Damping controller design based on FO-PID-EMA in VSC HVDC system to improve stability of hybrid power system

Abstract

Wind energy sources have different structures and functions from conventional power plants in the power system. These resources can affect the exchange of active and reactive power of the network. Therefore, power system stability will be affected by the performance of wind power plants, especially in the event of a fault. In this paper, the improvement of the dynamic stability in power system equipped by wind farm is examined through the supplementary controller design in the high voltage direct current (HVDC) based on voltage source converter(VSC) transmission system. In this regard, impacts of the VSC HVDC system and wind farm on the improvement of system stability are considered. Also, an algorithm based on controllability (observability) concept is proposed to select most appropriate and effective coupling between inputs-outputs (IO) signals of system in different work conditions. The selected coupling is used to apply damping controller signal. Finally, a fractional order PID controller (FO-PID) based on exchange market algorithm (EMA) is designed as damping controller. The analysis of the results shows that the wind farm does not directly contribute to the improvement of the dynamic stability of power system. However, it can increase the controllability of the oscillatory mode and improve the performance of the supplementary controller.