocity value output by the third-order angle observer and the third-order angle observer are multiplied to obtain the input angle compensation quantity of the third first cycle and the third-order angle observer.

It can be understood that, with the calculation, the difference between the nth first period and the N-1 st second period is smaller and smaller until the difference between the nth first period and the N-1 st second period is zero, that is, the end time of the nth first period and the end time of the N-1 st second period are the same, the end time of the N +1 st first period and the end time of the nth second period have not yet come, and thus, the end time of the N +1 st first period cannot obtain the discrete envelope acquired at the end time of the nth second period, and further, the end time of the N +2 th first period cannot obtain the discrete envelope acquired at the end time of the nth second period and calculate, and start a new cycle.

And S250, the third-order angle observer calculates a second rotor angle according to the first rotor angle, the angle compensation quantity and the third-order angle observation algorithm, wherein the first rotor angle is used as an initial value of a last integrator of the third-order angle observer.

The third-order angle observer firstly superposes the first rotor angle and the angle compensation quantity to obtain an accurate rotor angle, then carries out integral operation on the accurate rotor angle through a first integrator of the third-order angle observer to calculate angular acceleration, then calculates angular velocity according to the angular acceleration through a second integrator, and finally calculates a second rotor angle through a last integrator.

And S260, controlling the permanent magnet synchronous motor by the controller according to the second rotor angle.

The soft decoding algorithm program comprises a DSADC initialization function, a DSADC interruption function, a soft decoding initialization function automatically generated by the model and a rotor angle observation function, and the software flow is shown in FIG. 7a and FIG. 7 b. Fig. 7a is a partial software flowchart of a soft decoding algorithm provided in the second embodiment of the present invention, and fig. 7b is another partial software flowchart of a soft decoding algorithm provided in the second embodiment of the present invention. Referring to fig. 7a and 7b, a DSADC initialization function and a soft decoding initialization function are performed in a main function, wherein the DSADC initialization includes: the method comprises the following steps that DSADC initialization is started, carrier generation unit configuration, rotary transformer return signal channel configuration, modulation unit configuration, filtering unit configuration, shaping unit configuration and integration unit configuration are carried out, and DSADC initialization is finished. After the initialization of the DSADC is finished, a model function is initialized, so that total interruption is enabled (a function related to time starts to time), a main loop (each unit of the DSADC starts to work), and a rotation soft decoding fault is processed (namely whether the acquired discrete envelope is reasonable or not is judged), and if the acquired discrete envelope is reasonable, the main loop is returned; if the discrete envelope of the acquisition is not reasonable, it is concluded and the various modules of the DASDC are examined.

As shown in fig. 7b, after the initialization of the DSADC is completed, the carrier generation unit outputs a high-frequency carrier and a synchronization signal, the modulation unit receives a rotary transformer return signal, triggers the DSADC to interrupt (interrupt frequency is 9.7Khz), the interruption of the DSADC starts to acquire discrete envelope information of the rotary transformer return buffer signal, the interruption of the DSADC ends, the filtering unit filters the acquired discrete envelope information, the shaping unit shapes the filtered discrete envelope information, and the integration unit integrates the shaped discrete envelope information to acquire an envelope of the discrete rotary transformer signal. The synchronous signal generated by the carrier generation unit is input into the shaping unit, and the discrete envelope information after filtering is synchronously corrected.

Triggering DSADC interruption (9.7Khz) after a modulation unit of the DSADC module receives a rotary transformer return signal, and acquiring envelope information of an orthogonal differential signal in the DSADC interruption; the rotor angle observation function is executed in FOC main interruption, the interruption is triggered by PWM (10KHz), in the rotor angle observation function, envelope information output in DSADC interruption is read firstly, then initial rotor angle information is obtained through a four-quadrant arc tangent function ATAN2, combined rotor angle reference information is obtained through rotor angle compensation, then a rotor angle is obtained through a three-order angle observer, finally, the observed rotor angle is filtered, and the filtered rotor angle is transmitted to the FOC function to realize the directional control of the rotor magnetic field of the permanent magnet synchronous motor.

In the embodiment of the invention, the discrete envelope line of the orthogonal differential sine and cosine signal of the rotary transformer of the permanent magnet synchronous motor is acquired once every second period through the DSADC module; the controller acquires discrete envelope lines of orthogonal differential sine and cosine signals of the permanent magnet synchronous motor rotary transformer every other first period, wherein the second period is controlled to be larger than the first period, and the controller performs arc tangent operation on the discrete envelope lines of the orthogonal differential sine and cosine signals acquired each time to acquire a corresponding first rotor angle; the angle compensation quantity is obtained, the second rotor angle is obtained through calculation by combining the first rotor angle and a third-order angle observation algorithm, wherein the first rotor angle is determined as an initial value of a last integrator of a third-order angle observer, the problem of hysteresis of neglecting an integration link in the existing soft decoding algorithm is solved, the problem of obtaining an accurate initial rotor position is realized, the safety level of ISO26262 ASIL D is met, the smoothness of the motor during starting is improved, and the dynamic response characteristic is better.

EXAMPLE III

On the basis of the above embodiment, the third embodiment of the present invention further provides a soft decoding system for a resolver of a permanent magnet synchronous motor. Fig. 8 is a schematic structural diagram of a soft decoding system of a rotating transformer of a permanent magnet synchronous motor according to a third embodiment of the present invention, and as shown in fig. 8, the soft decoding system 10 of the rotating transformer of the permanent magnet synchronous motor includes:

the controller 100 acquires a discrete envelope curve of an orthogonal differential sine and cosine signal of the permanent magnet synchronous motor rotary transformer at a first period by the controller 100; and performing arc tangent operation on the discrete envelope curve of the orthogonal differential sine and cosine signal to obtain a first rotor angle corresponding to the discrete envelope curve of the orthogonal differential sine and cosine signal.

Specifically, the controller 100 in the soft decoding system 10 of the rotating transformer of the permanent magnet synchronous motor acquires the discrete envelope of the orthogonal differential sine and cosine signal every first period. It is understood that the first period, i.e. a time interval, corresponds to a certain frequency, and for example, the frequency of the first period may be 10 Khz. After acquiring the discrete envelope curve of the orthogonal differential sine and cosine signal each time, the controller 100 performs an arc tangent operation on the sine and cosine signal by using a four-quadrant arc tangent function ATAN2, and the acquired angle is the first rotor angle.

The third order angle observer 200, the third order angle observer 200 calculates the second rotor angle according to the first rotor angle and the third order angle observation algorithm, wherein the first rotor angle is used as the initial value of the third integrator 230 in the third order angle observer 200.

Specifically, the first integrator 210 of the third-order angle observer 200 in the soft decoding system 10 of the resolver of the permanent magnet synchronous motor performs integral operation on the first rotor angle to calculate the angular acceleration, then the second integrator 220 calculates the angular velocity according to the angular acceleration, and finally the second rotor angle is calculated through the last integrator, namely the third integrator 230, and the first rotor angle is defined as the initial value of the last integrator, namely the third integrator 230, of the third-order angle observer 230, so that the problem of hysteresis existing in integration is solved, the soft decoding system 10 can obtain the initial absolute position of the rotor at the first step length, the stability of a magnetic field orientation control system when the permanent magnet synchronous motor is started is ensured, and the soft decoding system has strong robustness.

The controller 100 is also configured to control the permanent magnet synchronous motor according to the second rotor angle.

On the basis of the above embodiment, the third embodiment of the present invention further provides a soft decoding system for a resolver of a permanent magnet synchronous motor. Fig. 9 is a schematic structural diagram of a soft decoding system of another rotating transformer of a permanent magnet synchronous motor according to a third embodiment of the present invention. Optionally, as shown in fig. 9, the soft decoding system 10 of the rotating transformer of the permanent magnet synchronous motor may further include: the DSADC module 300, the DSADC module 300 collects discrete envelope curves of orthogonal differential sine and cosine signals of the resolver of the permanent magnet synchronous motor at a second period, wherein the second period is greater than the first period.

The DSADC module 300 may include a carrier generation unit 310, a modulation unit 320, a filtering unit 330, a shaping unit 340, and an integration unit 350. The carrier generation unit 310 may generate positive and negative high-frequency PWM signals, and transmit the signals to the rotating excitation circuit 400. The carrier generation unit 310 may generate a synchronization signal while generating positive and negative PWM signals, and send the synchronization signal to the shaping unit 340, and the shaping unit 340 corrects the four orthogonal differential sine and cosine signals according to the synchronization signal. The resolver excitation circuit 400 converts the positive and negative PWM signals into sine excitation signals and cosine excitation signals, and transmits them to the resolver 500. The resolver 500 converts the sine excitation signal and the cosine excitation signal into four orthogonal differential sine and cosine signals, and transmits the signals to the resolver return buffer circuit 600. The rotary transformer return buffer circuit 600 performs offset adjustment and proportional adjustment on the four paths of orthogonal differential sine and cosine signals, and transmits the four paths of orthogonal differential sine and cosine signals to the modulation unit 320 through the channel of the DSADC module 300. The modulation unit 320 converts the four paths of orthogonal differential sine and cosine signals after bias adjustment and proportion adjustment into high-frequency 1-bit data stream signals, and transmits the data stream signals to the filtering unit 330. The filtering unit 330 converts the signal into a low frequency, multi-bit digital result and transmits the result to the shaping unit 340. The shaping unit 340 performs negative half-cycle inversion on the low-frequency multi-bit digital result output by the filtering unit 330 according to the synchronization signal, i.e., corrects the four paths of quadrature differential sine-cosine signals, and then transmits the four paths of quadrature differential sine-cosine signals to the integrating unit 350. Finally, the integration unit 350 obtains discrete envelope curves of the two orthogonal differential sine and cosine signals through integration.

The controller 100 is further configured to obtain an angle compensation amount for the first rotor angle. The third order angle observer 200 calculates the second rotor angle according to the first rotor angle, the angle compensation amount and the third order angle observation algorithm, wherein the first rotor angle is used as an initial value of the last integrator of the third order angle observer, i.e. the third integrator 230. The controller 100 controls the permanent magnet synchronous motor according to the second rotor angle.

The embodiment of the invention collects the discrete envelope line of the orthogonal differential sine and cosine signal of the permanent magnet synchronous motor rotary transformer once every second period through the DSADC module; the controller acquires discrete envelope lines of orthogonal differential sine and cosine signals of the permanent magnet synchronous motor rotary transformer every other first period, wherein the second period is controlled to be larger than the first period, and the controller performs arc tangent operation on the discrete envelope lines of the orthogonal differential sine and cosine signals acquired each time to acquire a corresponding first rotor angle; the angle compensation quantity is obtained, and the second rotor angle is obtained by combining the first rotor angle and a third-order angle observation algorithm, wherein the first rotor angle is determined as the initial value of the last integrator of the third-order angle observer, so that the problem of neglecting the hysteresis of an integration link in the existing soft decoding algorithm is solved, the problem of obtaining an accurate initial rotor position is realized, the smoothness of the motor during starting is improved while the safety level of ISO26262 ASIL D is met, and the dynamic response characteristic is better; the ASIL D requirement that the automobile manufacturer provided to motor rotor position acquisition is satisfied to no longer use extra hard piece decoding chip soon, the cost is reduced.

Example four

On the basis of the above embodiment, the fourth embodiment of the invention further provides a permanent magnet synchronous motor. Fig. 10 is a block diagram of a permanent magnet synchronous motor according to a fourth embodiment of the present invention, and as shown in fig. 10, the permanent magnet synchronous motor 1 includes the soft decoding system 10 of the resolver of the permanent magnet synchronous motor according to the third embodiment.

According to the permanent magnet synchronous motor provided by the fourth embodiment of the invention, the discrete envelope curve of the orthogonal differential sine and cosine signals of the rotary transformer of the permanent magnet synchronous motor is obtained once every other first period through the controller, and the arc tangent operation is carried out on the discrete envelope curve of the orthogonal differential sine and cosine signals obtained each time to obtain the corresponding first rotor angle; the third-order angle observer adopts a third-order angle observation algorithm to calculate and obtain a second rotor angle according to the first rotor angle, wherein the first rotor angle is determined as an initial value of a last integrator of the third-order angle observer, the problem of hysteresis of neglecting an integration link in the existing soft decoding algorithm is solved, the problem of obtaining an accurate initial rotor position is realized, the smoothness of the motor during starting is improved while the safety level of ISO26262 ASIL D is met, and the dynamic response characteristic is better.

It is to be noted that the foregoing is only illustrative of the preferred embodiments of the present invention and the technical principles employed. Those skilled in the art will appreciate that the present invention is not limited to the particular embodiments described herein, and that various obvious changes, rearrangements and substitutions will now be apparent to those skilled in the art without departing from the scope of the invention. Therefore, although the present invention has been described in greater detail by the above embodiments, the present invention is not limited to the above embodiments, and may include other equivalent embodiments without departing from the spirit of the present invention, and the scope of the present invention is determined by the scope of the appended claims.

Claims

1. A soft decoding method for a rotary transformer of a permanent magnet synchronous motor is characterized by comprising the following steps:

2. The soft decoding method for the PMSM resolver according to claim 1, further comprising, before the controller acquires the discrete envelope of the quadrature differential sine-cosine signal of the PMSM resolver at the first period:

3. The soft decoding method of the PMSM resolver according to claim 2, further comprising, after the controller acquires the first rotor angle corresponding to the discrete envelope of the quadrature differential sine-cosine signal:

the controller acquires an angle compensation quantity of the first rotor angle;

4. The soft decoding method of a PMSM resolver according to claim 3, wherein the controller obtaining the angle compensation amount of the first rotor angle includes:

5. The soft decoding method for the PMSM resolver according to claim 1 or 3, wherein before the controller performs the arctan operation on the discrete envelope of the quadrature differential sine-cosine signal, the method further comprises:

6. The soft decoding method of the PMSM resolver according to claim 2, wherein the DSADC module acquiring discrete envelope lines of the quadrature differential sine-cosine signal of the PMSM resolver at a second period comprises:

7. The soft decoding method of a PMSM resolver according to claim 6,

and the shaping unit of the DSADC module corrects the four paths of orthogonal differential sine and cosine signals according to the synchronous signals.

8. A soft decoding system of a permanent magnet synchronous motor rotary transformer is characterized by comprising:

9. The soft decoding system of a PMSM resolver according to claim 8, further comprising:

10. A permanent magnet synchronous machine comprising a soft decoding system of a permanent magnet synchronous machine resolver according to claim 8 or 9.