Permanent magnet synchronous motor flux weakening optimization control method and system based on voltage feedback

Abstract

The invention discloses a permanent magnet synchronous motor flux weakening optimization control method and system based on voltage feedback, and the method comprises the steps: calculating a virtualcurrent limit value according to a rotating speed feedback value through a current working point planning relation rule, and carrying out the difference of a rotating speed given value and a rotatingspeed feedback value; employing a rotating speed adjuster; employing an MTPA algorithm to calculate a reference current initial given value, acquiring the reference current given value by combining the current output through flux weakening control with the virtual current limit value, calculating difference between the reference current given value and the feedback current actual value, acquiringa reference voltage initial given value, and acquiring the reference voltage initial given value after feedforward decoupling; calculating the amplitude of the initial reference voltage vector, and judging a motor operation area; carrying out the amplitude judgment on the initial given value of the reference voltage to obtain a given value of the reference voltage, and controlling the output of the inverter in an SVPWM modulation mode. According to the method, the THD of the three-phase current can be reduced, the rotating speed overshoot in the speed increasing process when the steady-state working point is located in the current limit circle is reduced, and the dynamic performance of the system is improved.

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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