Research On High Precision Sensorless Control System Of Switched Reluctance Motor

With the rapid development of power electronic switching devices and high-performance motor control chips,switched reluctance motors have received widespread attention for their simple structure,low cost,and strong fault tolerance.Due to the structural characteristics of the switched reluctance motor,accurate rotor position information must be obtained for reliable operation.The traditional switched reluctance motor control system often adopts electromagnetic type,photoelectric type,hall type,rotary transformer,and other position sensors for position detection.In extremely harsh working environment,the use of position sensors will seriously affect the reliability of the control system.Therefore,in order to solve the above problems,domestic and foreign scholars have proposed a sensorless technology.This article takes the high-precision sensorless control system as the research content,and aims at the practical application of the project.In addition,the theoretical analysis and experimental verification of the high precision realization of the initial positioning,commutation strategy,real-time speed estimation and real-time rotor position estimation of the sensorless control system of switched reluctance motor are carried out.First,the current status of the research on the position sensorless technology is briefly described,and the characteristics of various position sensorless detection methods are analyzed.Secondly,he basic principle of the model of the switched reluctance motor and the highfrequency pulse injection position sensorless detection method are introduced.Thirdly,a highprecision initial positioning method based on high-frequency pulse injection is proposed.Based on the traditional initial positioning method to determine the interval of the rotor position,the rotor position is accurately positioned.At the same time,a new control method of motor operation is proposed.It reduces the negative torque effect of high-frequency pulse injection on the motor,reduces the power consumption of the power device,increases the system efficiency,and improves the position control accuracy.It can directly perform accurate calculation based on the opening and closing angles of each phase.Turn-on and turn-off control increases the flexibility of control,and can still maintain a high accuracy in the case of voltage fluctuations.Then,in order to quickly apply this method to switched reluctance motors of different specifications and models,an online parameter identification method is proposed,which no longer requires offline measurement of the motor parameters required in the proposed method,making it a universal sensorless control method.Finally,the relevant design of hardware and software was completed on the experimental platform.Using a switched reluctance motor for electric vehicles as a prototype,the proposed high-precision sensorless control method was realized.Using the Hall position sensor as the position reference,the position error was analyzed,and the experimental verification of the theoretical scheme was completed,which confirmed the feasibility and accuracy of the method.