CN106059419A - Permanent magnet synchronous motor parallel vector control scheme - Google Patents

Abstract

The invention discloses a permanent magnet synchronous motor parallel vector control scheme. A vector control technology is widely applied to controlling induction motors, permanent magnet synchronous motors and servo motors, a traditional motor vector control system adopts an inverter to control the motor. However, in some usage occasions, such as electric automobiles, electric locomotives, fans and air conditioning systems, and often two even more motors are needed to work simultaneously. The invention aims at providing a control scheme of simultaneously driving two permanent magnet synchronous motors by one vector inverter. Compared with the prior art, the scheme has the following advantages that the existing vector control system adopts one inverter to drive one permanent magnet synchronous motor, the control scheme provided by the invention is to simultaneously drive two permanent magnet synchronous motors by one vector inverter, and thus the hardware cost of the vector controller is saved. The control scheme of the invention is not more complex than traditional vector control in the aspect of amount of computation, and has practical significance in enriching permanent magnet synchronous motor vector control theories.

Description

A kind of permagnetic synchronous motor parallel connection vector control scheme

Technical field

The present invention relates to permagnetic synchronous motor and control technical field, particularly relate to a kind of permagnetic synchronous motor parallel connection vector Control method, the parallel drive that can be applicable to two permagnetic synchronous motors in fan, air conditioning system controls.

Background technology

Vector control technology has been widely used in the control of induction machine, permagnetic synchronous motor, servomotor, tradition Motor vector control system use one motor of an inverter control.But in some use occasion, such as electric automobile, electric power Locomotive, fan, air conditioning system etc., generally require 2 even multiple electric motors and work simultaneously.Such as a kind of double through-flow convertible frequency air-conditioners, Its indoor set just there are two permagnetic synchronous motors drive two set through-flow fan blade wheels to work respectively simultaneously.

There is scholar to propose the vector control scheme in parallel of induction machine, i.e. can share a vector controlled with multiple electric motors The control thinking of inverter.KELECY P M in 1994 et al. is at IEEE Power Electronics Specialists Conference proposes the method that two induction machine parallel connections share an inverter.Naval engineering university Nie Zi in 2009 Tinkling of pieces of jade et al. discloses one " parallel vector control system of induction motor " (application number 200910272737.8), it is proposed that two senses Answer the scheme that motor parallel is driven in rotor field-oriented vector-control frequency converter by a stylobate, and solve two motors by The unbalanced problem of torque is exported in the work process that parameter difference causes.

In vector control system, induction machine can be with parallel running, but about permagnetic synchronous motor parallel connection vector control technology The most also do not occurred.

Summary of the invention

The purpose of the present invention is to propose to an a kind of vector inverter and simultaneously drive the controlling party of two permanent magnet synchronous motors Case.In vector control system induction machine can with parallel running, but about permagnetic synchronous motor parallel connection vector control technology before Also do not occurred.

The purpose of the present invention can be achieved through the following technical solutions:

A kind of permagnetic synchronous motor parallel vector control system method, comprises the steps:

A) by the stator phase currents i of sampled measurements to two motor parallels_u、i_v, obtain the 3rd road stator electricity by calculating Stream i_w=-i_u-i_v.Different from the vector controlled of single motor, i here_u、i_v、i_wIt it is the stator phase currents of two motor parallels；

B) the mechanical angle θ of two motor rotor positions is respectively obtained by position detection encoder_r1、θ_r2, calculate two The average mechanical angle θ of individual motor rotor position_r=(θ_r1+θ_r2)/2, average electrical angle θ_e=p θ_r, p is motor number of pole-pairs, to θ_rMicro- Get the average mechanical rotational speed omega of two motors_r=d θ_r/dt；

C) different from the vector controlled of single motor, it is by average electrical angle θ here_eIt is supplied to Park conversion and inversion thereof Swap-in row calculates, by two motor parallel stator phase currents i_u、i_v、i_wTwo are obtained through carrying out Clarke conversion and PARK conversion The d axle component i of motor parallel stator current_dWith q axle component i_q；

D) speed ring uses PI regulation to control, given rotating speed ω_setInput as speed ring, the average machine of said two motor Tool rotational speed omega_rAs loop feedback, the output of speed ring is as stator current i_s, then calculate d respectively by torque angle beta Shaft current reference quantityWith q shaft current reference quantity

E) electric current loop uses PI regulation to control, described d, q shaft current reference quantityFor the input quantity of electric current loop, described D, q shaft current component i_d、i_qFor the feedback of electric current loop, the output of electric current loop is as the component of voltage V of d, q coordinate system_d、V_q；

F) V of described component of voltage_d、V_qAccording to average electrical angle θ_e, calculate α β rectangular coordinate system by Park inverse transformation Component of voltage V_α、V_β；

G) described component of voltage V_α、V_βThe dutycycle of six power tube conductings in power model is calculated by SVPWM；

H) two permagnetic synchronous motors in parallel are driven to work by three-phase PWM inverter.

The method includes parts implemented as described below: two permagnetic synchronous motors in parallel, two motor stator current acquisitions pass Sensor, two motor rotor positions detection encoder, motor position angle computing unit, Clarke converter unit, one Individual PARK converter unit, speed ring unit, two electric current loop unit, PARK inverse transformation block, SVPWM calculate Unit and a three-phase PWM inverter cell mesh.

Said two permagnetic synchronous motor winding parallel, shares same three-phase PWM inverter unit.

Described permagnetic synchronous motor is embedded permagnetic synchronous motor that model is identical or the identical surface-mount type permanent magnetism of model Synchronous motor.

Described permagnetic synchronous motor is used for governing system, and two permagnetic synchronous motor rotating speeds are equal.

In an embodiment of the present invention, from the principle of vector controlled, demonstrate permagnetic synchronous motor parallel connection vector controlled side The feasibility of method, when certain motor changes (increase or reduce) to the load torque of application, at two motor windings also In the case of connection, electromagnetic torque produced by this motor also produces corresponding change (increase or reduce), thus can be true Protect two motor in synchrony to run.

Compared with prior art, the invention have the advantages that existing vector control system uses a Driven by inverter One permanent magnet synchronous motors, the present invention proposes an a kind of inverter and simultaneously drives the controlling party of two permanent magnet synchronous motors Case, has saved the hardware cost of vector controller.Control program of the present invention controls multiple in terms of amount of calculation unlike conventional vector Miscellaneous.The present invention has practical significance to abundant permagnetic synchronous motor vector control theory.

By following specific embodiment and combine accompanying drawing, the present invention will become more fully apparent, and these accompanying drawings are used for explaining Embodiments of the invention.

Accompanying drawing explanation

The structure chart of Fig. 1 permagnetic synchronous motor of the present invention parallel vector control system.

When two motor loads of Fig. 2 are equal, the wherein basic vector figure of a motor.

When two motor loads of Fig. 3 are unequal, the bigger motor of load torque basic vector figure 1..

When two motor loads of Fig. 4 are unequal, load torque small electric machine basic vector figure 2..

Two motors of Fig. 5 drive load from static to the velocity wave form of given rotating speed.

The phase current waveform of two motor parallels of Fig. 6.

The output electromagnetic torque waveform of two motors in Fig. 7 parallel vector control system.

Detailed description of the invention

The present invention is described in detail with specific embodiment below in conjunction with the accompanying drawings.The present embodiment is with technical solution of the present invention Premised on implement, but protection scope of the present invention is not limited to following embodiment.

As a kind of embodiment, Fig. 1 is permanent magnet synchronous motor vector control system figure of the present invention, control system bag Include: two permagnetic synchronous motors in parallel, two motor stator current acquisition sensors, two motor rotor position detection codings Device, motor position angle computing unit, Clarke converter unit, PARK converter unit, speed ring unit, Two electric current loop unit, a PARK inverse transformation block, a SVPWM computing unit and a three-phase PWM inverter unit etc. Part.

The permagnetic synchronous motor parallel connection vector control method of the present invention, with tradition permagnetic synchronous motor vector control method Essential difference is in that:

1) two permanent magnet synchronous motors is in parallel, shares a three-phase PWM inverter unit.Two motors have following spy Property: the model of motor is identical (number of pole-pairs is equal, and the parameter of motor is of substantially equal), and two motors are in running medium speed phase The most of substantially equal Deng, institute's bringing onto load.

2) the stator current i in vector controlled calculates_u、i_v、i_wBe two motor parallels stator phase currents rather than Single electric machine phase current.

3) in vector controlled calculates, by average electrical angle θ of two motors_eIt is supplied to Park conversion and inversion swap-in thereof Row calculates.

In dq coordinate system, the voltage equation of permagnetic synchronous motor is:

$\{\begin{array}{c}{V}_d=R_s{i}_d+\frac{{\mathrm{d\ψ}}_d}{dt}-{\mathrm{\ω\ψ}}_q\\ V_q=R_s{i}_q+\frac{{\mathrm{d\ψ}}_q}{dt}+{\mathrm{\ω\ψ}}_d\end{array}---\left(1\right)$

Equation corresponding to Park inverse transformation is:

$\left\{\begin{array}{c}{V}_{\mathrm{\α}}=V_d\cos \mathrm{\θ}-V_q\sin \mathrm{\θ}\\ V_{\mathrm{\β}}=V_d\sin \mathrm{\θ}+V_q\cos \mathrm{\θ}\end{array}\right.---\left(2\right)$

D, q axle flux linkage equations is:

$\left\{\begin{array}{c}{\mathrm{\ψ}}_d=L_d{i}_d+{\mathrm{\ψ}}_f\\ {\mathrm{\ψ}}_q=L_q{i}_q\end{array}\right.---\left(3\right)$

Electromagnetic torque equation is:

T_em=p_n(ψ_di_q-ψ_qi_d) (4)

In formula (1)～(4): V_d、V_qComponent of voltage for dq axis coordinate system；V_α、V_βVoltage for α β rectangular coordinate system divides Amount；i_d、i_qFor dq shaft current component；R_sFor stator resistance；L_d、L_qIt is respectively d, q axle inductance；ψ_d、ψ_qIt is respectively d, q axle magnetic linkage；ψ_f For permanent magnet flux linkage；ω is angular rate；p_nFor motor number of pole-pairs；T_emFor electromagnetic torque.

The equation of motion of motor is:

$J\frac{{\mathrm{d\ω}}_r}{dt}=T_{em}-{\mathrm{B\ω}}_r-T_L---\left(5\right)$

In formula (5), J is the rotary inertia of rotor；ω_rFor mechanical angle speed；B is viscous damping coefficient；T_LFor load Torque.

The thinking that present invention demonstrates that the permagnetic synchronous motor parallel connection vector control method feasibility of the present invention is: when two electricity In machine, when certain motor to application load torque change (increase or reduce) time, at two motor winding parallels In the case of, electromagnetic torque produced by this motor also produces corresponding change (increase or reduce), thus may insure that two Platform motor in synchrony runs.

For the ease of analysis below, it is assumed that with motor 2. 1. these two motors be respectively motor, might as well suppose electricity simultaneously Machine load torque 1. is bigger than the meansigma methods of two motor torques, and motor load torque 2. is less than the meansigma methods of two motor torques. Relevant electromagnetism variable is distinguished also by increasing subscript.

Formula (3) is substituted into formula (1), draws the steady-state equation of voltage:

$\{\begin{array}{c}{V}_d=R_s{i}_d-{\mathrm{\ωL}}_q{i}_q\\ V_q=R_s{i}_q+{\mathrm{\ωL}}_d{i}_d+{\mathrm{\ω\ψ}}_f\end{array}---\left(6\right)$

Formula (6) is represented with vectogram, the vectogram of current commonly used permagnetic synchronous motor vector controlled can be obtained As shown in Figure 2.I in Fig. 2_sRepresent stator current；β represents angle of torsion；V_aRepresent the terminal voltage of winding；V₀Represent negligible resistance pressure Winding terminal voltage during fall.

$\left\{\begin{array}{c}{i}_d=-i_s\sin \mathrm{\β}\\ i_q=i_s\cos \mathrm{\β}\end{array}\right.---\left(7\right)$

$V_0=\sqrt{V_{0d}^2+V_{0q}^2}=\mathrm{\ω}\sqrt{{\left(L_q{i}_q\right)}^2+{(L_d{i}_d+{\mathrm{\ψ}}_f)}^2}---\left(8\right)$

$V_a=\sqrt{V_d^2+V_q^2}=\sqrt{(R_s{i}_d-{\mathrm{\ωL}}_q{i}_q)+{(R_s{i}_q+{\mathrm{\ωL}}_d{i}_d+{\mathrm{\ω\ψ}}_f)}^2}---\left(9\right)$

In Fig. 2, the direction of rotation of rotor is counterclockwise (CCW), as load T_LWhen increasing the weight of, motor rotor 1. Relative to motor direction of rotation can stagnant later angle δ, at this moment permanent magnet and d axle have an angle δ, the magnetic linkage that permanent magnet produces ψ_fAll produce one-component at d axle and q axle, copy (3) that load T can be write out_LMotor d, q axle flux linkage equations 1. when increasing the weight of:

$\left\{\begin{array}{c}{\mathrm{\ψ}}_{d1}=L_d{i}_{d1}+{\mathrm{\ψ}}_f\cos \mathrm{\δ}\\ {\mathrm{\ψ}}_{q1}=L_q{i}_{q1}-{\mathrm{\ψ}}_f\sin \mathrm{\δ}\end{array}\right.---\left(10\right)$

Motor d, q shaft voltage equation 1.:

$\left\{\begin{array}{c}{V}_{d1}=R_s{i}_{d1}-{\mathrm{\ωL}}_q{i}_{q1}-{\mathrm{\ω\ψ}}_f\sin \mathrm{\δ}\\ V_{q1}=R_s{i}_{q1}+{\mathrm{\ωL}}_d{i}_{d1}+{\mathrm{\ω\ψ}}_f\cos \mathrm{\δ}\end{array}\right.---\left(11\right)$

It is illustrated in figure 3 load T_LMotor vectogram 1., i when increasing the weight of_d1、i_q1Represent motor 1. dq shaft current component；i_s1 Represent stator current；β₁Represent angle of torsion；V_a1Represent the terminal voltage of winding；V₀₁Represent winding terminal electricity during negligible resistance pressure drop Pressure.

As load T_LDuring reduction, motor rotor 2. relative to motor direction of rotation can super previous angle δ, motor is 2. D, q axle flux linkage equations:

$\left\{\begin{array}{c}{\mathrm{\ψ}}_{d2}=L_d{i}_{d2}+{\mathrm{\ψ}}_f\cos \mathrm{\δ}\\ {\mathrm{\ψ}}_{q2}=L_q{i}_{q2}+{\mathrm{\ψ}}_f\sin \mathrm{\δ}\end{array}\right.---\left(12\right)$

Motor d, q shaft voltage equation 2.:

$\left\{\begin{array}{c}{V}_{d2}=R_s{i}_{d2}-{\mathrm{\ωL}}_q{i}_{q2}+{\mathrm{\ω\ψ}}_f\sin \mathrm{\δ}\\ V_{q2}=R_s{i}_{q2}+{\mathrm{\ωL}}_d{i}_{d2}+{\mathrm{\ω\ψ}}_f\cos \mathrm{\δ}\end{array}\right.---\left(13\right)$

It is illustrated in figure 4 load T_LThe vectogram of motor, i when alleviating_d2、i_q2Represent motor 2. dq shaft current component；i_s2Generation Table stator current；β₂Represent angle of torsion；V_a2Represent the terminal voltage of winding；V₀₂Represent winding terminal voltage during negligible resistance pressure drop.

The situation identical from two motor torques is different, and Fig. 3, two motor permanent magnet no longer overlap with d axle in 4, formula (11), (13) show that the component of voltage of two motor dq axis coordinate systems is unequal

V_d1≠V_d2, V_q1≠V_q2 (14)

But in parallel circuit, two motors share same set of SVPWM inverter circuit, are added in the end of two motor windings Voltage V_α、V_βIt is equal, Park inverse transformation equation (2) can derive further:

$V_{\mathrm{\α}}^2+V_{\mathrm{\β}}^2={(V_{d}cos\mathrm{\θ}-V_{q}sin\mathrm{\θ})}^2+{(V_{d}sin\mathrm{\θ}+V_{q}cos\mathrm{\θ})}^2=V_d^2+V_q^2---\left(15\right)$

Knowable to formula (9) and formula (15), when the load torque of two motors differs, it is added in the end of two motor windings Voltage V_a1、V_a2Terminal voltage V time identical with original two motor torques_aEqual:

V_a=V_a1=V_a2 (16)

If the pressure drop of negligible resistance, the terminal voltage of two motor windings is also equal:

V₀=V₀₁=V₀₂ (17)

Terminal voltages V based on two motor windings_a1、V_a2Equal principle, analysis chart 2,3, the vectogram of 4 three kind of situation It follows that as load T_LWhen increasing the weight of, Fig. 3 motor stator current i 1._s1More than the stator current i in Fig. 2_s, with Time Fig. 3 motor d shaft current i 1._d1Reduction compared with Fig. 2, q shaft current i_q1Increase compared with Fig. 2；As load T_LWhen alleviating, Fig. 4 Motor stator current i 2._s2Less than the stator current i in Fig. 2_s, Fig. 4 motor d shaft current i 2. simultaneously_d2Subtract compared with Fig. 2 Little, q shaft current i_q2Also reduce compared with Fig. 2.I.e. there is a relational expression:

$\left\{\begin{array}{c}{i}_{s1}>i_s>i_{s2}\\ i_{q1}>i_q>i_{q2}\\ i_{d1}=i_{d2}<i_d\end{array}\right.---\left(18\right)$

Formula (10), (12), (18) are substituted into formula (4), can obtain several in the case of relation between electromagnetic torque. Can derive from magnetic linkage formula (3), (10), (12):

$\left\{\begin{array}{c}{\mathrm{\&psi;}}_{d1}={\mathrm{\&psi;}}_{d2}<{\mathrm{\&psi;}}_d\\ {\mathrm{\&psi;}}_{q1}<{\mathrm{\&psi;}}_q<{\mathrm{\&psi;}}_{q2}\end{array}\right.---\left(19\right)$

Aggregative formula (18), (19) can be derived:

$\left\{\begin{array}{c}{\mathrm{\&psi;}}_{d1}{i}_{q1}>{\mathrm{\&psi;}}_{d2}{i}_{q2}\\ {\mathrm{\&psi;}}_{q1}{i}_{d1}<{\mathrm{\&psi;}}_{q2}{i}_{d2}\end{array}\right.---\left(20\right)$

Formula (20) is substituted into formula (4) can obtain:

T_em1=p_n(ψ_d1i_q1-ψ_q1i_d1)>p_n(ψ_d2i_q2-ψ_q2i_d2)=T_em2 (21)

Formula (21) proves, in parallel vector control system, when wherein a motor (being set to motor here 1.) is carried Load torque T_LWhen increasing the weight of, the electromagnetic torque output of this motor increases therewith；When wherein a motor (is set to motor here 2.) load torque T carried_LWhen alleviating, this motor electromagnetic torque output reduce therewith, each in parallel control system Motor each has the ability that torque is automatically adjusted, thus ensures that two motors can run simultaneously.

As a concrete embodiment of the present invention, the vector control scheme in parallel of the present invention is applied to a double Through-flow air-conditioning (model is KFR-72L/BP2DN1Y-IE), the specified refrigerating capacity of air-conditioning is 7200W, because of the indoor set of this air-conditioning In just have two permagnetic synchronous motors to drive two through-flow fan blades wheel to work respectively, so being referred to as double through-flow air-conditioning simultaneously.Here The permagnetic synchronous motor of two the same model of motors (ZKFN-30-8-2), the parameter of motor is as follows: rated direct voltage 310V； Speed adjustable range 500～1500rpm；Number of pole-pairs p_n=4；Stator resistance R_s=30 Ω；Stator d-axis inductance L_d=330mH；Stator is handed over Axle inductance L_q=350mH；Back emf coefficient k_e=80.0V/krpm.

The theoretical validation of embodiment of the present invention is to build the present invention forever by such as Fig. 1 on Matlab/Simulink platform The phantom of magnetic-synchro motor parallel vector control system.The parameter of electric machine uses model (ZKFN-30-8-2) parameter, gives and turns Speed 1200rpm, if the average output torque of two motors is 0.2Nm, turns to verify whether motor has under same rotational speed The ability that square is automatically adjusted, it is assumed that the load torque of two motors is unequal, might as well set motor load torque 1. as 0.22Nm, Motor load torque 2. is 0.18Nm.As in Fig. 5 parallel vector control system, two motors drive load from static to given The velocity wave form of rotating speed 1200rpm, wherein dotted line represents motor velocity wave form 1., and solid line represents motor velocity wave form 2., From figure 5 it can be seen that two motors are to given rotating speed from static, last two motors can reach steady-state operation.From amplify Speed waveform is seen, different from conventional control program, and when the load torque of two motors is unequal, the present invention program controls The steady-state speed of every motor is even to fluctuate up and down at 1200rpm, embodies every motor and constantly adjusts to realize synchronous operation Whole process.If Fig. 6 is that in starting process, maximum current is from starting the phase current waveform to two motor parallels of steady-state operation 2.5A, phase current magnitude during steady-state operation is 0.35A, this and independent output 0.4Nm permagnetic synchronous motor from starting to The phase current of stable state is identical.If Fig. 7 is the electromagnetic torque waveform that two motors export, because motor load torque 1. is than electricity Machine is 2. big, from figure 7, it is seen that the output electromagnetic torque (dotted line representatives) that motor is 1. is also than motor output electromagnetic torque (reality 2. Line represents) big, motor output electromagnetic torque 1. fluctuates near 0.22Nm, and motor output electromagnetic torque 2. is attached at 0.18Nm Nearly fluctuation.

Analyzed by Emulation of Electrical Machinery, prove in parallel vector control system further theoretically, when a wherein electricity Load torque T that machine is carried_LWhen increasing the weight of, the electromagnetic torque output of this motor increases therewith；When wherein motor is carried Load torque T_LWhen alleviating, this motor electromagnetic torque output reduce therewith, in parallel control system, each motor has The ability that torque is automatically adjusted, two motors have the ability of synchronous operation.

The experiment of embodiment of the present invention is divided into two steps, it is therefore an objective to contrast the single motor vector control scheme of tradition and this The control effect of control program described in example.The first step, by the most conventional method, drives this respectively with two controllers Two axial-flow fan motors in bright example air-conditioning model machine, the rotational speed setup of two motors is identical, allow two motors from 765rpm (corresponding minimum air output), progressively raising speed is to 1500rpm.On indoor apparatus of air conditioner special wind quantity test platform, can remember Record two power input to machines and, input current and, the data such as total discharge quantity of fan；The method that second step is given by the present invention, will The winding parallel of two axial-flow fan motors, shares a controller and drives, allow two motors progressively rise from 765rpm equally Speed to 1500rpm, record two power input to machines and, input current and and total discharge quantity of fan.

If table 1 is the experimental data contrast of single motor vector control scheme with control program as described in example of the present invention.From experiment Data are visible, use control program of the present invention to drive the work of two motor parallels, two power input to machines and, input current With, and the discharge quantity of fan that indoor apparatus of air conditioner is total, it is the most suitable with conventional single motor vector control scheme.Such as giving Determining at rotating speed 1500rpm, single motor vector control scheme, the actual speed of two motors is respectively 1495rpm, 1503rpm, control Device input power processed and be 63.6W, total discharge quantity of fan is 1425.0m³/h；When using control program of the present invention, two motors Actual speed is respectively 1506rpm, 1508rpm, controller input power and be 64.5W, and total discharge quantity of fan is 1471.2m³/ h, Owing to the actual speed of two motors of the present invention program is slightly larger, input power and total air output of controller the most slightly increase, Prove that two kinds of control programs are also the most suitable in terms of system effectiveness.

The single motor vector control scheme of table 1 contrasts with the experimental data of control program of the present invention

The ultimate principle of the present invention and principal character and advantages of the present invention have more than been shown and described.The technology of the industry Personnel, it should be appreciated that the present invention is not restricted to the described embodiments, simply illustrating this described in above-described embodiment and description The principle of invention, without departing from the spirit and scope of the present invention, the present invention also has various changes and modifications, and these become Change and improvement both falls within scope of the claimed invention.Claimed scope by appending claims and Equivalent defines.

Claims (5)

1. a permagnetic synchronous motor parallel vector control system method, it is characterised in that comprise the steps:

A) by the stator phase currents i of sampled measurements to two motor parallels_u、i_v, obtain the 3rd road stator current i by calculating_w =-i_u-i_v.Different from the vector controlled of single motor, i here_u、i_v、i_wIt it is the stator phase currents of two motor parallels；

B) the mechanical angle θ of two motor rotor positions is respectively obtained by position detection encoder_r1、θ_r2, calculate two electricity The average mechanical angle of machine rotor positionAverage electrical angle θ_e=p θ_r, p is motor number of pole-pairs, carries out micro-to time t Get the average mechanical rotational speed omega of two motors_r=d θ_r/dt；

C) different from the vector controlled of single motor, it is by average electrical angle θ here_eIt is supplied to Park conversion and inversion swap-in thereof Row calculates, by two motor parallel stator phase currents i_u、i_v、i_wTwo motors are obtained through carrying out Clarke conversion and PARK conversion The d axle component i of stator current in parallel_dWith q axle component i_q；

D) speed ring uses PI regulation to control, given rotating speed ω_setInputting as speed ring, said two motor average mechanical turns Speed ω_rAs loop feedback, the output of speed ring is as stator current i_s, then calculate d axle electricity respectively by torque angle beta Stream reference quantityWith q shaft current reference quantity

E) electric current loop uses PI regulation to control, described d, q shaft current reference quantityFor the input quantity of electric current loop, described d, q axle Current component i_d、i_qFor the feedback of electric current loop, the output of electric current loop is as the component of voltage V of d, q coordinate system_d、V_q；

F) V of described component of voltage_d、V_qAccording to average electrical angle θ_e, the electricity of α β rectangular coordinate system is calculated by Park inverse transformation Pressure component V_α、V_β；

G) described component of voltage V_α、V_βThe dutycycle of six power tube conductings in power model is calculated by SVPWM；

H) two permagnetic synchronous motors in parallel are driven to work by three-phase PWM inverter.

Permagnetic synchronous motor parallel vector control system method the most according to claim 1, it is characterised in that the method bag Include parts implemented as described below: two permagnetic synchronous motors in parallel, two motor stator current acquisition sensors, two rotors Position detection encoder, motor position angle computing unit, Clarke converter unit, PARK converter unit, one Individual speed ring unit, two electric current loop unit, a PARK inverse transformation block, a SVPWM computing unit and a three-phase PWM Inverter unit part.

Permagnetic synchronous motor parallel vector control system method the most according to claim 2, it is characterised in that said two Permagnetic synchronous motor winding parallel, shares same three-phase PWM inverter unit.

Permagnetic synchronous motor parallel vector control system method the most according to claim 2, it is characterised in that described permanent magnetism Synchronous motor is embedded permagnetic synchronous motor that model is identical or the identical surface-mount type permagnetic synchronous motor of model.

Permagnetic synchronous motor parallel vector control system method the most according to claim 2, it is characterised in that described permanent magnetism Synchronous motor is used for governing system, and two permagnetic synchronous motor rotating speeds are equal.