Abstract:The control moment gyroscope is the execution agency and it is one of the core components that ensure the expectancy life and work performance of the spacecraft. In order to improve the orbit life of the control moment gyroscope, it is necessary to inhibit the common mode voltage of the control moment gyroscope outer frame. This paper proposed the optimized three-phase four-leg topology and improved SVPWM modulation algorithm to inhibit the common mode voltage. This control strategy avoids the use of zero-vector, and it can keep the system in a balanced state. By comparing and analyzing the results of simulation and experiments, the strategy is verified that it can effectively suppress the common mode voltage of the system.