CN103248287A - Switching method of position-sensor-free direct torque motor control system - Google Patents

Abstract

The invention relates to a switching method of a position-sensor-free direct torque motor control system, wherein a non-disturbance switching section is added in the switching process of the open loop control starting state and the closed loop control operation state, in the non-disturbance switching section, the switching frequency operation is maintained in the switching time period, each parameter estimation quantity required by the motor closed loop control operation is obtained, the preparation is made for the motor from the open loop control starting state to the closed loop control operation state, in addition, each parameter estimation quantity is used as corresponding control parameters of the motor closed loop control operation during the switching, the non-disturbance switching of the motor from the open loop control starting state to the closed loop control operation state is realized, and the switching moment control stability is effectively ensured.

Description

A kind of changing method of position-sensor-free Direct Torque electric machine control system

Technical field

The present invention relates to a kind of changing method of position-sensor-free Direct Torque electric machine control system.

Background technology

Direct torque control (Direct Torque Control---DTC), external original text has is also referred to as Direct self-control---DSC, literal translation is directly control certainly, refer to that a torque directly controls as controlled volume, its essence is the analytical method with space vector, in the stator flux orientation mode, carry out directly actuated to motor stator magnetic linkage and electromagnetic torque.This method does not need complicated coordinate, but directly calculate the mould of magnetic linkage and the size of torque at the motor stator coordinate, and by the direct tracking realization PWM pulse-width modulation of magnetic linkage and torque and the high dynamic performance of system, in control procedure, need to have the position transducer of detection rotor position of magnetic pole, and by position transducer detection rotor position of magnetic pole, be used for realizing the subsequent control process.

Position transducer adopts mechanical position sensor such as resolver, electro-optical pickoff, magnetoresistive element, Hall element or high-frequency coupling formula position transducer usually in the tradition, but there are a lot of shortcomings, cause motor volume to increase as the installation site transducer, the consumption of parts such as position transducer and connecting line thereof has simultaneously caused the increase of motor cost again, and the output signal of position transducer generally all is the weakness signal, easily introduces and disturbs; Conditions of work such as operational environments such as high temperature, low temperature, foul atmosphere and vibration, high-speed cruising all can reduce the reliability of transducer.

For this reason, existing more about cancelling traditional mechanical position sensor in recent years, adopt the Electric Machine Control running technology that does not have (machinery) position transducer open, its operation principle is by the physical quantitys such as magnetic linkage, electric current and voltage to motor, handles indirect acquisition rotor-position accordingly.Existing method is generally mainly obtained rotor-position based on back-emf signal.And because the back electromotive force of motor when static or low speed is zero or very little, cause to obtain rotor-position accurately, cause electric motor starting to lose efficacy, therefore the starting that other method realizes motor need be set, disclosed method generally adopts open loop control starting at present, and then switch to closed-loop control operation, impact less stable but exist when switching.

Summary of the invention

The technical problem to be solved in the present invention provides a kind of changing method of position-sensor-free Direct Torque electric machine control system, has realized that motor switches to the no disturbance of closed-loop control operation from open loop control starting, has effectively guaranteed to switch the stability of moment control.

Because the defective that above-mentioned existing position-sensor-free Direct Torque electric machine control system exists in switching, the applicant is based on being engaged in practical experience and the professional knowledge that this type of product design manufacturing is enriched for many years, actively studied innovation, grope through a large amount of experiments, develop the present invention, can overcome the defective that existing position-sensor-free Direct Torque electric machine control system exists well when switching.

Technical scheme of the present invention adopts as follows:

A kind of changing method of position-sensor-free Direct Torque electric machine control system, wherein: in the handoff procedure of open loop control starting state and closed-loop control running status, increase no disturbance switching section, described no disturbance switching section refers to keep switching frequency to move in switching time in the section, obtain each parameter estimation amount that motor closed-loop control operation is needed, for motor is prepared to the closed-loop control running status from its open loop control starting state, and the corresponding control parameter of when switching, each parameter estimation amount being moved as the motor closed-loop control, switch to the no disturbance of closed-loop control running status from open loop control starting state to realize motor.

Preferably, described each parameter estimation amount comprises stator magnetic linkage, electromagnetic torque and spinner velocity; The corresponding control parameter of described motor closed-loop control operation comprises the initial value of stator magnetic linkage vector magnitude set point, the initial value of speed ring integration item and the initial value of moment ring integration item.

Preferably, the concrete steps of described no disturbance switching section are:

(1) described no disturbance switching section keeps the switching frequency operation in the section in switching time;

(2) according to the stator output voltage U _sThe stator current i that obtains with detection _sEstimation stator magnetic linkage estimation vector magnitude ψ _SfWith stator magnetic linkage estimation azimuth

(3) based on stator magnetic linkage estimation azimuth

Estimation spinner velocity estimated value W _Rf, and based on stator magnetic linkage estimation vector magnitude ψ _SfWith stator current i _sEstimation electromagnetic torque estimated value T _Ef

(4) when switching, with the spinner velocity estimated value W of moment before switching _RfRotor feedback speed as motor closed-loop control operation , with the electromagnetic torque estimated value T of moment before switching _EfFeedback moment as the moment ring , and this feedback moment value composed to speed ring integration item, as the initial value of speed ring integration item, the initial value of composing moment ring integration item is zero; Stator magnetic linkage is estimated vector magnitude ψ _SfAs stator magnetic linkage vector magnitude set point

Initial value.

Further preferably, the computational methods of described (2) step are:

${\mathrm{\ψ}}_{s\mathrm{\α}}={\displaystyle \∫U_{s\mathrm{\α}}?R_s}*i_{s\mathrm{\α}}$ ； ${\mathrm{\ψ}}_{s\mathrm{\β}}={\displaystyle \∫U_{s\mathrm{\β}}?R_s}*i_{s\mathrm{\β}}$ ；

${\mathrm{\ψ}}_{sf}=\sqrt{{\mathrm{\ψ}}_{s\mathrm{\α}}^2+{\mathrm{\ψ}}_{s\mathrm{\β}}^2}$ ； ${\mathrm{\θ}}_{{\mathrm{\ψ}}_s}=a\tan ({\mathrm{\ψ}}_{s\mathrm{\β}}/{\mathrm{\ψ}}_{s\mathrm{\α}})$ ；

In the formula, described U _{S α}, U _{S β}Be respectively the α under the rectangular coordinate system, the stator output voltage U of β axle _sComponent, R _sBe to detect the stator resistance that obtains, i _{S α}, i _{S β}Be respectively the α under the rectangular coordinate system, the stator current i of β axle _sComponent, ψ _{S α}, ψ _{S β}Be respectively the α under the rectangular coordinate system, the stator magnetic linkage estimation vector magnitude ψ of β axle _SfComponent.

Further preferably, the computational methods of described (3) step are:

$W_{rf}=d{\mathrm{\θ}}_{\mathrm{\ψ}s}/dt$ ；

$T_{ef}=1.5*P({\mathrm{\ψ}}_{s\mathrm{\α}}*i_{s\mathrm{\β}}?{\mathrm{\ψ}}_{s\mathrm{\β}}*i_{s\mathrm{\α}})$ ；

In the formula, described t is the time, and P is the number of pole-pairs of motor, ψ _{S α}, ψ _{S β}Be respectively the α under the rectangular coordinate system, the stator magnetic linkage estimation vector magnitude ψ of β axle _SfComponent, i _{S α}, i _{S β}Be respectively the α under the rectangular coordinate system, the stator current i of β axle _sComponent.

Motor of the present invention can be induction machine, also can be permagnetic synchronous motor, or the other types motor.

Preferably, described motor is permagnetic synchronous motor, in open loop control starting, adopts stator magnetic linkage is carried out the closed loop control method realization to the starting of permagnetic synchronous motor.

Preferably, the step that described stator magnetic linkage carries out closed-loop control is: based on the stator magnetic linkage increment Delta ψ of estimation, and detect the stator resistance R that obtains _sWith stator current i _sCalculate the stator output voltage U at last _s

Further preferably, described stator output voltage U _sComputational methods be:

$U_{s\mathrm{\α}}^{}=\frac{\mathrm{\Δ}{\mathrm{\ψ}}_{s\mathrm{\α}}}{\mathrm{\Δ}T}+R_s{i}_{s\mathrm{\α}}$ ；

$U_{s\mathrm{\β}}^{}=\frac{\mathrm{\Δ}{\mathrm{\ψ}}_{s\mathrm{\β}}}{\mathrm{\Δ}T}+R_s{i}_{s\mathrm{\β}}$ ；

In the formula, described Δ T is the update cycle of stator output voltage, U _{S α}, U _{S β}Be respectively the α under the rectangular coordinate system, the stator output voltage U of β axle _sComponent, Δ ψ _{S α}, Δ ψ _{S β}Be respectively the α under the rectangular coordinate system, the stator magnetic linkage increment Delta ψ component of β axle, i _{S α}, i _{S β}Be respectively the α under the rectangular coordinate system, the stator current i of β axle _sComponent.

Preferably, the estimation steps of described stator magnetic linkage increment Delta ψ is: based on stator output voltage frequency f, stator magnetic linkage estimation azimuth , stator magnetic linkage estimation vector magnitude ψ _Sf, stator magnetic linkage vector magnitude set point

Calculate stator magnetic linkage increment Delta ψ.

Further preferably, the computational methods of described stator magnetic linkage increment Delta ψ are:

$\mathrm{\Δ}{\mathrm{\ψ}}_{s\mathrm{\α}}={\mathrm{\ψ}}_s^{*}\cos ({\mathrm{\θ}}_{{\mathrm{\ψ}}_s}^{}+\mathrm{\Δ}\mathrm{\θ})?{\mathrm{\ψ}}_{sf}\cos ({\mathrm{\θ}}_{{\mathrm{\ψ}}_s}^{})$ ；

$\mathrm{\Δ}{\mathrm{\ψ}}_{s\mathrm{\β}}={\mathrm{\ψ}}_s^{*}\sin ({\mathrm{\θ}}_{{\mathrm{\ψ}}_s}^{}+\mathrm{\Δ}\mathrm{\θ})?{\mathrm{\ψ}}_{sf}\sin ({\mathrm{\θ}}_{{\mathrm{\ψ}}_s}^{})$ ；

In the formula, described Δ θ is stator magnetic linkage vector angle increment, obtains Δ ψ after its stator output voltage frequency f that obtains based on detection calculates _{S α}, Δ ψ _{S β}Be respectively the α under the rectangular coordinate system, the stator magnetic linkage increment Delta ψ component of β axle.

Preferably, according to the stator output voltage U _sThe stator current i that obtains with detection _sEstimation stator magnetic linkage estimation vector magnitude ψ _SfWith stator magnetic linkage estimation azimuth

Further preferably, concrete estimation equation is:

${\mathrm{\ψ}}_{s\mathrm{\α}}={\displaystyle \∫U_{s\mathrm{\α}}?R_s}*i_{s\mathrm{\α}}$ ； ${\mathrm{\ψ}}_{s\mathrm{\β}}={\displaystyle \∫U_{s\mathrm{\β}}?R_s}*i_{s\mathrm{\β}}$ ；

${\mathrm{\ψ}}_{sf}=\sqrt{{\mathrm{\ψ}}_{s\mathrm{\α}}^2+{\mathrm{\ψ}}_{s\mathrm{\β}}^2}$ ； ${\mathrm{\θ}}_{{\mathrm{\ψ}}_s}=a\tan ({\mathrm{\ψ}}_{s\mathrm{\β}}/{\mathrm{\ψ}}_{s\mathrm{\α}})$ ；

In the formula, described U _{S α}, U _{S β}Be respectively the α under the rectangular coordinate system, the stator output voltage U of β axle _sComponent, R _sBe to detect the stator resistance that obtains, i _{S α}, i _{S β}Be respectively the α under the rectangular coordinate system, the stator current i of β axle _sComponent, ψ _{S α}, ψ _{S β}Be respectively the α under the rectangular coordinate system, the stator magnetic linkage estimation vector magnitude ψ of β axle _SfComponent.

Above-mentioned stator magnetic linkage estimation vector magnitude ψ _SfEvaluation method be the theoretical calculation method of stator magnetic linkage, because in the practical application, adopt problems such as traditional evaluation method ubiquity dc shift to cause estimating that the estimation precision of stator magnetic linkage is poor, in order to improve estimation precision, preferably, can adopt the estimation algorithm of the improvement low pass filter of band amplitude and phase compensation to realize, further preferably, can be referring to the applicant's patent application formerly, application number is CN201210277136.8.

Preferably, described stator magnetic linkage vector magnitude set point

According to detecting the maximum load moment T that obtains in advance _LoadmaxTheory calculates calculated value, and according to the voltage loss situation of eliminating power model this calculated value is carried out determining behind the correction-compensation.This be since in the practical application because factor affecting such as the conduction voltage drop of power model (as IPM module or IGBT etc.) self and switching times, theoretical output voltage and the actual output voltage of power model there are differences, output voltage amplitude is more little, error is more big, and this error will cause motor maximum load moment T _LoadmaxTheoretical value and the difference between the actual value, finally cause stator magnetic linkage vector magnitude set point

Calculated value and actual value produce difference, therefore need carry out correction-compensation to calculated value according to the voltage loss situation of eliminating power model.

Further preferably, described stator magnetic linkage vector magnitude set point

Theoretical calculation formula as follows:

${\mathrm{\ψ}}_s^{*}>=\frac{T_{load\max }*L_s}{3/2n_p*{\mathrm{\ψ}}_r}$ ；

In the formula, described T _LoadmaxBe maximum load moment, L _sBe stator inductance, n _pBe the number of pole-pairs of motor, ψ _rIt is rotor flux.

Preferably, the described step that stator magnetic linkage is carried out closed-loop control comprises initial frequency section and the frequency section of climbing, described initial frequency section refers in the zero-time section with constant initial frequency operation, the described frequency section of climbing be the time-to-climb accelerate to run to switching frequency by initial frequency in the section, switch to motor closed-loop control running status after arriving switching frequency, namely finish the open loop control starting of permagnetic synchronous motor.

Initial frequency of the present invention, switching frequency all refer to stator output voltage frequency or stator magnetic linkage frequency.Detection method or the computational methods of the parameter that is not specifically related to for the present invention, and the hardware that adopts and connecting circuit thereof are those skilled in the art's common practise and routine techniques means, neither essence inventive point of the present invention, therefore carry out literal no longer one by one and give unnecessary details.

The present invention also need to prove, the present invention adopts the stator magnetic linkage closed-loop control in motor open loop control starting process, and each other parameter of Electric Machine Control such as electromagnetic torque, spinner velocity etc. still adopt open loop control, therefore still belong to open loop control starting, and motor closed-loop control operation of the present invention comprises the closed-loop control of each parameter such as stator magnetic linkage, electromagnetic torque and spinner velocity, adopt stator magnetic linkage closed-loop control and motor closed-loop control operation when motor open loop control therefore of the present invention is started, both are fully inequality.

Operation principle of the present invention and advantage:

1, the present invention adopts no disturbance switching section at motor from the process that open loop control starting state switches to the closed-loop control running status, obtain each parameter estimation amount that motor closed-loop control running status is needed by no disturbance switching section, for motor is prepared to the closed-loop control running status from its open loop control starting state, and the corresponding control parameter of when switching, each parameter estimation amount being moved as the motor closed-loop control, switch to the no disturbance of closed-loop control running status from open loop control starting state with the realization motor, and guaranteed that motor is in the stability of switching moment control; Simultaneously since the impact when switching reduce, thereby can reduce the capacity of power model, and then reduced the cost of controller;

2, on above-mentioned the 1st basis, the changing method that the present invention adopts is simple, be very easy to realize, and the reliability height, be fit to large-scale promotion application aborning;

3, the present invention changes the voltage-frequency of prior art the closed-loop control of into employing stator magnetic linkage to realize the open loop control starting of permagnetic synchronous motor than open loop control, stator magnetic linkage is estimated immediately and controlled, the maximum output torque of guaranteeing permagnetic synchronous motor of the present invention is not influenced by the load size, effectively avoids the phenomenon of permagnetic synchronous motor step-out to take place;

4, the present invention changes the orientation control of prior art into initial frequency section control of the present invention, efficiently solves the starting dead unit problem that directed control exists in the prior art.

Description of drawings

Accompanying drawing 1 is the computing block diagram of present embodiment 3 described no transducer Direct Torque electric machine control systems;

Accompanying drawing 2 is computing block diagrams that stator magnetic linkage carried out closed-loop control of the present invention;

Accompanying drawing 3 is accompanying drawing 2 described control block diagram;

Reference numeral: stator magnetic linkage increment Delta ψ, Δ ψ _{S α}, Δ ψ _{S β}, stator resistance R _s, stator current i _s, i _{S α}, i _{S β}, the stator output voltage U _s, U _{S α}, U _{S β}, the stator output voltage update cycle Δ T, stator output voltage frequency f, stator magnetic linkage estimation azimuth , stator magnetic linkage estimation vector magnitude ψ _Sf, ψ _{S α}, ψ _{S β}, stator magnetic linkage vector magnitude set point

, stator magnetic linkage vector angle increment Delta θ, spinner velocity estimated value W _Rf, the rotor feedback speed

, electromagnetic torque estimated value T _Ef, the moment ring feedback moment

, moment ring output parameter θ, maximum load moment T _LoadmaxStator inductance L _s, the number of pole-pairs n of motor _p, rotor flux ψ _r, t time, zero-time section t1-t2, initial frequency f1, the time-to-climb section t2-t3, switching frequency f2, switching time section t3-t4, permagnetic synchronous motor PMSM.

Embodiment

Embodiment 1, referring to shown in Figure 1, a kind of changing method of position-sensor-free Direct Torque electric machine control system, wherein: in the handoff procedure of open loop control starting state and closed-loop control running status, increase no disturbance switching section, described no disturbance switching section refers to keep switching frequency f2 to move in switching time in the section t3-t4, obtain each parameter estimation amount that motor closed-loop control operation is needed, for motor is prepared to the closed-loop control running status from its open loop control starting state, and the corresponding control parameter of when switching, each parameter estimation amount being moved as the motor closed-loop control, switch to the no disturbance of closed-loop control running status from open loop control starting state to realize motor.

Embodiment 2, referring to shown in Figure 1, a kind of changing method of position-sensor-free Direct Torque electric machine control system, wherein: described each parameter estimation amount comprises stator magnetic linkage, electromagnetic torque and spinner velocity; The corresponding control parameter of described motor closed-loop control operation comprises the initial value of stator magnetic linkage vector magnitude set point, the initial value of speed ring integration item and the initial value of moment ring integration item, and all the other are with embodiment 1.

Embodiment 3, as shown in Figure 1, a kind of changing method of position-sensor-free Direct Torque electric machine control system, wherein: described motor is permagnetic synchronous motor PMSM, and the concrete steps of described no disturbance switching section are:

(1) described no disturbance switching section keeps switching frequency f2 operation in the section t3-t4 in switching time;

(2) according to the stator output voltage U _sThe stator current i that obtains with detection _sEstimation stator magnetic linkage estimation vector magnitude ψ _SfWith stator magnetic linkage estimation azimuth

(3) based on stator magnetic linkage estimation azimuth

Estimation spinner velocity estimated value W _Rf, and based on stator magnetic linkage estimation vector magnitude ψ _SfWith stator current i _sEstimation electromagnetic torque estimated value T _Ef

(4) when switching, with the spinner velocity estimated value W of moment before switching _RfRotor feedback speed as motor closed-loop control operation

, with the electromagnetic torque estimated value T of moment before switching _EfFeedback moment as the moment ring

, and this feedback moment value composed to speed ring integration item, as the initial value of speed ring integration item, the initial value of composing moment ring integration item is zero, even the initial value of moment ring output parameter θ is zero; Stator magnetic linkage is estimated vector magnitude ψ _SfAs stator magnetic linkage vector magnitude set point

Initial value;

The computational methods of described (2) step are:

${\mathrm{\ψ}}_{s\mathrm{\α}}={\displaystyle \∫U_{s\mathrm{\α}}?R_s}*i_{s\mathrm{\α}}$ ； ${\mathrm{\ψ}}_{s\mathrm{\β}}={\displaystyle \∫U_{s\mathrm{\β}}?R_s}*i_{s\mathrm{\β}}$ ；

${\mathrm{\ψ}}_{sf}=\sqrt{{\mathrm{\ψ}}_{s\mathrm{\α}}^2+{\mathrm{\ψ}}_{s\mathrm{\β}}^2}$ ； ${\mathrm{\θ}}_{{\mathrm{\ψ}}_s}=a\tan ({\mathrm{\ψ}}_{s\mathrm{\β}}/{\mathrm{\ψ}}_{s\mathrm{\α}})$ ；

In the formula, described U _{S α}, U _{S β}Be respectively the α under the rectangular coordinate system, the stator output voltage U of β axle _sComponent; R _sBe to detect the stator resistance that obtains, i _{S α}, i _{S β}Be respectively the α under the rectangular coordinate system, the stator current i of β axle _sComponent, ψ _{S α}, ψ _{S β}Be respectively the α under the rectangular coordinate system, the stator magnetic linkage estimation vector magnitude ψ of β axle _SfComponent;

The computational methods of described (3) step are:

$W_{rf}=d{\mathrm{\θ}}_{\mathrm{\ψ}s}/dt$ ；

$T_{ef}=1.5*P({\mathrm{\ψ}}_{s\mathrm{\α}}*i_{s\mathrm{\β}}?{\mathrm{\ψ}}_{s\mathrm{\β}}*i_{s\mathrm{\α}})$ ；

In the formula, described t is the time; P is the number of pole-pairs of motor, ψ _{S α}, ψ _{S β}Be respectively the α under the rectangular coordinate system, the stator magnetic linkage estimation vector magnitude ψ of β axle _SfComponent, i _{S α}, i _{S β}Be respectively the α under the rectangular coordinate system, the stator current i of β axle _sComponent, all the other are with embodiment 1 or embodiment 2.

Embodiment 4, referring to shown in Figure 2, a kind of changing method of position-sensor-free Direct Torque electric machine control system, wherein: described motor is permagnetic synchronous motor, in open loop control starting, employing is carried out the closed loop control method realization to the starting of permagnetic synchronous motor to stator magnetic linkage, and all the other are with embodiment 1 or embodiment 2 or embodiment 3.

Embodiment 5, as shown in Figure 2, a kind of changing method of position-sensor-free Direct Torque electric machine control system, wherein: the step that described stator magnetic linkage carries out closed-loop control is: based on the stator magnetic linkage increment Delta ψ of estimation, and detect the stator resistance R that obtains _sWith stator current i _sCalculate the stator output voltage U at last _s, described stator output voltage U _sComputational methods be:

$U_{s\mathrm{\α}}^{}=\frac{\mathrm{\Δ}{\mathrm{\ψ}}_{s\mathrm{\α}}}{\mathrm{\Δ}T}+R_s{i}_{s\mathrm{\α}}$ ；

$U_{s\mathrm{\β}}^{}=\frac{\mathrm{\Δ}{\mathrm{\ψ}}_{s\mathrm{\β}}}{\mathrm{\Δ}T}+R_s{i}_{s\mathrm{\β}}$ ；

In the formula, described Δ T is the update cycle of stator output voltage, U _{S α}, U _{S β}Be respectively the α under the rectangular coordinate system, the stator output voltage U of β axle _sComponent, Δ ψ _{S α}, Δ ψ _{S β}Be respectively the α under the rectangular coordinate system, the stator magnetic linkage increment Delta ψ component of β axle, i _{S α}, i _{S β}Be respectively the α under the rectangular coordinate system, the stator current i of β axle _sComponent, all the other are with embodiment 4.

The changing method of embodiment 6, a kind of position-sensor-free Direct Torque electric machine control system, wherein: the estimation steps of described stator magnetic linkage increment Delta ψ is: based on stator output voltage frequency f, stator magnetic linkage estimation azimuth , stator magnetic linkage estimation vector magnitude ψ _Sf, stator magnetic linkage vector magnitude set point

Calculate stator magnetic linkage increment Delta ψ, the computational methods of described stator magnetic linkage increment Delta ψ are:

$\mathrm{\Δ}{\mathrm{\ψ}}_{s\mathrm{\α}}={\mathrm{\ψ}}_s^{*}\cos ({\mathrm{\θ}}_{{\mathrm{\ψ}}_s}^{}+\mathrm{\Δ}\mathrm{\θ})?{\mathrm{\ψ}}_{sf}\cos ({\mathrm{\θ}}_{{\mathrm{\ψ}}_s}^{})$ ；

$\mathrm{\Δ}{\mathrm{\ψ}}_{s\mathrm{\β}}={\mathrm{\ψ}}_s^{*}\sin ({\mathrm{\θ}}_{{\mathrm{\ψ}}_s}^{}+\mathrm{\Δ}\mathrm{\θ})?{\mathrm{\ψ}}_{sf}\sin ({\mathrm{\θ}}_{{\mathrm{\ψ}}_s}^{})$ ；

In the formula, described Δ θ is stator magnetic linkage vector angle increment, obtains Δ ψ after its stator output voltage frequency f that obtains based on detection calculates _{S α}, Δ ψ _{S β}Be respectively the α under the rectangular coordinate system, the stator magnetic linkage increment Delta ψ component of β axle, all the other are with embodiment 5.

The changing method of embodiment 7, a kind of position-sensor-free Direct Torque electric machine control system, wherein: according to the stator output voltage U _sThe stator current i that obtains with detection _sEstimation stator magnetic linkage estimation vector magnitude ψ _SfWith stator magnetic linkage estimation azimuth

, concrete estimation equation is:

${\mathrm{\ψ}}_{s\mathrm{\α}}={\displaystyle \∫U_{s\mathrm{\α}}?R_s}*i_{s\mathrm{\α}}$ ； ${\mathrm{\ψ}}_{s\mathrm{\β}}={\displaystyle \∫U_{s\mathrm{\β}}?R_s}*i_{s\mathrm{\β}}$ ；

${\mathrm{\ψ}}_{sf}=\sqrt{{\mathrm{\ψ}}_{s\mathrm{\α}}^2+{\mathrm{\ψ}}_{s\mathrm{\β}}^2}$ ； ${\mathrm{\θ}}_{{\mathrm{\ψ}}_s}=a\tan ({\mathrm{\ψ}}_{s\mathrm{\β}}/{\mathrm{\ψ}}_{s\mathrm{\α}})$ ；

In the formula, described U _{S α}, U _{S β}Be respectively the α under the rectangular coordinate system, the stator output voltage U of β axle _sComponent, R _sBe to detect the stator resistance that obtains, i _{S α}, i _{S β}Be respectively the α under the rectangular coordinate system, the stator current i of β axle _sComponent, ψ _{S α}, ψ _{S β}Be respectively the α under the rectangular coordinate system, the stator magnetic linkage estimation vector magnitude ψ of β axle _SfComponent, all the other are with embodiment 6.

The changing method of embodiment 8, a kind of position-sensor-free Direct Torque electric machine control system, wherein: adopt the estimation algorithm of the improvement low pass filter of band amplitude and phase compensation to realize stator magnetic linkage estimation vector magnitude ψ _SfWith stator magnetic linkage estimation azimuth

Estimation, all the other are with embodiment 7.

The changing method of embodiment 9, a kind of position-sensor-free Direct Torque electric machine control system, wherein: described stator magnetic linkage vector magnitude set point

According to detecting the maximum load moment T that obtains in advance _LoadmaxTheory calculates calculated value, and according to the voltage loss situation of eliminating power model this calculated value is carried out determining behind the correction-compensation described stator magnetic linkage vector magnitude set point

Theoretical calculation formula as follows:

${\mathrm{\ψ}}_s^{*}>=\frac{T_{load\max }*L_s}{3/2n_p*{\mathrm{\ψ}}_r}$ ；

In the formula, described T _LoadmaxBe maximum load moment, L _sBe stator inductance, n _pBe the number of pole-pairs of motor, ψ _rBe rotor flux, all the other are with embodiment 6 or embodiment 7 or embodiment 8.

Embodiment 10, as shown in Figure 3, a kind of changing method of position-sensor-free Direct Torque electric machine control system, wherein: the described step that stator magnetic linkage is carried out closed-loop control comprises initial frequency section t1-t2 and the frequency section of climbing t2-t3, described initial frequency section refers in zero-time section t1-t2 with constant initial frequency f1 operation, the described frequency section of climbing be the time-to-climb accelerate to run to switching frequency f2 by initial frequency f1 in the section t2-t3, switch to motor closed-loop control running status after arriving switching frequency f2, namely finish the open loop control starting of permagnetic synchronous motor, all the other are with any one embodiment among the embodiment 4-9.

The various parameter estimations of the embodiment of the invention or computational methods all can be by combination corresponding hardware controls as shown in Figure 1, wait (each corresponding PI controller generally comprises ratio and regulates item and integration item) of specific implementation as PI controller, speed ring PI controller and moment ring PI controller, and concrete computational methods and the replacement method thereof of motor closed-loop control shown in Figure 1 operation, believe that these specific implementations and computational methods are those skilled in the art's common practise, carry out literal no longer one by one at this and give unnecessary details.

The above only is preferred implementation of the present invention; should be understood that; for the person of ordinary skill of the art; under the prerequisite that does not break away from the principle of the invention; as each concrete estimation parameter is selected; and concrete computational methods, estimation steps and coordinate system etc. make and are equal to improved properties or replacement, these improvement and replace and also should be considered as protection scope of the present invention.

Claims (11)

1. the changing method of a position-sensor-free Direct Torque electric machine control system, it is characterized in that: in the handoff procedure of open loop control starting state and closed-loop control running status, increase no disturbance switching section, described no disturbance switching section refers to keep switching frequency (f2) operation in section switching time (t3-t4), obtain each parameter estimation amount that motor closed-loop control operation is needed, for motor is prepared to the closed-loop control running status from its open loop control starting state, and the corresponding control parameter of when switching, each parameter estimation amount being moved as the motor closed-loop control, switch to the no disturbance of closed-loop control running status from open loop control starting state to realize motor.

2. the changing method of position-sensor-free Direct Torque electric machine control system as claimed in claim 1, it is characterized in that: described each parameter estimation amount comprises stator magnetic linkage, electromagnetic torque and spinner velocity; The corresponding control parameter of described motor closed-loop control operation comprises the initial value of stator magnetic linkage vector magnitude set point, the initial value of speed ring integration item and the initial value of moment ring integration item.

3. the changing method of position-sensor-free Direct Torque electric machine control system as claimed in claim 1 or 2, it is characterized in that: the concrete steps of described no disturbance switching section are:

(1) described no disturbance switching section keeps switching frequency (f2) operation in section switching time (t3-t4);

(2) according to stator output voltage (U _s) and detect the stator current (i that obtains _s) estimation stator magnetic linkage estimation vector magnitude (ψ _Sf) and stator magnetic linkage estimation azimuth (

);

(3) based on stator magnetic linkage estimation azimuth (

) estimation spinner velocity estimated value (W _Rf), and based on stator magnetic linkage estimation vector magnitude (ψ _Sf) and stator current (i _s) estimation electromagnetic torque estimated value (T _Ef);

(4) when switching, with the spinner velocity estimated value (W of moment before switching _Rf) as the rotor feedback speed of motor closed-loop control operation (

), with the electromagnetic torque estimated value (T of moment before switching _Ef) as the feedback moment of moment ring ( ), and this feedback moment value composed to speed ring integration item, as the initial value of speed ring integration item, the initial value of composing moment ring integration item is zero; Stator magnetic linkage is estimated vector magnitude (ψ _Sf) as stator magnetic linkage vector magnitude set point (

) initial value.

4. the changing method of position-sensor-free Direct Torque electric machine control system as claimed in claim 3, it is characterized in that: the computational methods of described (2) step are:

${\mathrm{\ψ}}_{s\mathrm{\α}}={\displaystyle \∫U_{s\mathrm{\α}}?R_s}*i_{s\mathrm{\α}}$ ； ${\mathrm{\ψ}}_{s\mathrm{\β}}={\displaystyle \∫U_{s\mathrm{\β}}?R_s}*i_{s\mathrm{\β}}$ ；

${\mathrm{\ψ}}_{sf}=\sqrt{{\mathrm{\ψ}}_{s\mathrm{\α}}^2+{\mathrm{\ψ}}_{s\mathrm{\β}}^2}$ ； ${\mathrm{\θ}}_{{\mathrm{\ψ}}_s}=a\tan ({\mathrm{\ψ}}_{s\mathrm{\β}}/{\mathrm{\ψ}}_{s\mathrm{\α}})$ ；

In the formula, described U _{S α}, U _{S β}Be respectively the α under the rectangular coordinate system, the stator output voltage U of β axle _sComponent, R _sBe to detect the stator resistance that obtains, i _{S α}, i _{S β}Be respectively the α under the rectangular coordinate system, the stator current i of β axle _sComponent, ψ _{S α}, ψ _{S β}Be respectively the α under the rectangular coordinate system, the stator magnetic linkage estimation vector magnitude ψ of β axle _SfComponent.

5. the changing method of position-sensor-free Direct Torque electric machine control system as claimed in claim 3, it is characterized in that: the computational methods of described (3) step are:

$W_{rf}=d{\mathrm{\θ}}_{\mathrm{\ψ}s}/dt$ ；

$T_{ef}=1.5*P({\mathrm{\ψ}}_{s\mathrm{\α}}*i_{s\mathrm{\β}}?{\mathrm{\ψ}}_{s\mathrm{\β}}*i_{s\mathrm{\α}})$ ；

In the formula, described t is the time, and P is the number of pole-pairs of motor, ψ _{S α}, ψ _{S β}Be respectively the α under the rectangular coordinate system, the stator magnetic linkage estimation vector magnitude ψ of β axle _SfComponent, i _{S α}, i _{S β}Be respectively the α under the rectangular coordinate system, the stator current i of β axle _sComponent.

6. as claim 1 or 2 or the changing method of 3 or 4 or 5 described position-sensor-free Direct Torque electric machine control systems, it is characterized in that: described motor is permagnetic synchronous motor, in open loop control starting, adopt stator magnetic linkage is carried out the closed loop control method realization to the starting of permagnetic synchronous motor.

7. the changing method of position-sensor-free Direct Torque electric machine control system as claimed in claim 6, it is characterized in that: the step that described stator magnetic linkage carries out closed-loop control is: based on the stator magnetic linkage increment (Δ ψ) of estimation, and detect the stator resistance (R that obtains _s) and stator current (i _s) calculate stator output voltage (U at last _s).

8. the changing method of position-sensor-free Direct Torque electric machine control system as claimed in claim 7, it is characterized in that: the estimation steps of described stator magnetic linkage increment (Δ ψ) is: based on stator output voltage frequency (f), stator magnetic linkage estimation azimuth (

), stator magnetic linkage estimation vector magnitude (ψ _Sf), stator magnetic linkage vector magnitude set point (

) calculate stator magnetic linkage increment (Δ ψ).

9. the changing method of position-sensor-free Direct Torque electric machine control system as claimed in claim 8 is characterized in that: according to stator output voltage (U _s) and detect the stator current (i that obtains _s) estimation stator magnetic linkage estimation vector magnitude (ψ _Sf) and stator magnetic linkage estimation azimuth (

).

10. the changing method of position-sensor-free Direct Torque electric machine control system as claimed in claim 8 is characterized in that: described stator magnetic linkage vector magnitude set point (

) according to detecting the maximum load moment (T that obtains in advance _Loadmax) theory calculates calculated value, and according to the voltage loss situation of eliminating power model this calculated value is carried out determining behind the correction-compensation.

11. as claim 6 or 7 or the changing method of 8 or 9 or 10 described position-sensor-free Direct Torque electric machine control systems, it is characterized in that: the described step that stator magnetic linkage is carried out closed-loop control comprises initial frequency section (t1-t2) and the frequency section of climbing (t2-t3), described initial frequency section refers to move with constant initial frequency (f1) in zero-time section (t1-t2), the described frequency section of climbing be the time-to-climb accelerate to run to switching frequency (f2) by initial frequency (f1) in section (t2-t3), switch to motor closed-loop control running status after arriving switching frequency (f2), namely finish the open loop control starting of permagnetic synchronous motor.

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