CN103872951B - Permanent magnet synchronous motor torque control method based on sliding mode flux linkage observer - Google Patents

Abstract

The invention discloses a permanent synchronization motor torque control method based on a sliding mode flux linkage observer. Direct torque control is performed on a permanent synchronization motor through a 3/2 coordinate conversion module, the sliding mode flux linkage observer, an electromagnetic torque calculation module, a rotating speed PI adjustor, a torque PI adjustor, a flux linkage self-adaptation module, an expected voltage calculation module, an SVPWM module and an inverter. The sliding mode flux linkage observer is adopted for estimating the size, phase and rotator speed of stator flux linkage, and set torque is processed through the flux linkage self-adaptation module to obtain a set value of the stator flux linkage. Expected voltage calculation is performed on size and phase estimation values and the set value of the stator flux linkage and the output quantity of the torque PI adjustor, so that two-phase alternating-current voltage reference values on a two-phase static coordinate system are obtained, and then through SVPWM conversion, a switching signal is obtained to drive the voltage source inverter to achieve direct torque control over the permanent synchronization motor.

Description

Permagnetic synchronous motor method for controlling torque based on Sliding-Mode Flux Observer of AC

Technical field

The invention belongs to magneto control field, more particularly to a kind of permanent magnet synchronous electric based on Sliding-Mode Flux Observer of AC Machine moment controlling system.

Background technology

Permagnetic synchronous motor has the advantages that small volume, efficiency high, is easy to safeguard and strong to environmental suitability, in many High-grade drives are widely used in field.Direct Torque Control has that torque response is fast, system architecture is simple and right The advantages of Parameters variation strong robustness and the extremely concern of people.Need to obtain fixed in permagnetic synchronous motor Direct Torque Control Sub- magnetic linkage, and whether magnetic linkage signal accurately decides the control performance of system.Therefore, it is straight for high performance permagnetic synchronous motor Torque Control Drive System is connect, how stator magnetic linkage is accurately observed particularly important.In traditional Direct Torque Control, typically adopt With voltage model or current model calculating stator magnetic linkage.However, in voltage model, due to being to stator winding back-emf Integration, when motor low cruise, stator flux estimation precision degradation, the system of even resulting in can not work；In current-mode In type, need to know rotor-position, increased extra position sensor, this will increase the cost of control system, reduce system Reliability, while can also limit the use occasion of permagnetic synchronous motor.In addition, traditional stagnant chain rate compared with direct control in, Also there is torque and magnetic linkage pulsation be big, the shortcomings of switching frequency is not fixed, also, motor operation introduce when zero load it is idle Electric current, so as to cause motor power factor to decline.Therefore, to solve the above problems, it is necessary to improving switching frequency and reduction When unloaded on the premise of direct-axis current, a kind of new Flux Observation Method is proposed, to improve permagnetic synchronous motor Direct torque The dynamic and static state performance of system processed, reliability, robustness and antijamming capability.

The content of the invention

Technical problem：For the deficiency that above-mentioned prior art is present, there is provided a kind of permanent magnetism based on Sliding-Mode Flux Observer of AC Synchronous electric machine torque control method, when improving switching frequency and reducing unloaded on the premise of direct-axis current, improves permanent-magnet synchronous Motor Direct Torque Control robustness and antijamming capability.

Technical scheme：Based on the permagnetic synchronous motor method for controlling torque of Sliding-Mode Flux Observer of AC, by 3/2 coordinate transform Module, Sliding-Mode Flux Observer of AC, electromagnetic torque computing module, rotating speed pi regulator, PI torque controller, magnetic linkage adaptive mode Block, expection voltage computing module, SVPWM modules and inverter carry out Direct Torque Control to permagnetic synchronous motor, including as follows Concrete steps：

Step 1), detect the three-phase current i of permagnetic synchronous motor_a、i_b、i_cWith three-phase voltage u_a、u_b、u_c, the change of the coordinates of Jing 3/2 The current component i under the static exchange coordinate of two-phase is obtained after changing_α、i_βWith component of voltage u_α、u_β, then by the current component i_α、 i_βWith component of voltage u_α、u_βDeliver to Sliding-Mode Flux Observer of AC, and by current component i_α、i_βDeliver to electromagnetic torque computing module；

Step 2), according to the current component i_α、i_βWith component of voltage u_α、u_β, the Sliding-Mode Flux Observer of AC module estimation Stator magnetic linkage magnitude estimation valueWith stator magnetic linkage phase estimation valueAnd spinner velocity estimated value

Step 3), by given rotating speed ω^*With the spinner velocity estimated valueAfter making difference, obtain Jing after rotating speed pi regulator Given torque Te^*；

Step 4), according to the stator magnetic linkage magnitude estimation valueAnd the current component i_α、i_β, the electricity Magnetic Torque Calculation of Magnetic module obtains actual motor torque Te；

Step 5), the given torque Te^*Jing magnetic linkage adaptation modules obtain stator flux linkage set value ψ_sref；

Step 6), by the given torque Te^*Make after difference with the actual motor torque Te, Jing after PI torque controller To output quantity Δ δ；

Step 7), the output quantity Δ δ, stator flux linkage set value ψ_s.ref, stator magnetic linkage magnitude estimation valueWith And stator magnetic linkage phase estimation valueJing expection voltage computing modules, obtain the two-phase alternating current pressure ginseng in two-phase rest frame Examine value

Step 8), according to stator magnetic linkage vector position and two-phase alternating current pressure reference valueFrom switch shape After corresponding space voltage vector is selected in state table, SVPWM modules described in Jing export modulated signal to inverter, by described inverse Become the Direct Torque Control that device realizes permagnetic synchronous motor.

As the preferred version of the present invention, the step 2) comprise the following specific steps that：

Step 2.1), according to the current component i_α、i_βWith component of voltage u_α、u_β, build sliding mode observer and obtain motor Counter electromotive force e_α、e_β；

Step 2.2), according to the counter electromotive force e_α、e_β, rotor estimated position is obtained by rotor-position computing module

Step 2.3), according to the rotor estimated positionCurrent stator magnetic linkage arrow is obtained by stator flux estimation module Amount ψ_α、ψ_β；

Step 2.4), according to the current stator magnetic linkage vector ψ_α、ψ_β, stator magnetic linkage size is obtained by flux observer Estimated valueAnd spinner velocity estimated value

Step 2.5), according to the stator magnetic linkage magnitude estimation valueDetermined by magnetic linkage position computation module Sub- magnetic linkage phase estimation value

As the present invention improvement, step 2.1) described in sliding mode observer structure changes function be sigmoid functions.

Beneficial effect：The present invention estimates stator magnetic linkage and rotor-position with sliding mode control algorithm, can be accurately real-time Control stator magnetic linkage, and realize based on the permagnetic synchronous motor Direct Torque Control of position Sensorless Control, with as follows Beneficial effect：

(1) this method combines SVPWM technologies and magnetic linkage adaptive method, therefore can reduce torque and magnetic in Direct Torque Control Chain is pulsed, and switching frequency is greatly improved, to improve current waveform, while d-axis electricity when also reducing empty load of motor or shock load Flow component, so as to reduce the loss of electric machine, improves electric efficiency；

(2) Sliding-Mode Flux Observer of AC estimation stator magnetic linkage and spinner velocity are constructed, stator magnetic linkage estimates when improve low speed Precision is calculated, so as to improve system low-speed performance, while position sensor is eliminated, so as to reduce the cost of control system, The reliability of system is improve, system architecture is simplified；

(3) first magnetic linkage adaptive method, Sliding-Mode Flux Observer of AC and SVPWM triplicitys to be applied to into permanent magnetism same for this method In step motor direct Torque Control, control system is set not only to retain the good dynamic and static state performance in sliding formwork control, anti-interference Ability and robustness, have also widened the range of operation of system；

(4) method therefor amount of calculation is little, it is easy to accomplish, be conducive to the engineering of new theory and practical.

Description of the drawings

Fig. 1 is structured flowchart of the present invention based on the torsion control system of synchronization generator with everlasting magnetic of Sliding-Mode Flux Observer of AC；

Fig. 2 is Sliding-Mode Flux Observer of AC theory structure block diagram.

Specific embodiment

Technical scheme is described in further detail with reference to Fig. 1, Fig. 2.

As shown in figure 1, torsion control system of synchronization generator with everlasting magnetic of the present invention based on Sliding-Mode Flux Observer of AC includes permanent magnetism Synchronous motor, 3/2 coordinate transform, Sliding-Mode Flux Observer of AC, electromagnetic torque calculating, rotating speed pi regulator, PI torque controller, magnetic Chain self adaptation, expection voltage calculating, SVPWM modules and inverter.

Specific implementation step of the present invention based on the permagnetic synchronous motor method for controlling torque of Sliding-Mode Flux Observer of AC is as follows：

Step 1), detect the three-phase current i of permagnetic synchronous motor_a、i_b、i_cWith three-phase voltage u_a、u_b、u_c, the change of the coordinates of Jing 3/2 The current component i under the static exchange coordinate of two-phase is obtained after changing_α、i_βWith component of voltage u_α、u_β, then by current component i_α、i_βWith Component of voltage u_α、u_βDeliver to Sliding-Mode Flux Observer of AC, and by current component i_α、i_βDeliver to electromagnetic torque computing module；

Step 2), according to current component i_α、i_βWith component of voltage u_α、u_β, with Sliding-Mode Flux Observer of AC module stator is estimated Magnetic linkage magnitude estimation valueWith stator magnetic linkage phase estimation valueAnd spinner velocity estimated valueIts theory diagram is such as Shown in Fig. 2, specific algorithm is as follows：

Step 2.1), according to current component i_α、i_βWith component of voltage u_α、u_β, build the anti-electricity that sliding mode observer obtains motor Kinetic potential e_α、e_β；Wherein, sliding formwork current observer is constructed, it is specific as follows：

Permagnetic synchronous motor Mathematical Modeling is expressed as under α β coordinate systems：

Wherein, L_sFor the synchronous inductance of motor；ψ_fFor permanent magnet flux linkage；ω is rotor angular rate；R_sFor stator electricity Resistance；e_αAnd e_βFor the α of winding back emf, beta -axis component；

According to sliding mode control theory, when system is slided on sliding-mode surface, have：

Wherein,For electric current estimated value；i_s=[i_αi_β]^TFor current actual value；

To reduce system chatter, the switch function of traditional sliding moding structure is replaced using sigmoid functions, become as sliding formwork Structure function, then：

Wherein, k is sliding formwork coefficient；H is sigmoid functions；WithTo estimate α, the beta -axis component of stator current；

Define structure changes function as follows：

Wherein, S is the difference for estimating electric current and actual current；A is the real number more than zero, can be adjusted according to actual conditions；

Formula (3) is subtracted each other with formula (1), the dynamical equation of sliding mode observer is obtained：

Wherein, S_αAnd S (X)_β(X) be the difference for estimating electric current and actual current α, beta -axis component；

According to the existence and stability condition of sliding formwork motion, the premise that the rotor-position of motor can be estimated smoothly is must Must meet：

Then：

K ＞ max (| e_α|, | e_β|) (6)

Therefore, k takes sufficiently large, it is ensured that the asymptotic stability of sliding formwork motion, when system reaches sliding-mode surface, has：

Above formula is substituted into into formula (5) can obtain the counter electromotive force e of motor_α、e_β：

Step 2.2), according to counter electromotive force e_α、e_β, the rotor estimated position of motor is obtained by rotor-position computing module For：

Step 2.3), according to rotor estimated positionAnd with reference to current component i under two-phase rest frame_αAnd i_β, by fixed Sub- flux estimate algorithm module primary Calculation obtains current stator magnetic linkage vector ψ_α、ψ_β：

Due to step 2.1) in contain high fdrequency component, therefore the stator magnet for estimating in the sliding formwork current observer that constructed Chain also contains high fdrequency component, needs to be filtered using low pass filter, but the use of low pass filter can bring phase delay, The precision of flux estimate algorithm is affected, is the estimation precision for improving magnetic linkage, the present invention constructs a kind of new flux observer；

Step 2.4), according to current stator magnetic linkage vector ψ_α、ψ_β, stator magnetic linkage magnitude estimation is obtained by flux observer ValueAnd spinner velocity estimated valueComprise the following steps that：

Construction flux observer, to improve the estimation precision of magnetic linkage, and using Lyapunov quantitative analysis flux observers Stability, it is specific as follows：

To formula (10) derivation, can obtain：

Wherein, ω is rotor angular rate；

According to above formula, flux observer can be constructed：

Wherein, l is flux observer gain, and its value is more than zero；It is estimation magnetic linkage dividing in α β coordinate systems Amount；Angular rate is estimated for rotor；

Formula (7) is substituted in formula (12), can be obtained：

Formula (13) is poor with formula (11), and the error equation for obtaining flux observer is：

Wherein, ω is rotor angular rate；L is flux observer gain, and its value is more than zero；For estimation Component of the magnetic linkage in α β coordinate systems；Angular rate is estimated for rotor；

Using the stability of Lyapunov theorem proving flux observers, have：

Formula (15) derivation is had：

Formula (14) is substituted into into formula (16) to arrange and can obtain：

By formula (17) as can be seen that the flux observer is asymptotically stable, therefore, it is fixed to be calculated according to formula (14) Sub- flux estimate algorithm valueWith turn count value

Step 2.5), according to stator magnetic linkage magnitude estimation valueStator magnet is obtained by magnetic linkage position computation module Chain phase estimation value

Step 3), by given rotating speed ω^*With spinner velocity estimated valueAfter making difference, given Jing after rotating speed pi regulator Torque Te^*；

Step 4), according to stator magnetic linkage magnitude estimation valueAnd the current component i under two-phase static coordinate_α、i_β, Jing electromagnetic torque computing modules obtain actual motor torque Te, specific as follows：

Wherein, p₀For the number of pole-pairs of motor；

Step 5), give torque Te^*Jing magnetic linkage adaptation modules obtain stator flux linkage set value ψ_s.ref, it is specific as follows：

Permanent-magnetic synchronous motor stator magnetic linkage ac-dc axis component ψ_sq、ψ_sdFor：

Wherein, L_dAnd L_qFor the dq axle components of stator inductance, i_dAnd i_qFor the dq axle components of stator current；

Relation between motor torque and stator magnetic linkage component is as follows：

Wherein, ψ_sFor stator magnetic linkage, δ is power angle；

In formula (20), i is made_d=0, in conjunction with formula (21), reference value ψ of stator flux linkage set can be obtained_srefFor：

Step 6), by given torque Te^*Make after difference, to obtain defeated Jing after PI torque controller with the actual motor torque Te Output Δ δ；

Step 7), output quantity Δ δ, stator flux linkage set value ψ_s.ref, stator magnetic linkage magnitude estimation valueAnd it is fixed Sub- magnetic linkage phase estimation valueJing expection voltage computing modules, obtain the two-phase alternating current pressure reference value in two-phase rest frame

Step 8), according to stator magnetic linkage vector position and two-phase alternating current pressure reference valueFrom switch shape After corresponding space voltage vector is selected in state table, Jing SVPWM modules export modulated signal to inverter, are realized by inverter The Direct Torque Control of permagnetic synchronous motor.

In the present invention, the estimation of stator magnetic linkage vector and spinner velocity adopt Sliding-Mode Flux Observer of AC, not only with cunning Modulo n arithmetic is simple, strong robustness the advantages of, and, relative to traditional voltage model, the estimation precision of stator magnetic linkage during low speed Greatly improve, improve motor low cruise performance；Relative to traditional current model, without the need for extra position sensor, control System cost processed is reduced, and the reliability of system is improved；Stator flux linkage set value is obtained by magnetic linkage adaptive method, its value is according to load Size and change, therefore, reduce direct-axis current of the motor operation when heavy duty of unloaded or impact, improve electric efficiency. It is of the invention real-time monitored and control stator magnetic linkage and magnetic linkage adaptive method and SVPWM technologies to be combined, can effectively reduce torque with Magnetic linkage is pulsed, and improves switching frequency and electric efficiency, widens the range of operation of system, meanwhile, also with good sound state property Energy, reliability, robustness and antijamming capability.

The above is only the preferred embodiment of the present invention, it is noted that for the ordinary skill people of the art For member, under the premise without departing from the principles of the invention, some improvements and modifications can also be made, these improvements and modifications also should It is considered as protection scope of the present invention.

Claims (2)

1. the permagnetic synchronous motor method for controlling torque of Sliding-Mode Flux Observer of AC is based on, it is characterised in that：By 3/2 coordinate transform Module, Sliding-Mode Flux Observer of AC, electromagnetic torque computing module, rotating speed pi regulator, PI torque controller, magnetic linkage adaptive mode Block, expection voltage computing module, SVPWM modules and inverter carry out Direct Torque Control to permagnetic synchronous motor, including as follows Concrete steps：

Step 1), detect the three-phase current i of permagnetic synchronous motor_a、i_b、i_cWith three-phase voltage u_a、u_b、u_c, Jing after 3/2 coordinate transform Obtain the current component i under the static exchange coordinate of two-phase_α、i_βWith component of voltage u_α、u_β, then by the current component i_α、i_βWith Component of voltage u_α、u_βDeliver to Sliding-Mode Flux Observer of AC, and by current component i_α、i_βDeliver to electromagnetic torque computing module；

Step 2), according to the current component i_α、i_βWith component of voltage u_α、u_β, the Sliding-Mode Flux Observer of AC module estimation stator Magnetic linkage magnitude estimation valueWith stator magnetic linkage phase estimation valueAnd spinner velocity estimated valueIncluding following concrete Step：

Step 2.1), according to the current component i_α、i_βWith component of voltage u_α、u_β, build the anti-electricity that sliding mode observer obtains motor Kinetic potential e_α、e_β；

Step 2.2), according to the counter electromotive force e_α、e_β, rotor estimated position is obtained by rotor-position computing moduleStep 2.3), according to the rotor estimated positionCurrent stator magnetic linkage vector ψ is obtained by stator flux estimation module_α、ψ_β；

Step 2.4), according to the current stator magnetic linkage vector ψ_α、ψ_β, stator magnetic linkage magnitude estimation is obtained by flux observer ValueAnd spinner velocity estimated valueComprise the following steps that：

Flux linkage equations derivation to permagnetic synchronous motor, can obtain：

$\left\{\begin{array}{c}\frac{{\mathrm{d\ψ}}_{\mathrm{\α}}}{dt}=L_s\frac{{\mathrm{di}}_{\mathrm{\α}}}{dt}-{\mathrm{\ω\ψ}}_{\mathrm{\β}}+{\mathrm{\ωL}}_s{i}_{\mathrm{\β}}\\ \frac{{\mathrm{d\ψ}}_{\mathrm{\β}}}{dt}=L_s\frac{{\mathrm{di}}_{\mathrm{\β}}}{dt}+{\mathrm{\ω\ψ}}_{\mathrm{\α}}-{\mathrm{\ωL}}_s{i}_{\mathrm{\α}}\end{array}\right.---\left(11\right)$

Wherein, L_sFor the synchronous inductance of motor；ω is rotor angular rate；

According to above formula, flux observer can be constructed：

$\left\{\begin{array}{c}\frac{d{\widehat{\mathrm{\ψ}}}_{\mathrm{\α}}}{dt}=L_s\frac{d{\hat{i}}_{\mathrm{\α}}}{dt}-\widehat{\mathrm{\ω}}{\widehat{\mathrm{\ψ}}}_{\mathrm{\β}}+\widehat{\mathrm{\ω}}{L}_s{\hat{i}}_{\mathrm{\α}}-k({\hat{i}}_{\mathrm{\α}}-i_{\mathrm{\α}})-l({\widehat{\mathrm{\ψ}}}_{\mathrm{\α}}-{\mathrm{\ψ}}_{\mathrm{\α}})\\ \frac{d{\widehat{\mathrm{\ψ}}}_{\mathrm{\β}}}{dt}=L_s\frac{d{\hat{i}}_{\mathrm{\β}}}{dt}+\widehat{\mathrm{\ω}}{\widehat{\mathrm{\ψ}}}_{\mathrm{\α}}-\widehat{\mathrm{\ω}}{L}_s{\hat{i}}_{\mathrm{\β}}-k({\hat{i}}_{\mathrm{\β}}-i_{\mathrm{\β}})-l({\widehat{\mathrm{\ψ}}}_{\mathrm{\β}}-{\mathrm{\ψ}}_{\mathrm{\β}})\\ \frac{d\widehat{\mathrm{\ω}}}{dt}=({\hat{i}}_{\mathrm{\α}}-i_{\mathrm{\α}}){\hat{i}}_{\mathrm{\β}}-({\hat{i}}_{\mathrm{\β}}-i_{\mathrm{\β}}){\hat{i}}_{\mathrm{\α}}+({\widehat{\mathrm{\ψ}}}_{\mathrm{\α}}-{\mathrm{\ψ}}_{\mathrm{\α}}){\widehat{\mathrm{\ψ}}}_{\mathrm{\β}}-({\widehat{\mathrm{\ψ}}}_{\mathrm{\β}}-{\mathrm{\ψ}}_{\mathrm{\β}}){\widehat{\mathrm{\ψ}}}_{\mathrm{\α}}\end{array}\right.---\left(12\right)$

Wherein, l is flux observer gain, and its value is more than zero；K is sliding formwork coefficient；WithTo estimate α, β axle of stator current Component；

When system reaches sliding-mode surface, can obtain：

$\left\{\begin{array}{c}\frac{d{\widehat{\mathrm{\ψ}}}_{\mathrm{\α}}}{dt}=L_s\frac{d{\hat{i}}_{\mathrm{\α}}}{dt}-\widehat{\mathrm{\ω}}{\widehat{\mathrm{\ψ}}}_{\mathrm{\β}}+\widehat{\mathrm{\ω}}{L}_s{\hat{i}}_{\mathrm{\α}}-l({\widehat{\mathrm{\ψ}}}_{\mathrm{\α}}-{\mathrm{\ψ}}_{\mathrm{\α}})\\ \frac{d{\widehat{\mathrm{\ψ}}}_{\mathrm{\β}}}{dt}=L_s\frac{d{\hat{i}}_{\mathrm{\β}}}{dt}+\widehat{\mathrm{\ω}}{\widehat{\mathrm{\ψ}}}_{\mathrm{\α}}-\widehat{\mathrm{\ω}}{L}_s{\hat{i}}_{\mathrm{\β}}-l({\widehat{\mathrm{\ψ}}}_{\mathrm{\β}}-{\mathrm{\ψ}}_{\mathrm{\β}})\\ \frac{d\widehat{\mathrm{\ω}}}{dt}=({\widehat{\mathrm{\ψ}}}_{\mathrm{\α}}-{\mathrm{\ψ}}_{\mathrm{\α}}){\widehat{\mathrm{\ψ}}}_{\mathrm{\β}}-({\widehat{\mathrm{\ψ}}}_{\mathrm{\β}}-{\mathrm{\ψ}}_{\mathrm{\β}}){\widehat{\mathrm{\ψ}}}_{\mathrm{\α}}\end{array}\right.---\left(13\right)$

Formula (13) is poor with formula (11), and the error equation for obtaining flux observer is：

$\left\{\begin{array}{c}\frac{d{\widetilde{\mathrm{\ψ}}}_{\mathrm{\α}}}{dt}=-\widetilde{\mathrm{\ω}}{\widehat{\mathrm{\ψ}}}_{\mathrm{\β}}+\widehat{\mathrm{\ω}}{\widetilde{\mathrm{\ψ}}}_{\mathrm{\β}}-l{\widetilde{\mathrm{\ψ}}}_{\mathrm{\α}}\\ \frac{d{\widetilde{\mathrm{\ψ}}}_{\mathrm{\β}}}{dt}=-\widetilde{\mathrm{\ω}}{\widehat{\mathrm{\ψ}}}_{\mathrm{\α}}+\widehat{\mathrm{\ω}}{\widetilde{\mathrm{\ψ}}}_{\mathrm{\α}}-l{\widetilde{\mathrm{\ψ}}}_{\mathrm{\β}}\\ \frac{d\widehat{\mathrm{\ω}}}{dt}={\widetilde{\mathrm{\ψ}}}_{\mathrm{\α}}{\widehat{\mathrm{\ψ}}}_{\mathrm{\β}}-{\widetilde{\mathrm{\ψ}}}_{\mathrm{\β}}{\widehat{\mathrm{\ψ}}}_{\mathrm{\α}}\end{array}\right.---\left(14\right)$

Wherein, ω is rotor angular rate；L is flux observer gain, and its value is more than zero；

Stator magnetic linkage magnitude estimation value can be calculated according to formula (14)With rotor speed estimated value

Step 2.5), according to the stator magnetic linkage magnitude estimation valueStator magnet is obtained by magnetic linkage position computation module Chain phase estimation value

Step 3), by given rotating speed ω^*With the spinner velocity estimated valueAfter making difference, given Jing after rotating speed pi regulator Torque Te^*；

Step 4), according to the stator magnetic linkage magnitude estimation valueAnd the current component i_α、i_β, the electromagnetism turn Square computing module obtains actual motor torque Te；

Step 5), the given torque Te^*Jing magnetic linkage adaptation modules obtain stator flux linkage set value ψ_sref；

Step 6), by the given torque Te^*Make after difference, to obtain defeated Jing after PI torque controller with the actual motor torque Te Output △ δ；

Step 7), the output quantity △ δ, stator flux linkage set value ψ_sref, stator magnetic linkage magnitude estimation valueAnd stator Magnetic linkage phase estimation valueJing expection voltage computing modules, obtain the two-phase alternating current pressure reference value in two-phase rest frame

Step 8), according to stator magnetic linkage vector position and two-phase alternating current pressure reference valueFrom on off state table Middle to select after corresponding space voltage vector, SVPWM modules described in Jing export modulated signal to inverter, by the inverter Realize the Direct Torque Control of permagnetic synchronous motor.

2. the permagnetic synchronous motor method for controlling torque based on Sliding-Mode Flux Observer of AC according to claim 1, its feature It is：Step 2.1) described in sliding mode observer structure changes function be sigmoid functions.