UPS/APF power conversion equipment with a seamless mode transfer

The paper proposes a control algorithm for an integrated inverter system to maintain desired output voltage waveform when Power Quality disturbances occur. Most reason for these events are an instantaneous voltage sag and a momentary interruption. To solve these problem, when the power source voltage is out of normal range or a momentary power outage causes the problem, power is supplied to load through inverter stored in the battery voltage. Until they recover from the previous problem occurred, this proposed control method has little steady-state error, and good transient response characteristic. If power source voltage is supplying normal range, it operates based on current-controlled (APF mode). But if source voltage is supplying sag and momentary interruption, it operates based on voltage-controlled (UPS mode) that is supplying continuous voltage to load. During the UPS operation, when the source voltage returns to the normal range, it operates as an APF. In this paper proposed method has the advantage of the lower cost and smaller space, major automation equipment protects from a momentary interruption and sag of within one second, and this system designed sinusoidal that output waveform. In this paper System Control (APF, Boost Vdc, Mode Conversion) will discuss.