SUPRESSION OF LOW FREQUENCY OSCILLATIONS(LFO) IN THE POWER SYSTEM BY NUERO FUZZY LOGIC CONTROLLER
Keywords:
Neuro-Fuzzy Controller, Low Frequency Oscillations (LFO), Unified Power Flow Controller (UPFC), Single Machine-Infinite Bus (SMIB).Abstract
Low-frequency oscillations (LPF) in electric power systems due to the uncontrollability of the disturbance in the power system. These oscillations need to be controlled to maintain system stability. Several control devices, such as power system stabilizers, lead lag controllers are used to enhance power system stability. The UPFC can be used to effectively control these low-frequency power system oscillations. It is done by designing a supplementary signal based on either the real power flow along the transmission line to the series converter side or to the shunt converter side through the modulation of the voltage magnitude reference signal. In this work the linearized model of synchronous machine connected to infinite bus (Single Machine-Infinite Bus: SMIB) with UPFC, adaptive neuro fuzzy controller for UPFC is designed and simulated to suppress the low frequency oscillations. Simulation is performed on the characteristics of the fuzzy controlled bus system. It is evident that the fuzzy logic controller has effective operation than the conventional lead-lag controller through the obtained results.
