A New Efficient Scheme for Frequency Control in an Isolated Power System with a Wind Generator

Abstract

Stable operation of a power system is indebted to establishing and maintaining instance balancing between power generation and consumption and, hence, successful control of the system frequency. The fluctuating nature of the wind power can pose considerable problems for the frequency control. This article proposes an efficient control scheme in handling the frequency of an isolated power system with a high wind penetration level, while the wind speed and the load are changed. The frequency can be managed by several methods, including blade pitch angle regulation of the wind turbine and dump load and energy storage systems, such as the flywheel energy storage system. However, the dump load dissipates the power and causes the efficiency of the whole system to degrade. In order to cope with this defection, a coordinator unit has been designed to enhance joint operation of the pitch angle regulation and the dump load. Since an energy storage device, depending on its capacity, can play an effective role in keeping the system frequency in a range of interest, a flywheel energy storage system is added. Simulation results obtained under various operating conditions are presented to evaluate the effectiveness of the control scheme performance when the isolated system is equipped with a flywheel energy storage system.