Field Weakening Optimal Control Method and System for Permanent Magnet Synchronous Motor Based on Voltage Feedback

Abstract

The invention discloses a method and system for optimizing the field weakening of a permanent magnet synchronous motor based on voltage feedback. The method includes calculating the virtual current limit value according to the speed feedback value through the current operating point planning relationship law, and combining the speed given value and the speed feedback value. Make a difference, through the speed regulator, use the MTPA algorithm to calculate the initial given value of the reference current, combine the current output through the field weakening control and the virtual current limit value to get the reference current given value, and make a difference with the actual value of the feedback current to get the reference voltage The initial given value, and then after feed-forward decoupling, the initial given value of the reference voltage is obtained; the amplitude of the initial reference voltage vector is calculated to judge the operating area of ​​the motor; the amplitude of the initial given value of the reference voltage is judged to obtain the given reference voltage value, using SVPWM modulation to control the inverter output. The method can reduce the three-phase current THD, reduce the speed overshoot during the speed-up process when the steady-state operating point is within the current limit circle, and improve the dynamic performance of the system.

Description

technical field [0001] The invention belongs to the technical field of motors, and relates to a motor control technology, in particular to a method and system for optimizing the field weakening of a permanent magnet synchronous motor based on voltage feedback. Background technique [0002] With the rapid development of the current intelligent manufacturing and equipment fields, the demand for motor performance such as high power density, high efficiency, low cost and smaller volume is also increasing. High-speed permanent magnet synchronous motors have been widely used because of their high efficiency, energy saving, small size, and good control effects. It has been used in flywheel energy storage, electric vehicles and other fields and plays an important role. [0003] As the motor speed increases, the back electromotive force of the motor increases, and the voltage at the motor terminal will also increase accordingly. The operating range of the motor is constrained due t...

AI Technical Summary

Problems solved by technology

When the actual speed accelerates to the target speed, the electromagnetic torque at this time is greater than the load torque, and the motor will continue to increase speed until the electromagnetic torque is equal to the load torque, and then gradually decelerate until the current operating point converges to the target operating point. The process makes the speed overshoot, which deteriorates the dynamic performance of the motor

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