A placement method of fuzzy based unified power flow controller to enhance voltage stability margin

This paper presents a placement method of fuzzy logic based unified power flow controller (UPFC) in power system network by analyzing dynamic voltage stability. Voltage stability indices namely LQP and voltage collapse point indicators (VCPI) indices are used to determine the weakest line for UPFC by dynamic load variation. The controllers of the shunt and series converters of the UPFC are developed using fuzzy logic (FL) and proportional integral (PI) controllers respectively to enhance the dynamic voltage stability of the power system network.The simulation has been conducted in power system computer-aided design (PSCAD) environment where IEEE-5 and IEEE-14 bus system have been chosen as test bench systems. The results obtained through simulations have ensured the effectiveness of the proposed placement method since fuzzy based UPFC´s placement in the obtained locations resulted in significant improvment in voltage stability.