Abstract: The driver is the core part of the satellite antenna.An Alternating Current servo system for making rotary antenna at an accurately constant speed.Based on the design ideas of the polygon flux linkage locus,construct is used to get the switch table of three-phase inverter.The hardware and software of the system have been designed and debugged on the CPU of special motor controller-TMS320F240.Simulation result shows that the error of angle measure is within ±0.07° and precision of scan cycle can be within ±0.34ms in this system.