Vector control method based on counter potential feedforward control

Abstract

The invention relates to a vector control method based on counter potential feedforward control, comprising the following steps: the V / F ratio of a motor is solved to obtain the needed counter potential amplitude of an asynchronous traction motor; exciting current and torque current are given; a counter potential phase angle is obtained by output frequency integral of an inverter; sampling is carried out to obtain the current of a three-phase stator of the motor, and the stator current vector amplitude and the phase angle are calculated; the offset voltage vector amplitude for stator impedance and the phase angle are solved; the stator current vector is decoupled into the torque current and the exciting current; the decoupled exciting current and the given exciting current form a PI(proportional-integral) regulator, and the output of the PI regulator is the counter potential amplitude regulated value; the decoupled torque current and the given torque current form a PI regulator, and the output of the PI regulator controls the slip of the motor directly; and the stator voltage amplitude output by the inverter is the sum of the regulated values of the counter potential amplitude of the motor, the offset voltage vector and the counter potential amplitude. In the invention, the control precision is high and the application range is wide.

Description

technical field [0001] The invention relates to a vector control method of an asynchronous traction motor, in particular to a vector control method based on back electromotive force feedforward control. Background technique [0002] Since the dynamic mathematical model of the asynchronous traction motor is a high-order, nonlinear, strongly coupled multivariable system, how to precisely control the asynchronous traction motor has always been concerned. In the 1970s, Siemens engineer F. Blaschke first proposed the use of asynchronous motor vector control theory to solve the control problem of AC motor torque. The basic principle of vector control is to measure the stator current vector of the asynchronous motor, and decompose the stator current vector of the asynchronous motor into the current component that generates the magnetic field (called the excitation current) and the current component that generates the torque (called the excitation current) according to the principle...

AI Technical Summary

Problems solved by technology

In addition, the constant voltage area of ​​the traction motor usually adopts square wave modulation. If the traditional vector control method is used, the current or voltage will be oversaturated, the torque will easily pulsate, and the control accuracy will be low.

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