Active Power Flow Control Using Phase Shifting Transformer and UPFC in AC Transmission Line

Electrical power system is huge interconnected power system to meet the consumer demand without interruption and to maintain the stability, to utilize existing system to their maximum limit within stability limit of the system, to solve the congestion problem and improve the power flow in the line. Phase shifting transformer (PST) is used to control the active power flow in transmission line. This active flow control is obtained by adjusting phase angle of voltages at PST terminal. Unified power flow controller (UPFC) is facts device, it can control both the active and reactive power in transmission line by controlling the line parameter like voltage, phase angle and line impedance there by adjusting the line reactance in real time. The power system simulation model for PST and UPFC are developed in MATLAB. By simulating the model without PST and UPFC and then model with PST and UPFC is simulated to obtain the results. Results are compared for different loading condition to analyze the performance of the system with both the model.