Load Alleviation in Transmission System by Using Phase Shifting Transformer

This research aims to present the method of Load Alleviation in Transmission System by using Phase Shifting Transformer (PST). The study was done by creating the simulation in PowerWorld software. The tendency of using electric power in Thailand will be increasing in the future. Therefore, the NBL-UD1 Line in the network is going to have the increased loading percentage 88.8 in 2030. PST was used in spreading the load in that line by adjusting the voltage's phase angle of the bus at the end of the PST. The power flow, as a result, in that line had been changed. The model of PST at NBL-UD1 line was adjust by 6 degrees phase shift, and -2.5 degrees phase shift at UD1-UD3 line, caused the NBL-UD1 line loading percentage to be decreased, 64.4. The result shows that the proper of phase shifting of Phase Shifting Transformer can be used in the load alleviation of the transmission system by using power flow control to transfer to others line.