CN102790566B - Method capable of reducing torque tracking error of switched reluctance motor - Google Patents

Abstract

The invention discloses a method capable of reducing a torque tracking error of a switched reluctance motor. The method is characterized in that a flexible torque distribution mode is adopted to control an instantaneous torque, and the degree of the torque tracking error, which serves as a control variable, is limited through the online regulation of a turn-on angle, so as to allow the instantaneous torque output by the motor to track a reference torque in a small deviation manner as far as possible, so that both torque ripple and noise of the motor are reduced, and the smooth operation of the motor is ensured.

Description

A kind of method that reduces switched reluctance machines torque tracking error

Technical field

The present invention relates to a kind of method that reduces switched reluctance machines torque tracking error, belong to the torque control field of switched reluctance machines.

Background technology

Switched reluctance machines is simple in structure firm, and starting current is little, torque is large, is the very potential New-type electric machine of one, but because of its torque pulsation and noise larger, limited this motor and further applied.The torque pulsation that how to suppress motor becomes the focus of this kind of motor research, and is a main research direction from the torque pulsation that control strategy improves motor.

In prior art, traditional current chopping control (CCC), angle position control (APC) and voltage chopping control (PWM) is not using instantaneous torque as control variables, can not fine control export torque, easily cause larger torque pulsation, instantaneous torque control method based on torque distribution is using the each phase instantaneous torque of motor as control variables, press fixing pro rate to the each phase of motor with reference to torque, thereby the variation of the every phase instantaneous torque of limiting motor, but the serious non-linear Changing Pattern of instantaneous torque that makes of motor itself is more complicated, the rising of instantaneous torque and decline can not be all the time according to the described trail changes of partition function, if a certain phase or two-phase instantaneous torque do not reach this phase torque reference all the time, just can cause synthetic output torque to be less than torque reference, produce very large torque tracking error.If online design is changed the partition function of shape, can increase the complexity of computing.So the method sets up that torque distribution function difficulty is larger accurately.

At present, various control methods all, less than directly making ACTIVE CONTROL for the torque tracking error size of motor, limit the size of tracking error.

Summary of the invention

The present invention is for avoiding the existing weak point of above-mentioned prior art, a kind of method that reduces switched reluctance machines torque tracking error is provided, to the error between output torque and the torque reference of minimizing switched reluctance machines, improve the smoothness of output torque, thereby reduce the torque pulsation of motor.

The technical problem that the present invention solves adopts following technical scheme:

The feature of a kind of method that reduces switched reluctance machines torque tracking error of the present invention is to carry out as follows:

Step 1: the torque reference T of given switched reluctance machines ^*;

Step 2: according to switched reluctance machines " angle-electric current-torque " tables of data, obtain the current i of switched reluctance machines at different rotor angle θ and each phase stator winding _klower corresponding instantaneous torque T _k, k=0,1,2 ... n, any phase that k is motor, n is the total number of phases of motor;

Described switched reluctance machines " angle-electric current-torque " tables of data is the current i of every phase stator winding of collecting of position transducer collects while turning round according to switched reluctance machines rotor angle and current sensor _kutilize formula (1) calculated off-line to obtain:

$T_k=\frac{\∂}{\∂\mathrm{\θ}}{\∫}_0^{i_k}{\∫}_0^{t_k}(u_k-i_k{R}_k){\mathrm{dt}}_k{\mathrm{di}}_k---\left(1\right)$

In formula (1), R _kfor stator winding resistance value, u _kfor imposing on the magnitude of voltage of stator winding, t _kfor the electric current of each phase stator winding changes to i from 0 _ktime;

Step 3: utilize formula (2) to obtain the m phase torque reference T of motor conducting _m ^*for:

${T_m}^{*}=T^{*}-(\underset{k=1}{\overset{m-1}{\mathrm{\Σ}}}+\underset{k=m+1}{\overset{n}{\mathrm{\Σ}}})T_k---\left(2\right)$

In formula (1), the conducting phase that m is motor, m=0,1,2 ... n;

Step 4: the instantaneous torque T that obtains described conducting phase m according to described switched reluctance machines " angle-electric current-torque " tables of data _m, utilize described torque reference T _m ^*, through type (3) obtains the torque tracking error Δ T of m phase:

ΔT=T _m–T _m ^*(3)

Step 5: the relatively size of the torque tracking error limit value ε of torque tracking error Δ T and setting, and according to the on off operating mode of comparative result adjustment conducting phase winding, the size of torque-limiting tracking error Δ T;

Step 6: utilize that formula (4) obtains m phase stator conduction period torque tracking error with ∑ Δ T:

$\mathrm{\Σ\ΔT}={\∫}_0^{t_k}\mathrm{\Δ}{\mathrm{Tdt}}_k;---\left(4\right)$

Adjust the turn-on angle of switched reluctance machines according to the interval internal torque of described single-phase conducting size error and ∑ Δ T and described torque tracking error limit value ε, peak value and the amplitude of adjusting instantaneous torque according to the turn-on angle of described switched reluctance machines, reduce torque tracking error.

The feature of the method that reduces switched reluctance machines torque tracking error of the present invention is also:

In described step 1, when switched reluctance machines electric operation, described torque reference T ^*for just; When switched reluctance machines deceleration or running under braking, described torque reference T ^*for negative;

In described step 5, the on off operating mode adjustment of described conducting phase winding is carried out according to the following rules:

When switched reluctance machines electric operation: if Δ T≤ε keeps the conducting state of conducting phase winding constant; If Δ T > is ε, turn-off conducting phase winding;

When switched reluctance machines deceleration or running under braking: if Δ T >=-ε keeps the conducting state of conducting phase winding constant; If Δ T is <-ε, turn-off conducting phase winding;

In described step 6, the turn-on angle of described switched reluctance machines is adjusted as follows:

When switched reluctance machines electric operation: if when ∑ Δ T > ε, delay the position of turn-on angle, postpone next phase stator winding conducting moment; In the time of ∑ Δ T <-ε, the position of turn-on angle in advance, in advance next phase stator winding conducting moment; In the time of-ε≤∑ Δ T≤ε, keep the invariant position of turn-on angle;

When switched reluctance machines deceleration or running under braking: in the time of ∑ Δ T > ε, the position of turn-on angle in advance, in advance next phase stator winding conducting moment; In the time of ∑ Δ T <-ε, delay the position of turn-on angle, postpone next phase stator winding conducting moment; In the time of-ε≤∑ Δ T≤ε, keep the invariant position of turn-on angle;

Described in advance or the position of delaying turn-on angle determine as follows: using described m phase stator from conducting interval internal torque error with the difference of ∑ Δ T and described torque tracking error limit value ε as input, adopt FUZZY ALGORITHMS FOR CONTROL or pid algorithm to adjust described turn-on angle, the output valve of acquisition is the variation delta θ of turn-on angle position.

Compared with the prior art, beneficial effect of the present invention is embodied in:

1, the present invention utilizes the instantaneous torque of switched reluctance machines as control variables, can effectively control output torque, and torque pulsation inhibited; Thereby avoid motor in the time of operation, to produce larger torque tracking error.

2, the present invention has adopted torque distribution mode flexibly, reach the control to instantaneous torque, be not limited to the partition function of solid shape, thereby adapt to preferably the complexity of switched reluctance machines instantaneous torque Changing Pattern, avoided existing distribution method need set up the difficulty of torque distribution function accurately;

3, the present invention, using torque tracking error as control variables, limits the size of tracking error by opening the online adjustment of angle, track reference torque that the instantaneous torque that motor is exported is tried one's best little deviation, thus reduce motor torque ripple and noise.

The features such as 4, the present invention has fast operation, easy to operate, reliability is high, strong adaptability, are applicable to the switched reluctance machines of the various numbers of phases, structure, are widely used, and can effectively reduce torque tracking error, thereby ensure motor smooth operation.

Brief description of the drawings:

Fig. 1 is the flow chart of the embodiment of the present invention;

Fig. 2 is 0 ° of position of switched reluctance machines m phase minimum inductance schematic diagram in the embodiment of the present invention one;

Fig. 3 is 30 ° of schematic diagrames of switched reluctance machines m phase rotor-position in the embodiment of the present invention one;

Fig. 4 is 45 ° of positions of switched reluctance machines m phase maximum induction schematic diagram in the embodiment of the present invention one;

Fig. 5 is 75 ° of schematic diagrames of switched reluctance machines m phase rotor-position in the embodiment of the present invention one;

Fig. 6 is 90 ° of positions of switched reluctance machines m phase minimum inductance schematic diagram in the embodiment of the present invention one;

Fig. 7 is 0 ° of position of switched reluctance machines m phase minimum inductance schematic diagram in the embodiment of the present invention two;

Fig. 8 is 20 ° of schematic diagrames of switched reluctance machines m phase rotor-position in the embodiment of the present invention two;

Fig. 9 is 30 ° of positions of switched reluctance machines m phase maximum induction schematic diagram in the embodiment of the present invention two;

Figure 10 is 50 ° of schematic diagrames of switched reluctance machines m phase rotor-position in the embodiment of the present invention two;

Figure 11 is 60 ° of positions of switched reluctance machines m phase minimum inductance schematic diagram in the embodiment of the present invention two.

Embodiment:

Embodiment mono-: taking the switched reluctance machines of three-phase 6/4 structure as example, as shown in Figure 1, comprise the following steps in the present embodiment:

Step 1: the torque reference T of given switched reluctance machines ^*;

When switched reluctance machines electric operation, torque reference T ^*for just; When switched reluctance machines deceleration or running under braking, torque reference T ^*for negative;

Step 2: according to switched reluctance machines " angle-electric current-torque " tables of data, obtain the current i of switched reluctance machines at different rotor angle θ and each phase stator winding _klower corresponding instantaneous torque T _k, k=0,1,2 ... n, any phase that k is motor, n is the total number of phases of motor, n=3 in the present embodiment;

Switched reluctance machines " angle-electric current-torque " tables of data is the current i of every phase stator winding of collecting of position transducer collects while turning round according to switched reluctance machines rotor angle and current sensor _kutilize formula (1) calculated off-line to obtain:

$T_k=\frac{\&PartialD;}{\&PartialD;\mathrm{\&theta;}}{\&Integral;}_0^{i_k}{\&Integral;}_0^{t_k}(u_k-i_k{R}_k){\mathrm{dt}}_k{\mathrm{di}}_k---\left(1\right)$

In formula (1), R _kfor stator winding resistance value, u _kfor imposing on the magnitude of voltage of stator winding, t _kfor the electric current of each phase stator winding changes to i from 0 _ktime;

Step 3: utilize formula (2) to obtain the m phase torque reference T of motor conducting _m ^*for:

${T_m}^{*}=T^{*}-(\underset{k=1}{\overset{m-1}{\mathrm{\&Sigma;}}}+\underset{k=m+1}{\overset{n}{\mathrm{\&Sigma;}}})T_k---\left(2\right)$

In formula (1), the conducting phase that m is motor, m=0,1,2 ... n;

Step 4: the instantaneous torque T that obtains conducting phase m according to switched reluctance machines " angle-electric current-torque " tables of data _mwith torque reference T _m ^*, utilize formula (3) to obtain the torque tracking error Δ T of m phase:

ΔT=T _m–T _m ^*(3)

Step 5: the relatively size of the torque tracking error limit value ε of torque tracking error Δ T and setting, and according to the on off operating mode of comparative result adjustment conducting phase winding, the size of torque-limiting tracking error Δ T;

The on off operating mode adjustment of conducting phase winding is carried out according to the following rules:

When switched reluctance machines electric operation: if Δ T≤ε keeps the conducting state of conducting phase winding constant; If Δ T > is ε, turn-off conducting phase winding;

When switched reluctance machines deceleration or running under braking: if Δ T >=-ε keeps the conducting state of conducting phase winding constant; If Δ T is <-ε, turn-off conducting phase winding;

In the present embodiment, the torque of the phase winding outside conducting m phase freely changes, and does not do ACTIVE CONTROL;

Step 6: utilize that formula (4) obtains m phase stator conduction period torque tracking error with ∑ Δ T:

$\mathrm{\&Sigma;\&Delta;T}={\&Integral;}_0^{t_k}\mathrm{\&Delta;}{\mathrm{Tdt}}_k---\left(4\right)$

Adjust the turn-on angle of switched reluctance machines according to the interval internal torque of single-phase conducting size error and ∑ Δ T and torque tracking error limit value ε, adjust peak value and the amplitude of instantaneous torque according to the turn-on angle of switched reluctance machines, reduce torque tracking error.

The turn-on angle of switched reluctance machines is adjusted as follows:

When switched reluctance machines electric operation: conducting m phase after 0 ° in the minimum inductance position shown in Fig. 2, wherein the phase maximum induction position of switched reluctance machines is the position of the rotor salient pole shown in Fig. 4 when relative, and phase minimum inductance position is the position of the stator salient poles shown in Fig. 2 or Fig. 6 during just to adjacent two rotor centers.If when ∑ Δ T > ε, delay the position of turn-on angle, postpone next phase stator winding conducting moment, but can not lag behind the position of closing the angle of rupture; In the time of ∑ Δ T <-ε, the in advance position of turn-on angle, next phase stator winding conducting moment in advance, the most front can be to ° position, 0 of minimum inductance; In the time of-ε≤∑ Δ T≤ε, keep the invariant position of turn-on angle; Now, 30 ° of positions that the pass angle of rupture of switched reluctance machines is fixed on before the maximum induction position shown in Fig. 3 do not adjust.

When switched reluctance machines deceleration or running under braking: conducting m phase after 45 ° in the maximum induction position shown in Fig. 4; In the time of ∑ Δ T > ε, the in advance position of turn-on angle, next phase stator winding conducting moment in advance, the most front can be to ° position, 45 of maximum induction; In the time of ∑ Δ T <-ε, delay the position of turn-on angle, postpone next phase stator winding conducting moment, but can not lag behind the pass angle of rupture; In the time of-ε≤∑ Δ T≤ε, keep the invariant position of turn-on angle; Now, 75 ° of positions that the pass angle of rupture of switched reluctance machines is fixed on before the minimum inductance position shown in Fig. 5 do not adjust.

In advance or the position of delaying turn-on angle determine as follows: using m phase stator from conducting interval internal torque error with the difference of ∑ Δ T and torque tracking error limit value ε as input, adopt FUZZY ALGORITHMS FOR CONTROL or pid algorithm to adjust turn-on angle, the output valve of acquisition is the variation delta θ of turn-on angle position.

The angular dimension of switch reluctance machine rotor be the position transducer that is arranged on 0 ° shown in Fig. 2 be that reference point is determined.

Embodiment bis-: mutually the switched reluctance machines of 8/6 structures is as example taking four for the present embodiment, and step is as shown in Figure 1, different from embodiment mono-:

1, n=4 in the present embodiment;

2, in the present embodiment, the phase maximum induction position of switched reluctance machines is the position of the rotor salient pole shown in Fig. 9 when relative, and phase minimum inductance position is the position of the stator salient poles shown in Fig. 7 or Figure 11 during just to adjacent two rotor centers.

3,, in the present embodiment, when switched reluctance machines electric operation, close 20 ° of positions that the angle of rupture is fixed on before the maximum induction position shown in Fig. 8 and do not adjust.

4, in the present embodiment, when switched reluctance machines deceleration or running under braking, conducting m phase after 30 ° in maximum induction position; In the time of ∑ Δ T > ε, the in advance position of turn-on angle, next phase stator winding conducting moment in advance, the most front can be to ° position, 30 of maximum induction; Now, 50 ° of positions that the pass angle of rupture of switched reluctance machines is fixed on before the minimum inductance position shown in Figure 10 do not adjust.

Claims (4)

1. reduce a method for switched reluctance machines torque tracking error, it is characterized in that carrying out as follows:

Step 1: the torque reference T of given switched reluctance machines ^*;

Step 2: according to switched reluctance machines " angle-electric current-torque " tables of data, obtain the current i of switched reluctance machines at different rotor angle θ and each phase stator winding _klower corresponding instantaneous torque T _k, k=0,1,2 ... n, any phase that k is motor, n is the total number of phases of motor;

Described switched reluctance machines " angle-electric current-torque " tables of data is that the current i k of every phase stator winding of collecting of position transducer collects while turning round according to switched reluctance machines rotor angle and current sensor utilizes formula (1) calculated off-line to obtain:

$T_k=\frac{\&PartialD;}{\&PartialD;\mathrm{\&theta;}}{\&Integral;}_0^{i_k}{\&Integral;}_0^{t_k}(u_k-i_k{R}_k){\mathrm{dt}}_k{\mathrm{di}}_k---\left(1\right)$

In formula (1), R _kfor stator winding resistance value, u _kfor imposing on the magnitude of voltage of stator winding, t _kfor the electric current of each phase stator winding changes to i from 0 _ktime;

Step 3: utilize formula (2) to obtain the m phase torque reference T of motor conducting _m ^*for:

${T_m}^{*}=T^{*}-(\underset{k=1}{\overset{m-1}{\mathrm{\&Sigma;}}}+\underset{k=m+1}{\overset{n}{\mathrm{\&Sigma;}}})T_k---\left(2\right)$

In formula (1), the conducting phase that m is motor, m=0,1,2 ... n;

Step 4: the instantaneous torque T that obtains described conducting phase m according to described switched reluctance machines " angle-electric current-torque " tables of data _m, utilize described torque reference T _m ^*, through type (3) obtains the torque tracking error Δ T of m phase:

ΔT＝T _m–T _m ^*(3)

Step 5: the relatively size of the torque tracking error limit value ε of torque tracking error Δ T and setting, and according to the on off operating mode of comparative result adjustment conducting phase winding, the size of torque-limiting tracking error Δ T;

Step 6: utilize that formula (4) obtains m phase stator conduction period torque tracking error with ∑ Δ T:

$\mathrm{\&Sigma;\&Delta;T}={\&Integral;}_0^{t_k}\mathrm{\&Delta;}{\mathrm{Tdt}}_k---\left(4\right)$

Adjust the turn-on angle of switched reluctance machines according to size described m phase stator conduction period torque tracking error and ∑ Δ T and described torque tracking error limit value ε, peak value and the amplitude of adjusting instantaneous torque according to the turn-on angle of described switched reluctance machines, reduce torque tracking error.

2. the method that reduces switched reluctance machines torque tracking error according to claim 1, is characterized in that:

In described step 1, when switched reluctance machines electric operation, described torque reference T ^*for just; When switched reluctance machines deceleration or running under braking, described torque reference T ^*for negative.

3. the method that reduces switched reluctance machines torque tracking error according to claim 1, is characterized in that:

In described step 5, the on off operating mode adjustment of described conducting phase winding is carried out according to the following rules:

When switched reluctance machines electric operation: if Δ T≤ε keeps the conducting state of conducting phase winding constant; If Δ T ﹥ is ε, turn-off conducting phase winding;

When switched reluctance machines deceleration or running under braking: if Δ T >=-ε keeps the conducting state of conducting phase winding constant; If Δ T is ﹤-ε, turn-off conducting phase winding.

4. the method that reduces switched reluctance machines torque tracking error according to claim 1, is characterized in that:

In described step 6, the turn-on angle of described switched reluctance machines is adjusted as follows:

When switched reluctance machines electric operation: if when ∑ Δ T ﹥ ε, delay the position of turn-on angle, postpone next phase stator winding conducting moment; In the time of ∑ Δ T ﹤-ε, the position of turn-on angle in advance, in advance next phase stator winding conducting moment; In the time of-ε≤∑ Δ T≤ε, keep the invariant position of turn-on angle;

When switched reluctance machines deceleration or running under braking: in the time of ∑ Δ T ﹥ ε, the position of turn-on angle in advance, in advance next phase stator winding conducting moment; In the time of ∑ Δ T ﹤-ε, delay the position of turn-on angle, postpone next phase stator winding conducting moment; In the time of-ε≤∑ Δ T≤ε, keep the invariant position of turn-on angle;

Described in advance or the position of delaying turn-on angle determine as follows: using described m phase stator from conducting interval internal torque error with the difference of ∑ Δ T and described torque tracking error limit value ε as input, adopt FUZZY ALGORITHMS FOR CONTROL or pid algorithm to adjust described turn-on angle, the output valve of acquisition is the variation delta θ of turn-on angle position.