CN103684179A - Compensation device and compensation method of current filtering and dead zone of permanent magnet synchronous motor - Google Patents

Abstract

The invention relates to a compensation device and a compensation method of current filtering and the dead zone of a permanent magnet synchronous motor. The input end of a position sensor is connected with the output end of the permanent magnet synchronous motor, and the output end of the position sensor is connected with a rotating speed calculation module, a coordinate transformation module and a current inverse transformation module respectively. The output value of the rotating speed calculation module is used as the input of a speed ring PI adjuster. A current sensor inputs the detected two-phase current of the permanent magnet synchronous motor to the coordinate transformation module through a summation module, meanwhile the two-phase current is input into the coordinate transformation module, the coordinate transformation module transforms the coordinate of three-phase currents and then inputs the currents to an incremental kalman filter, and the output end of the incremental kalman filter is connected with the current inverse transformation module, a q-axis current ring and a d-axis current ring. The output end of a first current ring PI adjuster and the output end of a second current ring PI adjuster are connected with an inverter through a voltage inverse transformation module, the output end of the current inverse transformation module is connected with the input end of a dead zone compensation module, the output end of the dead zone compensation module is connected with the input end of the inverter, and the output end of the inverter is connected with the input end of the permanent magnet synchronous motor.

Description

A kind of permagnetic synchronous motor current filtering and dead area compensation device and compensation method

Technical field

The present invention relates to a kind of current of electric filtering and dead area compensation device and compensation method, particularly about a kind of permagnetic synchronous motor current filtering and dead area compensation device and compensation method.

Background technology

Permagnetic synchronous motor has high efficiency, high power density, the advantage such as non-carbonate, in servo occasion, is applied widely.Actual system generally all includes noise to a certain degree, and the current noise source of PMSM Servo System can be divided into two kinds, and a kind of is the white noise causing due to non-ideal factors such as interference, sampling errors, and this is unavoidable.Another kind is due to the state of system in closed-loop control, original white noise is used as to error originated from input and regulates, and causes system to export frequent disturbance, thereby causes larger noise.For the noise of this type, can take rational filtering method, at feedback path, by the filtering to greatest extent of system white noise, avoid causing that system exports unnecessary disturbance, thereby reach the object of attenuating noise.

Low pass filter is a kind of conventional filtering method, and it has feature simple in structure, calculated load is little.Moving average filter is exactly a kind of easy low pass filter in essence, and in servo field, it is widely used in the high-frequency random noises in the signals such as filtering electric current, rotating speed.But, in principle of lowpass filter, all be there is to time delay in all frequency contents in signal, the dynamic property of such time delay meeting impair system.

Kalman filtering is a kind of modern filtering method growing up the sixties in last century, and it is the optimum linearity method of estimation in a kind of minimum variance meaning.Different from principle of lowpass filter, Kalman filter has used system mathematic model, is equivalent to obtain more system information, based on Mathematical Modeling, can realize the filtering of system state amount or estimation, but cost is calculated load, obviously increases.PMSM Servo System generally adopts three-phase PWM voltage source inverter to drive.For fear of two switches conductings simultaneously on same brachium pontis, generally take the mode of inserting Dead Time to guarantee that another switch turn-offs before a switch conduction.The insertion in dead band be equivalent to the superpose interference voltage of one-period pulsation, this interference voltage can cause phase current distortion and then cause the pulsation of motor output electromagnetic torque.

In order to obtain the better phase current waveform of sinusoidal degree, generally pass through the impact of the mode deadband eliminating effect of dead area compensation.The interference voltage causing due to dead band and the polarity of phase current exist close ties, and the phase current polarity judgement mistake compensation causing that makes mistakes can cause that larger distortion appears in electric current, so the key of dead area compensation is the detection of phase current zero crossing.The detected value judgement phase current polarity being directly converted to according to A/D is easily subject to the impact of sampling noiset, and the probability that mistake compensation occurs is larger.Conventional method is according to the position judgment phase current polarity of output voltage vector, the adverse effect of having avoided current sample noise to bring, propose only need be to the strategy that wherein a phase output voltage compensates in specific currents region simultaneously, yet the computational methods to " angle between voltage vector and induced electromotive force " are only applicable to steady-state process, the servo system for operating modes such as rotating speed and electric currents in frequent fluctuation is also inapplicable.

While adopting digital control approach, applying of controlled quentity controlled variable exists one to clap hysteresis time delay.In this case, if still using the current status of current period as the foundation of judgement phase current polarity, to the compensation in dead band, also can postpone a bat so.If current polarity changes in current period, due to digital control one impact clap lagging behind, bucking voltage can not be made an immediate response in current period, must wait until that the soonest next cycle just can make adjustment.In this case, the dead area compensation in current period is just equivalent to mistake compensation.For one of dead area compensation, clap hysteresis problem, study at present less.

Summary of the invention

For the problems referred to above, the object of this invention is to provide a kind of effective weakening current noise and suppress permagnetic synchronous motor current filtering and dead area compensation device and the compensation method of the electromagnetic torque pulsation that dead band causes.

For achieving the above object, the present invention takes following technical scheme: a kind of permagnetic synchronous motor current filtering and dead area compensation device, is characterized in that: it comprises position transducer, permagnetic synchronous motor, rotating speed computing module, coordinate transformation module, electric current inverse transform block, speed ring pi regulator, current sensor, summation module, increment type Kalman filter, the first electric current loop pi regulator 1, voltage inverse transform block, the second electric current loop pi regulator, inverter and dead area compensation module; Described coordinate transformation module, increment type Kalman filter and the first electric current loop pi regulator form q shaft current ring; Described coordinate transformation module, increment type Kalman filter and the second electric current loop pi regulator form d shaft current ring, and described q shaft current ring and d shaft current ring form electric current loop; The input of described position transducer connects the output of described permagnetic synchronous motor, the output of described position transducer connects respectively described rotating speed computing module, described coordinate die change piece and electric current inverse transform block, and the electrical degree θ collecting is transferred to described rotating speed computing module, described coordinate die change piece and electric current inverse transform block; The rotational speed omega of described rotating speed computing module output is as negative feedback, and with given rotating speed command value ω ^*get after difference, as the input of described speed ring pi regulator; Described current sensor connects the stator of described permagnetic synchronous motor, and the biphase current in the three-phase current of the permanent-magnetic synchronous motor stator detecting is got after negative and inputted described coordinate transformation module through the summation of described summation module; Described current sensor is also inputted described coordinate transformation module by described biphase current simultaneously, and described coordinate transformation module carries out described three-phase current to input described increment type Kalman filter after dq coordinate transform, q shaft current detected value i _qwith d shaft current detected value i _dafter described increment type Kalman filter is processed, by q shaft current predictive filtering value i _{q_pre}input respectively described q shaft current ring and electric current inverse transform block, by described d shaft current predictive filtering value i _{d_pre}input respectively described d shaft current ring and electric current inverse transform block; Described q shaft current predictive filtering value i _{q_}as the negative feedback of q shaft current ring, with the output comparison of described speed ring pi regulator, comparison value is input to described the first electric current loop pi regulator and obtains q shaft voltage

, q shaft voltage

transfer to described voltage inverse transform block; Described d shaft current detected value i _{d_}as the ring negative feedback of d shaft current and electric current given in advance

relatively, comparison value is input to described the second electric current loop pi regulator and obtains d shaft voltage

, d shaft voltage

transfer to described voltage inverse transform block; The output of described voltage inverse transform block connects the input of described inverter; The output of described electric current inverse transform block connects the input of described dead area compensation module, and the output of described dead area compensation module connects the input of described inverter, and the output of described inverter connects the input of described permagnetic synchronous motor.

Permagnetic synchronous motor current filtering and dead-zone compensation method based on a kind of permagnetic synchronous motor current filtering and dead area compensation device, comprise the following steps: 1) current sensor is by the permagnetic synchronous motor threephase stator current i detecting _a, i _band i _cinput in coordinate transformation module, the coordinate transform that it is carried out to abc/ α β, obtains the current component i under two-phase rest frame _α, i _β:

$\left[\begin{array}{c}{i}_{\mathrm{\α}}\\ i_{\mathrm{\β}}\end{array}\right]=\sqrt{\frac{2}{3}}\left[\begin{array}{ccc}1& -\frac{1}{2}& -\frac{1}{2}\\ 0& \frac{\sqrt{3}}{2}& \frac{\sqrt{3}}{2}\end{array}\right]\left[\begin{array}{c}{i}_{\mathrm{\α}}\\ i_b\\ i_c\end{array}\right],$ In formula, i _cfor i _a, i _bwith negative value;

2), in coordinate transformation module, the electrical degree θ rotating through according to the permanent-magnetic synchronous motor rotor receiving, to the current component i under two-phase rest frame _α, i _βcarry out again α β/dq coordinate transform, obtain the current detection value i under two-phase synchronous rotary dq coordinate system _d, i _q:

$\left[\begin{array}{c}{i}_d\\ i_q\end{array}\right]=\left[\begin{array}{cc}\cos \mathrm{\θ}& \sin \mathrm{\θ}\\ -\sin \mathrm{\θ}& \cos \mathrm{\θ}\end{array}\right]\left[\begin{array}{c}{i}_{\mathrm{\α}}\\ i_{\mathrm{\β}}\end{array}\right],$ In formula, θ is the electrical degree that permanent-magnetic synchronous motor rotor rotates through, and by position transducer, is obtained;

3) the electrical degree θ that permanent-magnetic synchronous motor rotor rotates through inputs in rotating speed computing module, and electrical degree θ is carried out to differential, obtains speed feedback value ω; Speed feedback value ω and rotary speed instruction value ω given in advance ^*as the input of speed ring pi regulator, through calculation process, obtain current instruction value

; 4) current detection value i _q, i _dbe input in increment type Kalman filter, by increment type Kalman filter output d shaft current predictive filtering value i _{d_pre}with q shaft current predictive filtering value i _{q_pre}; 5) current instruction value

electric current given in advance respectively with d shaft current predictive filtering value i _{d_pre}with q shaft current predictive filtering value i _{q_pre}relatively, comparison value, respectively as the input of the first electric current loop pi regulator, the second electric current loop pi regulator, obtains respectively the reference voltage of the first electric current loop pi regulator, the second electric current loop adjuster output through calculation process ; 6) d shaft current predictive filtering value i _{d_pre}, q shaft current predictive filtering value i _{q_pre}the electrical degree θ rotating through with the permanent-magnetic synchronous motor rotor of position transducer output is input to respectively electric current inverse transform block, by electric current inverse transform block output three-phase predicted current i _{a_pre}, i _{b_pre}and i _{c_pre}; 7) three-phase predicted current i _{a_pre}, i _{b_pre}and i _{c_pre}input dead area compensation module, dead area compensation module is according to three-phase predicted current i _{a_pre}, i _{b_pre}and i _{c_pre}polarity export corresponding bucking voltage; 8) reference voltage

input voltage inverse transform block, voltage inverse transform block output three-phase voltage u _a, u _b, u _c, with three-phase predicted current i _{a_pre}, i _{b_pre}and i _{c_pre}corresponding bucking voltage respectively with three-phase voltage u _a, u _b, u _cinput inverter after stack, inverter is exported corresponding three-phase voltage to permagnetic synchronous motor, drives permagnetic synchronous motor work.

In described step 4), increment type Kalman filter is to current detection value i _d, i _qprocessing comprise the following steps:

(1) under synchronous rotating frame, the stator d axle of permagnetic synchronous motor, q shaft voltage equation are:

U _d=Ri _d+ L _ddi _d/ dt-ω L _qi _q, u _q=Ri _q+ L _qdi _q/ dt+ ω L _di _d+ ω ψ _f, u wherein _d, u _qbe respectively stator d, q shaft voltage, i _d, i _qbe respectively stator d, q shaft current, R is stator resistance, L _d, L _qbe respectively stator d, q axle inductance, ψ _ffor permanent magnet flux linkage, ω is rotor speed; (2) according to the stator q shaft voltage equation in step (1), at current period (k) T _swith (k-1) T of the upper cycle _sinside set up respectively the discrete voltage equation of permagnetic synchronous motor:

u _q(k)=R _e(i _q(k)+i _{q_pre}(k+1))/2+L _e(i _{q_pre}(k+1)-i _q(k))/T _s+ω(L _di _d+ψ _f)，

u _q(k-1)=R(i _q(k)+i _q(k-1))/2+L _q(i _q(k)-i _q(k-1))/T _s ⁺ω(L _di _d+ψ _f)，

I wherein _{q_pre}(k+1) be the predicted value to next of q shaft current in current period the zero hour in cycle, be called for short current forecasting value, i _q(k) be the current detection value of current period, i _q(k-1) a upper periodic permanent magnet synchronous motor stator q shaft current detected value, T _sfor control cycle, u _q(k) be current period stator q shaft voltage, u _q(k-1) be a upper cycle stator q shaft voltage, R _e, L _ebe respectively permanent-magnetic synchronous motor stator resistance R, stator q axle inductance L _qestimated value; (3) ignore the variation of the voltage item relevant to rotating speed, two formula in step (2) are subtracted each other, obtain the simplification current increment formula of permagnetic synchronous motor, because R _emuch smaller than L _e/ T _s, therefore ignore the impact of R, obtain in current period the predicted value i to next of d shaft current the zero hour in cycle _{d_pre}(k+1), and by current increment formula change into matrix form:

$x_k=\left[\begin{array}{c}{i}_q\left(k\right)\\ i_q(k-1)\end{array}\right],x_{k-1}=\left[\begin{array}{c}{i}_q(k-1)\\ i_q(k-2)\end{array}\right],F_{k-1}=\begin{array}{c}\left[\begin{array}{cc}2& -1\\ 1& 0\end{array}\right]\end{array}\begin{array}{c},B_{k-1}=\left[\begin{array}{c}{T}_s/L_q\\ 0\end{array}\right],C={\left[\begin{array}{c}1\\ 0\end{array}\right]}^T\end{array};$

(4) according to the Mathematical Modeling of the current increment Formula increment type Kalman filter of step (3) matrix form, be:

$\left\{\begin{array}{c}{x}_k=F_{k-1}{x}_{k-1}+B_{k-1}{u}_{k-1}+w\\ y_k=C{x}_k+v\end{array}\right.,$

Wherein, w is input noise vector, and v is output noise vector; x _k, x _k-1for system mode vector, y _kfor system output vector, u _k-1for dominant vector; F _k-1, B _k-1, C is coefficient matrix;

(5) according to the Mathematical Modeling of increment type Kalman filter, its correlated variables is carried out to iteration, obtain optimal estimation value

In described step (5), described optimal estimation value computational methods comprise the following steps:

1. calculate prior estimate vector value with corresponding error matrix

${\hat{x}}_k^{-}=F_{k-1}{\hat{x}}_{k-1}{B}_{k-1}{u}_{k-1},P_k^{-}=F_{k-1}{P}_{k-1}{P}_{k-1}^T+Q_{k-1},$

Wherein, Q _k-1for noise matrix Q _k-1, optimal estimation vector value for system state variables in the state vector in (k-1) cycle,

being k cycle prior estimate vector, is an intermediate variable,

being k cycle prior estimate error matrix, is also intermediate variable matrix, P _k-1for the error matrix of system in (k-1) cycle;

2. calculated gains matrix K _k: $K_k=P_k^{-}{C}^T{(C{P}_k^{-}{C}^T+R_{k-1})}^{-1};$

3. computing system is in the optimal estimation value of k periodic system state variable

Wherein ${\hat{x}}_k=\left[\begin{array}{c}{i}_{q\_}\left(k\right)\\ i_{q\_}(k-1)\end{array}\right],$ I _{q_}(k-1) be permanent-magnetic synchronous motor rotor (k-1) current detection value i _qoptimal estimation value, i _{q_}(k) be that permanent-magnetic synchronous motor rotor is at k periodic current detected value i _qoptimal estimation value;

4. calculate the error matrix P in k cycle _koptimal estimation value:

, wherein, Q _k-1, R is respectively the covariance matrix of noise w, v, error matrix P _kfor the error matrix of the optimal estimation value in estimation process, by iteration repeatedly, error matrix P _kfinally can converge to null matrix.

In described step 6), in described electric current inverse transform block, processing procedure comprises the following steps:

1. dope next periodic permanent magnet synchronous electric motor rotor coordinate transform angle θ _pre, because permagnetic synchronous motor mechanical time constant is much larger than electrical time constant, think motor remain a constant speed at short notice operation state, permanent-magnetic synchronous motor rotor is consistent with the angle θ turning in current period in next cycle;

2. in conjunction with the predictive filtering value of dq shaft current, by coordinate transform, obtain the predicted value i of the three-phase current in next cycle _{a_pre}, i _{b_pre}and i _{c_pre}for:

$\left[\begin{array}{c}{i}_{a\_\mathrm{pre}}\\ i_{b\_\mathrm{pre}}\\ i_{c\_\mathrm{pre}}\end{array}\right]=\begin{array}{c}\left[\begin{array}{cc}\cos {\mathrm{\θ}}_{\mathrm{pre}}& -\sin {\mathrm{\θ}}_{\mathrm{pre}}\\ \cos ({\mathrm{\θ}}_{\mathrm{pre}}-\frac{2\mathrm{\π}}{3})& -\sin ({\mathrm{\θ}}_{\mathrm{pre}}-\frac{2\mathrm{\π}}{3})\\ \mathrm{ocs}({\mathrm{\θ}}_{\mathrm{pre}}+\frac{2\mathrm{\π}}{3})& -\sin ({\mathrm{\θ}}_{\mathrm{pre}}+\frac{2\mathrm{\π}}{3})\end{array}\right]\end{array}\left[\begin{array}{c}{i}_{d\_\mathrm{pre}}\\ i_{q\_\mathrm{pre}}\end{array}\right],$

And according to above formula, calculate the predicted value i of next cycle three-phase current _{a_pre}, i _{b_pre}and i _{c_pre}.

In described step 7), described dead area compensation comprises the following steps:

1. dead area compensation module is according to next the cycle three-phase predicted current i receiving _{a_pre}, i _{b_pre}and i _{c_pre}, obtain the relevant voltage error delta u that next cycle three-phase predicted current produces respectively _a, Δ u _bwith Δ u _c:

${\mathrm{\Δu}}_a=\frac{T_d+T_{\mathrm{on}}-T_{\mathrm{off}}}{T_s}{V}_{\mathrm{dc}}\mathrm{sign}\left(i_{a\_\mathrm{pre}}\right),{\mathrm{\Δu}}_b=\frac{T_d+T_{\mathrm{on}}-T_{\mathrm{off}}}{T_s}{V}_{\mathrm{dc}}\mathrm{sign}\left(i_{b\_\mathrm{pre}}\right),{\mathrm{\Δu}}_c=\frac{T_d+T_{\mathrm{on}}-T_{\mathrm{off}}}{T_s}{V}_{\mathrm{dc}}\mathrm{sign}\left(i_{c\_pre}\right),$

Sign () is the polarity of predicted current, and during predicted current value >0, sign () value is 1, otherwise is-1;

2. by three-phase predicted current i _{a_pre}, i _{b_pre}and i _{c_pre}the voltage error Δ u producing _a, Δ u _bwith Δ u _cget respectively negative value, obtain and three-phase predicted current i _{a_pre}, i _{b_pre}and i _{c_pre}corresponding bucking voltage.

The present invention is owing to taking above technical scheme, it has the following advantages: 1, the present invention adopts the dq shaft current filtering method of increment type Kalman filter, with filter value, replace actual current detection value as the feed back input of electric current loop adjuster, can eliminate the interference of sampling noiset.2, the system state equation order of current filtering method that the present invention is based on increment type Kalman filter is only for second order, and calculated load significantly reduces, and has avoided the estimation to the voltage item relevant with rotating speed simultaneously, and system complexity and sensitivity to parameter obviously reduce.3, the present invention is by the voltage error that causes with dead band in inverter link stack contrary voltage just in time, effectively deadband eliminating interference.4, the present invention adopts incremental forecasting method can in current period, calculate in advance next cycle dq shaft current, therefore can eliminate one of digital control approach and clap hysteresis time delay.5, the present invention does closed-loop control by dq shaft current filter value, can reduce noise, reduce the pulsation of dq shaft voltage; With the phase current predicted value obtaining with prediction after filtering, make dead area compensation, be conducive to reduce the mistake compensation causing because the erroneous judgement of phase current polarity is disconnected, eliminate the impact of a bat hysteresis time delay simultaneously.The present invention is applicable to permagnetic synchronous motor SERVO CONTROL field.

Accompanying drawing explanation

Fig. 1 is the PMSM Servo System overall structure schematic diagram that the present invention adopts;

Fig. 2 is current sample sequential schematic diagram of the present invention;

Fig. 3 is the affect schematic diagram of prior art dead band on stator phase voltage;

Fig. 4 is the schematic diagram that is related to of prior art permagnetic synchronous motor dq shaft voltage error and rotor electrical degree;

Fig. 5 is current filtering of the present invention and dead-zone compensation method schematic diagram;

Fig. 6 adopts the filter effect contrast schematic diagram of distinct methods to q shaft current, Fig. 6 (a) adopts the filter effect schematic diagram of moving average filter to q shaft current, and Fig. 6 (b) adopts the filter effect schematic diagram of increment type Kalman filter of the present invention to q shaft current;

Dq shaft voltage when Fig. 7 is employing prior art and the stable state that adopts current filtering of the present invention and the comparison of wave shape schematic diagram of dq shaft current, wherein, Fig. 7 (a) be adopt prior art with adopt filtering of the present invention stable state time dq shaft voltage comparison of wave shape schematic diagram, Fig. 7 (b) be adopt prior art with adopt filtering of the present invention stable state time the comparison of wave shape schematic diagram of dq shaft current;

Fig. 8 is stator phase current i while adopting current filtering of the present invention _a, i _bpredicted value and detected value schematic diagram;

Fig. 9 is three kinds of employing the present invention under rotating speed and does not adopt stator phase current i when of the present invention _a, i _b, q shaft current i _q, q shaft voltage u _qcomparison of wave shape schematic diagram, stator phase current i when employing the present invention when wherein Fig. 9 (a) is 1000rpm for permanent-magnetic synchronous motor rotor rotating speed and employing prior art _a, i _b, q shaft current i _q, q shaft voltage u _qcomparison of wave shape schematic diagram, stator phase current i when employing the present invention when Fig. 9 (b) is 200rpm for permanent-magnetic synchronous motor rotor rotating speed and employing prior art _a, i _b, q shaft current i _q, q shaft voltage u _qcomparison of wave shape schematic diagram, stator phase current i when employing the present invention when Fig. 9 (c) is 50rpm for permanent-magnetic synchronous motor rotor rotating speed and employing prior art _a, i _b, q shaft current i _q, q shaft voltage u _qcomparison of wave shape schematic diagram;

Figure 10 is that permanent-magnetic synchronous motor rotor rotating speed is that 1200rpm does not adopt the present invention and the Steady Experimental comparison of wave shape schematic diagram that adopts dq shaft current and dq shaft voltage when of the present invention, Figure 10 (a) is the Steady Experimental waveform schematic diagram that does not adopt dq shaft current and dq shaft voltage when of the present invention, and Figure 10 (b) is the Steady Experimental waveform schematic diagram that adopts dq shaft current and dq shaft voltage when of the present invention;

Figure 11 is that permagnetic synchronous motor rotating speed does not adopt the present invention while being 1200rpm and adopts permanent-magnetic synchronous motor stator monophase current experimental waveform contrast schematic diagram when of the present invention, Figure 11 (a) is permanent-magnetic synchronous motor stator monophase current waveform schematic diagram while not adopting dead-zone compensation method of the present invention, and Figure 11 (b) is permanent-magnetic synchronous motor stator monophase current waveform schematic diagram while adopting dead-zone compensation method of the present invention;

Figure 12 is that permanent-magnetic synchronous motor rotor rotating speed does not adopt the present invention and the Steady Experimental comparison of wave shape schematic diagram that adopts dq shaft current of the present invention and dq shaft voltage while being 500rpm, Figure 12 (a) is the Steady Experimental waveform schematic diagram that does not adopt dq shaft current and dq shaft voltage when of the present invention, and Figure 12 (b) is the Steady Experimental waveform schematic diagram that adopts dq shaft current and dq shaft voltage when of the present invention;

Figure 13 is permagnetic synchronous motor rotating speed permanent-magnetic synchronous motor stator monophase current experimental waveform contrast schematic diagram when not adopting dead-zone compensation method of the present invention while being 500rpm and adopting dead-zone compensation method of the present invention;

Figure 14 is the stator monophase current experimental waveform schematic diagram of permagnetic synchronous motor rotating speed while not adopting dead-zone compensation method of the present invention respectively when two kinds of low speed, Figure 14 (a) is the stator monophase current experimental waveform schematic diagram of permagnetic synchronous motor rotating speed while being 170rpm and while not adopting dead-zone compensation method of the present invention, and Figure 14 (b) is the stator monophase current experimental waveform schematic diagram of permagnetic synchronous motor rotating speed while being 80rpm and while not adopting dead-zone compensation method of the present invention;

Embodiment

Below in conjunction with drawings and Examples, the present invention is described in detail.

As shown in Figure 1, take PMSM Servo System as example, the present invention includes position transducer 1, permagnetic synchronous motor (PMSM) 2, rotating speed computing module 3, coordinate transformation module 4, electric current inverse transform block 5, speed ring pi regulator 6, current sensor 7, summation module 8, increment type Kalman filter 9, the first electric current loop pi regulator 10, voltage inverse transform block 11, the second electric current loop pi regulator 12, inverter 13 and dead area compensation module 14.Wherein coordinate transformation module 4, increment type Kalman filter 9 and the first electric current loop pi regulator 10 form q shaft current ring; Coordinate transformation module 4, increment type Kalman filter 9 and the second electric current loop pi regulator 12 form d shaft current ring, and q shaft current ring and d shaft current ring form electric current loop.

The input of position transducer 1 connects the output of permagnetic synchronous motor 2, the output of position transducer 1 connects respectively rotating speed computing module 3, coordinate die change piece 4 and electric current inverse transform block 5, and the electrical degree θ collecting is transferred to rotating speed computing module 3, coordinate die change piece 4 and electric current inverse transform block 5.The rotational speed omega of rotating speed computing module 3 output is as negative feedback, and with given rotating speed command value ω ^*get after difference, as the input of speed ring pi regulator 6.Current sensor 7 connects the stator of permagnetic synchronous motor 2, for detection of the biphase current i in the three-phase current of permagnetic synchronous motor 2 stators _aand i _b, then by biphase current i _aand i _binput summation module 8,8 couples of biphase current i of summation module _awith i _band get negative value after obtain third phase current i _c, and by third phase current i _cinput coordinate conversion module 4.Current sensor 7 is simultaneously also by biphase current i _aand i _binput coordinate conversion module 4, the electrical degree θ that coordinate transformation module 4 bases receive is by three-phase current i _a, i _band i _ccarry out exporting q shaft current detected value i after coordinate transform _qwith d shaft current detected value i _d, and through increment type Kalman filter 9 by q shaft current detected value i _qwith d shaft current detected value i _dafter predictive filtering is processed, by q shaft current predictive filtering value i _{q_pre}input respectively q shaft current ring and electric current inverse transform block 5, by d shaft current predictive filtering value i _{d_pre}input respectively d shaft current ring and electric current inverse transform block 5.Q shaft current predictive filtering value i _{q_}as the negative feedback of q shaft current ring, with the output of speed ring pi regulator 6 be current-order

compare, comparison value is input to the first electric current loop pi regulator 10 and obtains q shaft voltage , the first electric current loop pi regulator 10 is by q shaft voltage

transfer to voltage inverse transform block 11; D shaft current detected value i _{d_}as the ring negative feedback of d shaft current and electric current given in advance

compare, comparison value is input to the second electric current loop pi regulator 12 and obtains d shaft voltage

, the second electric current loop pi regulator 12 is by d shaft voltage

transfer to voltage inverse transform block 11.The output of voltage inverse transform block 11 connects the input of inverter 13; The output of electric current inverse transform block 5 connects the input of dead area compensation module 14, and the output of dead area compensation module 14 connects the input of inverter 13, and the output of inverter 13 connects the input of permagnetic synchronous motor 2.

Permagnetic synchronous motor current filtering of the present invention and dead-zone compensation method comprise the following steps:

1) as shown in Figure 1, current sensor 7 is by the permagnetic synchronous motor detecting 2 threephase stator current i _a, i _band i _cinput in coordinate transformation module 4, it is carried out to the coordinate transform of three-phase/two-phase, i.e. the coordinate transform of abc/ α β, obtains the current component i under two-phase rest frame _α, i _β:

$\left[\begin{array}{c}{i}_{\mathrm{\α}}\\ i_{\mathrm{\β}}\end{array}\right]=\sqrt{\frac{2}{3}}\left[\begin{array}{ccc}1& -\frac{1}{2}& -\frac{1}{2}\\ 0& \frac{\sqrt{3}}{2}& \frac{\sqrt{3}}{2}\end{array}\right]\left[\begin{array}{c}{i}_{\mathrm{\α}}\\ i_b\\ i_c\end{array}\right],$

In formula, i _cfor i _a, i _bwith negative value.

2), in coordinate transformation module 4, the electrical degree θ crossing according to permagnetic synchronous motor 2 rotors that receive, to the current component i under two-phase rest frame _α, i _βcarry out static-rotating coordinate transformation, i.e. α β/dq coordinate transform, obtains the current detection value i under two-phase synchronous rotary dq coordinate system again _d, i _q:

$\left[\begin{array}{c}{i}_d\\ i_q\end{array}\right]=\left[\begin{array}{cc}\cos \mathrm{\θ}& \sin \mathrm{\θ}\\ -\sin \mathrm{\θ}& \cos \mathrm{\θ}\end{array}\right]\left[\begin{array}{c}{i}_{\mathrm{\α}}\\ i_{\mathrm{\β}}\end{array}\right],$

In formula, θ is the electrical degree that permagnetic synchronous motor 2 rotors are crossed, and by position transducer 1, is obtained.

3) the electrical degree θ that permagnetic synchronous motor 2 rotors are crossed inputs in rotating speed computing module 3, and electrical degree θ is carried out to differential, obtains speed feedback value ω; Speed feedback value ω and rotary speed instruction value ω given in advance ^*as the input of speed ring pi regulator 6, through calculation process, obtain current instruction value

4) current detection value i _q, i _dbe input in increment type Kalman filter 9, by increment type Kalman filter 9 output d shaft current predictive filtering value i _{d_pre}with q shaft current predictive filtering value i _{q_pre};

5) current instruction value

electric current given in advance

respectively with d shaft current predictive filtering value i _{d_pre}with q shaft current predictive filtering value i _{q_pre}relatively, comparison value as the input of the first electric current loop pi regulator 10, the second electric current loop pi regulator 12, obtains respectively the output of the first electric current loop pi regulator 10, the second electric current loop pi regulator 12, i.e. reference voltage respectively through calculation process

6) d shaft current predictive filtering value i _{d_pre}, q shaft current predictive filtering value i _{q_pre}the electrical degree θ crossing with permagnetic synchronous motor 2 rotors of position transducer 1 output is input to respectively electric current inverse transform block 5, by electric current inverse transform block 5 output three-phase predicted current i _{a_pre}, i _{b_pre}and i _{c_pre};

7) three-phase predicted current i _{a_pre}, i _{b_pre}and i _{c_pre}input dead area compensation module 14, dead area compensation module 14 is according to three-phase predicted current i _{a_pre}, i _{b_pre}and i _{c_pre}polarity export corresponding bucking voltage;

8) reference voltage

input voltage inverse transform block 11, voltage inverse transform block 11 output three-phase voltage u _a, u _b, u _c, with three-phase predicted current i _{a_pre}, i _{b_pre}and i _{c_pre}corresponding bucking voltage respectively with three-phase voltage u _a, u _b, u _cinput inverter 13 after stack, the corresponding three-phase voltage of inverter 13 output, to permagnetic synchronous motor 2, drives permagnetic synchronous motor 2 work.

In above-mentioned steps 4) in, 9 couples of current detection value i of increment type Kalman filter _d, i _qprocessing comprise the following steps:

(1) under synchronous rotating frame, the stator d axle of permagnetic synchronous motor 2, q shaft voltage equation are:

u _d=Ri _d+L _ddi _d/dt-ωL _qi _q， （1）

u _q=Ri _q+L _qdi _q/dt+ωL _di _d+ωψ _f， （2）

U wherein _d, u _qbe respectively stator d, q shaft voltage, i _d, i _qbe respectively stator d, q shaft current, R is stator resistance, L _d, L _qbe respectively stator d, q axle inductance, ψ _ffor permanent magnet flux linkage, ω is rotor speed.

(2) according to the stator q shaft voltage equation in step (1), at current period kT _swith (k-1) T of the upper cycle _sinside set up respectively the discrete voltage equation of permagnetic synchronous motor 2:

u _q(k)=R _e(i _q(k)+i _{q_pre}(k+1))/2+L _e(i _{q_pre}(k+1)-i _q(k))/T _s+ω(L _di _d+ψ _f)， （3）

u _q(k-1)=R(i _q(k)+i _q(k-1))/2+L _q(i _q(k)-i _q(k-1))/T _s+ω(L _di _d+ψ _f)， （4）

I wherein _{q_pre}(k+1) be the predicted value to next of q shaft current in current period the zero hour in cycle, be called for short current forecasting value, i _q(k) be the current detection value of current period, i _q(k-1) a upper periodic permanent magnet synchronous motor stator q shaft current detected value, T _sfor control cycle, u _q(k) be current period stator q shaft voltage, u _q(k-1) be a upper cycle stator q shaft voltage, R _e, L _ebe respectively permanent-magnetic synchronous motor stator resistance R, stator q axle inductance L _qestimated value, current sample sequential is as shown in Figure 2.

(3) ignore the variation of the voltage item relevant to rotating speed, formula (3) and formula (4) subtracted each other, obtain the current increment formula of permagnetic synchronous motor 2:

$i_{q\_\mathrm{pre}}(k+1)=\frac{u_q\left(k\right)-u_q(k-1)+\frac{L_e}{T_s}({2i}_q\left(k\right)-i_q(k-1))+\frac{R_e}{2}{i}_q(k-1)}{\frac{{\mathrm{<figure-callout\; id="2"\; label="R\; e"\; filenames="HDA0000439431250000051.png,HDA0000439431250000052.png"\; state="\{\{state\}\}">R</figure-callout>}}_e}{2}+\frac{L_e}{T_s}},---\left(5\right)$

Because R _emuch smaller than L _e/ T _s, therefore can ignore the impact of R, the q shaft current predicted value that obtains permagnetic synchronous motor 1 after simplified style (5) is:

$i_{q\_\mathrm{pre}}(k+1)=\frac{T_s}{L_e}(u_q\left(k\right)-u_q(k-1))+({2i}_q\left(k\right)-i_q(k-1)),---\left(6\right)$

In like manner can draw in current period the predicted value i to next of d shaft current the zero hour in cycle _{d_pre}, write formula (6) as coefficient matrix and be followed successively by,

$x_k=\left[\begin{array}{c}{i}_q\left(k\right)\\ i_q(k-1)\end{array}\right],$

$x_{k-1}=\left[\begin{array}{c}{i}_q(k-1)\\ i_q(k-2)\end{array}\right],$

$F_{k-1}=\left[\begin{array}{cc}2& -1\\ 1& 0\end{array}\right],$

$B_{k-1}=\left[\begin{array}{c}{T}_s/{\mathrm{<figure-callout\; id="0"\; label="L\; q"\; filenames="HDA0000439431250000011.png,HDA0000439431250000021.png"\; state="\{\{state\}\}">L</figure-callout>}}_q\\ 0\end{array}\right],$

$C={\left[\begin{array}{c}1\\ 0\end{array}\right]}^T;$

(4) according to the Mathematical Modeling of the current increment Formula increment type Kalman filter 9 of step (3) matrix form, be:

$\left\{\begin{array}{c}{x}_k=F_{k-1}{x}_{k-1}+B_{k-1}{u}_{k-1}+w\\ y_k=C{x}_k+v\end{array}\right.,---\left(9\right)$

Wherein: w is input noise (system noise) vector, v is output noise (measurement noise) vector; x _k, x _k-1for system mode vector, y _kfor system output vector, u _k-1for dominant vector; F _k-1, B _k-1, C is coefficient matrix, and x _k, x _k-1, u _k-1, F _k-1, B _k-1, C takes from the value in step (3).

(5) according to the Mathematical Modeling of increment type Kalman filter 9, its correlated variables is carried out to iteration, obtain optimal estimation value

it comprises the steps:

1. calculate prior estimate vector value

with corresponding error matrix

${\hat{x}}_k^{-}=F_{k-1}{\hat{x}}_{k-1}{B}_{k-1}{u}_{k-1},---\left(10\right)$

$P_k^{-}=F_{k-1}{P}_{k-1}{F}_{k-1}^T+Q_{k-1},---\left(11\right)$

Wherein, noise matrix Q _k-1choose relevantly with site environment, it is chosen generally can not affect final effect, only can affect the speed of convergence,

optimal estimation vector value for system state variables

in the state vector in (k-1) cycle, and optimal estimation vector value

initial value can choose at random, its initial value is chosen can not affect final optimal estimation value,

being k cycle prior estimate vector, is an intermediate variable,

being k cycle prior estimate error matrix, is also intermediate variable matrix, P _k-1for the error matrix of system in (k-1) cycle.

2. calculated gains matrix K _k:

$K_k=P_k^{-}{C}^T{({\mathrm{CP}}_k^{-}{C}^T+R_{k-1})}^{-1},---\left(12\right)$

3. computing system is in the optimal estimation value of k periodic system state variable

${\hat{x}}_k={\hat{x}}_k^{-}+K_k(y_k-C{\hat{x}}_k^{-}),---\left(13\right)$

Wherein ${\hat{x}}_k=\left[\begin{array}{c}{i}_{q\_}\left(k\right)\\ i_{q\_}(k-1)\end{array}\right],$ I _{q_}(k-1) be permagnetic synchronous motor 2 rotor (k-1) current detection value i _qoptimal estimation value, i _{q_}(k) be that permagnetic synchronous motor 2 rotors are at k periodic current detected value i _qoptimal estimation value;

4. calculate the error matrix P in k cycle _koptimal estimation value:

$P_k=P_k^{-}-K_{k}C{P}_k^{-},---\left(14\right)$

Wherein, Q _k-1, R is respectively the covariance matrix of noise w, v, error matrix P _kfor the error matrix of the optimal estimation value in estimation process, by iteration repeatedly, error matrix P _kfinally can converge to null matrix.

In above-mentioned steps 6) in, the interior processing procedure of electric current inverse transform block 5 comprises the steps:

1. dope next periodic permanent magnet synchronous electric motor rotor coordinate transform angle θ _pre, because permagnetic synchronous motor mechanical time constant is much larger than electrical time constant, can think motor remain a constant speed at short notice operation state, permanent-magnetic synchronous motor rotor is consistent with the angle θ turning in current period in next cycle;

2. in conjunction with the predictive filtering value of dq shaft current, by coordinate transform, obtain the predicted value i of the three-phase current in next cycle _{a_pre}, i _{b_pre}and i _{c_pre}, shown in (19):

$\left[\begin{array}{c}{i}_{a\_\mathrm{pre}}\\ i_{b\_\mathrm{pre}}\\ i_{c\_\mathrm{pre}}\end{array}\right]=\begin{array}{c}\left[\begin{array}{cc}\cos {\mathrm{\&theta;}}_{\mathrm{pre}}& -\sin {\mathrm{\&theta;}}_{\mathrm{pre}}\\ \cos ({\mathrm{\&theta;}}_{\mathrm{pre}}-\frac{2\mathrm{\&pi;}}{3})& -\sin ({\mathrm{\&theta;}}_{\mathrm{pre}}-\frac{2\mathrm{\&pi;}}{3})\\ \mathrm{ocs}({\mathrm{\&theta;}}_{\mathrm{pre}}+\frac{2\mathrm{\&pi;}}{3})& -\sin ({\mathrm{\&theta;}}_{\mathrm{pre}}+\frac{2\mathrm{\&pi;}}{3})\end{array}\right]\end{array}\left[\begin{array}{c}{i}_{d\_\mathrm{pre}}\\ i_{q\_\mathrm{pre}}\end{array}\right],---\left(19\right)$

According to formula (19), calculate the predicted value i of next cycle three-phase current _{a_pre}, i _{b_pre}and i _{c_pre}.

In above-mentioned steps 7) in, dead area compensation comprises the following steps:

1. dead area compensation module 14 is according to next the cycle three-phase predicted current i receiving _{a_pre}, i _{b_pre}and i _{c_pre}, obtain the relevant voltage error delta u that next cycle three-phase predicted current produces respectively _a, Δ u _bwith Δ u _c, Δ u _afor predicted current i _{a_pre}the voltage error producing, sign (i _{a_pre}) be predicted current i _{a_pre}polarity, i _{a_pre}during >0, sign (i _{a_pre}) value is 1, otherwise is-1.

${\mathrm{\&Delta;u}}_a=\frac{T_d+T_{\mathrm{on}}-T_{\mathrm{off}}}{T_s}{V}_{\mathrm{dc}}\mathrm{sign}\left(i_{a\_\mathrm{pre}}\right),---\left(20\right)$

In like manner can obtain predicted current i _{b_pre}and i _{c_pre}the voltage error Δ u producing _bwith Δ u _c;

${\mathrm{\&Delta;u}}_b=\frac{T_d+T_{\mathrm{on}}-T_{\mathrm{off}}}{T_s}{V}_{\mathrm{dc}}\mathrm{sign}\left(i_{b\_\mathrm{pre}}\right),---\left(21\right)$

${\mathrm{\&Delta;u}}_c=\frac{T_d+T_{\mathrm{on}}-T_{\mathrm{off}}}{T_s}{V}_{\mathrm{dc}}\mathrm{sign}\left(i_{c\_\mathrm{pre}}\right),---\left(22\right)$

2. by three-phase predicted current i _{a_pre}, i _{b_pre}and i _{c_pre}the voltage error Δ u producing _a, Δ u _bwith Δ u _cget respectively negative value, obtain and three-phase predicted current i _{a_pre}, i _{b_pre}and i _{c_pre}corresponding bucking voltage.

As shown in Figure 3, the insertion in dead band there are differences virtual voltage and the desired voltage of inverter 13 outputs, and electric current flows to permagnetic synchronous motor 2 for the positive direction of electric current from inverter 13, as a phase current i _afor timing, the error delta u that phase voltage produces _a-for:

${\mathrm{\&Delta;u}}_a=\frac{T_d+T_{\mathrm{on}}-T_{\mathrm{off}}}{T_s}{V}_{\mathrm{dc}}---\left(23\right)$

Wherein, T _dfor the Dead Time arranging, T _on, T _offbe respectively break-over of device time and turn-off time, T _sfor control cycle, V _dcfor DC bus-bar voltage.

In like manner, current i _awhen negative, phase voltage error delta u _a-for:

$\mathrm{\&Delta;}{u}_{a-}=-\frac{T_d+T_{\mathrm{on}}-T_{\mathrm{off}}}{T_s}{V}_{\mathrm{dc}}---\left(24\right)$

Therefore the phase voltage error that, cause in dead band is:

$\mathrm{\&Delta;}{u}_a=\frac{T_d+T_{\mathrm{on}}-T_{\mathrm{off}}}{T_s}{V}_{\mathrm{dc}}\mathrm{sign}\left(i_a\right)---\left(25\right)$

In formula, sign (i _a) be phase current i _apolarity, i _aduring >0, sign (i _a) value is 1, otherwise is-1.

For b, two electric currents of c, obtain corresponding phase voltage error.By coordinate transform, can arrive the dq shaft voltage error that dead band causes, as follows:

$\left[\begin{array}{c}\mathrm{\&Delta;}{u}_d\\ \mathrm{\&Delta;}{u}_q\end{array}\right]=\left[\begin{array}{ccc}\cos \mathrm{\&theta;}& \cos (\mathrm{\&theta;}-\frac{2\mathrm{\&pi;}}{3})& \cos (\mathrm{\&theta;}+\frac{2\mathrm{\&pi;}}{3})\\ -\sin \mathrm{\&theta;}& -\sin (\mathrm{\&theta;}-\frac{2\mathrm{\&pi;}}{3})& -\sin (\mathrm{\&theta;}+\frac{2\mathrm{\&pi;}}{3})\end{array}\right]\&CenterDot;\left[\begin{array}{c}\mathrm{sign}\left(i_a\right)\\ \mathrm{sign}\left(i_b\right)\\ \mathrm{sign}\left(i_c\right)\end{array}\right]\frac{T_d+T_{\mathrm{on}}-T_{\mathrm{off}}}{T_s}{V}_{\mathrm{dc}}---\left(26\right)$

Dead time effect causes the one-period pulsation that superposeed in contravarianter voltage instruction to disturb, and then causes the distortion of inverter output voltage.Therefore, remedial measure is at inverter link stack pulsating voltage in contrast, thereby offsets the impact of dead time effect.

As shown in Figure 4, wherein, busbar voltage V _dc=310V, T _d=125 μ s, T _on=T _off.The dq shaft voltage error can dead band causing presents 6 times to the pulsation of fundamental frequency, wherein, and q shaft voltage error delta u _qfor pulsation amplitude less but have the steamed bun ripple of larger direct current biasing, d shaft voltage error delta u _dsawtooth waveforms for the about 10V of amplitude.

During permagnetic synchronous motor low cruise, when permanent-magnetic synchronous motor rotor rotating speed is less than 300rpm, the dq shaft voltage error delta u that dead band causes _d, Δ u _qripple frequency is lower, relies on merely the regulating action of electric current loop self, and the current distortion that just can cause in the dq shaft voltage error to a certain degree dead band being caused is adjusted in time.In addition, during low cruise, phase current is longer in the near zero-crossing point time, and the judgement of phase current polarity occurs that the wrong possibility of mistake compensation that causes is larger, and mistake compensation may bring the phenomenons such as zero crossing clamper, causes the distortion that electric current is larger.Therefore, considering above-mentioned two aspect factors, during motor low cruise, can rely on the impact of the regulating action deadband eliminating effect of electric current loop self, is also feasible thereby do not carry out extra compensation.

During permagnetic synchronous motor high-speed cruising, permanent-magnetic synchronous motor rotor rotating speed when 300rpm is above, the dq shaft voltage error delta u that dead band causes _d, Δ u _qripple frequency is higher.In general, electric current loop bandwidth is limited, is generally 1kHz left and right.When the motor of four pairs of utmost points moves by power frequency 50Hz, phase current fundamental frequency is 200Hz, the dq shaft voltage error delta u that dead band causes _d, Δ u _qripple frequency is 1.2kHz, substantially meets or exceeds electric current loop bandwidth.Therefore,, under high frequency situations, because the ripple frequency of error voltage is suitable with electric current loop bandwidth, rely on merely the regulating action of electric current loop self to be difficult to the impact of deadband eliminating effect.In addition,, during high-speed cruising, because phase current zero passage required time is shorter, be subject to noise jamming and occur that the possibility of mistake compensation is relatively low.Therefore, situation during with low cruise is contrary, during permagnetic synchronous motor high-speed cruising, can take dead area compensation measure, the voltage error causing with dead band in inverter link stack is contrary voltage just in time, reaches and eliminate the object of disturbing the better current waveform of the sinusoidal degree of acquisition.

As shown in Figure 5, output current i _{q_}, i _{d_}the electrical degree θ crossing with permagnetic synchronous motor 2 rotors of position transducer 1 output is input to respectively electric current inverse transform block 5, electric current inverse transform block 5 output three-phase predicted current i _{a_pre}, i _{b_pre}and i _{c_pre}, according to three-phase predicted current i _{a_pre}, i _{b_pre}and i _{c_pre}the corresponding bucking voltage of polarity judgement output; Reference voltage

input voltage inverse transform block 11, voltage inverse transform block 11 output three-phase voltage u _a, u _b, u _c, the bucking voltage of dead area compensation module 14 output respectively with three-phase voltage u _a, u _band u _cstack.

As shown in Figure 6, permagnetic synchronous motor is first controlled after reaching certain rotating speed (230rpm) and is switched to current loop control mode, the instruction of q shaft current through speed closed loop

be set to the AC signal of direct current biasing 1.75A, frequency 100Hz, amplitude 0.2A, current detection value i _qfeed back input as electric current loop adjuster.Electric motor load torque is constant is 2Nm.Threephase stator current i _a, i _band i _ceach amplitude that superposes is about the noise of 0.06A.Inverter adopts perfect switch device, as shown in Figure 6 (a), adopts moving average filter to current detection value i _qprocess, sliding window length is set to 8, can observe current detection value i _qexist obvious phase place to lag behind or time delay with filter value, its difference is just being rendered as (remaining) string waveform, has proved the existence of time delay.As shown in Figure 6 (b), adopt increment type Kalman filter to current detection value i _qcarry out filtering, the difference of detected value and filter value is rendered as near the burr zero, does not occur significantly fluctuation, and increment type kalman filter method does not bring extra time delay or phase place to lag behind.

As shown in Figure 7, permagnetic synchronous motor is first controlled after reaching certain rotating speed (about 230rpm) and is switched to current loop control mode, the instruction of q shaft current through speed closed loop

be set to the AC signal of direct current biasing 1.75A, frequency 100Hz, amplitude 0.2A, current detection value i _qfeed back input as electric current loop adjuster.Electric motor load torque is constant is 2Nm.Threephase stator current i _a, i _band i _ceach amplitude that superposes is about the noise of 0.06A.Inverter adopts perfect switch device, at 0.065s, before the moment, contains noisy current detection value i _qdo not do any processing directly as the feed back input of current regulator 9; After this moment, detected value is through being input to current regulator after the filtering of increment type Kalman filter again.After processing after filtering, as shown in Figure 7 (a), dq shaft current noise amplitude decreases, and as shown in Figure 7 (b) shows, dq shaft voltage noise amplitude obviously reduces, and increment type Kalman filter of the present invention can effectively reduce system noise.

As shown in Figure 8, wherein, inverter 14 adopts perfect switch, phase current i _a, i _beach amplitude that superposes is about the noise of 0.06A.Electric motor load torque 1.5Nm, rotary speed instruction is set to constant 1000rpm, and in Fig. 8, solid line represents phase current detected value; Dq shaft current detected value calculates predicted value through increment type Kalman filter filtering and incremental forecasting method, then by inverse transformation, obtains the predicted value of phase current, as the predicted value of phase current in Fig. 8 dots.Owing to having passed through filter and predication link, the predicted value of phase current is more level and smooth than detected value, and this is conducive to reduce the current polarity judgement that noise causes and makes mistakes and cause mistake compensation; Meanwhile, in sequential, the predicted value of phase current is carried the previous sampling period than detected value, can eliminate the impact of a digital control bat hysteresis time delay, can reduce system noise, reduce the pulsation of dq shaft voltage; According to filtered prediction phase current, draw corresponding bucking voltage, be conducive to reduce the mistake compensation causing because the erroneous judgement of phase current polarity is disconnected.

As shown in Figure 9, sampling period T _s=125 μ s, voltage dead band time setting is 6 μ s, permagnetic synchronous motor load torque is made as constant 1.5Nm.First stage, adopt 9 couples of current detection value i of increment type Kalman filter _d, i _qcarry out filtering and then input respectively the first electric current loop pi regulator 10 and the second electric current loop pi regulator 12, dead-zone compensation method of the present invention works; Second stage, the first electric current loop pi regulator 10 and the second electric current loop pi regulator 12 feed back inputs switch to current detection value i _d, i _q, dead-zone compensation method of the present invention no longer works simultaneously.In Fig. 9 (a), during permanent-magnetic synchronous motor rotor high speed (1000rpm), when the current filtering that employing the present invention proposes and dead-zone compensation method, phase current i _a, i _band q shaft current i _q, q shaft voltage u _qin waveform, noise content is fewer, and phase current is smoother at zero crossing annex; Stop adopting after the present invention phase current i _a, i _band q shaft current i _q, q shaft voltage u _qall contain obvious noise, and phase current i _a, i _bat zero crossing annex, there is significantly distortion, by above contrast, can prove the validity of current filtering of the present invention and voltage dead-zone compensation method.

As Fig. 9 (b)-9(c) as shown in, during permanent-magnetic synchronous motor rotor low speed.Than the high-speed case shown in Fig. 9 a, although q shaft voltage u _qwaveform still exists notable difference before and after institute of the present invention extracting method works, but phase current i _a, i _band q shaft current i _qthere is not significant difference in waveform.The voltage cycle interfering frequency that during permanent-magnetic synchronous motor rotor low speed, voltage dead time effect causes is lower, the curent change that electric current loop causes it has enough regulating powers, even if do not take in this case dead area compensation measure, also can obtain the reasonable current waveform of sinusoidal degree.

As shown in figure 10, the instruction of q shaft current is set to constant 0.5A, by regulating dynamometer machine output torque to make motor speed be stabilized in 1200rpm left and right.While not taking the measure of voltage dead area compensation, as shown in Figure 10 (a) shows, all there is regular dither in dq shaft current and voltage, and wherein current pulsation amplitude has reached positive and negative 0.1A left and right; And after current filtering of the present invention and dead-zone compensation method work, as shown in Figure 10 (b), current pulsation frequency obviously slows down, mains ripple amplitude significantly reduces simultaneously, has proved the validity of current filtering of the present invention and dead-zone compensation method.

As shown in figure 11, the experiment condition of Figure 11 and Figure 10 is identical, contrast can obviously be seen, as shown in Figure 11 (a) shows, do not adopt the phase current waveform of current filtering of the present invention and dead-zone compensation method to have very large distortion, and adopt after current filtering of the present invention and dead-zone compensation method, as shown in Figure 11 (b), it is very level and smooth that phase current waveform becomes, and distortion significantly reduces, and has proved validity of the present invention.

Shown in Figure 12, the instruction of q shaft current is set to constant 0.5A, by regulating dynamometer machine output torque to make permagnetic synchronous motor 2 stabilizations of speed at 500rpm.Contrast Figure 10 and Figure 12, due to the reduction of rotating speed, in Figure 12 (a) and Figure 12 (b), dq shaft current and mains ripple frequency reduce, even if do not taking under the prerequisite of dead area compensation measure, pulsation amplitude also has obvious reduction.Along with the reduction of frequency, the ability of the anti-dead time effect impact of electric current loop has obtained reinforcement.

As shown in figure 13, the experiment condition of Figure 13 and Figure 12 is identical, and because rotating speed is lower, even if do not take dead area compensation measure, the pulsation amplitude of stator phase current also has obvious reduction, and along with the reduction of frequency, the ability of the anti-dead time effect impact of electric current loop has obtained reinforcement.

As shown in figure 14, in Figure 14 (a) and Figure 14 (b), the instruction of q shaft current is set to constant 0.5A, by regulating dynamometer machine output torque to make permagnetic synchronous motor 2 rotating speeds be stabilized in respectively 170rpm and 170rpm.Further reduction along with permagnetic synchronous motor rotating speed, even if do not take dead area compensation measure, stator monophase current can obtain the reasonable waveform of sinusoidal degree, during low speed, owing to relying on merely the regulating action of electric current loop adjuster self can obtain, relatively approach sinusoidal stator phase current waveform, then it is not obvious that dead band is compensated to meaning.Meanwhile, during low speed, phase current is elongated in the time of annex delay at zero point, the judgement of current polarity is more easily subject to the impact of noise, occurs that the possibility of mistake compensation is larger.Therefore, can not take indemnifying measure during low speed and rely on the impact that the regulating action of current regulator self can deadband eliminating effect.

The various embodiments described above are only for illustrating the present invention; wherein the structure of each parts, connected mode and manufacture craft etc. all can change to some extent; every equivalents of carrying out on the basis of technical solution of the present invention and improvement, all should not get rid of outside protection scope of the present invention.

Claims (6)

1. permagnetic synchronous motor current filtering and a dead area compensation device, is characterized in that: it comprises position transducer, permagnetic synchronous motor, rotating speed computing module, coordinate transformation module, electric current inverse transform block, speed ring pi regulator, current sensor, summation module, increment type Kalman filter, the first electric current loop pi regulator 1, voltage inverse transform block, the second electric current loop pi regulator, inverter and dead area compensation module; Described coordinate transformation module, increment type Kalman filter and the first electric current loop pi regulator form q shaft current ring; Described coordinate transformation module, increment type Kalman filter and the second electric current loop pi regulator form d shaft current ring, and described q shaft current ring and d shaft current ring form electric current loop;

The input of described position transducer connects the output of described permagnetic synchronous motor, the output of described position transducer connects respectively described rotating speed computing module, described coordinate die change piece and electric current inverse transform block, and the electrical degree θ collecting is transferred to described rotating speed computing module, described coordinate die change piece and electric current inverse transform block; The rotational speed omega of described rotating speed computing module output is as negative feedback, and gets after difference with given rotating speed command value ω *, as the input of described speed ring pi regulator; Described current sensor connects the stator of described permagnetic synchronous motor, and the biphase current in the three-phase current of the permanent-magnetic synchronous motor stator detecting is got after negative and inputted described coordinate transformation module through the summation of described summation module; Described current sensor is also inputted described coordinate transformation module by described biphase current simultaneously, and described coordinate transformation module carries out described three-phase current to input described increment type Kalman filter after dq coordinate transform, q shaft current detected value i _qwith d shaft current detected value id after described increment type Kalman filter is processed, by q shaft current predictive filtering value i _{q_pre}input respectively described q shaft current ring and electric current inverse transform block, by described d shaft current predictive filtering value i _{d_pre}input respectively described d shaft current ring and electric current inverse transform block; Described q shaft current predictive filtering value i _{q_}as the negative feedback of q shaft current ring, with the output comparison of described speed ring pi regulator, comparison value is input to described the first electric current loop pi regulator and obtains q shaft voltage

q shaft voltage

transfer to described voltage inverse transform block; Described d shaft current detected value i _{d_}as the ring negative feedback of d shaft current and electric current given in advance

relatively, comparison value is input to described the second electric current loop pi regulator and obtains d shaft voltage d shaft voltage

transfer to described voltage inverse transform block; The output of described voltage inverse transform block connects the input of described inverter; The output of described electric current inverse transform block connects the input of described dead area compensation module, and the output of described dead area compensation module connects the input of described inverter, and the output of described inverter connects the input of described permagnetic synchronous motor.

2. the compensation method of a kind of permagnetic synchronous motor current filtering as claimed in claim 1 and dead area compensation device, it comprises the following steps:

1) current sensor is by the permagnetic synchronous motor threephase stator current i detecting _a, i _band i _cinput in coordinate transformation module, the coordinate transform that it is carried out to abc/ α β, obtains the current component i under two-phase rest frame _α, i _β:

$\left[\begin{array}{c}{i}_{\mathrm{\&alpha;}}\\ i_{\mathrm{\&beta;}}\end{array}\right]=\sqrt{\frac{2}{3}}\left[\begin{array}{ccc}1& -\frac{1}{2}& -\frac{1}{2}\\ 0& \frac{\sqrt{3}}{2}& \frac{\sqrt{3}}{2}\end{array}\right]\left[\begin{array}{c}{i}_{\mathrm{\&alpha;}}\\ i_b\\ i_c\end{array}\right],$

In formula, i _cfor i _a, i _bwith negative value;

2), in coordinate transformation module, the electrical degree θ rotating through according to the permanent-magnetic synchronous motor rotor receiving, to the current component i under two-phase rest frame _α, i _βcarry out again α β/dq coordinate transform, obtain the current detection value i under two-phase synchronous rotary dq coordinate system _d, i _q:

$\left[\begin{array}{c}{i}_d\\ i_q\end{array}\right]=\left[\begin{array}{cc}\cos \mathrm{\&theta;}& \sin \mathrm{\&theta;}\\ -\sin \mathrm{\&theta;}& \cos \mathrm{\&theta;}\end{array}\right]\left[\begin{array}{c}{i}_{\mathrm{\&alpha;}}\\ i_{\mathrm{\&beta;}}\end{array}\right],$

In formula, θ is the electrical degree that permanent-magnetic synchronous motor rotor rotates through, and by position transducer, is obtained;

3) the electrical degree θ that permanent-magnetic synchronous motor rotor rotates through inputs in rotating speed computing module, and electrical degree θ is carried out to differential, obtains speed feedback value ω; Speed feedback value ω and rotary speed instruction value ω given in advance ^*as the input of speed ring pi regulator, through calculation process, obtain current instruction value

4) current detection value i _q, i _dbe input in increment type Kalman filter, by increment type Kalman filter output d shaft current predictive filtering value i _{d_pre}with q shaft current predictive filtering value i _{q_pre};

5) current instruction value

electric current given in advance

respectively with d shaft current predictive filtering value i _{d_pre}with q shaft current predictive filtering value i _{q_pre}relatively, comparison value, respectively as the input of the first electric current loop pi regulator, the second electric current loop pi regulator, obtains respectively the reference voltage of the first electric current loop pi regulator, the second electric current loop adjuster output through calculation process

6) d shaft current predictive filtering value i _{d_pre}, q shaft current predictive filtering value i _{q_pre}the electrical degree θ rotating through with the permanent-magnetic synchronous motor rotor of position transducer output is input to respectively electric current inverse transform block, by electric current inverse transform block output three-phase predicted current i _{a_pre}, i _{b_pre}and i _{c_pre};

7) three-phase predicted current i _{a_pre}, i _{b_pre}and i _{c_pre}input dead area compensation module, dead area compensation module is according to three-phase predicted current i _{a_pre}, i _{b_pre}and i _{c_pre}polarity export corresponding bucking voltage;

8) reference voltage

input voltage inverse transform block, voltage inverse transform block output three-phase voltage u _a, u _b, u _c, with three-phase predicted current i _{a_pre}, i _{b_pre}and i _{c_pre}corresponding bucking voltage respectively with three-phase voltage u _a, u _b, u _cinput inverter after stack, inverter is exported corresponding three-phase voltage to permagnetic synchronous motor, drives permagnetic synchronous motor work.

3. a kind of permagnetic synchronous motor current filtering as claimed in claim 2 and dead-zone compensation method, is characterized in that: in described step 4), increment type Kalman filter is to current detection value i _d, i _qprocessing comprise the following steps:

(1) under synchronous rotating frame, the stator d axle of permagnetic synchronous motor, q shaft voltage equation are:

u _d=Ri _d+L _ddi _d/dt-ωL _qi _q，

u _q=Ri _q+L _qdi _q/dt+ωL _di _d+ωψ _f，

U wherein _d, u _qbe respectively stator d, q shaft voltage, i _d, i _qbe respectively stator d, q shaft current, R is stator resistance, L _d, L _qbe respectively stator d, q axle inductance, ψ _ffor permanent magnet flux linkage, ω is rotor speed;

(2) according to the stator q shaft voltage equation in step (1), at current period (k) T _swith (k-1) T of the upper cycle _sinside set up respectively the discrete voltage equation of permagnetic synchronous motor:

u _q(k)=R _e(i _q(k)+i _{q_pre}(k+1))/2+L _e(i _{q_pre}(k+1)-i _q(k))/T _s+ω(L _di _d+ψ _f)，

u _q(k-1)=R(i _q(k)+i _q(k-1))/2+L _q(i _q(k)-i _q(k-1))/T _s+ω(L _di _d+ψ _f)，

I wherein _{q_pre}(k+1) be the predicted value to next of q shaft current in current period the zero hour in cycle, be called for short current forecasting value, i _q(k) be the current detection value of current period, i _q(k-1) a upper periodic permanent magnet synchronous motor stator q shaft current detected value, T _sfor control cycle, u _q(k) be current period stator q shaft voltage, u _q(k-1) be a upper cycle stator q shaft voltage, R _e, L _ebe respectively permanent-magnetic synchronous motor stator resistance R, stator q axle inductance L _qestimated value;

(3) ignore the variation of the voltage item relevant to rotating speed, two formula in step (2) are subtracted each other, obtain the simplification current increment formula of permagnetic synchronous motor, because R _emuch smaller than L _e/ T _s, therefore ignore the impact of R, obtain in current period the predicted value i to next of d shaft current the zero hour in cycle _{d_pre}(k+1), and by current increment formula change into matrix form:

$x_k=\left[\begin{array}{c}{i}_q\left(k\right)\\ i_q(k-1)\end{array}\right],$

$x_{k-1}=\left[\begin{array}{c}{i}_q(k-1)\\ i_q(k-2)\end{array}\right],$

$F_{k-1}=\left[\begin{array}{cc}2& -1\\ 1& 0\end{array}\right],$

$B_{k-1}=\left[\begin{array}{c}{T}_s/L_q\\ 0\end{array}\right],$

$C={\left[\begin{array}{c}1\\ 0\end{array}\right]}^T;$

(4) according to the Mathematical Modeling of the current increment Formula increment type Kalman filter of step (3) matrix form, be:

$\left\{\begin{array}{c}{x}_k=F_{k-1}{x}_{k-1}+B_{k-1}{u}_{k-1}+w\\ y_k=C{x}_k+v\end{array}\right.,$

Wherein, w is input noise vector, and v is output noise vector; x _k, x _k-1for system mode vector, y _kfor system output vector, u _k-1for dominant vector; F _k-1, B _k-1, C is coefficient matrix;

(5) according to the Mathematical Modeling of increment type Kalman filter, its correlated variables is carried out to iteration, obtain optimal estimation value

4. a kind of permagnetic synchronous motor current filtering as claimed in claim 3 and dead-zone compensation method, is characterized in that: in described step (5), and described optimal estimation value

computational methods comprise the following steps:

1. calculate prior estimate vector value

with corresponding error matrix

${\hat{x}}_k^{-}=F_{k-1}{\hat{x}}_{k-1}{B}_{k-1}{u}_{k-1},$

$P_k^{-}=F_{k-1}{P}_{k-1}{F}_{k-1}^T+Q_{k-1},$

Wherein, Q _k-1for noise matrix Q _k-1,

optimal estimation vector value for system state variables

in the state vector in (k-1) cycle,

being k cycle prior estimate vector, is an intermediate variable, being k cycle prior estimate error matrix, is also intermediate variable matrix, P _k-1for the error matrix of system in (k-1) cycle;

2. calculated gains matrix K _k:

$K_k=P_k^{-}{C}^T{({\mathrm{CP}}_k^{-}{C}^T+R_{k-1})}^{-1};$

3. computing system is in the optimal estimation value of k periodic system state variable

${\hat{x}}_k={\hat{x}}_k^{-}+K_k(y_k-C{\hat{x}}_k^{-}),$

Wherein ${\hat{x}}_k=\left[\begin{array}{c}{i}_{q\_}\left(k\right)\\ i_{q\_}(k-1)\end{array}\right],$ I _{q_}(k-1) be permanent-magnetic synchronous motor rotor (k-1) current detection value i _qoptimal estimation value, i _{q_}(k) be that permanent-magnetic synchronous motor rotor is at k periodic current detected value i _qoptimal estimation value;

4. calculate the error matrix P in k cycle _koptimal estimation value:

$P_k=P_k^{-}-K_{k}C{P}_k^{-},$

Wherein, Q _k-1, R is respectively the covariance matrix of noise w, v, error matrix P _kfor the error matrix of the optimal estimation value in estimation process, by iteration repeatedly, error matrix P _kfinally can converge to null matrix.

5. a kind of permagnetic synchronous motor current filtering as claimed in claim 2 and dead-zone compensation method, is characterized in that: in described step 6), in described electric current inverse transform block, processing procedure comprises the following steps:

1. dope next periodic permanent magnet synchronous electric motor rotor coordinate transform angle θ _pre, because permagnetic synchronous motor mechanical time constant is much larger than electrical time constant, think motor remain a constant speed at short notice operation state, permanent-magnetic synchronous motor rotor is consistent with the angle θ turning in current period in next cycle;

2. in conjunction with the predictive filtering value of dq shaft current, by coordinate transform, obtain the predicted value i of the three-phase current in next cycle _{a_pre}, i _{b_pre}and i _{c_pre}for:

$\left[\begin{array}{c}{i}_{a\_\mathrm{pre}}\\ i_{b\_\mathrm{pre}}\\ i_{c\_\mathrm{pre}}\end{array}\right]=\begin{array}{c}\left[\begin{array}{cc}\cos {\mathrm{\&theta;}}_{\mathrm{pre}}& -\sin {\mathrm{\&theta;}}_{\mathrm{pre}}\\ \cos ({\mathrm{\&theta;}}_{\mathrm{pre}}-\frac{2\mathrm{\&pi;}}{3})& -\sin ({\mathrm{\&theta;}}_{\mathrm{pre}}-\frac{2\mathrm{\&pi;}}{3})\\ \mathrm{ocs}({\mathrm{\&theta;}}_{\mathrm{pre}}+\frac{2\mathrm{\&pi;}}{3})& -\sin ({\mathrm{\&theta;}}_{\mathrm{pre}}+\frac{2\mathrm{\&pi;}}{3})\end{array}\right]\end{array}\left[\begin{array}{c}{i}_{d\_\mathrm{pre}}\\ i_{q\_\mathrm{pre}}\end{array}\right],$

And according to above formula, calculate the predicted value i of next cycle three-phase current _{a_pre}, i _{b_pre}and i _{c_pre}.

6. a kind of permagnetic synchronous motor current filtering as claimed in claim 2 and dead-zone compensation method, is characterized in that: in described step 7), described dead area compensation comprises the following steps:

1. dead area compensation module is according to next the cycle three-phase predicted current i receiving _{a_pre}, i _{b_pre}and i _{c_pre}, obtain the relevant voltage error delta u that next cycle three-phase predicted current produces respectively _a, Δ u _bwith Δ u _c:

${\mathrm{\&Delta;u}}_a=\frac{T_d+T_{\mathrm{on}}-T_{\mathrm{off}}}{T_s}{V}_{\mathrm{dc}}\mathrm{sign}\left(i_{a\_\mathrm{pre}}\right),$

${\mathrm{\&Delta;u}}_b=\frac{T_d+T_{\mathrm{on}}-T_{\mathrm{off}}}{T_s}{V}_{\mathrm{dc}}\mathrm{sign}\left(i_{b\_\mathrm{pre}}\right),$

${\mathrm{\&Delta;u}}_c=\frac{T_d+T_{\mathrm{on}}-T_{\mathrm{off}}}{T_s}{V}_{\mathrm{dc}}\mathrm{sign}\left(i_{c\_\mathrm{pre}}\right),$

Sign () is the polarity of predicted current, and during predicted current value >0, sign () value is 1, otherwise is-1;

2. by three-phase predicted current i _{a_pre}, i _{b_pre}and i _{c_pre}the voltage error Δ u producing _a, Δ u _bwith Δ u _cget respectively negative value, obtain and three-phase predicted current i _{a_pre}, i _{b_pre}and i _{c_pre}corresponding bucking voltage.

Images