Load frequency control for wind-diesel hybrid systems

A wind-diesel hybrid power system is a feasible and economic method to supply power for remote areas. To maintain a sustainable and dependable power supply, the frequency of the system must be kept a constant. This paper adopts a two-degree-of-freedom internal model control (IMC) method to study the load frequency control problem for a wind-diesel hybrid power system. The method needs only to tune two parameters and is effective in rejecting disturbance. Due to the high-order transfer function of the system model, a PID reduction method is proposed to reduce the high-order IMC controller for easy implementation of the control system in practice. The design and simulation results show that the load frequency controller at the diesel generator can regulate the system frequency quickly, while the pitch controller at the wind turbine can attenuate the effect of the wind uncertainties on system frequency.