State Space Modeling and Robust Wind Power Generation System

Abstract

As producing power from renewable energy is increasing, facing new problems emerging from this phenomenon is becoming a good challenge for power system engineers. One of these problems is the dynamic and transient stability of such systems when they are connected to a power network. In this paper, a variable speed cage machine wind generation system is considered as the case study. The concept of power system stabilizer, which has been extensively developed for thermal and hydro power plants, is for the first time suggested for such systems. To be able to apply advanced control strategies, such as H¥ robust control, a state space representation of the system is required. First, a nonlinear state space model is developed and then linearized for use in robust power system stabilizer. As the wind speed changes randomly, the parameters of the equivalent linear model are quite uncertain. These parameters’ uncertainties are taken into account in the robust power system stabilizer. The reference values of direct and quadratic axis of the PWM inverter are considered as the inputs. The simulation results show that the proposed controller damps the power oscillation more rapidly and improves stability of overall system.