Study On Protection Circuit Of High Frequency Chopper Cascade Speed Control System

At present Cascade speed control are increasingly being used in the field of large motors of energy-saving speed control. Chopper cascade speed control is a new type of cascade speed control with the development of power electronics, computers and other new technologies, methods and techniques. It not only inherits the advantages of the conventional cascade speed control technology, but also to overcome shortcomings of the conventional cascade speed control Harmonic big and inverter capacity and poor reliability. So depth study of the protection circuit of the high-frequency chopping cascade speed control system, can greatly improve the speed control system stability, reliability.Firstly, This paper is according to the contactor’s protect the main circuit structure of the high-frequency chopping cascade speed control system, analysis of process of the contactor’s protect in speed control failure. Against the drawbacks of the contactor protection, is designed main circuit topology of electronic and the contactor protection, then analysis the process of action to protect in speed control failure. Against transient process for the high-voltage power failure, derived in detail the theoretical, and is obtained the basis of theoretical analysis in the case of high voltage power failure. Combination of the main circuit parameters of high frequency chopper cascade speed control system, and analysis and calculation of the ideal parameters of the electronic protection devices. According to the calculated parameters, is selected the appropriate electronic protection devices. And finally build a simulation model, Simulation results show that the design of electronic protection plus contactor to protect of the main circuit topology is correct.