Optimal location determination of UPFC based on techno-economic criteria and security constraints

Abstract

Desirable power flow control in a deregulated power system is achieved independently or simultaneously by the Unified Power Flow Controller (UPFC), which is the most versatile and suitable Flexible AC Transmission Systems (FACTS) device. Performance analysis of the UPFC is done in this work considering practical security constraints and implemented using MiPower. In order to reduce the search space and computation time, performance assessment of the device is executed only at the weaker buses and weaker lines of the system, which are identified using Fast Voltage Stability Index (FVSI). The UPFC losses such as switching losses of converters, losses due to coupling transformers and power transmission losses in UPFC are taken into account for power flow calculation. Considering practical upper and lower limits of voltage magnitude, an innovative voltage profile enhancement index (VPEI) is formulated. In this paper, objective functions, namely, overall improvement in FVSI, VPEI, reduction in losses and expenditure of UPFC are considered altogether in order to determine the optimal location of UPFC on IEEE 30-bus test system.