Abstract
Abstract A Conventional distribution transformer consists of bulky windings, cores and coolant liquid hence it is weighty and large in size. Now days, supporting by development of power semiconductor devices, the idea to develop distribution transformers using switching power converter technology becomes viable. This paper proposed a new structure of a solid state transformer (SST) for power electrical distribution system. The proposed SST works without utilizes high frequency isolating transformer. Instead, high gain cascaded Buck converters are used. The design of Buck Converters involves calculation of the applied components such as Inductors and Capacitors. Simulation result verifies that Buck Converters work well to reduce DC voltage of 25 kV DC voltage to 620 V DC without excessive ripple. The proposed SST is successfully operated to step down 20 KV of AC voltage to 400 V with THD of output voltage less than 2 %.