Commutation torque ripple suppression method for permanent magnet brushless DC motor

Abstract

The invention belongs to the technical field of motor control, and relates to a commutation torque ripple suppression method for a permanent magnet brushless DC motor. The method comprises the following steps of: detecting a rising edge or falling edge of a Hall signal, starting commutation, and executing the commutation torque ripple suppression method; acquiring a non-commutation current sampling value and a motor running speed at a current moment; calculating back electromotive forces of phases of a three-phase winding at the next moment according to the motor running speed and a commutation mode respectively; obtaining the voltages to power earth of end points of the three-phase winding in different inverter circuit switching-on states at the next moment respectively; predicting predicted values of non-commutation current in the different inverter circuit switching-on states at the next moment respectively; performing estimation on the predicted values of the non-commutation current in the different inverter circuit switching-on states by utilizing a value function; selecting the inverter circuit switching-on state in which the value function has the smallest value as the inverter circuit switching-on state of the next moment, and generating a corresponding inverter circuit control signal; and detecting the current of a corresponding switched-off phase is reduced to zero, finishing the commutation process, and stopping the commutation torque ripple suppression method. By the method, the commutation process can be accurately determined, and control over the inverter circuit switching-on state can be realized relatively better at the moment of commutation to realize commutation torque ripple suppression.

Description

technical field [0001] The invention provides a method for suppressing commutation torque fluctuations of a permanent magnet brushless direct current motor, which belongs to the technical field of motor control, and in particular relates to the technical field of permanent magnet brushless direct current motor control. Background technique [0002] The permanent magnet brushless DC motor adopts electronic commutation, which eliminates the mechanical contact device composed of commutator and brush, so the maintenance cost is low and the service life is long; the excitation is obtained through the permanent magnet of the rotor, no excitation current is required, no excitation loss, and the efficiency is high. Higher; has a smaller moment of inertia, has a faster response under a given electromagnetic torque, and has a relatively high torque inertia; the rotor loss is negligible, has high operating efficiency, and avoids the problem of rotor heat dissipation; the volume is small...

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Problems solved by technology

[0004] In the previous literature research, the current control strategy in the commutation process is mostly based on the PWM modulation strategy, and most of the current commutation torque fluctuation suppression strategies consider the high and low speed running states of the motor separately, which increases the complexity of the system and control strategy , so in practical applications, it is necessary to find a unified method that can effectively suppress commutation torque fluctuations in the entire speed range, improve the operating performance of permanent magnet brushless DC motors, and expand its application fields

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