A Novel VSG Control Strategy for UPS Voltage Source Inverter with Impulsive Load

Abstract

This paper proposes a novel control strategy to alleviate the impulsive current for Uninterruptible Power Supply (UPS), which is designed based on the theory of virtual synchronous generator (VSG) and dynamic switching method. The power quality of UPS will become distortion when the instantaneous impulsive load is imposed on UPS. Especially, the output current of UPS will increase quickly in short time. In order to maintain the uninterrupted output voltage and reduce the distortion of output voltage of UPS under the action of instantaneous impulse load, Dynamic switching method is proposed to resist impulse load with large scale impulse current, Meanwhile, the VSG control strategy is adopted to deal with the slow power switching and provide virtual inertia for the system, so that the output voltage of UPS can remain uninterrupted and stable. Finally, simulation and experimental results show that this method can effectively suppress the impulse current, reduce the output voltage distortion of UPS inverter, and ensure the good performance of On-line UPS under impulse load.