CN102790566A - 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 big, is a kind of very potential New-type electric machine, but because of its torque pulsation and noise are bigger, has limited this motor and further used.The torque pulsation that how to suppress motor becomes the focus of this kind 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) with voltage chopping control (PWM) not with instantaneous torque as control variables, can not fine control export torque, cause bigger torque pulsation easily; Based on the instantaneous torque control method of torque distribution with each phase instantaneous torque of motor as control variables; Give each phase of motor with torque reference by fixing pro rate, thus the variation of the every phase instantaneous torque of restriction motor, but the severe nonlinear of motor own makes that the Changing Pattern of instantaneous torque is complicated; The rising of instantaneous torque and decline can not change according to the described track of partition function all the time; If a certain phase or two phase instantaneous torques do not reach this phase torque reference all the time, just can cause synthetic output torque less than torque reference, produce very big torque tracking error.If online design is changed the partition function of shape, then can increase the complexity of computing.So the method sets up that torque distribution function difficulty is bigger accurately.

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

Summary of the invention

The present invention is for avoiding above-mentioned existing in prior technology weak point; A kind of method that reduces switched reluctance machines torque tracking error is provided; In the hope of the output torque of minimizing switched reluctance machines and the error between the torque reference; 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:

A kind of characteristics that reduce the method for switched reluctance machines torque tracking error of the present invention are to carry out as follows:

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

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

The current i of said switched reluctance machines " angle-electric current-torque " tables of data every stator winding mutually that to be position transducer collects when turning round according to switched reluctance machines rotor angle collect with current sensor _kCalculated off-line obtained to utilize formula (1):

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

In the formula (1), R _kBe 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 the formula (1), m is the conducting phase of motor, m=0,1,2 ... N;

Step 4: the instantaneous torque T that obtains said conducting phase m according to said switched reluctance machines " angle-electric current-torque " tables of data _m, utilize said 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 size of torque tracking error Δ T and the torque tracking error limit value ε of setting relatively, and adjust the on off operating mode of conducting phase winding, the size of torque-limiting tracking error Δ T according to comparative result;

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

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

Turn-on angle according to the interval internal torque of said single-phase conducting size adjustment error and ∑ Δ T and said torque tracking error limit value ε switched reluctance machines; Peak value and amplitude according to the turn-on angle of said switched reluctance machines adjustment instantaneous torque reduce the torque tracking error.

The characteristics that reduce the method for switched reluctance machines torque tracking error of the present invention also are:

In the said step 1, during the switched reluctance machines electric operation, said torque reference T ^*For just; When switched reluctance machines deceleration or running under braking, said torque reference T ^*For negative;

In the said step 5, the adjustment of the on off operating mode of said conducting phase winding is undertaken by following rule:

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

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

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

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

Switched reluctance machines slows down or during running under braking: when ∑ Δ T＞ε, and the position of turn-on angle in advance, next phase stator winding conducting in advance is constantly; When ∑ Δ T＜-during ε, delay the position of turn-on angle, postpone next phase stator winding conducting constantly; When-ε≤∑ Δ T≤ε, keep the invariant position of turn-on angle;

Said in advance or the position of delaying turn-on angle confirm as follows: with said m phase stator from the interval internal torque of conducting error with difference ∑ Δ T and said torque tracking error limit value ε as input; Adopt FUZZY ALGORITHMS FOR CONTROL or pid algorithm that said turn-on angle is adjusted, the output valve of acquisition is the variation delta θ of turn-on angle position.

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

1, the present invention utilize switched reluctance machines instantaneous torque as control variables, can control the output torque effectively, and torque pulsation inhibited; Thereby avoided motor when operation, to produce big torque tracking error.

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

3, as control variables, the size of the online adjustment restriction tracking error through opening angle makes the little deviation ground track reference torque of trying one's best of the instantaneous torque of motor output, thereby has reduced motor torque ripple and noise with the torque tracking error in the present invention.

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

Description of drawings:

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

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

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

Fig. 4 is 45 ° of sketch mapes in switched reluctance machines m phase maximum induction position in the embodiment of the invention one;

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

Fig. 6 is 90 ° of sketch mapes in switched reluctance machines m phase minimum inductance position in the embodiment of the invention one;

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

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

Fig. 9 is 30 ° of sketch mapes in switched reluctance machines m phase maximum induction position in the embodiment of the invention two;

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

Figure 11 is 60 ° of sketch mapes in switched reluctance machines m phase minimum inductance position in the embodiment of the invention two.

Embodiment:

Embodiment one: the switched reluctance machines with three-phase 6/4 structure in the present embodiment is example, and is as shown in Figure 1, may further comprise the steps:

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

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

The current i of switched reluctance machines " angle-electric current-torque " tables of data every stator winding mutually that to be position transducer collects when turning round according to switched reluctance machines rotor angle collect with current sensor _kCalculated off-line obtained to utilize formula (1):

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

In the formula (1), R _kBe 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 the formula (1), m is the conducting phase of 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 size of torque tracking error Δ T and the torque tracking error limit value ε of setting relatively, and adjust the on off operating mode of conducting phase winding, the size of torque-limiting tracking error Δ T according to comparative result;

The on off operating mode adjustment of conducting phase winding is undertaken by following rule:

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

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

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

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

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

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

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

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

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

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

The angular dimension of switch reluctance machine rotor is to be that reference point is confirmed to be installed in 0 ° position transducer shown in Figure 2.

Embodiment two: present embodiment with four mutually the switched reluctance machines of 8/6 structure be example, step is as shown in Figure 1, different with embodiment one is:

1, n=4 in the present embodiment;

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

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

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

Claims (4)

1. method that reduces switched reluctance machines torque tracking error is characterized in that carrying out as follows:

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

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

The current i of said switched reluctance machines " angle-electric current-torque " tables of data every stator winding mutually that to be position transducer collects when turning round according to switched reluctance machines rotor angle collect with current sensor _kCalculated off-line obtained to utilize formula (1):

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

In the formula (1), R _kBe 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 the formula (1), m is the conducting phase of motor, m=0,1,2 ... N;

Step 4: the instantaneous torque T that obtains said conducting phase m according to said switched reluctance machines " angle-electric current-torque " tables of data _m, utilize said 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 size of torque tracking error Δ T and the torque tracking error limit value ε of setting relatively, and adjust the on off operating mode of conducting phase winding, the size of torque-limiting tracking error Δ T according to comparative result;

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

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

Turn-on angle according to the interval internal torque of said single-phase conducting size adjustment error and ∑ Δ T and said torque tracking error limit value ε switched reluctance machines; Peak value and amplitude according to the turn-on angle of said switched reluctance machines adjustment instantaneous torque reduce the torque tracking error.

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

In the said step 1, during the switched reluctance machines electric operation, said torque reference T ^*For just; When switched reluctance machines deceleration or running under braking, said 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 the said step 5, the adjustment of the on off operating mode of said conducting phase winding is undertaken by following rule:

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

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

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

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

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

Switched reluctance machines slows down or during running under braking: when ∑ Δ T＞ε, and the position of turn-on angle in advance, next phase stator winding conducting in advance is constantly; When ∑ Δ T＜-during ε, delay the position of turn-on angle, postpone next phase stator winding conducting constantly; When-ε≤∑ Δ T≤ε, keep the invariant position of turn-on angle;

Said in advance or the position of delaying turn-on angle confirm as follows: with said m phase stator from the interval internal torque of conducting error with difference ∑ Δ T and said torque tracking error limit value ε as input; Adopt FUZZY ALGORITHMS FOR CONTROL or pid algorithm that said turn-on angle is adjusted, the output valve of acquisition is the variation delta θ of turn-on angle position.

Images