Research And Application Of SVPWM Algorithm On Modern Cascade Speed Control System

Due to main power of the fans and pumpsthe is three-phase motor, the core problem to improve the running efficiency of fans and pumps is asynchronous motor speed control. Cascade speed control is the most classical asynchronous motor speed control method, long-term since people on this theory have done a lot of research, but because the technology and other reasons, has not been widely used. With the development of modern power electronic technology and computer control technology development, the cascade speed control technology, has obtained the revolutionary improvement, making its performance meeting the large-scale industrial application requirements.Modern cascade control system inverter is usually adopted thyristor composed of three-phase bridge inverter, because of the problems of inverter harmonics and easy occurrence inverter subversion, so the cascade speed control system has disadvantages of low power factor and low reliability.Therefore, this paper proposes the use of algorithm based on SVPWM IGBT three-phase inverter circuits instead of traditional inverter using thyristor circuits, to improve the power factor and the reliability of the modern cascade speed control system. Firstly, the paper introduces the thought of the voltage space vector pulse width modulation algorithm, and summarize the process; Secondly, in the MATLAB/Simulink environment respectively on SVPWM, SPWM and SCR active inverter modeling, simulation result by comparison found SVPWM hasing the lower harmonics and the higher power factor; Again, realize SVPWM active inverter algorithm using HDL, and verify its correctness in ModelSim joint simulation environment, Finally, combined the cascade speed control system model and the HDL model in MATLAB and ModelSim joint simulation environment has proved that the algorithm can be applied in cascade control system, and can improve the power factor of system.Therefore, the paper concluded that the IGBT three-phase active inverter using SVPWM algorithm can replace traditional inverter using SCR in modern cascade control system, and can improve the power factor of system.