Damping of Power System Oscillations by using ANFIS based UPFC supplementary controller

Abstract

The main purpose of this paper is to investigate an Adaptive Neuron- Fuzzy Inference System (ANFIS) based supplementary Unified Power Flow Controller (UPFC) in superimposing a damping function on the control signal of UPFC who’s incorporated in multi-machines power system. By using a hybrid learning procedure, the proposed ANFIS construct an input –output mapping based on stipulated input-output data pairs.This control scheme designed to produce supplementary signal for damping oscillations in the interconnected power systems. Oscillations in power systems have to be taken a serious note when the fault takes place in any part of the system; else this might lead to the instability mode and shutting down of the power system. The UPFC device is modelled using dynamic phasor method and interfaced with an interconnected power system. The improved damping performance was studied and it is validated on a benchmark power system example taken from literature. The systems model is evaluated via simulations during unbalanced faults. The control actions are formulated as a set of local controllers, namely the generator excitation controller, power system stabilizer (PSS) and unified power flow controller, which are coordinated to maintain transient angle stability, transient voltage stability and damping of inter-area and local oscillations following a disturbance.