Pure hardware separation system of non sensor brushless DC motor zero start

Abstract

The disclosed pure hardware discrete system for zero-startup of no-sensor brushless dc motor comprises: a brushless dc motor, a brushless dc motor controller, a feedback compensation circuit, a voltage stabilizing circuit, a filter delay circuit, and a zero-cross detection circuit. This invention bases on back electromotive for zero-cross detection, responds in very short time, reduces calculation load, low cost, high reliable, and 90deg hardware time delay.

Description

technical field [0001] The invention relates to the field of sensorless control of a brushless direct current motor, in particular to the sensorless control of a 300w / 500w brushless direct current motor in the electric bicycle industry. Background technique [0002] Brushless DC motors use electronic switching devices to replace the mechanical commutation of traditional brushed motors, avoiding commutation sparks and noise caused by mechanical commutation of carbon brushes, and have good speed regulation characteristics, dynamic performance, small size and simple structure , High power density, more and more widely used. [0003] Usually, a Hall sensor or other type of position sensor is installed inside the brushless DC motor to obtain the rotor position information, so as to determine the commutation point of the electronic switch. The introduction of the position sensor can make the commutation of the brushless motor precise, so as to realize a series of excellent charac...

AI Technical Summary

Problems solved by technology

The existing sensorless brushless DC control strategy has the following shortcomings: 1. Poor zero-start performance, frequent out-of-step phenomena, back-off phenomena, and stalled rotor phenomena, and insufficient starting torque for initial rotor positioning; 2. Using The DSP chip processes the high-frequency injection signal to detect the spatial position of the rotor, the calculation load is heavy, and the reliability and stability need to be improved; 3. It is not compatible with the original brushless DC motor hardware system and software system. Using the sensorless brushless DC motor control strategy will give The original production process, operation method, and system design have brought huge changes, the risk of upgrading is too high, and cost control is difficult

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