Commutation control circuit of square wave brushless direct current generator and commutation signal extraction method

Abstract

The invention provides a commutation control circuit of a square wave brushless direct current generator and a commutation signal extraction method.The commutation control circuit comprises a voltage detection module and a central processing unit CPU, the input end of the voltage detection module is connected with the three-phase output end of the square wave brushless direct current generator, and the output end of the voltage detection module is connected with the three-phase output end of the square wave brushless direct current generator; the neutral point of the square wave brushless direct current generator is connected with the input end of the voltage detection module, the voltage detection module detects the phase voltage of the square wave brushless direct current generator, the central processing unit CPU samples and processes the phase voltage to obtain a commutation moment, and meanwhile, a PWM signal is triggered to control a power module of the square wave brushless direct current generator to realize commutation. The square wave brushless direct current generator commutation signal extraction circuit overcomes the defects that an existing square wave brushless direct current generator commutation signal extraction circuit is too complex, high in cost and high in failure rate, the cost is effectively reduced, the failure rate is small, the control algorithm is simple, and the commutation stability of a square wave brushless direct current generator is improved.

Description

technical field [0001] The invention relates to the technical field of generators, in particular to a commutation control circuit and a commutation signal extraction method of a square-wave brushless DC generator. Background technique [0002] The square wave brushless DC generator has the advantages of long life, large output torque, high power density and simple control. It is widely used in aerospace and wind power generation and other fields. The control method is divided into square wave brushless DC generator with position sensor Motor control and position sensorless square wave brushless DC generator control. The square wave brushless DC generator with position sensor is controlled by implanting a Hall sensor inside the generator to detect the position of the rotor, but there are disadvantages such as being susceptible to interference, difficult to work in high and low temperature environments, and heavy, which limits its widely used. The square-wave brushless DC ge...

AI Technical Summary

Problems solved by technology

[0006] However, the above method of extracting the commutation signal of the square wave brushless DC generator is too complicated due to the hardware circuit, which leads to high cost and high failure rate.

At the same time, the filtering of the terminal voltage will cause the phase shift of the back electromotive force signal, making the back electromotive force zero-crossing signal inaccurate, requiring phase compensation and increasing the complexity of the control algorithm

Images