Improving the performance of the northeastern part of the Syrian High Voltage network 230 kV using UPFC

Abstract

Modern power systems have become large, complex, and extended beyond limits. Therefore, they are constantly faced with the issue of stability, its

challenges, and its types, and how it is possible to increase the transmitted power on transmission lines. On the other hand, Flexible AC Transmission Systems (FACTs) have emerged, which depend in their work on advanced power electronics elements with high rated-voltages and currents, and very small switching time, which will play an important role in improving the stability of the power system, performance of transmission and distribution networks. FACTs can be classified into two groups, the first group of which relies on thyristors (GTO), which controls reactors or capacitors, to draw or inject reactive power, while the second group uses more advanced power electronics transistors (IGBT), through which the flow is controlled real power in the power system and the improvement of the voltage profile.

The previous functions can be combined in one FACTs system, this system is Unified Power Flow Controller (UPFC). The working principle of UPFC is based on extracting reactive power from the network and injecting it in the form of real power, and thus the power flow becomes optimal in the network, and it also contributes to improving transient stability and voltage profiles in networks, especially micro-grid, and also supports transient stability and helps to dampen power vibrations.This study was carried out  to improve the performance of part of the Syrian high-voltage network (230kV), as the study relied on results taken from the Ministry of Electricity, indicating that there is clear decrease in voltage of the studied network, so the suggested solution is to install the UPFC system to improve the network

performance, and it showed Results: The voltage drop improved so that it became at most within the limits of (5%), and the transmitted power on the transmission line increased by the limits of (0.05 p.u.), the rotor angles curves also became more stable during the transient state, and the voltage dips during the fault occurrence became significantly less.