Abstract：The traditional AC/AC variable frequency speed regulation system using thyristor as power device is characterized by many power devices and higher cost. Based on the analysis of traditional AC/AC frequency conversion speed regulation system and plugged pulse principle, a variable frequency regulating system on the base of three-phase continuous plugged pulse principle was studied by adopting constant voltage frequency ratio control strategy. According to the area equivalent rule, the control mode of variable pulse width chopping for the output voltage after plugged was analyzed in detail, and the algorithmic expression of output voltage amplitude in the variable pulse width chopping control was deduced, which provide the basis for the control of the output voltage amplitude. The variable frequency regulating system based on three-phase continuous plugged pulse principle was designed, and the output voltage and frequency could be adjusted simultaneously. The system simulation model was established under the environment of Matlab/Simulink, and the simulation experiment was carried out. The results showed that the proposed method was correct and had such advantages as simple control, better sinusoidal output voltage, less power devices, strong carrying capacity, and small size. It was suitable for low speed operation of the motor, and had certain practical application value.

Keyword：plugged pulse principle;three-phase continuous control;AC/AC frequency regulating;Matlab simulation;regulating system;