Zero reactive power control method for permanent magnet synchronous motor

Abstract

The invention discloses a zero reactive power control method for a permanent magnet synchronous motor. The method comprises five parts: motor speed loop closing, a distribution method of alternating and current shaft currents, double loop closing of alternating and current shaft currents, feedforward decoupling of alternating and current shaft voltages and space vector modulation. The vector amplitudes of the alternating and current shaft currents of the motor are given by means of a motor speed ring, the alternating and current shaft currents demands are distributed by means of the distribution method of alternating and current shaft currents, and tracing of a given value on the actual current of the motor by the double loop closing of alternating and current shaft currents is ensured, sothat the aims of meeting the load demands by the active power of the permanent magnet synchronous motor and zero reactive power are achieved. Zero reactive power operation of the permanent magnet synchronous motor is achieved, the loss of the reactive power of a power grid is reduced, the voltage quality of the power grid is improved, and the method has important meaning in national economic development. A speed adjustor and a current adjustor are a PI adjustor, a PID adjustor, a fuzzy PI adjustor, a fuzzy PID adjustor, a slide film adjustor or a neural network adjustor.

Description

technical field [0001] The invention relates to a control method for a permanent magnet synchronous motor, in particular to a zero reactive power control method for a permanent magnet synchronous motor. Background technique [0002] In recent years, scholars have conducted in-depth research on the control strategies of permanent magnet synchronous motors, mainly including direct torque control strategies, i d =0 control strategy, field weakening control strategy, maximum torque current ratio control strategy, etc. The direct torque control strategy does not need the motor position angle and does not need to depend on the motor parameters. The whole control structure is simple and robust. It controls the motor torque and the motor stator flux to meet the load requirements of the motor. However, the hysteresis control is adopted. The PWM frequency is not fixed and other shortcomings. [0003] The vector control technology is based on the idea that the armature current of the...

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Problems solved by technology

[0004] However, the above permanent magnet synchronous motor control strategy does not consider reactive power. If there are a large number of permanent magnet synchronous motor loads on the load side, the capacity of the reactive power compensation device in the grid will be insufficient, resulting in a decrease in grid voltage and quality.

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