CN103944476B - Torque controller of electric vehicle - Google Patents

Abstract

The invention discloses a torque controller of an electric vehicle. A PI torque controller is combined with a sliding-mode torque controller, a switch module weights a torque current obtained by the PI torque controller and a torque current obtained by the sliding-mode torque controller through different weight coefficients according to a motor speed error to obtain given torque currents, when the motor speed error |delta omega [r] | is larger than or equal to delta omega [r] max, the torque current is completely provided by the sliding-mode torque controller to improve following performance of the rotating speed; when the motor speed error |delta omega [r]| is smaller than delta omega [r] min, the torque current is provided by the PI torque controller, so that floating tracking of the given rotating speed is ensured; when the motor speed error |delta omega [r] | is larger than the delta omega [r] min and smaller than the delta omega [r] max, the two torque controllers operate at the same time so that smooth transition can be ensured. According to the torque controller of the electric vehicle, due to the fact that the PI torque controller is combined with the sliding-mode torque controller, control rapidity is improved, the magnitude of shakes of sliding mode control can be reduced, the rapid following performance of control over an induction motor is improved, and stability of rotating speed control is improved.

Description

A kind of electric automobile torque controller

Technical field

The invention belongs to motor in electric automobile control technology field, more specifically, it is related to a kind of electric automobile torque Controller.

Background technology

With becoming increasingly conspicuous the problems such as social development and the energy, environmental protection, pure electric automobile is with its zero-emission, noise Low advantage is increasingly paid attention to by countries in the world, and electric automobile has become the developing direction of 21 century automobile industry, is green One of topmost developing direction of color vehicle.Motor and motor drive controller are as the important portion of " three is horizontal " technology Point, it is the direct offer mechanism providing electric automobile to drive power, the quality of its drive characteristic directly determines electric automobile row Sail the quality of performance.In conventional electric automotive control system the general traditional pi torque controller adopting of torque controller and Sliding formwork torque controller.

Fig. 1 is a kind of drive system of electric automobile theory diagram based on pi torque controller.As shown in figure 1, pi (proportional integral, proportional integral) torque controller 12 is according to the given rotating speed of gas pedal 11And motor Actual speed ω of 17 feedbacks_rGenerate given torque current i_sq, its control formula is:

i_sq(t)=k_pe(t)+k_i∫e(t)dt

Wherein, k_p,k_iIt is respectively proportionality coefficient and the integral coefficient of pi torque controller；E (t) is error originated from input,

Pi torque controller 12 provides given torque current i_sq ^*To indirect vector control module 16, this electric automobile drives System adopts weak magnetic controller 13 to provide given exciting current i_sd ^*To indirect vector control module 16, indirect vector control module 16 generate svpwm (space vector pulse width modulation, space vector pulse width modulation) ripples to control power Six road igbt (insulated gate bipolar transistor, the insulated gate bipolar transistor) power tube of module 15 Turn on and off the time be indirectly controlled motor 17 output actual speed, 3/2 conversion module 14 motor collecting 17 three-phase current i_a、i_b、i_cIt is converted into the exciting current i needed for indirect vector control module 16_sdWith torque current i_sqIn addition Closed loop control.

Although pi torque controller algorithm is simple, practical, pi torque controller has the shortcomings that intrinsic: is directed to The pi parameter of same control system different rotating speeds is changeless, thus rotating speed response can be led to slow, speed overshoot amount Greatly, pi parameter is difficult to adjust.

Fig. 2 is a kind of example principles block diagram of the drive system of electric automobile based on sliding formwork torque controller.As Fig. 2 institute Show, the same with pi torque controller 12, sliding formwork torque controller 22 is according to the given rotating speed of gas pedal 21Anti- with motor 27 Actual speed ω of feedback_rGenerate given torque current i_sq, its control formula is:

i_sq(t)=- kx (t)-β sgn (x (t))

$sgn\left(x\right(t\left)\right)=\left\{\begin{array}{c}1,\left(x\left(t\right)\right)>0\\ -1,\left(x\left(t\right)\right)<0\end{array}\right.$

$\left\{\begin{array}{c}k>0\\ \mathrm{\&beta;}>\frac{l_r{t}_l}{{\mathrm{pl}}_m^2{i}_{sd}^{\&prime;}}>0\end{array}\right.$

Wherein, k, β are the setting coefficient of sliding mode controller, can be by arranging the receipts of coefficient k, β adjustment sliding mode controller Hold back speed.X (t) is given rotating speedWith actual speed ω_rThe error of (t), l_rFor the rotor self-induction of motor 27, t_lFor motor The maximum load torque that 27 can bear, p is the number of pole-pairs of motor 27, l_mFor the mutual inductance of motor 27, i '_sdSpecified for motor 27 Exciting current.

Likewise, sliding formwork torque controller 22 provides given torque current i_sq ^*To indirect vector control module 26, using weak Magnetic controller 23 provides given exciting current i_sd ^*To indirect vector control module 26, indirect vector control module 26 generates svpwm Ripple come to control power model 25 six road igbt power tubes turn on and off the time be indirectly controlled motor 27 output reality Border rotating speed, the three-phase current i of the motor 27 that 3/2 conversion module 24 collects_a、i_b、i_cIt is converted into indirect vector control module 26 Required exciting current i_sdWith torque current i_sqClosed loop control in addition.

Sliding formwork torque controller has that algorithm is simple, fast response time, to external world noise jamming and Parameter Perturbation have Shandong Rod, without system on-line identification, physics realization simple the advantages of.But the intrinsic defect of sliding formwork torque controller itself exists Shake can be trembled in system in sliding-mode surface up and down so that motor actual speed can fluctuate up and down in given rotating speed and then affect its control Device normally runs.

Content of the invention

It is an object of the invention to overcoming the deficiencies in the prior art, a kind of electric automobile torque controller being provided, combines and make With pi torque controller and sliding formwork torque controller, improve the quick followability of speed and the stability of drive system of electric automobile.

For achieving the above object, electric automobile torque controller of the present invention, including pi torque controller, sliding formwork torque Controller, switch handover module, wherein:

Pi torque controller receives the given rotating speed ω from electric automobile pedal_r ^*Reality with motor in electric automobile Rotational speed omega_r, generate torque current i_sq1 ^*Input switch handover module；

Sliding formwork torque controller receives the given rotating speed ω of the electric automobile pedal from gas pedal_r ^*With electronic vapour Actual speed ω of vehicle motor_r, generate torque current i_sq2 ^*Input switch handover module；

Switch handover module receives the given rotating speed ω from gas pedal_r ^*Actual speed ω with motor_r, and pi turns Square controller and the torque current i of sliding formwork torque controller generation_sq1 ^*And i_sq2 ^*, obtain torque current i_sq ^*:

i_sq ^*=λ * i_sq1 ^*+(1-λ)*i_sq2 ^*

Wherein, λ is weighting parameter, and the method for determination is:

$\left\{\begin{array}{c}\mathrm{\&lambda;}=1,\left|{\mathrm{\&delta;\&omega;}}_r\right|\&le;{\mathrm{\&delta;\&omega;}}_r\min \\ \mathrm{\&lambda;}=1-\frac{\left|{\mathrm{\&delta;\&omega;}}_r\right|-{\mathrm{\&delta;\&omega;}}_r\min }{{\mathrm{\&delta;\&omega;}}_r\max -{\mathrm{\&delta;\&omega;}}_r\min },{\mathrm{\&delta;\&omega;}}_r\min <\left|{\mathrm{\&delta;\&omega;}}_r\right|<{\mathrm{\&delta;\&omega;}}_r\max \\ \mathrm{\&lambda;}=0,{\mathrm{\&delta;\&omega;}}_r\max \&le;\left|{\mathrm{\&delta;\&omega;}}_r\right|\end{array}\right.$

Wherein, δ ω_r=ω_r-ω_r ^*,Represent slow-speed of revolution error dot,Represent high speed error point.

Electric automobile torque controller of the present invention, pi torque controller and sliding formwork torque controller is combined, is cut by switch Pi torque controller and sliding formwork torque controller are respectively obtained with different weights coefficients by die change tuber according to motor revolution error Torque current be weighted obtaining given torque current.Work as motor revolution errorWhen, by sliding formwork torque control Device processed provides torque current to accelerate speed follower completely.Work as motor revolution errorWhen, by pi torque control Device processed provides to ensure speed astatic tracking given speed with this.Work as motor revolution errorWhen, two kinds of torque controllers run guarantee simultaneously and seamlessly transit.Adopt in this way, can Ensure that the rapidity controlling also can weaken sliding formwork control shake, increase the quick followability that induction machine rotating speed controls, improve The stability that rotating speed controls.

Brief description

Fig. 1 is a kind of drive system of electric automobile theory diagram based on pi torque controller；

Fig. 2 is a kind of drive system of electric automobile theory diagram based on sliding formwork torque controller；

Fig. 3 is a kind of specific embodiment of the drive system of electric automobile based on electric automobile torque controller of the present invention Theory diagram；

Fig. 4 is the function curve of weighting parameter λ；

Fig. 5 be driven based on pi torque controller the three-phase current of induction machine, torque, actual speed schematic diagram；

Fig. 6 be driven based on sliding formwork torque controller the three-phase current of induction machine, torque, actual speed schematic diagram；

Fig. 7 be driven based on the present invention the three-phase current of induction machine, torque, actual speed schematic diagram.

Specific embodiment

Below in conjunction with the accompanying drawings the specific embodiment of the present invention is described, so that those skilled in the art is preferably Understand the present invention.Requiring particular attention is that, in the following description, when known function and design detailed description perhaps Can desalinate the present invention main contents when, these descriptions will be ignored here.

Embodiment

Fig. 3 is a kind of specific embodiment of the drive system of electric automobile based on electric automobile torque controller of the present invention Theory diagram.As shown in figure 3, electric automobile torque controller 32 of the present invention includes pi torque controller 321, sliding formwork direct torque Device 322, switch handover module 323.

Pi torque controller 321 receives the given rotating speed ω from electric automobile pedal 31_r ^*And motor in electric automobile 37 actual speed ω_r, generate torque current i_sq1 ^*Input switch handover module 323.

As pi torque controller 321, sliding formwork torque controller 322 receives the electric automobile from gas pedal The given rotating speed ω of pedal_r ^*Actual speed ω with motor in electric automobile_r, generate torque current i_sq2 ^*Input switch handover module 323.

In the present invention, pi torque controller 321 and sliding formwork torque controller 322 are according to respective direct torque mode respectively Generate torque current, but this two torque currents are not to directly input follow-up indirect vector control module 36, but First input to switch handover module 323, final given torque current is obtained by switch handover module 323.

Switch handover module 323 receives the given rotating speed ω from gas pedal 31_r ^*Actual speed ω with motor_r, with And the torque current i that pi torque controller 321 and sliding formwork torque controller 322 generate_sq1 ^*And i_sq2 ^*, obtain given torque current i_sq ^*:

i_sq ^*=λ * i_sq1 ^*+(1-λ)*i_sq2 ^*

Wherein, λ is weighting parameter.

Because sliding formwork torque controller has response speed quickly, pi torque controller can give speed with DAZ gene Degree, in the present invention, switch handover module 323 needs according to motor revolution error δ ω_rTo switch different torque controllers Give torque current i to control accordingly_sq ^*, to reach the purpose of precise control motor speed.Motor revolution error δ ω_r= ω_r-ω_r ^*.As motor revolution error δ ω_r?Qu Shi, is provided given completely by sliding formwork torque controller 322 Torque current i_sq ^*To accelerate followability, now weighting parameter λ=0；As motor revolution error δ ω_r?Area When, because the intrinsic jittering characteristic of sliding mode controller itself can not follow the tracks of given speed well, given torque therefore now Electric current i_sq ^*Completely provide to ensure speed astatic tracking given speed, now weighting parameter λ with this by pi torque controller =1.It is the speed error switching point of the torque controller switching of artificial setting,For the slow-speed of revolution Error dot,For high speed error point, it is on the occasion of value being arranged according to practical situation, generally

Because the switching rule of torque controller and handoff procedure are all to be realized by program in switch handover module 323 , so switching rule can flexibly design the stability it is contemplated that when torque controller switches, the present invention is using change The method of weighting realizes the slowly switching of two kinds of torque controllers.In handoff procedure, that is, Weighting parameter is:

$\mathrm{\&lambda;}=1-\frac{\left|{\mathrm{\&delta;\&omega;}}_r\right|-{\mathrm{\&delta;\&omega;}}_{r}min}{{\mathrm{\&delta;\&omega;}}_r\max -{\mathrm{\&delta;\&omega;}}_{r}min}$

In sum, in the present invention, the determination method of weighting parameter λ is:

$\left\{\begin{array}{c}\mathrm{\&lambda;}=1,\left|{\mathrm{\&delta;\&omega;}}_r\right|\&le;{\mathrm{\&delta;\&omega;}}_r\min \\ \mathrm{\&lambda;}=1-\frac{\left|{\mathrm{\&delta;\&omega;}}_r\right|-{\mathrm{\&delta;\&omega;}}_r\min }{{\mathrm{\&delta;\&omega;}}_r\max -{\mathrm{\&delta;\&omega;}}_r\min },{\mathrm{\&delta;\&omega;}}_r\min <\left|{\mathrm{\&delta;\&omega;}}_r\right|<{\mathrm{\&delta;\&omega;}}_r\max \\ \mathrm{\&lambda;}=0,\left|{\mathrm{\&delta;\&omega;}}_r\right|\&greaterequal;{\mathrm{\&delta;\&omega;}}_r\max \end{array}\right.$

It can be seen that, weighting parameter λ is one with motor revolution error δ ω_rPiecewise function for variable.Fig. 4 is weighting parameter The function curve of λ.

Below beneficial effects of the present invention are illustrated with an example.Respectively by pi torque controller, sliding formwork direct torque Device and the present invention are applied to 3kw induction machine is carried out with the simulink Simulation drive system of indirect vector controlled.Table 1 is The technical parameter of 3kw induction machine.

Table 1

This emulation experiment is in induction machine torque at rated load 20.04n*m, and given rotating speed is to carry out under 10rad/s 's.

In pi torque controller, proportionality coefficient k_p=0.5, integral coefficient k_i=1.4.

In sliding formwork torque controller, undetermined coefficient k and the span of β are calculated according to induction machine technical parameter, wherein The maximum load torque t that motor can bear_lShould be nominal torque 20.04n*m that motor can provide, then:

$\left\{\begin{array}{c}k>0\\ \mathrm{\&beta;}>\frac{l_r{t}_l}{{\mathrm{pl}}_m^2{i}_{sd}}=\frac{0.196*20.04}{2*{0.187}^2*6.0}=9.36\end{array}\right.$

K=0.4, β=9.4 are taken in this emulation experiment.And because sliding formwork control has buffeting characteristic in itself, by sliding formwork Sign function sgn (x (t)) in torque controller replaces largely cutting with continuous saturation function sat (x (t)) Weak system chatter.Saturation function employed in this emulation experiment is as follows:

$sat\left(x\right(t\left)\right)=\left\{\begin{array}{c}1,x\left(t\right)\&greaterequal;\frac{\mathrm{\&pi;}}{\sqrt{2}}\mathrm{\&epsiv;}\\ sin\left(\frac{x\left(t\right)}{\sqrt{2}\mathrm{\&epsiv;}}\right),-\frac{\mathrm{\&pi;}}{\sqrt{2}}\mathrm{\&epsiv;}<x\left(t\right)<\frac{\mathrm{\&pi;}}{\sqrt{2}}\mathrm{\&epsiv;}\\ -1,x\left(t\right)\&le;-\frac{\mathrm{\&pi;}}{\sqrt{2}}\mathrm{\&epsiv;}\end{array}\right.$

ε is undetermined coefficient, arranges ε=1 in this emulation experiment.

Pi torque controller employed in electric automobile torque controller of the present invention and sliding formwork torque controller with individually The pi torque controller using is identical with sliding formwork torque controller.In this emulation experimentIt is set to 0.1rad/s,It is set to 1rad/s.

Fig. 5 be driven based on pi torque controller the three-phase current of induction machine, torque, actual speed schematic diagram.Fig. 6 Be driven based on sliding formwork torque controller the three-phase current of induction machine, torque, actual speed schematic diagram.Fig. 7 is based on this The three-phase current of induction machine of invention driving, torque, actual speed schematic diagram.Knowable to Fig. 5, Fig. 6, Fig. 7 are contrasted, three The performance planting torque controller is attained by preferable level, and three-phase current wave distortion is little, and the torque of output is also relatively stable. But from the point of view of in terms of the rotating speed and followability, pi torque controller needs 6s to reach given rotating speed, and torque controller of the present invention Only need to 1.9s and can reach given rotating speed.From the point of view of eliminating static difference and weakening and trembling in terms of shake, sliding formwork torque controller is due to depositing Lead to ultimately fail to stablize in given rotating speed trembling shake, and torque controller of the present invention, due to there being the effect of pi link finally can Stablize in given rotating speed and nothing trembles shake phenomenon.

Although to the present invention, illustrative specific embodiment is described above, in order to the technology of the art Personnel understand the present invention, the common skill it should be apparent that the invention is not restricted to the scope of specific embodiment, to the art For art personnel, as long as various change is in the spirit and scope of the present invention of appended claim restriction and determination, these Change is it will be apparent that all utilize the innovation and creation of present inventive concept all in the row of protection.

Claims (3)

1. a kind of electric automobile torque controller is it is characterised in that include pi torque controller, sliding formwork torque controller, switch Handover module, wherein:

Pi torque controller receives the given rotating speed ω from electric automobile pedal_r ^*Actual speed with motor in electric automobile ω_r, generate torque current i_sq1 ^*Input switching switch handover module；

Sliding formwork torque controller receives the given rotating speed ω of the electric automobile pedal from gas pedal_r ^*With electric automobile electricity Actual speed ω of machine_r, generate torque current i_sq2 ^*Input switch handover module；

Switch handover module receives the given rotating speed ω from gas pedal_r ^*Actual speed ω with motor_r, and pi torque control Device processed and the torque current i of sliding formwork torque controller generation_sq1 ^*And i_sq2 ^*, obtain torque current i_sq ^*:

i_sq ^*=λ * i_sq1 ^*+(1-λ)*i_sq2 ^*

Wherein, λ is weighting parameter, and the method for determination is:

$\left\{\begin{array}{c}\mathrm{\&lambda;}=1,\left|\mathrm{\&delta;}{\mathrm{\&omega;}}_r\right|\&le;\mathrm{\&delta;}{\mathrm{\&omega;}}_r\min \\ \mathrm{\&lambda;}=1-\frac{\left|{\mathrm{\&delta;\&omega;}}_r\right|-{\mathrm{\&delta;\&omega;}}_r\min }{{\mathrm{\&delta;\&omega;}}_r\max -{\mathrm{\&delta;\&omega;}}_r\min },\mathrm{\&delta;}{\mathrm{\&omega;}}_r\min <\left|\mathrm{\&delta;}{\mathrm{\&omega;}}_r\right|<\mathrm{\&delta;}{\mathrm{\&omega;}}_r\max \\ \mathrm{\&lambda;}=0,\mathrm{\&delta;}{\mathrm{\&omega;}}_r\max \&le;\left|\mathrm{\&delta;}{\mathrm{\&omega;}}_r\right|\end{array}\right.$

Wherein, δ ω_r=ω_r-ω_r ^*, δ ω_rMin represents slow-speed of revolution error dot, δ ω_rMax represents high speed error point.

2. electric automobile torque controller according to claim 1 is it is characterised in that described slow-speed of revolution error dot δ ω_rMin and high speed error point δ ω_rMax meets 2 δ ω_rmin≤δω_rmax.

3. electric automobile torque controller according to claim 1 is it is characterised in that in described sliding formwork torque controller Sign function adopts continuous saturation function.