Main circuit diagram of single-phase conversion UPS power supply with static switch

UPS power supply can be divided into conversion type and parallel type according to the inverter combination method. The main circuit block diagram of single-phase conversion type UPS power supply with static switch is shown in the figure. It can be seen from the figure that when the mains power is normal, the inverter output is used as the main power supply to supply the load. In order to facilitate maintenance, a manual maintenance bypass switch is set up, that is, during maintenance, first close the bypass switch S, and then open S2, S3 and the static switch. If the backup power supply is used to supply power to the load, the UPS system will be separated from the bypass system. At this time, the inverter and static switch can be repaired. When the inverter is used as the main power supply, first close the static switch and bypass switches S2 and S3, and then open S1.