Brushless direct current motor control method based on magnetic linkage tracking

Abstract

A brushless direct current motor control method based on magnetic linkage tracking comprises the steps of determining a reference magnetic linkage psi (n) according to expected rotating speed w and an expected torque Tp of a brushless direct current motor, constructing a virtual magnetic linkage according to an incremental model to approach to the reference magnetic linkage psi (n), and finally controlling an inverter to output to obtain required PWM (pulse-width modulation) drive according to a state corresponding to an approaching result. The method utilizes a magnetic linkage tracking technology, and can automatically realize seamless switch from overmodulation (six-beat-wave) output to linear modulation output. When the brushless direct current motor operates in a large torque state, a controller outputs six-beat-wave level to allow the motor to have the maximum direct current bus voltage utilization ratio; and when the motor operates in a small torque state, the controller can be smoothly switched to a PWM wave state with the output subjected to linear modulation so as to allow the motor to run stably.

Description

technical field [0001] The invention relates to a modulation method of a brushless DC motor speed controller, in particular to a brushless DC motor control method based on flux linkage tracking that can effectively reduce motor torque ripple under small torque conditions. Background technique [0002] At present, as the concept of green and environmental protection is becoming more and more popular, electric vehicles, as a clean and environmentally friendly means of transportation that can achieve zero emissions and zero pollution, are increasingly being valued by people. However, the brushless DC motor speed-regulating controller used in the existing electric vehicles still has many problems during work. Among them, the motor torque ripple in the case of small torque is an important defect factor. [0003] The traditional brushless DC motor speed controller always works in the output six-beat mode to simulate the mechanical commutation of the traditional DC motor and outpu...

AI Technical Summary

Problems solved by technology

In fact, the linear modulation scheme based on space voltage vector modulation technology (SVPWM) has been developed very maturely, but because the traditional SVPWM-based over-modulation strategy algorithm is too complex, the SVPWM method that only uses linear modulation directly affects DC bus voltage utilization

Therefore, this problem also limits the application of traditional SVPWM schemes on brushless DC motor controllers.

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