CN110323982A - A kind of method for controlling permanent magnet synchronous motor considering cross-coupling and saturation effect - Google Patents

Abstract

The invention relates to the technical field of motors, in particular to a permanent magnet synchronous motor control method considering cross-coupling and saturation effects. The current control method for permanent magnet synchronous motors is based on a linear model with constant motor parameters and does not consider magnetic circuit saturation and cross-coupling phenomena. The control method of completely decoupling the orthogonal axis is used, and the control performance and accuracy are not good. , the present invention provides a permanent magnet synchronous motor control method considering cross-coupling and saturation effects, establishes a permanent magnet synchronous motor nonlinear model taking into account cross-coupling and saturation effects, and calculates the influence of cross-coupling and saturation effects on motor parameters In each calculation iteration, the influence of cross-coupling and saturation effects is reduced, the control accuracy of the permanent magnet synchronous motor is improved, and the dynamic and static performance is improved.

Description

A Control Method of Permanent Magnet Synchronous Motor Considering Cross-Coupling and Saturation Effect

technical field

The invention relates to the technical field of motors, in particular to a permanent magnet synchronous motor control method considering cross-coupling and saturation effects.

Background technique

High power density permanent magnet synchronous motors have attracted more and more attention from researchers and manufacturers due to their small size, light weight, and high efficiency, especially in aerospace, industrial automation equipment, electric vehicles and other applications, because of limited installation space, The motor is required to be smaller in size, higher in efficiency, and lighter in weight, that is to say, the motor is required to have a higher power density.

However, the compact structure of the permanent magnet synchronous motor with high power density leads to significant magnetic circuit saturation and dq-axis cross-coupling. On the one hand, when the motor magnetic circuit is saturated, the inductance model of the motor changes nonlinearly with the change of the armature current. On the other hand, the cross-coupling inductance generated by the cross-coupling phenomenon affects the motor flux model and causes the orthogonal axis inductance parameters to change. However, the current control method for permanent magnet synchronous motors is based on a linear model with constant motor parameters and does not consider the phenomenon of magnetic circuit saturation and dq-axis cross-coupling. The dq-axis is completely decoupled. The control performance and precision of the control system cannot meet the requirements.

Contents of the invention

(1) Technical problems to be solved

Based on the above-mentioned problems, the present invention provides a permanent magnet synchronous motor control method that overcomes the above-mentioned problems or at least partially solves the above-mentioned problems, reduces the influence caused by changes in motor parameters due to cross-coupling and saturation effects, and improves Motor control accuracy and dynamic and static performance make up for the shortcomings of traditional vector control methods.

(2) Technical solution

Based on the above technical problems, the present invention provides a permanent magnet synchronous motor control method considering cross-coupling and saturation effects, the control method comprising the following steps:

S1. The given torque is obtained through the PI regulator through the difference between the given speed and the actual speed of the feedback motor;

S2. Obtain the direct-axis current increment and the quadrature-axis current increment through the current increment control strategy through the given torque, the initial value of the torque, the initial value of the voltage, and the initial value of the AC-D axis current;

S3. Add the direct-axis current increment and the quadrature-axis current increment to the feedback initial value of the direct-axis current and the initial value of the quadrature-axis current respectively to obtain the given value of the direct-axis current and the given value of the quadrature-axis current, which are passed through the PI regulator The given value of the direct-axis voltage and the given value of the quadrature-axis voltage are respectively obtained, and the control of the permanent magnet synchronous motor is realized through coordinate transformation and space vector pulse width modulation;

The described current increment control strategy comprises the following steps:

S2.1. Establish a nonlinear model of permanent magnet synchronous motor that takes into account cross-coupling and saturation effects;

S2.2. On the basis of the nonlinear model, with the current limit circle as the constraint, establish the motor torque increment dT _e and voltage increment dU _s in the current increment plane considering the magnetic circuit saturation and cross-coupling effects The linearization equation of ;

S2.3. Judging the relative positions of torque and voltage increments within the current limit circle, according to six different positional relationships, six current increments in different situations are obtained:

S2.3.1. Judging whether LU>I _max , if the result is yes, it is judged as case 1;

S2.3.2, if the result of S2.3.1 is no, then judge whether LT>I _max ;

S2.3.3. If the result of S2.3.2 is yes, then judge whether D _sv ≥ 0, if the result is yes, then judge as case 2;

S2.3.4. If the result of S2.3.3 is no, it is judged as case three;

S2.3.5. If the result of S2.3.2 is no, then judge whether D _sv ≥ 0, if the result is yes, then judge as case 4;

S2.3.6. If the result of S2.3.5 is negative, judge the position of the intersection point. If it is inside the circle, it will be judged as case 5, if it is outside the circle, it will be judged as case 6;

Among them, LU is the distance between the center of the current limit circle and the straight line of the voltage increment, LT is the distance between the center of the current limit circle and the straight line of the torque increment, I _max is the maximum current value, that is, the radius of the current limit circle, and D _sv is the voltage The increment minus the actual increment of the voltage is used as a basis for judging whether the intersection of the torque increment straight line and the voltage increment straight line is on the left or right of the initial point in the current increment plane.

Further, in the steps S2 and S3, the initial value of the torque, the initial value of the voltage, the initial value of the direct-axis current and the initial value of the quadrature-axis current are all the actual values of the previous calculation cycle, that is, the previous The result of the iteration is used as the initial value for the next iteration.

Further, the non-linear model of the permanent magnet synchronous motor considering the cross-coupling and saturation effects described in step S2.1, that is, the motor flux model is:

Among them, ψ _d is the direct axis flux linkage, ψ _q is the quadrature axis flux linkage, ψ _f is the permanent magnet flux linkage, L _d is the direct axis component of the stator inductance, L _q is the quadrature axis component of the stator inductance, and L _qd is the cross Coupled inductance, _{id is the direct-axis component of the stator current, and i q is} the quadrature-axis component of the stator current.

Further, with di _d as the independent variable and di _q as the dependent variable, the motor torque increment dT _e and the voltage The linearization equations for the increment dU _s are respectively:

di _q ＝(-z _d /z _q )di _d +(1/(1.5pz _q ))dT _e

di _q ＝(-r _d /r _q )di _d +(|U _s |/r _q )dU _s

in:

z _d =(L _d -L _q )i _q -2L _qd i _d , z _q =ψ _f +(L _d -L _q )i _d +2L _dq i _q

r _d =(R _s -ω _e L _qd )u _d +ω _e L _d u _q ,r _q =(R _s +ω _e L _qd )u _q -ω _e L _q u _d

Among them, di _d is the direct axis current increment, di _q is the quadrature axis current increment, dT _e is the torque increment, dU _s is the voltage increment, U _s is the stator voltage, p is the number of pole pairs of the motor, i _d is the direct-axis component of the stator current, i _q is the quadrature-axis component of the stator current, ψ _f is the flux linkage of the permanent magnet, L _d is the direct-axis component of the stator inductance, L _q is the quadrature-axis component of the stator inductance, and L _qd is the cross Coupled inductance, u _d is the direct axis component of the voltage, u _q is the quadrature axis component of the voltage, R _s is the stator resistance, ω _e is the electrical angular velocity.

Further, the six different positional relationships described in step 2.3, and the corresponding current increments in six different situations are:

Case 1: When LU>I _max , the intersection point of the torque increment line and the voltage increment line is outside the current limit circle, and the current increment vector value corresponding to the vertical foot of the vertical line from the initial point to the voltage increment line is taken as the current Increment to achieve the minimum overcurrent, the obtained dq axis current increment is

Situation 2: When LT>I _max , LU≤I _max , and the actual voltage increment is less than or equal to dU _s , that is, when D _sv ≥ 0, take the perpendicular line between the initial point and the torque increment line and the current limit circle The intersection point corresponds to the current increment vector value as the current increment, and the obtained dq axis current increment is

Case 3: When LT>I _max , LU≤I _max and D _sv <0, it will meet both the voltage increment requirement and the current limit constraint and be as close as possible to the point of the torque increment line, that is, the voltage increment line and The intersection point of the current limit circle corresponds to the current increment vector value as the current increment, and the obtained dq axis current increment is

Situation 4: When LT≤I _max , LU≤I _max and D _sv ≥0, the current increment vector value obtained by satisfying the maximum torque-to-current ratio control algorithm is used as the current increment, and the obtained dq axis current increment is

Situation 5: When LT≤I _max , LU≤I _max and D _sv <0, in this case, when the intersection point of the torque and voltage increment line is within the current circle, take the intersection point of the torque increment line and the voltage increment line The corresponding current increment vector value is used as the current increment, and the obtained dq axis current increment is

Situation 6: When LT≤I _max , LU≤I _max and D _sv <0, in this case, when the intersection of the torque and the voltage increment line is outside the current circle, take the current corresponding to the intersection of the voltage increment line and the current limit circle The incremental vector value is used as the current increment, and the obtained dq axis current increment is

Among them, z _d =(L _d -L _q )i _q -2L _qd i _d , z _q =ψ _f +(L _d -L _q )i _d +2L _dq i _q

r _d =(R _s -ω _e L _qd )u _d +ω _e L _d u _q ,r _q =(R _s +ω _e L _qd )u _q -ω _e L _q u _d

Among them, LU is the distance between the center of the current limit circle and the straight line of the voltage increment, LT is the distance between the center of the current limit circle and the straight line of the torque increment, I _max is the maximum current value, that is, the radius of the current limit circle, and D _sv is the voltage The increment minus the actual increment of the voltage is used as the judgment basis to judge whether the intersection of the torque increment line and the voltage increment line is on the left or right side of the initial point in the current increment plane, and di _d is the direct axis current increment , di _q is the quadrature axis current increment, i _d0 is the direct axis component of the initial current, i _q0 is the quadrature axis component of the initial current, i _dm is the direct axis component of the current reference value, and i _qm is the quadrature axis of the current reference value component, i _dc is the _d -axis coordinate of the intersection point of the torque increment line and the voltage increment line, i _qc is the di _q -axis coordinate of the intersection point of the torque increment line and the voltage increment line, and L _cross is the intersection point described in this case The distance between the initial point and the vertical foot of the voltage increment straight line, dU _s is the voltage increment, dT _e is the torque increment, p is the number of pole pairs of the motor, _id is the direct axis component of the stator current, i _q is the quadrature axis component of the stator current, ψ _f is the flux linkage of the permanent magnet, L _d is the direct axis component of the stator inductance, L _q is the quadrature axis component of the stator inductance, L _qd is the cross coupling inductance, u _d is the voltage Direct axis component, u _q is the quadrature axis component of the voltage, R _s is the stator resistance, ω _e is the electrical angular velocity.

(3) Beneficial effects

The technical scheme of the present invention has the following advantages:

(1) the present invention considers the impact of cross-coupling and saturation effects on the inductance model in the mathematical model of the permanent magnet synchronous motor, improves the accuracy of the model, makes the mathematical model closer to the actual motor model; (2) changes the parameters Considering that in each iteration of the current increment control strategy, judge the relative position of the required increment of torque and voltage within the limit circle, and use the discrete calculation method to use the current increment result of the previous iteration as the next iteration The initial value is iteratively optimized to achieve the target control effect, reducing the influence of cross-coupling and saturation effects, and improving the accuracy of motor control; (3) The current incremental control strategy can realize the smooth switching between constant torque and constant power areas, omitting the traditional vector The voltage feedback comparison loop in the control simplifies the control system and shows good dynamic performance.

Description of drawings

The features and advantages of the present invention will be more clearly understood by referring to the accompanying drawings, which are schematic and should not be construed as limiting the invention in any way. In the accompanying drawings:

Fig. 1 is a schematic diagram of the positional relationship between the torque increment and the voltage increment in the current increment plane according to an embodiment of the present invention;

Fig. 2 is a flowchart of a current increment control strategy according to an embodiment of the present invention.

Detailed ways

The specific implementation manners of the present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. The following examples are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

A permanent magnet synchronous motor control method considering cross-coupling and saturation effects provided by the present invention comprises the following steps:

S1. The given torque is obtained through the PI regulator through the difference between the given speed and the actual speed of the feedback motor;

S2. Obtain the direct-axis current increment and the quadrature-axis current increment through the current increment control strategy through the given torque, the initial value of the torque, the initial value of the voltage, and the initial value of the AC-D axis current;

S3. Add the direct-axis current increment and the quadrature-axis current increment to the feedback initial value of the direct-axis current and the initial value of the quadrature-axis current respectively to obtain the given value of the direct-axis current and the given value of the quadrature-axis current, which are passed through the PI regulator The given value of the direct-axis voltage and the given value of the quadrature-axis voltage are respectively obtained, and the control of the permanent magnet synchronous motor is realized through coordinate transformation and space vector pulse width modulation.

In the steps S2 and S3, the initial value of the torque, the initial value of the voltage, the initial value of the direct-axis current and the initial value of the quadrature-axis current are all actual values of the previous calculation cycle, that is, the results of the previous iteration as the initial value for the next iteration.

As shown in Figure 2, the described current incremental control strategy includes the following steps:

S2.1. Establish a nonlinear model of permanent magnet synchronous motor that takes into account cross-coupling and saturation effects;

When the magnetic circuit is saturated, the motor inductance model changes nonlinearly with the armature current, and the dq-axis inductance parameters L _d and L _q are rewritten as L _d (i _d , i _q ) and L _q (i _d , i _q ). Therefore, when considering the saturation of the magnetic circuit, the flux linkage expression of the orthogonal axis is:

While considering the saturation of the magnetic circuit of the motor, the magnetic circuit coupling of the dq axis should also be considered. Because of the existence of cross-coupling phenomenon, the flux linkage model of the motor needs to consider the influence of cross-coupling inductance, so the flux linkage expression of the orthogonal axis can be rewritten for:

Among them, ψ _d is the direct axis flux linkage, ψ _q is the quadrature axis flux linkage, ψ _f is the permanent magnet flux linkage, L _d is the direct axis component of the stator inductance, L _q is the quadrature axis component of the stator inductance, and L _qd is the cross Coupled inductance, _{id is the direct-axis component of the stator current, and i q is} the quadrature-axis component of the stator current.

S2.2. On the basis of the nonlinear model, with the current limit circle as the constraint, establish the motor torque increment dT _e and voltage increment dU _s in the current increment plane considering the magnetic circuit saturation and cross-coupling effects The linearization equation of ;

According to the motor flux linkage model, it can be obtained that the nonlinear voltage vector equation considering the magnetic circuit saturation and cross-coupling effects is:

The electromagnetic torque equation considering the magnetic circuit saturation and cross-coupling effects is:

Among them, u _d is the direct-axis component of the voltage, u _q is the quadrature-axis component of the voltage, T _e is the torque, p is the number of pole pairs of the motor, R _s is the stator resistance, and ω _e is the electrical angular velocity.

The nonlinear voltage vector equation and electromagnetic torque equation considering the magnetic circuit saturation and cross-coupling effects are rewritten as the linearity of the torque increment dT _e and the voltage increment dU _s with di _d as the independent variable and di _q as the dependent variable The equations are:

di _q ＝(-z _d /z _q )di _d +(1/(1.5pz _q ))dT _e

di _q ＝(-r _d /r _q )di _d +(|U _s |/r _q )dU _s

in:

z _d =(L _d -L _q )i _q -2L _qd i _d , z _q =ψ _f +(L _d -L _q )i _d +2L _dq i _q

r _d =(R _s -ω _e L _qd )u _d +ω _e L _d u _q ,r _q =(R _s +ω _e L _qd )u _q -ω _e L _q u _d

Among them, di _d is the direct axis current increment, di _q is the quadrature axis current increment, dT _e is the torque increment, dU _s is the voltage increment, U _s is the stator voltage.

S2.3. Judging the relative positions of torque and voltage increments within the current limit circle, according to six different positional relationships, six current increments in different situations are obtained:

S2.3.1. Judging whether LU>I _max , if the result is yes, it is judged as case 1;

S2.3.2, if the result of S2.3.1 is no, then judge whether LT>I _max ;

S2.3.3. If the result of S2.3.2 is yes, then judge whether D _sv ≥ 0, if the result is yes, then judge as case 2;

S2.3.4. If the result of S2.3.3 is no, it is judged as case three;

S2.3.5. If the result of S2.3.2 is no, then judge whether D _sv ≥ 0, if the result is yes, then judge as case 4;

S2.3.6. If the result of S2.3.5 is negative, judge the position of the intersection point. If it is inside the circle, it will be judged as case 5, if it is outside the circle, it will be judged as case 6;

Among them, LU is the distance between the center of the current limit circle and the straight line of the voltage increment, LT is the distance between the center of the current limit circle and the straight line of the torque increment, I _max is the maximum current value, that is, the radius of the current limit circle, and D _sv is the voltage The increment minus the actual increment of the voltage is used as a basis for judging whether the intersection of the torque increment straight line and the voltage increment straight line is on the left or right of the initial point in the current increment plane.

As shown in Figure 1, the position relationship between torque increment and voltage increment on the current increment plane, according to six different positional relationships, the current increment in six different situations can be obtained:

Case 1: When LU>I _max , the intersection point of the torque increment line and the voltage increment line is outside the current limit circle, and the current increment vector value corresponding to the vertical foot of the vertical line from the initial point to the voltage increment line is taken as the current Increment to achieve the minimum overcurrent, the obtained dq axis current increment is

Situation 2: When LT>I _max , LU≤I _max , and the actual voltage increment is less than or equal to dU _s , that is, when D _sv ≥ 0, take the perpendicular line between the initial point and the torque increment line and the current limit circle The corresponding current increment vector value is used as the current increment, and the obtained dq axis current increment is

Case 3: When LT>I _max , LU≤I _max and D _sv <0, it will meet both the voltage increment requirement and the current limit constraint and be as close as possible to the point of the torque increment line, that is, the voltage increment line and The intersection point of the current limit circle corresponds to the current increment vector value as the current increment, and the obtained dq axis current increment is

Situation 4: When LT≤I _max , LU≤I _max and D _sv ≥0, the current increment vector value obtained by satisfying the maximum torque-to-current ratio control algorithm is used as the current increment, and the obtained dq axis current increment is

Situation 5: When LT≤I _max , LU≤I _max and D _sv <0, in this case, when the intersection point of the torque and voltage increment line is within the current circle, take the intersection point of the torque increment line and the voltage increment line The corresponding current increment vector value is used as the current increment, and the obtained dq axis current increment is

Situation 6: When LT≤I _max , LU≤I _max and D _sv <0, in this case, when the intersection of the torque and the voltage increment line is outside the current circle, take the current corresponding to the intersection of the voltage increment line and the current limit circle The incremental vector value is used as the current increment, and the obtained dq axis current increment is

Among them, i _d0 is the direct-axis component of the initial current, i _q0 is the quadrature-axis component of the initial current, i _dm is the direct-axis component of the current reference value, i _qm is the quadrature-axis component of the current reference value, and i _dc is the torque increase The di _d -axis coordinates of the intersection point of the measurement straight line and the voltage increment straight line, i _qc is the di _q -axis coordinate of the intersection point of the torque increment straight line and the voltage increment straight line, and L _cross is the intersection point and the initial point to the voltage increment straight line described in this case The distance between the vertical feet of the vertical line.

In summary, it is different from the traditional permanent magnet synchronous motor, which is based on the constant motor parameters and does not consider the magnetic circuit saturation and cross-coupling linear model, and adopts the dq axis complete decoupling control method, the present invention considers cross-coupling The permanent magnet synchronous motor control method with coupling and saturation effects has the following beneficial effects:

(1) Establish a nonlinear model of permanent magnet synchronous motor that takes into account cross-coupling and saturation effects, which is closer to the actual model of the motor and improves accuracy;

(2) Calculate the influence of cross-coupling and saturation effects on the motor parameters into the calculation iteration of each current increment, reduce the influence of cross-coupling and saturation effects, and improve the control accuracy of the motor;

(3) The discrete calculation method is used to use the current incremental result of the previous iteration as the initial value of the next iteration, and iterative optimization is repeated to achieve the target control effect, to track the actual running trajectory of the motor more accurately, and to further reduce the cross-coupling and saturation effects. Influence, improve the control accuracy of the motor;

(4) The current incremental control strategy can realize the smooth switching between constant torque and constant power areas, omits the voltage feedback contrast loop in traditional vector control, simplifies the control system, and has good dynamic performance;

(5) The control method of the present invention takes the rotating speed as the control outer ring, and has good static performance;

(6) The current increment control strategy uses the maximum torque current ratio control method to achieve the minimum overcurrent that meets the torque condition, which is beneficial to the work of the power switching device of the inverter and reduces the copper consumption of the motor.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them; although the embodiments of the present invention have been described in conjunction with the accompanying drawings, those skilled in the art can Various modifications and variations are made within the scope and scope of the invention, and such modifications and variations fall within the scope defined by the appended claims.

Claims (5)

1. a permanent magnet synchronous motor control method considering cross-coupling and saturation effects, is characterized in that, comprises the following steps: S1. The given torque is obtained through the PI regulator through the difference between the given speed and the actual speed of the feedback motor; S2. Obtain the direct-axis current increment and the quadrature-axis current increment through the current increment control strategy through the given torque, the initial value of the torque, the initial value of the voltage, and the initial value of the AC-D axis current; S3. Add the direct-axis current increment and the quadrature-axis current increment to the feedback initial value of the direct-axis current and the initial value of the quadrature-axis current respectively to obtain the given value of the direct-axis current and the given value of the quadrature-axis current, which are passed through the PI regulator The given value of the direct-axis voltage and the given value of the quadrature-axis voltage are respectively obtained, and the control of the permanent magnet synchronous motor is realized through coordinate transformation and space vector pulse width modulation; The described current increment control strategy comprises the following steps: S2.1. Establish a nonlinear model of permanent magnet synchronous motor that takes into account cross-coupling and saturation effects; S2.2. On the basis of the nonlinear model, with the current limit circle as the constraint, establish the motor torque increment dT _e and voltage increment dU _s in the current increment plane considering the magnetic circuit saturation and cross-coupling effects The linearization equation of ; S2.3. Judging the relative positions of torque and voltage increments within the current limit circle, according to six different positional relationships, six current increments in different situations are obtained: S2.3.1. Judging whether LU>I _max , if the result is yes, it is judged as case 1; S2.3.2, if the result of S2.3.1 is no, then judge whether LT>I _max ; S2.3.3. If the result of S2.3.2 is yes, then judge whether D _sv ≥ 0, if the result is yes, then judge as case 2; S2.3.4. If the result of S2.3.3 is no, it is judged as case three; S2.3.5. If the result of S2.3.2 is no, then judge whether D _sv ≥ 0, if the result is yes, then judge as case 4; S2.3.6. If the result of S2.3.5 is negative, judge the position of the intersection point. If it is inside the circle, it will be judged as case 5, if it is outside the circle, it will be judged as case 6; Among them, LU is the distance between the center of the current limit circle and the straight line of the voltage increment, LT is the distance between the center of the current limit circle and the straight line of the torque increment, I _max is the maximum current value, that is, the radius of the current limit circle, and D _sv is the voltage The increment minus the actual increment of the voltage is used as a basis for judging whether the intersection of the torque increment straight line and the voltage increment straight line is on the left or right of the initial point in the current increment plane. 2. The permanent magnet synchronous motor control method considering cross-coupling and saturation effects according to claim 1, characterized in that, in the steps S2 and S3, the initial value of the torque, the initial value of the voltage, the direct axis current Both the initial value and the initial value of the quadrature-axis current are the actual values of the previous calculation cycle, that is, the result of the previous iteration is used as the initial value of the next iteration. 3. The permanent magnet synchronous motor control method considering cross-coupling and saturation effects according to claim 1, characterized in that, the nonlinear model of permanent magnet synchronous motors considering cross-coupling and saturation effects described in step S2.1, That is, the motor flux model is: Among them, ψ _d is the direct axis flux linkage, ψ _q is the quadrature axis flux linkage, ψ _f is the permanent magnet flux linkage, L _d is the direct axis component of the stator inductance, L _q is the quadrature axis component of the stator inductance, and L _qd is the cross Coupled inductance, _{id is the direct-axis component of the stator current, and i q is} the quadrature-axis component of the stator current. 4. the permanent magnet synchronous motor control method considering cross-coupling and saturation effect according to claim 1, is characterized in that, with di _d as independent variable, di _q as dependent variable, step S2.2 described in current increase The linearization equations of motor torque increment dT _e and voltage increment dU _s established in the measurement plane considering the magnetic circuit saturation and cross-coupling effects are respectively: di _q ＝(-z _d /z _q )di _d +(1/(1.5pz _q ))dT _e di _q ＝(-r _d /r _q )di _d +(|U _s |/r _q )dU _s in: z _d =(L _d -L _q )i _q -2L _qd i _d , z _q =ψ _f +(L _d -L _q )i _d +2L _dq i _q r _d =(R _s -ω _e L _qd )u _d +ω _e L _d u _q ,r _q =(R _s +ω _e L _qd )u _q -ω _e L _q u _d Among them, di _d is the direct axis current increment, di _q is the quadrature axis current increment, dT _e is the torque increment, dU _s is the voltage increment, U _s is the stator voltage, p is the number of pole pairs of the motor, i _d is the direct-axis component of the stator current, i _q is the quadrature-axis component of the stator current, ψ _f is the flux linkage of the permanent magnet, L _d is the direct-axis component of the stator inductance, L _q is the quadrature-axis component of the stator inductance, and L _qd is the cross Coupled inductance, u _d is the direct axis component of the voltage, u _q is the quadrature axis component of the voltage, R _s is the stator resistance, ω _e is the electrical angular velocity. 5. The permanent magnet synchronous motor control method considering cross-coupling and saturation effects according to claim 1, characterized in that, the six different positional relationships described in step 2.3, and the corresponding current increments of six different situations for: Case 1: When LU>I _max , the intersection point of the torque increment line and the voltage increment line is outside the current limit circle, and the current increment vector value corresponding to the vertical foot of the vertical line from the initial point to the voltage increment line is taken as the current Increment to achieve the minimum overcurrent, the obtained dq axis current increment is Situation 2: When LT>I _max , LU≤I _max , and the actual voltage increment is less than or equal to dU _s , that is, when D _sv ≥ 0, take the perpendicular line between the initial point and the torque increment line and the current limit circle The intersection point corresponds to the current increment vector value as the current increment, and the obtained dq axis current increment is Case 3: When LT>I _max , LU≤I _max and D _sv <0, it will meet both the voltage increment requirement and the current limit constraint and be as close as possible to the point of the torque increment line, that is, the voltage increment line and The intersection point of the current limit circle corresponds to the current increment vector value as the current increment, and the obtained dq axis current increment is Situation 4: When LT≤I _max , LU≤I _max and D _sv ≥0, the current increment vector value obtained by satisfying the maximum torque-to-current ratio control algorithm is used as the current increment, and the obtained dq axis current increment is Situation 5: When LT≤I _max , LU≤I _max and D _sv <0, in this case, when the intersection point of the torque and voltage increment line is within the current circle, take the intersection point of the torque increment line and the voltage increment line The corresponding current increment vector value is used as the current increment, and the obtained dq axis current increment is Situation 6: When LT≤I _max , LU≤I _max and D _sv <0, in this case, when the intersection of the torque and the voltage increment line is outside the current circle, take the current corresponding to the intersection of the voltage increment line and the current limit circle The incremental vector value is used as the current increment, and the obtained dq axis current increment is Among them, z _d =(L _d -L _q )i _q -2L _qd i _d , z _q =ψ _f +(L _d -L _q )i _d +2L _dq i _q r _d =(R _s -ω _e L _qd )u _d +ω _e L _d u _q ,r _q =(R _s +ω _e L _qd )u _q -ω _e L _q u _d Among them, LU is the distance between the center of the current limit circle and the straight line of the voltage increment, LT is the distance between the center of the current limit circle and the straight line of the torque increment, I _max is the maximum current value, that is, the radius of the current limit circle, and D _sv is the voltage The increment minus the actual increment of the voltage is used as the judgment basis to judge whether the intersection of the torque increment line and the voltage increment line is on the left or right side of the initial point in the current increment plane, and di _d is the direct axis current increment , di _q is the quadrature axis current increment, i _d0 is the direct axis component of the initial current, i _q0 is the quadrature axis component of the initial current, i _dm is the direct axis component of the current reference value, and i _qm is the quadrature axis of the current reference value component, i _dc is the _d -axis coordinate of the intersection point of the torque increment line and the voltage increment line, i _qc is the di _q -axis coordinate of the intersection point of the torque increment line and the voltage increment line, and L _cross is the intersection point described in this case The distance between the initial point and the vertical foot of the voltage increment straight line, dU _s is the voltage increment, dT _e is the torque increment, p is the number of pole pairs of the motor, _id is the direct axis component of the stator current, i _q is the quadrature axis component of the stator current, ψ _f is the flux linkage of the permanent magnet, L _d is the direct axis component of the stator inductance, L _q is the quadrature axis component of the stator inductance, L _qd is the cross coupling inductance, u _d is the voltage Direct axis component, u _q is the quadrature axis component of the voltage, R _s is the stator resistance, ω _e is the electrical angular velocity.