CN105915144A - Permanent magnet synchronous motor rotating speed tracking control method - Google Patents

Abstract

The invention discloses a permanent magnet synchronous motor rotating speed tracking control method. The permanent magnet synchronous motor rotating speed tracking control method comprises the steps of acquiring a motor rotating speed estimated value by means of an extended Kalman filter, generating a control signal according to a current actual value and a reference value by means of a controller, and implementing control on motor rotating speed via an inverter. A control system for implementing the permanent magnet synchronous motor rotating speed tracking control method comprises an extended Kalman filtering module, a rotating speed control module, a current control module, the inverter and a controlled motor. The permanent magnet synchronous motor rotating speed tracking control method is simple and clear, and can perform tracking control on rotating speed of a permanent magnet synchronous motor accurately. Compared with the traditional vector control method, the permanent magnet synchronous motor rotating speed tracking control method is simple in system structure, and has a certain application prospect.

Description

A kind of permagnetic synchronous motor rotary speed tracing control method

Technical field

The present invention relates to control and the application of permagnetic synchronous motor, be specifically related to a kind of permagnetic synchronous motor rotating speed controlling party Method.

Background technology

Permagnetic synchronous motor has and operates steadily, and efficiency is high, and the feature of good speed adjustment features, along with New-type electric machine control theory Fast development, permasyn morot has obtained rapid popularization and application in many fields.

Want to realize motor high accuracy to control, it is to be appreciated that arrive rotor speed and the positional information of motor, the most generally make Obtain with position sensor.But the use of position sensor can increase system cost, it is unfavorable for safeguarding and maintenance.Severe Under operation ring is quiet, bigger error may be produced, reduce reliability.Sensorless Control Technique utilizes motor itself Mathematical model, by the electric moter voltage arrived measured, electric current, uses estimating algorithm to obtain motor rotor speed and positional information Estimated value, has therefore obtained widely studied.

Method for controlling permanent magnet synchronous motor mainly has Direct Torque Control and vector control method at present, and these methods are usual Including direct torque ring and the current regulator of superposition, and obtained control signal by PI controller, finally utilize SVPWM to control skill Inverter is controlled by art.These methods rely on the parameter of electric machine accurately, and structure is complex, are not easy to application.

Summary of the invention

Goal of the invention: the present invention seeks to provide a kind of effective permagnetic synchronous motor method for controlling number of revolution, simplify and control System structure, it is ensured that motor actual speed can accurately follow the tracks of given rotating speed.

Technical scheme: a kind of permagnetic synchronous motor rotary speed tracing control method, comprises the following steps:

(1) use extended Kalman filter to estimate motor speed value, and obtain torque reference value by PI controller；

(2) from the 6 of inverter kinds of active voltage vectors, arbitrarily choose two, compare and be respectively adopted two voltage vector controls Error between actual current and the reference current of signal rear motor processed, when the voltage vector that Select Error is little is sampled as this The control voltage carved；

(3) voltage vector that the error chosen according to step (2) is little controls inverter switching states, thus carries out motor Control；

(4) enter next sampling instant, repeat step (1)～(4).

Further, in two voltage vectors that step (2) is chosen, the current error ε that any voltage vector is corresponding_nCalculate Method is

Wherein, n is the sequence number of the voltage vector that correspondence is chosen, and n takes 1,2；i₀For the electric current gone out according to motor Equation for Calculating Component；v_nThe voltage vector chosen for correspondence；Δ t is the discrete sampling time, L_d、L_qIt is respectively motor d, q axle equivalent inductance, i^* For reference current；Wherein, i^*And i₀It is respectively calculated as follows:

Wherein,For torque reference value, p is motor number of pole-pairs, and ψ is permanent magnet flux linkage, and R is stator resistance, i_d,k、i_q,kPoint Not Wei current sample time d, q shaft current, ω_kFor motor angular rate.

Further, the voltage vector that in step (2), Select Error is little is as the control voltage of this sampling instant, specifically For:

Order

Wherein, θ is motor rotor position；

When T≤0, choose v₁As controlling voltage；

As T ＞ 0, choose v₂As controlling voltage.

Further, two voltage vectors chosen in step (2) are respectively

Wherein, V_DCFor DC voltage, θ is motor rotor position.

Beneficial effect: pass through proposed method for controlling number of revolution and can obtain inverter switching device signal, directly inverter is carried out Control.Eliminate SVPWM module, only choose two Control of Voltage vectors, simplied system structure, be more beneficial for engineering construction.And And motor speed is obtained by EKF with position in this method, it is not necessary to position sensor, thus reduce system Cost, improves system rotating speed and controls response speed, improve operational reliability.

Accompanying drawing explanation

Fig. 1 is complete control system structured flowchart of the present invention；

Fig. 2 is motor control method flow chart of the present invention.

Detailed description of the invention

The present invention is according to permagnetic synchronous motor i_d=0 control strategy, is calculated target current value by given rotating speed.Then After comparing the current error that two Control of Voltage vectors produce, choose the less conduct of error and control voltage, finally by inverse Become device and realize the control to motor speed.In conjunction with extended Kalman filter, it is possible to achieve permagnetic synchronous motor position sensorless Device controls, simplied system structure, reduces cost.

Below in conjunction with the accompanying drawings specific implementation method of the present invention is illustrated.

As shown in accompanying drawing 1,2, Clark and Park conversion is first used to obtain motor d, q axle equivalent current, then by extension Kalman filter obtain motor estimate rotating speed, with given tracking rotating ratio relatively after, PI rotational speed governor can obtain electricity Magnetic torque set-point

According to permagnetic synchronous motor electromagnetic torque T_emCalculation expression

When using i_dDuring=0 control strategy, given reference current i^*As follows:

In formula, ψ is permanent magnet flux linkage, and p is motor number of pole-pairs, i_d,k、i_q,kIt is respectively current sample time d, q shaft current, L_d、L_qIt is respectively motor d, q axle equivalent inductance.

From 6 kinds of active voltage vectors of inverter output, arbitrarily choose two, compare and be respectively adopted this two voltages arrows Error between actual current and the reference current of amount control signal rear motor, the voltage vector that Select Error is little is adopted as this The control voltage in sample moment.The present embodiment chooses following two voltage vectors:

Wherein, V_DCFor DC voltage, θ is motor rotor position.Matrix [0 0 1]^T, [0 1 0]^TInversion can be reflected Device on off state.

Use voltage vector v_nAfter motor is controlled, actual current vector i_nFor:

In formula, n takes 1,2, i₀For the current component gone out according to motor Equation for Calculating, Δ t is the discrete sampling time；Wherein:

In formula, R is stator resistance, i_d,k、i_q,kIt is respectively current sample time d, q shaft current, ω_kFor motor electric angle speed Degree.

Next calculate the most respectively after using these two to control voltage vectors, actual current that each voltage vector is corresponding and ginseng Examine the error ε of electric current_nFor:

Calculate the modulus value of error vector, the little vector of Select Error as the control voltage of this sampling instant, specifically For:

Order

When T≤0, choose v₁As controlling voltage；

As T ＞ 0, choose v₂As controlling voltage.

Control inverter switching states according to the voltage vector chosen, motor is controlled.

Subsequently into next sampling instant, repeat above step and can realize the rotating-speed tracking control to permasyn morot System.

But this method is also only not limited to this, optional two controls all can chosen as the present invention in 6 kinds of active voltage vectors Voltage processed.

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

Claims (4)

1. a permagnetic synchronous motor rotary speed tracing control method, it is characterised in that comprise the following steps:

(1) use extended Kalman filter to estimate motor speed value, and obtain torque reference value by PI controller；

(2) from the 6 of inverter kinds of active voltage vectors, arbitrarily choose two, compare and be respectively adopted two voltage vectors control letters Error between actual current and the reference current of number rear motor, the little voltage vector of Select Error is as this sampling instant Control voltage；

(3) voltage vector that the error chosen according to step (2) is little controls inverter switching states, thus controls motor System；

(4) enter next sampling instant, repeat step (1)～(4).

2. as claimed in claim 1 permagnetic synchronous motor rotary speed tracing control method, it is characterised in that: step (2) choose two In bar voltage vector, the current error ε that any voltage vector is corresponding_nComputational methods are

${\mathrm{\ϵ}}_n=i^{*}-i_0-v_n\·\mathrm{\Δ}t\left[\begin{array}{cc}1/L_d& \\ & 1/L_q\end{array}\right]$

Wherein, n is the sequence number of the voltage vector that correspondence is chosen, and n takes 1,2；i₀For the current component gone out according to motor Equation for Calculating； v_nThe voltage vector chosen for correspondence；Δ t is the discrete sampling time, L_d、L_qIt is respectively motor d, q axle equivalent inductance, i^*For reference Electric current；Wherein, i^*And i₀It is respectively calculated as follows:

$i^{*}=\left[\begin{array}{c}0\\ \frac{2T_{em}^{*}}{3p\mathrm{\ψ}}\end{array}\right],i_0=\left[\begin{array}{c}{i}_{d.k}(1-\frac{R}{L_d}\mathrm{\Δ}t)+{\mathrm{\ω}}_k\frac{L_q}{L_d}\mathrm{\Δ}t\·i_{q,k}\\ i_{q,k}(1-\frac{R}{L_q}\mathrm{\Δ}t)-{\mathrm{\ω}}_k\frac{L_d}{L_q}\mathrm{\Δ}t\·i_{d,k}-{\mathrm{\ω}}_k\frac{\mathrm{\ψ}}{L_q}\mathrm{\Δ}t\end{array}\right]$

Wherein,For torque reference value, p is motor number of pole-pairs, and ψ is permanent magnet flux linkage, and R is stator resistance, i_d,k、i_q,kIt is respectively Current sample time d, q shaft current, ω_kFor motor angular rate.

3. permagnetic synchronous motor rotary speed tracing control method as claimed in claim 2, it is characterised in that: step (2) selects by mistake Differ from the little voltage vector control voltage as this sampling instant, particularly as follows:

Order

$\begin{array}{c}T={\mathrm{\ϵ}}_1-{\mathrm{\ϵ}}_2\\ =|i^{*}-i_0-v_1\·\mathrm{\Δ}t\left[\begin{array}{cc}1/L_d& \\ & 1/L_q\end{array}\right]|-|i^{*}-i_0-v_2\·\mathrm{\Δ}t\left[\begin{array}{cc}1/L_d& \\ & 1/L_q\end{array}\right]|\\ =\mathrm{\Δ}t\·\[(2+\sqrt{3})\cos \mathrm{\θ}-\sqrt{3}\sin \mathrm{\θ}\]-6i_{d,k}(L_d-R\mathrm{\Δ}t)-{\mathrm{\ω}}_k{L}_q\mathrm{\Δ}t\·i_{q,k}\end{array}$

Wherein, θ is motor rotor position；

When T≤0, choose v₁As controlling voltage；

As T ＞ 0, choose v₂As controlling voltage.

4. permagnetic synchronous motor rotary speed tracing control method as claimed in claim 1, it is characterised in that: step (2) is chosen Article two, voltage vector is respectively

$v_1=V_{DC}\left[\begin{array}{cc}cos\mathrm{\θ}& \sin \mathrm{\θ}\\ -sin\mathrm{\θ}& cos\mathrm{\θ}\end{array}\right]\left[\begin{array}{ccc}\frac{2}{3}& -\frac{1}{3}& -\frac{1}{3}\\ 0& \frac{1}{\sqrt{3}}& -\frac{1}{\sqrt{3}}\end{array}\right]\left[\begin{array}{c}0\\ 0\\ 1\end{array}\right],v_2=V_{DC}\left[\begin{array}{cc}cos\mathrm{\θ}& \sin \mathrm{\θ}\\ -sin\mathrm{\θ}& cos\mathrm{\θ}\end{array}\right]\left[\begin{array}{ccc}\frac{2}{3}& -\frac{1}{3}& -\frac{1}{3}\\ 0& \frac{1}{\sqrt{3}}& -\frac{1}{\sqrt{3}}\end{array}\right]\left[\begin{array}{c}0\\ 1\\ 0\end{array}\right]$

Wherein, V_DCFor DC voltage, θ is motor rotor position.