Study of Resistive SFCL and UPFC for Transient Behavior Enhancement of Multi-Machine Power System

Abstract

Based on a resistive-type superconducting fault current limiter (SFCL) as well as a unified power flow controller (UPFC), this paper researches the combined utilization of them to improve a multi-machine power system’s transient stability. The SFCL is firstly to provide a fault current-limitation. Then, the UPFC is to realize an efficient power flow adjustment and a precise stabilizing control. Related modeling and control are presented, and a four-machine two-area test system including a SFCL and a UPFC is simulated in MATLAB. Different simulation conditions are applied, and it can be concluded that: (i) The SFCL-UPFC enables to more directly and powerfully refrain the fault current surge, mitigate the bus voltage sag and alleviate the inter-area oscillation. (ii) As the increase of fault clearance time, the power system’s demand for the SFCL-UPFC’s stabilizing effect would be very critical. (iii) Compared to the asymmetric fault, the SFCL-UPFC owns a better ability to handle the symmetric fault.