Research on Sensorless Fuzzy PID Control of BDCM based on Improved State Observer

Abstract: Relative to traditional methods of back-EMF zero crossing points (ZCPs) delay detect, a new method to detect the rotor position of BLDCM is proposed by constructing a state observer to estimate line back-EMF based on line voltage and line current in this paper.And improve the observer, the linear error function is added to the original nonlinear error feedback coefficient of the observer. The combination of the two functions helps accelerate the convergence of the observer and improve the stability of the observer.In order to make its rotate speed more stable, the fuzzy PID is used to replace the traditional PID for the outer ring of the rotate speed.Finally, the simulation results show that this method can accurately estimate the position information of the rotor. With the help of the fuzzy PID control method, the precise control of BLDCM can be realized in a wide speed range.