CN105529979A - Closed-loop control method for motor starting speed - Google Patents

Abstract

The invention relates to a motor control technology and aims at solving the problem of starting failure of a permanent magnet synchronous DC motor under the condition of heavy load. The invention provides a closed-loop control method for a motor starting speed. The closed-loop control method comprises a positioning stage, an asynchronous dragging stage, a transitional stage from asynchronous dragging to position sensorless speed closed-loop and a position sensorless speed closed-loop stage, in the transitional stage of the position sensorless speed closed-loop, a d axis current command value is controlled to ID * = 0, and a q axis current command value Iq * is determined according to maximum torque control or PI regulation control. The closed-loop control method for the motor starting speed is used for improving the positioning stage, the asynchronous dragging stage and the position sensorless speed closed-loop stage. The closed-loop control method provided by the invention is suitable for permanent magnet synchronous DC motors.

Description

A kind of electric motor starting velocity close-loop control method

Technical field

The present invention relates to electric machines control technology, particularly permanent magnet synchronous DC motor is asynchronous drags the method terminating to be switched to closed-loop control.

Background technology

Traditional electric motor starting technology, generally comprises location, asynchronous dragging, asynchronously drags to the transition of position-sensor-free speed closed loop and position-sensor-free velocity close-loop control technology.In location and asynchronous dragging stage, electric current loop ACR closed-loop control, and speed ring ASR opened loop control, in the asynchronous dragging stage, although speed ring open loop, but software is detecting motor position and speed always, at the end of asynchronous dragging, although the motor position that detects of software and speed have certain error, when being switched to closed-loop control, generally can realize seamlessly transitting of motor smoothly, be switched to closed-loop control smoothly.

After asynchronous dragging terminates, when being switched to closed-loop control, traditional control method is, the q axle controlling to obtain motor by maximum moment controls current command value I _q ^*current command value I is controlled with d axle _d ^*even if, under the condition that moment is constant, I _d ^*also a negative value can be changed to rapidly, along with I _d* minimizing, I _q ^*also can reduce rapidly, cause motor to start unsuccessfully under the condition of heavy load.

The method that patent " permanent-magnet synchronous DC brushless motor starts control method (CN201410508796) " is introduced, the rotating speed method adopting time delay to detect motor controls, although detected motor speed precision can be improved, but do not relate to motor and be transitioned into position-sensor-free velocity close-loop control method from asynchronous dragging, " a kind of electric motor starting control method (CN201510129234) " is although the detailed startup describing motor and asynchronous drive technology, do not introduce in detail and be switched to velocity close-loop control technology yet, " starting method (CN201410431250) of permanent magnetic brushless " is although processed the conversion of d/q shaft current preferably, avoid and entering closed loop moment, because d shaft current is not 0, and cause d shaft current to 0 even to negative value transition time, q shaft current reduces rapidly and causes starting problem, but exist d axle from 0 to negative value conversion trend and q shaft current I _q ^*reduction, cause and start the generation of failure problem.

Traditional maximum moment control method, the formula adopted is:

$I_q*=\frac{{\mathrm{\τ}}^{*}}{1.5p\[{K_E}^{*}+({L_d}^{*}-{L_q}^{*}){I_{d-1}}^{*}\]}---\left(1\right)$

$I_d*=-\frac{{K_E}^{*}}{2({L_d}^{*}-{L_q}^{*})}-\sqrt{{\[\frac{{K_E}^{*}}{2({L_d}^{*}-{L_q}^{*})}\]}^2+{I_q}^2}---\left(2\right)$

Wherein τ ^*for torque command value, I _d-1 ^*for motor d shaft current bid value last time, I _q ^*for this motor q shaft current bid value, I _d ^*for this motor d shaft current bid value, K _e ^*for counter electromotive force of motor constant, L _d ^*for motor d axle inductance, L _q ^*for motor q axle inductance.K _e ^*, L _d ^*, L _q ^*for the parameter of electric machine.Due to L _d ^*<L _q ^*, at τ ^*under constant condition, work as I _d-1 ^*be not 0, and I _d-1 ^*during >0, from formula (1), at I _d-1 ^*during decline, I _q ^*also reduce, I _q ^*substitute into formula (2) visible, I _d ^*for negative value (being 0 to the maximum), next circulation time, I _d ^*for negative value, when substituting into (1), obtain less I _q ^*, cause I _q ^*rapid reduction.In order to avoid I _d-1 ^*when >0 is to negative value transition, I _d ^*sudden change, terminates in asynchronous dragging, when being switched to velocity close-loop control, usually adopts I _d ^*carry out low-pass filtering.But I _d ^*reduction cause I _q ^*reduction, start the generation of failure problem when asynchronous dragging can be caused to be switched to speed ring closed-loop control.

Summary of the invention

The invention provides a kind of electric motor starting velocity close-loop control method, for solve heavy load condition under start failed problem.

The present invention solves its technical problem, the technical scheme adopted is, a kind of electric motor starting velocity close-loop control method, comprise positioning stage, asynchronous dragging stage, asynchronously drag to position-sensor-free speed closed loop transition stage and position-sensor-free velocity close-loop control stage, it is characterized in that, in position-sensor-free speed closed loop transition stage, control d shaft current bid value I _d ^*=0, q shaft current bid value I _q ^*determine according to maximum moment control or PI regulable control.

Particularly, in the asynchronous dragging stage, according to I _d ^*=I _{d_B} ^*cos (γ), I _q ^*=I _{d_B} ^*sin (γ) carries out control motor d/q shaft current bid value, wherein I _{d_B} ^*for localizing objects electric current, asynchronous dragging angle γ value increases to asynchronous drag target angle γ gradually from 0 _d, γ _dbe 90 °, control I _d ^*from I _d ^*=I _{d_B} ^*to I _d ^*=0 change, I _q ^*for motor q shaft current bid value, I _d ^*for motor d shaft current bid value.

Particularly, in asynchronous dragging stage and position-sensor-free speed closed loop transition stage, to the angle θ of rotor ₁with rotor speed f ₁estimate, in the closed-loop control stage, closed-loop control motor rotor speed and angle adopt the angle θ of the rotor estimated ₁with rotor speed f ₁, I _d ^*with I _q ^*then return to conventional maximum moment to control or weak magnetics detect, control the operation of motor.

Particularly, at positioning stage, make I _qn ^*=0, n is natural number, I _d ^*at T ₀in time, increase to localizing objects electric current I gradually from 0 _{d_B} ^*, i _d0=0, motor running frequency f ₀=0, the angle simultaneously between location current vector and fixed coordinates axle α axle is θ ₀, T ₀>0, stops T afterwards ₁time, maintain current state constant, force rotor to forward the position of current flow vector to, T ₁>=0.

Particularly, in the asynchronous dragging stage, at T ₂in time, maintain the size of current phasor constant, current phasor with asynchronous dragging frequency f from f=0 to f=f _nby counterclockwise rotating, 0<f _n<=f _d, wherein f _dfor asynchronous drag target frequency, f ₀=0 _,asynchronous dragging angle γ changes to γ from 0 ° _d, γ _dbe 90 °, γ ₀=0, asynchronous drawing current I _dn ^*=I _{d_B} ^*cos (γ _n), I _qn ^*=I _{d_B} ^*sin (γ _n).

Particularly, position-sensor-free speed closed loop transition stage is dragged to, at T asynchronous ₃time internal fixtion d shaft current bid value I _d ^*=0, and q shaft current bid value I _q ^*to determine according to maximum moment dominated formulate or PI regulable control is determined, T ₃>0.

Particularly, maximum moment dominated formulate is

$I_q*=\frac{{\mathrm{\&tau;}}^{*}}{1.5p\&lsqb;{K_E}^{*}+({L_d}^{*}-{L_q}^{*}){I_{d-1}}^{*}\&rsqb;}$

$I_d*=-\frac{{K_E}^{*}}{2({L_d}^{*}-{L_q}^{*})}-\sqrt{{\&lsqb;\frac{{K_E}^{*}}{2({L_d}^{*}-{L_q}^{*})}\&rsqb;}^2+{I_q}^2}$

Wherein τ ^*for torque command value, I _d-1 ^*for motor d shaft current bid value last time, I _q ^*for this motor q shaft current bid value, I _d ^*for this motor d shaft current bid value, K _e ^*for counter electromotive force of motor constant, L _d ^*for motor d axle inductance, L _q ^*for motor q axle inductance, K _e ^*, L _d ^*, L _q ^*for the parameter of electric machine.

The invention has the beneficial effects as follows, by a kind of above-mentioned electric motor starting velocity close-loop control method, can under the condition that motor load is heavy, particularly under the condition of refrigerator motor back pressure startup, the operation of success starter motor, overcome the technical problem that Traditional control technology can not realize back pressure startup, realize refrigerator back pressure and start.

Accompanying drawing explanation

Fig. 1 is fixed coordinate system α β coordinate system and the rotation d/q coordinate system variable schematic diagram with rotor running.

Embodiment

The present invention solves its technical problem, and the technical scheme of employing is, at positioning stage, makes I _qn ^*=0, wherein subscript n is natural number, lower same.I _d ^*at T ₀in time, increase to localizing objects electric current I gradually from 0 _{d_B} ^*, i _d0=0 _,motor running frequency f ₀=0, the angle simultaneously between location current vector and fixed coordinates axle α axle is θ ₀, T ₀>0, stops T afterwards ₁time, maintain current state constant, force rotor to forward the position of current flow vector to, T ₁>=0; In the asynchronous dragging stage, at T ₂in time, maintain the size of current phasor constant, current phasor with asynchronous dragging frequency f from f=0 to f=f _nby counterclockwise rotating, 0<f _n<=f _d, wherein f _dfor asynchronous drag target frequency, f ₀=0 _,asynchronous dragging angle γ changes to γ from 0 ° _d,γ _dbe generally 90 °, γ ₀=0 _,asynchronous drawing current I _dn ^*=I _{d_B} ^*cos (γ _n), I _qn ^*=I _{d_B} ^*sin (γ _n), the angle between asynchronous drawing current vector and fixed coordinates axle α axle is (θ ₀+ ∫ 2 π fdt).After asynchronous dragging terminates, at the asynchronous T dragging to position-sensor-free speed closed loop transition stage ₃time internal fixtion d shaft current bid value I _d ^*=0, and q shaft current bid value I _q ^*to determine according to maximum moment dominated formulate (1) or PI regulable control is determined, T ₃>0, enters closed-loop control subsequently, and closed-loop control motor rotor speed and angle adopt asynchronous dragging stage T ₂with speed ring closed loop transition stage T in time ₃the speed estimated in time and angle, and I _d ^*with I _q ^*then return to conventional maximum moment to control or weak magnetics detect.Realize refrigerator back pressure to start.

A kind of electric motor starting velocity close-loop control method, comprises the following steps:

A. at positioning stage, I is made _qn ^*=0, n is natural number, I _d ^*at T ₀in time, increase to localizing objects electric current I gradually from 0 _{d_B} ^*, i _d0=0, motor running frequency f ₀=0, the angle simultaneously between location current vector and fixed coordinates axle α axle is θ ₀, T ₀>0, stops T afterwards ₁time, maintain current state constant, make rotor forward the position of current flow vector to, T ₁>=0;

B. in the asynchronous dragging stage, at T ₂in time, maintain the size of current phasor constant, current phasor with asynchronous dragging frequency f from f=0 to f=f _nby counterclockwise rotating, 0<f _n<=f _d, wherein f _dfor asynchronous drag target frequency, f ₀=0 _,asynchronous dragging angle γ changes to γ from 0 ° _d, γ _dbe 90 °, γ ₀=0, asynchronous drawing current I _dn ^*=I _{d_B} ^*cos (γ _n), I _qn ^*=I _{d_B} ^*sin (γ _n), the angle between asynchronous drawing current vector and fixed coordinates axle α axle is (θ ₀+ ∫ 2 π fdt);

C. position-sensor-free speed closed loop transition stage is dragged to, at T asynchronous ₃time internal fixtion d shaft current bid value I _d ^*=0, and q shaft current bid value I _q ^*to determine according to maximum moment dominated formulate or PI regulable control is determined, T ₃>0;

D. at asynchronous dragging stage T ₂position-sensor-free speed closed loop transition stage T is dragged to asynchronous in time ₃in time, the angle θ of presumption rotor ₁with rotor speed f ₁;

E. in the closed-loop control stage, closed-loop control motor rotor speed and angle adopt the angle θ of the rotor estimated ₁with rotor speed f ₁, and I _d ^*with I _q ^*then return to conventional maximum moment to control or weak magnetics detect.

Claims (7)

1. an electric motor starting velocity close-loop control method, comprise positioning stage, asynchronous dragging stage, asynchronously drag to position-sensor-free speed closed loop transition stage and position-sensor-free velocity close-loop control stage, it is characterized in that, in position-sensor-free speed closed loop transition stage, control d shaft current bid value I _d ^*=0, q shaft current bid value I _q ^*determine according to maximum moment control or PI regulable control.

2. a kind of electric motor starting velocity close-loop control method as claimed in claim 1, is characterized in that, in the asynchronous dragging stage, according to I _d ^*=I _{d_B} ^*cos (γ), I _q ^*=I _{d_B} ^*sin (γ) carries out control motor d/q shaft current bid value, wherein I _{d_B} ^*for localizing objects electric current, asynchronous dragging angle γ value increases to asynchronous drag target angle γ gradually from 0 _d, γ _dbe 90 °, control I _d ^*from I _d ^*=I _{d_B} ^*to I _d ^*=0 change, I _q ^*for motor q shaft current bid value, I _d ^*for motor d shaft current bid value.

3. a kind of electric motor starting velocity close-loop control method as claimed in claim 1, is characterized in that, in asynchronous dragging stage and position-sensor-free speed closed loop transition stage, to the angle θ of rotor ₁with rotor speed f ₁estimate, in the closed-loop control stage, closed-loop control motor rotor speed and angle adopt the angle θ of the rotor estimated ₁with rotor speed f ₁, I _d ^*with I _q ^*then return to conventional maximum moment to control or weak magnetics detect, control the operation of motor.

4. a kind of electric motor starting velocity close-loop control method as claimed in claim 3, is characterized in that, at positioning stage, make I _qn ^*=0, n is natural number, I _d ^*at T ₀in time, increase to localizing objects electric current I gradually from 0 _{d_B} ^*, i _d0=0, motor running frequency f ₀=0, the angle simultaneously between location current vector and fixed coordinates axle α axle is θ ₀, T ₀>0, stops T afterwards ₁time, maintain current state constant, force rotor to forward the position of current flow vector to, T ₁>=0.

5. a kind of electric motor starting velocity close-loop control method as claimed in claim 4, is characterized in that, in the asynchronous dragging stage, at T ₂in time, maintain the size of current phasor constant, current phasor with asynchronous dragging frequency f from f=0 to f=f _nby counterclockwise rotating, 0<f _n<=f _d, wherein f _dfor asynchronous drag target frequency, f ₀=0, asynchronous dragging angle γ changes to γ from 0 ° _d, γ _dbe 90 °, γ ₀=0, asynchronous drawing current I _dn ^*=I _{d_B} ^*cos (γ _n), I _qn ^*=I _{d_B} ^*sin (γ _n).

6. a kind of electric motor starting velocity close-loop control method as claimed in claim 5, is characterized in that, drags to position-sensor-free speed closed loop transition stage, at T asynchronous ₃time internal fixtion d shaft current bid value I _d ^*=0, q shaft current bid value I _q ^*to determine according to maximum moment dominated formulate or PI regulable control is determined, T ₃>0.

7. a kind of electric motor starting velocity close-loop control method as described in claim 1 to 6 any one, it is characterized in that, maximum moment dominated formulate is

$I_q*=\frac{{\mathrm{\&tau;}}^{*}}{1.5p\&lsqb;{K_E}^{*}+({L_d}^{*}-{L_q}^{*}){I_{d-1}}^{*}\&rsqb;}$

$I_d*=-\frac{{K_E}^{*}}{2({L_d}^{*}-{L_q}^{*})}-\sqrt{{\&lsqb;\frac{{K_E}^{*}}{2({L_d}^{*}-{L_q}^{*})}\&rsqb;}^2+{I_q}^2}$

Wherein τ ^*for torque command value, I _d-1 ^*for motor d shaft current bid value last time, I _q ^*for this motor q shaft current bid value, I _d ^*for this motor d shaft current bid value, K _e ^*for counter electromotive force of motor constant, L _d ^*for motor d axle inductance, L _q ^*for motor q axle inductance, K _e ^*, L _d ^*, L _q ^*for the parameter of electric machine.