Load Frequency Control of Multi-Area Interconnected System Comprising DFIG-Based Wind Turbine Equipped with Coordinated Control

Abstract

Traditionally, wind power generation has not contributed to power system frequency regulation due to decoupling between generator speed and grid frequency by power electronics devices. It has an adverse effect on load frequency control problem with increasing wind power level. The major focus of this article is to demonstrate load frequency controller for multi-area interconnected system comprising DFIG-based wind power plants equipped with coordinated frequency control technique. Single control technique such as inertial control, pitch angle control, or rotor speed control is not sufficient for all zones of wind speed. Therefore, coordination between theses controllers is required for frequency regulation of grid. In the present paper, two-area and three-area interconnected power systems comprising non-reheat thermal unit and wind power plant with coordinated control technique have been implemented. Two-area interconnected power system has been analyzed for different step load perturbations in each area. The novelty of this work is apparent from the fact that coordinated control of wind turbine for load frequency control problem of two-area and three-area interconnected power systems has not been reported in literature so far. Load frequency control incorporating coordinated control of wind turbine has been compared with inertial controller, combination of inertial and droop controller, and combination of inertial, droop and pitch angle control techniques in the case of the two-area interconnected power system, whereas it has been compared with combination of inertial, droop, and pitch angle control for the three-area interconnected power system. It has been established from the simulation results of the proposed controller that frequency and tie line power deviations have shown remarkable improvements for all wind speed zones.