Dead-beat control system and method for permanent magnet synchronous motor with complex vector modeling in discrete domain

Abstract

The invention discloses a dead-beat control system and a method for a permanent magnet synchronous motor with complex vector modeling in a discrete domain, which is characterized in that the system comprises a permanent magnet synchronous motor, an encoder, an abc-dq coordinate conversion unit, a speed outer loop PI controller, a current dead-beat controller, a dq-Alphabeta coordinate conversion unit, an SVPWM modulation module, and an inverter. The invention has the beneficial effects that: in the modeling process of the current prediction model, the inverter and the motor are regarded as a whole modeling, the delay action of the inverter is considered, and the established model is more accurate than the traditional current prediction model; a current error integral compensation module isadded to the dead-beat controller, the stator current control static error is greatly improved, and finally the purpose of no-beat control at low switching frequency is achieved. The results show that the motor speed and stator current are well controlled, the motor stator current control static error is small, and the output torque ripple is also improved.

Description

technical field [0001] The invention relates to a permanent magnet synchronous motor deadbeat control system and method based on discrete domain complex vector modeling, and belongs to the technical field of motor control. Background technique [0002] Permanent magnet synchronous traction motors for rail transit generally have a large power of hundreds of kilowatts. Due to the limitation of switching losses, in reality, an inverter with a low switching frequency of about 500 Hz has to be used to control the drive motor. [0003] At present, permanent magnet synchronous motors generally use dual-PI vector control strategies, but at low switching frequencies, the system sampling delay will be greatly increased, which will destroy the dynamic decoupling in the vector control system, and the motor control is difficult to meet the control requirements, and the output stator The current contains a large number of harmonics, which makes the output torque of the motor fluctuate gre...

AI Technical Summary

Problems solved by technology

[0006] In order to solve the deficiencies in the prior art, the object of the present invention is to provide a permanent magnet synchronous motor deadbeat control system and method based on discrete domain complex vector modeling, which solves the problem of traditional permanent magnet synchronous motor deadbeat control systems at low switching frequencies. There are problems such as poor control effect, large current static difference, and large output torque pulsation. The deadbeat control strategy has a good control effect at low switching frequency, and the current control static difference is also small.

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