Fuzzy logic control of a 400 KV transmission line by a statcom based on NPC multilevel voltage inverters

Abstract

Recent developments in power systems mean that it will be increasingly difficult to reliably control power

transfers in highly interconnected systems using traditional slow response time control systems such as phase- shifting transformers and passives shunts or series compensators.

This has recently led to studies of a new generation of FACTS (Flexible AC Transmission System) control devices, using new power static components that can control both opening and closing: a FACTS device. This paper introduces the STATCOM, a power device reliant on a semiconductor power switches for controlling electrical networks. It serves to enhance the regulation of both active and reactive power transmitted through power lines. Specifically, the STATCOM compensates the reactive energy of the lines, maintains the voltage levels at the bus bars and enables the power source to operate with a unity power factor. After a concise introduction to the operating principle of the STATCOM, a model is presented featuring key control loops including Phase-Locked Loop (PLL), DC bus voltage control, and power control. Linear controllers (Proportional Integral PI) are used and an approach using Fuzzy Logic Controllers (FLC) is tested. Simulation results for a 400 kV line conducted within the Matlab/Simulink environment are presented, providing a comparative analysis and discussion on the effectiveness of the adopted control strategies in addressing both dynamic and static aspects of the