Design And Implemention Of SEC Cascade Speed System IGBT Source Inverter Control

High voltage three-phase asynchronous motor has been used in fans, pumps and other large machineries. In today’s society, people advocated to save energy. The core problem to improve the running efficiency of fans and pumps is asynchronous motor speed control. Cascade speed control as a classical speed control technology, has been widely used in motor speed fields.Although the use of chopper control technology has greatly improved the power factor,modern cascade speed control technology adopts commonly thyristor inverter to feedback the slip power of the motor’ rotor to grid, there are still many disadvantages:the voltage waveform of grid is distort, the power factor is reduced in lower speed and the inverter subversion can be happened some cases because the use of thyristor inverter.For lack of above, this paper proposes the use of based on IGBT three-phase inverter circuits instead of traditional inverter using thyristor circuits, with its advantages: controllability.Firstly, because traditional thyristor has inverter subversion,this paper introduced the work principle of based on IGBT three-phase inverter. Secondly, this paper designed the structures of speed control system and active inverter, form the angle of the theory proved it can work stable. This paper selected the relevant electric devices, designed the relevant hardware circuits and wrote relevant software programs. These things are ready for building the experiment table and prototype. Lastly, this paper deeply analyzed the cascade control technology, proved it can improve the power factor of system form the theory and debugged the experiment table and prototype. Therefore, it verifies the specific realization method that IGBT active inverter applies in modern cascade control system, and can improve the power factor of system.