Study On The Sensorless Control System Of Switched Reluctance Motor

Traditional closed-loop control system of switched reluctance motor is dependent on the rotor position sensor, which increases the cost and the complexity of the whole system very much, while reducing the reliability and robustness. So this paper has developed a new senserless system of SRD.Firstly basic mathematical equations and main control method of Switched Reluctance Motor Drive system (SRD) are elaborated, due to the advantages of finite element analysis method in the field of electrical and magnetic calculation, finite element analysis method was carried on for 18.5 kW SRM prototype. The flux linkage characteristics of SRM measurement method is presented, and the specific experimental measurement results and theoretical finite element analysis results were analyzed. According to the compared data result, the end effect compensation.of SRM was abtained.Because of the non-linear characteristic model of SRM, such models as inductor model, finite element method (FEM) model and neural network model and their own advantages and disadvantages are explored in this paper. Then, comparative analysis between experimental results and theoretical data is conducted. Based the FEM analysis of prototype of 18.5kW SRM, detailed results was given, which laid the foundation for the optimization design of SRM.A bi-directional power converter topology, with front-end power converter using PWM rectifier to achieve the energy feedback, high power factor and low harmonic current network side, and to allowing electrical braking energy feedback, is presented in this paper, which increased efficiency of the whole system. Then, mathematical model of three phases PWM rectifier is built with analysis of basic principals. Experiment verification is performed based the control of vectors of gird voltage.Considering good self-adaptability and robustness against the external disturbances and non-linear characteristic of SRM, the sliding mode observer (SMO) was applied in position sensorless control of SRM. After describing the basic principle of the variable structure control of sliding mode, this paper proposed a block diagram of sensorless control of SRM based of sliding mode observer. At the same time, a specific characteristic of SMO in sensorless control for SRM is presented, and detailed algorithms and design methods of SMO are given. Simulation results show that the algorithm is simple and reliable.For the design of position sensorless control system of SRM, this paper presents control strategies such as pulse incentive method and flux-current method and simple but applicable to industrial and mining applications and concrete implementation steps and software charts, with improving the identification accuracy of resistance and flux are given in this paper. Then, practical free-start motor with a load and no inversion, which being verified by experiment of prototype platform of 18.5kW SRM, is achieved. Results show that sensorless position strategies using in control system of SRM is effective.