Non-inductive boost topological driving brushless DC motor commutation torque ripple suppression method

Abstract

The invention provides a non-inductive boost topological driving brushless DC motor commutation torque ripple suppression method. A non-inductive DC-DC converter is designed to be additionally arranged before a three-phase voltage source inverter so that the overall system forms a non-inductive boost topological three-phase voltage source inverter driving circuit; the effect of different switching vectors on the motor input voltage and the non-inductive DC-DC converter output voltage is analyzed; when a brushless DC motor operates in the non-commutation stage, three working modes of a normal mode, a boost mode and a buck mode are designed according to the effect of the switching vectors; the output voltage of the DC-DC converter is regulated under the premise of guaranteeing normal speed regulation of the brushless DC motor by selecting three working modes; and when the brushless DC motor operates in the commutation stage, the two fixed switching vectors are adopted to suppress the commutation torque ripple of the brushless DC motor. The size and the cost of the driving system can be greatly saved, and the time of the commutation process can be effectively shortened in suppressing the commutation torque ripple so that the reliability of motor operation can be enhanced.

Description

Technical field [0001] The invention relates to a brushless DC motor. In particular, it relates to a method for suppressing commutation torque ripple of a brushless DC motor driven by a non-inductive boost topology. Background technique [0002] Brushless DC motors are widely used in industrial control, aerospace and electric vehicles due to their simple structure, high power density and stable and reliable operation. However, because the motor inductance and the limited inverter voltage hinder the rapid change of the phase current during the commutation process, the motor generates large torque fluctuations during the commutation process, and the maximum commutation torque fluctuation can reach the average torque. 50%. The commutation torque fluctuation will cause vibration and noise of the motor system, and reduce the load capacity of the motor, which is one of the main problems that limit the high-performance operation of the brushless DC motor. [0003] In recent years, scho...

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Problems solved by technology

[0004] However, there are still some problems in the existing commutation torque fluctuation suppression methods: For the PWM method, when the motor is running at a higher speed below the rated speed, under the limited inverter DC side voltage limit, this type of method cannot It is to suppress the commutation torque fluctuation by prolonging the off-phase current drop time, which will prolong the undesired commutation process time

For the existing front-stage DC-DC converter method, the power switches of the added front-stage DC-DC converter are more, and additional inductance needs to be added, which increases the size and cost of the drive system

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