CN105227021A - Based on the asynchronous electromotor rotor resistance offline identification method of single-phase phase-locked loop - Google Patents

Abstract

The invention discloses a kind of asynchronous electromotor rotor resistance offline identification method based on single-phase phase-locked loop, belong to Motor Control Field.This method sets up asynchronous machine single-phase alternating current closed-loop control system, wherein adjusting of current regulator parameter considers the waveform quality of current of electric and current regulator output voltage, adopt the single-phase phase-locked loop based on Second Order Generalized Integrator to carry out filtering process to electric moter voltage, electric current simultaneously, and reconstruct the quadrature component of electric moter voltage, electric current, from active power angle identification rotor resistance.This invention, except possessing the advantage of monophase current closed-loop identification rotor resistance scheme, also has the following advantages: 1, not with current-order on current of electric perfect tracking for target carrys out tuning Regulator, this makes current regulator parameter adjustment become easy; 2, data processing avoids fast fourier transform to programme, but reconstructs voltage, electric current by single-phase phase-locked loop, solves rotor resistance from power perspective, and this makes rotor resistance identification precision not rely on current-order on current of electric perfect tracking.

Description

Based on the asynchronous electromotor rotor resistance offline identification method of single-phase phase-locked loop

Technical field

The present invention relates to Motor Control Field, be specifically related to the asynchronous electromotor rotor resistance offline identification method based on single-phase phase-locked loop.

Background technology

It is simple that induction machine has structure, the advantages such as cost is lower, and along with the development of AC speed-regulating theory and power electronic device, the induction motor speed regulation system based on field-oriented vector control technology obtains applying more and more widely.But the current PI parameter tuning of Vector Control System for Asynchronous Machine needs the parameter knowing controlled motor, the accuracy of field orientation relies on the parameter of electric machine simultaneously, therefore needs to carry out parameter identification to asynchronous machine.Parameter of electric machine identification is divided into off-line and online two classes, and asynchronous machine off-line identification parameter generally comprises stator and rotor resistance parameters, stator and rotor leakage inductance, magnetizing inductance five parameters.Stator resistance of asynchronous motor carries out data linear fit by direct current experiment and obtains, magnetizing inductance then can be rotated by constant voltage constant frequency control motor and carry out identification, or under motor inactive state, injects direct current to asynchronous machine and superpose the less interchange of amplitude to realize identification.

For asynchronous electromotor rotor resistance off-line identification, be entitled as " induction motor parameter offline identification method experimental study " (Wang Gaolin, Shang Zhen, Yu Yong, Xu Dianguo, electrical micro-machine, 42nd volume the 6th phase 4-7 page in 2009) article, propose to apply single-phase sinusoidal voltage at motor winding terminal, with reference voltage zero crossing for benchmark carries out fast fourier transform analysis to current of electric, but the method belongs to open current loop to be controlled, apply voltage need a process increased gradually and this magnitude of voltage to choose the improper current of electric that may cause excessive, infringement motor.

Be entitled as " non-synchronous motor parameter off-line identification innovatory algorithm " (He Yanhui, Wang Yue, Wang Zhaoan, electrotechnics journal, 26th volume the 6th phase 73-80 page in 2011) article and be entitled as " the static parameter identification method of the asynchronous machine based on adaptive equalization " (Chen Wei, Yu Yong, Xu Dianguo, Xu Zhuan, Proceedings of the CSEE, 32nd volume the 6th phase 156-162 page in 2012) article, the monophase current closed-loop control of adoption rate-integral controller is proposed respectively, after current stabilization with given current phase zero crossing for benchmark, fast fourier transform (FFT) is carried out to voltage and solves rotor resistance, but these two schemes are all by the zero crossing being chosen as given electric current zero point of voltage FFT conversion, do not consider the error between given electric current and the true feedback current of motor, this makes rotor resistance identification result depend on current of electric tracking accuracy.

In sum, mainly there is following deficiency in existing technology:

1, under open current loop controls, apply voltage need a process increased gradually and this magnitude of voltage to choose the improper current of electric that may cause excessive, infringement motor;

2, on the basis of monophase current closed-loop control, with given current zero-crossing point for benchmark depends on current of electric tracking accuracy to the method that electric moter voltage carries out fast fourier transform analysis.

Summary of the invention

The object of the invention is, for the not good enough problem of the identification precision existed in existing asynchronous electromotor rotor resistance offline identification method, to provide a kind of asynchronous electromotor rotor resistance offline identification method based on single-phase phase-locked loop.

The present invention is mainly achieved through the following technical solutions:

Based on an asynchronous electromotor rotor resistance offline identification method for single-phase phase-locked loop, comprise the sampling of asynchronous machine current signal, its step is as follows:

Step 1: be I according to amplitude _ref1, angular frequency is the asynchronous machine A phase-current reference value I of ω ^*with the asynchronous machine A phase current I obtained that samples _{m α 1}, the α shaft voltage U under overcurrent controller obtains two-phase rest frame _{m α 1};

Step 2: according to the asynchronous machine A phase current I obtained in step 1 _{m α 1}with α shaft voltage U _{m α 1}, obtain filtered α shaft current I respectively through phase-locked loop module _{α 1}and with filtered α shaft current I _{α 1}orthogonal β shaft current I _{β 1}, filtered α shaft voltage U _{α 1}and with filtered α shaft voltage U _{α 1}orthogonal β shaft voltage U _{β 1};

Step 3: according to the α shaft current I obtained in step 2 _{α 1}, β shaft current I _{β 1}with the α shaft voltage U obtained in step 2 _{α 1}, β shaft voltage U _{β 1}, calculate module obtain asynchronous machine A phase current peak I respectively through current peak computing module, active power ₁, active-power P ₁;

Step 4: keep asynchronous machine A phase-current reference value I ^*angular frequency constant, change asynchronous machine A phase-current reference value I ^*amplitude be I _ref2, repeat step 1 to step 3, obtain corresponding asynchronous machine A phase current peak I ₂, active-power P ₂;

Step 5: the current peak I obtained according to step 3 ₁, active-power P ₁with the current peak I that step 4 obtains ₂, active-power P ₂, obtain rotor resistance R through rotor resistance accounting equation _r.

Preferably, the current controller described in step 1 is proportional, integral (PI) controller, and expression formula is:

$U_{m\mathrm{\α}1}=(k_p+\frac{k_i}{s})(I^{*}-I_{m\mathrm{\α}1})$

Wherein k _p, k _ibe respectively proportionality coefficient and integral coefficient, s is Laplacian.

Preferably, the phase-locked loop module described in step 2 comprises voltage accounting equation and Current calculation equation, and its expression formula is respectively:

Voltage accounting equation:

$U_{\mathrm{\α}1}=\frac{k\mathrm{\ω}s}{s^2+k\mathrm{\ω}s+{\mathrm{\ω}}^2}{U}_{m\mathrm{\α}1}$

$U_{\mathrm{\β}1}=\frac{{\mathrm{k\ω}}^2}{s^2+k\mathrm{\ω}s+{\mathrm{\ω}}^2}{U}_{m\mathrm{\α}1}$

Current calculation equation:

$I_{\mathrm{\α}1}=\frac{k\mathrm{\ω}s}{s^2+k\mathrm{\ω}s+{\mathrm{\ω}}^2}{I}_{m\mathrm{\α}1}$

$I_{\mathrm{\β}1}=\frac{{\mathrm{k\ω}}^2}{s^2+k\mathrm{\ω}s+{\mathrm{\ω}}^2}{I}_{m\mathrm{\α}1}$

Wherein k is bandwidth of phase lock loop control coefrficient, and ω is asynchronous machine A phase-current reference value I ^*angular frequency, s is Laplacian.

Preferably, the expression formula of the current peak computing module described in step 3 is:

$I_1=\sqrt{I_{\mathrm{\α}1}^2+I_{\mathrm{\β}1}^2}.$

Preferably, the expression formula that the active power described in step 3 calculates module is:

P ₁＝U _α1I _α1+U _β1I _β1。

Preferably, the rotor resistance R described in step 5 _rthe expression formula of accounting equation is:

$R_r=\frac{P_1{I}_2-P_2{I}_1}{I_2{I}_1^2-I_1{I}_2^2}-R_s$

Wherein R _sfor stator resistance value, obtained by direct current experiment.

Preferably, asynchronous machine A phase-current reference value I described in step 1 ^*amplitude I _ref1for the 40%-100% of the specified phase current peak value of tested asynchronous machine, angular frequency is the 1%-10% of the specified angular frequency of tested asynchronous machine.

Preferably, asynchronous machine A phase-current reference value I described in step 4 ^*amplitude I _ref2for the 40%-100% of the specified phase current peak value of tested asynchronous machine.

Preferably, the value of described bandwidth of phase lock loop control coefrficient k is 0.2-1.5.

The present invention relative to the beneficial effect of prior art is:

After adopting the present invention, except possessing the advantage of monophase current closed-loop identification rotor resistance scheme, also have the following advantages:

1, not with current-order on current of electric perfect tracking for target carrys out tuning Regulator, this makes current regulator parameter adjustment become easy;

2, data processing avoids fast fourier transform to programme, but reconstructs voltage, electric current by single-phase phase-locked loop, solves rotor resistance from power perspective, and this makes rotor resistance identification precision not rely on current-order on asynchronous machine electric current perfect tracking.

Accompanying drawing explanation

Fig. 1 is the flow chart that the present invention performs;

Fig. 2 is asynchronous machine equivalent circuit diagram under single phase alternating current (A.C.) closed-loop control;

Fig. 3 is the single-phase phase-locked loop control block diagram based on Second Order Generalized Integrator.

Embodiment

Below in conjunction with accompanying drawing, technical scheme of the present invention is described in further detail.

See Fig. 1, implementation process of the present invention is as follows:

Step 1: be I according to amplitude _ref1, angular frequency is the asynchronous machine A phase-current reference value I of ω ^*with the asynchronous machine A phase current I obtained that samples _{m α 1}both subtract each other through overcurrent controller control make motor three-phase windings type of attachment be equivalent to motor B, C two-phase winding parallel after connect with motor A phase winding again, now asynchronous machine equivalent circuit diagram as shown in Figure 2, obtains the α shaft voltage U under the two-phase rest frame of current controller output after motor is stable _{m α 1}; Wherein:

Asynchronous machine A phase-current reference value I ^*amplitude I _ref1span is the 40%-100% of the specified phase current peak value of tested asynchronous machine, in the present embodiment, and I _ref1value is 80%.

Consider that in asynchronous machine operation, slip frequency is less, in order to directly rotor resistance identification result is used for Vector Control System of Induction Motor, avoids kelvin effect on the impact of rotor resistance identification result, motor A phase-current reference value I simultaneously ^*angular frequency span be the 1%-10% of tested Rated motor frequency, in the present embodiment, ω value is 5%.

Current controller is pi controller, its proportionality coefficient k _pwith integral coefficient k _igather obtain by examination, because the method that adopts of the present invention do not rely on current tracking precision, so current controller parameter is comparatively easily adjusted.

Step 2: according to the asynchronous machine A phase current I obtained in step 1 _{m α 1}with α shaft voltage U _{m α 1}, obtain filtered α shaft current I respectively through phase-locked loop module _{α 1}and and filtered I _{α 1}orthogonal β shaft current I _{β 1}, filtered α shaft voltage U _{α 1}and and filtered U _{α 1}orthogonal β shaft voltage U _{β 1}; Wherein:

Phase-locked loop module is the single-phase phase-locked loop based on Second Order Generalized Integrator, and this phase-locked loop module is single input, a double-outputting system, and control block diagram as shown in Figure 3, is calculated by phase-locked loop module:

α shaft voltage U _{α 1}: $U_{\mathrm{\α}1}=\frac{k\mathrm{\ω}s}{s^2+k\mathrm{\ω}s+{\mathrm{\ω}}^2}{U}_{m\mathrm{\α}1};$

β shaft voltage U _{β 1}: $U_{\mathrm{\β}1}=\frac{{\mathrm{k\ω}}^2}{s^2+k\mathrm{\ω}s+{\mathrm{\ω}}^2}{U}_{m\mathrm{\α}1};$

α shaft current I _{α 1}: $I_{\mathrm{\α}1}=\frac{k\mathrm{\ω}s}{s^2+k\mathrm{\ω}s+{\mathrm{\ω}}^2}{I}_{m\mathrm{\α}1};$

β shaft current I _{β 1}: $I_{\mathrm{\β}1}=\frac{{\mathrm{k\ω}}^2}{s^2+k\mathrm{\ω}s+{\mathrm{\ω}}^2}{I}_{m\mathrm{\α}1};$

In phase-locked loop module, parameter k is phase-locked loop systems bandwidth control coefrficient, and span is 0.2-1.5, and in the present embodiment, k value is 0.8.

Step 3: according to the mutually orthogonal electric current I obtained in step 2 _{α 1}, I _{β 1}with the voltage U that step 2 obtains _{α 1}, U _{β 1}, pass through formula: calculate motor A phase current peak I ₁, pass through formula: P ₁=U _{α 1}i _{α 1}+ U _{β 1}i _{β 1}calculate active-power P ₁.

Step 4: keep asynchronous machine A phase-current reference value I ^*angular frequency constant, change asynchronous machine A phase-current reference value I ^*amplitude be I _ref2, repeat step 1 to step 3, obtain corresponding asynchronous machine A phase current peak I ₂, active-power P ₂;

Wherein asynchronous machine A phase-current reference value I ^*amplitude I _ref2span is the 40%-100% of the specified phase current peak value of tested asynchronous machine, I in the present embodiment _ref2value is 100%.

Step 5: the current peak I obtained according to step 3 ₁, active-power P ₁with the current peak I that step 5 obtains ₂, active-power P ₂, calculate rotor resistance R by formula (1) _r:

$R_r=\frac{P_1{I}_2-P_2{I}_1}{I_2{I}_1^2-I_1{I}_2^2}-R_s---\left(1\right),$

Wherein R _sfor stator resistance value, obtained by direct current experiment.

The principle of such calculating is: due to the existence of Inverter Dead-time time, makes current controller output voltage and be applied between the real voltage on motor to there is error voltage u _d, specification error voltage u _damplitude be U _d.At asynchronous machine A phase-current reference value I ^*amplitude be respectively I _ref1, I _ref2time, motor active-power P ₁, P ₂meet formula (2), formula (3) respectively:

$P_1=I_1^2(R_s+R_r)+U_d{I}_1---\left(2\right),$

$P_2=I_2^2(R_s+R_r)+U_d{I}_2---\left(3\right),$

Simultaneous formula (2), formula (3) can be tried to achieve

$R_r=\frac{P_1{I}_2-P_2{I}_1}{I_2{I}_1^2-I_1{I}_2^2}-R_s.$

Claims (8)

1. based on an asynchronous electromotor rotor resistance offline identification method for single-phase phase-locked loop, comprise the sampling of asynchronous machine current signal, it is characterized in that key step is as follows:

Step 1: be I according to amplitude _ref1, angular frequency is the asynchronous machine A phase-current reference value I of ω ^*with the asynchronous machine A phase current I obtained that samples _{m α 1}, the α shaft voltage U under overcurrent controller obtains two-phase rest frame _{m α 1};

Step 2: according to the asynchronous machine A phase current I obtained in step 1 _{m α 1}with α shaft voltage U _{m α 1}, obtain filtered α shaft current I respectively through phase-locked loop module _{α 1}and with filtered α shaft current I _{α 1}orthogonal β shaft current I _{β 1}, filtered α shaft voltage U _{α 1}and with filtered α shaft voltage U _{α 1}orthogonal β shaft voltage U _{β 1};

Step 3: according to the α shaft current I obtained in step 2 _{α 1}, β shaft current I _{β 1}with the α shaft voltage U obtained in step 2 _{α 1}, β shaft voltage U _{β 1}, calculate module obtain asynchronous machine A phase current peak I respectively through current peak computing module, active power ₁, active-power P ₁;

Step 4: keep asynchronous machine A phase-current reference value I ^*angular frequency constant, change asynchronous machine A phase-current reference value I ^*amplitude be I _ref2, repeat step 1 to step 3, obtain corresponding asynchronous machine A phase current peak I ₂, active-power P ₂;

Step 5: the current peak I obtained according to step 3 ₁, active-power P ₁with the current peak I that step 4 obtains ₂, active-power P ₂, obtain rotor resistance R through rotor resistance accounting equation _r.

2. the asynchronous electromotor rotor resistance offline identification method based on single-phase phase-locked loop according to claim 1, it is characterized in that the current controller described in step 1 is proportional, integral (PI) controller, expression formula is:

$U_{m\mathrm{\α}1}=\left(k_p+\frac{k_i}{s}\right)(I^{*}-I_{m\mathrm{\α}1})$

Wherein k _p, k _ibe respectively proportionality coefficient and integral coefficient, s is Laplacian.

3. the asynchronous electromotor rotor resistance offline identification method based on single-phase phase-locked loop according to claim 1, it is characterized in that the phase-locked loop module described in step 2 comprises voltage accounting equation and Current calculation equation, its expression formula is respectively:

Voltage accounting equation:

$U_{\mathrm{\α}1}=\frac{k\mathrm{\ω}s}{s^2+k\mathrm{\ω}s+{\mathrm{\ω}}^2}{U}_{m\mathrm{\α}1}$

$U_{\mathrm{\β}1}=\frac{{\mathrm{k\ω}}^2}{s^2+k\mathrm{\ω}s+{\mathrm{\ω}}^2}{U}_{m\mathrm{\α}1}$

Current calculation equation:

$I_{\mathrm{\α}1}=\frac{k\mathrm{\ω}s}{s^2+k\mathrm{\ω}s+{\mathrm{\ω}}^2}{I}_{m\mathrm{\α}1}$

$I_{\mathrm{\β}1}=\frac{{\mathrm{k\ω}}^2}{s^2+k\mathrm{\ω}s+{\mathrm{\ω}}^2}{I}_{m\mathrm{\α}1}$

Wherein k is bandwidth of phase lock loop control coefrficient, and ω is asynchronous machine A phase-current reference value I ^*angular frequency, s is Laplacian.

4. the asynchronous electromotor rotor resistance offline identification method based on single-phase phase-locked loop according to claim 1, is characterized in that the expression formula of the current peak computing module described in step 3 is:

$I_1=\sqrt{I_{\mathrm{\α}1}^2+I_{\mathrm{\β}1}^2}.$

The expression formula that active power calculates module is:

P ₁＝U _α1I _α1+U _β1I _β1。

5. the asynchronous electromotor rotor resistance offline identification method based on single-phase phase-locked loop according to claim 1, is characterized in that the expression formula of the rotor resistance accounting equation described in step 5 is:

$R_r=\frac{P_1{I}_2-P_2{I}_1}{I_2{I}_1^2-I_2{I}_2^2}-R_s,$

Wherein R _sfor stator resistance value, obtained by direct current experiment.

6. the asynchronous electromotor rotor resistance offline identification method based on single-phase phase-locked loop according to claim 1, is characterized in that asynchronous machine A phase-current reference value I described in step 1 ^*amplitude I _ref1for the 40%-100% of the specified phase current peak value of tested asynchronous machine, angular frequency is the 1%-10% of the specified angular frequency of tested asynchronous machine.

7. the asynchronous electromotor rotor resistance offline identification method based on single-phase phase-locked loop according to claim 1, is characterized in that asynchronous machine A phase-current reference value I described in step 4 ^*amplitude I _ref2for the 40%-100% of the specified phase current peak value of tested asynchronous machine.

8. the asynchronous electromotor rotor resistance offline identification method based on single-phase phase-locked loop according to claim 3, is characterized in that the value of described bandwidth of phase lock loop control coefrficient k is 0.2-1.5.