Research On Control Method Of Variable Frequency Speed Ajusting Of Asynchronous Electromotor

Along with the appearance of new electronic elements and intelligent power IC, the development of modern control theory and the application of computer technologies, the technology of adjusting speed of AC induction electromotor changes quickly and new control method appears ceaselessly. DC electromotor is replaced by the AC induction electromotor in wide range. The AC variable frequency speed regulation is generally acknowledged by the home and abroad that it has a great future with excellent speed regulation,high efficiency saving energy,extensive scope of application and other merits,Variable-frequency adjusting-speed for induction motor is implemented by sine pulse width modulation(SPWM) and space vector pulse width modulation(SVPWM) in this paper.In this control system, 80C196MC is used as the main high performance microprocessor chip which is produced by Intel company and is special for motor control. Three phase modulating wave is generated by wave form generator in CPU. The AC-DC-AC topological structrue is adopted in main circuit. IPM(Intelligent Power Module) is used as the power device. The algorithm structure of SVPWM and SPWM based on 80C196MC single-chip computer, the relative parameters' calculation and the setting method of some registers of the wave form generator are detailed in this paper.The design scheme is tested and debugged on an asynchronous motor. The scene results show that lower current harmonic , more efficient use of supply voltage ,lower noise can be achieved by the method of SVPWM than the sine pulse width modulation(SPWM).