Voltage and frequency control of a hybrid Wind-Diesel system using SVC and predictively controlled SMES

Abstract

This paper focuses on the simultaneous frequency and voltage control of an isolated hybrid wind-diesel power system using Superconducting magnetic energy storage (SMES) system and static Var compensator(SVC). Since inertia of the system is small, any disturbance in load will cause electromechanical oscillations which degrades the power quality(both voltage and frequency) of the system. Center of inertia technique (COI) is used to estimate the system frequency which is used for controlling SMES unit. SMES unit is used to modulate the active power using an adaptive predictive control scheme which generates reference power for the SMES and forces it to follow the power command. Reactive power control is achieved by SVC. Both SMES and SVC are modelled as controlled current sources and act as sources/sinks of active and reactive power respectively. Simulation results show that the deviations in voltage and frequency are reduced considerably by incorporation of SMES and SVC at a specified bus in the system.