Enhancement of frequency regulation in tidal turbine power plant using virtual inertia from capacitive energy storage system

Abstract

Frequency stability has been a significant issue for a long time for the proper operation of isolated microgrids. Most distributed energy sources have converter-based interface and do not normally respond to frequency deviations. By increasing the penetration of the renewable sources like tidal power, solar power, wind power etc. into the microgrid provides power support but at the expense of a diminishing in inertia and initial frequency regulation. Owing to this, both the maximum frequency nadir and the rate of change of frequency deviation worsen, which creates a risk to frequency regulation. In this investigation, the support of the deloaded tidal power plants with various degree of infiltration in frequency regulation utilising controlling methods such as inertia control and droop control are evaluated. This investigation proposes an integral tilt derivative droop controller in deloaded area to suppress frequency deviation (ΔF) over fixed and proportional integral derivative (PID) droop controllers. Outcomes of these controllers have been evaluated in MATLAB Simulink. Supplementary support of virtual inertia from capacitive energy storage system is also investigated on frequency regulation. Moreover, the effect of consolidated outcomes of inertia and droop controlling methodologies with capacitive energy storage systems on frequency response is likewise discussed. To demonstrate the robustness of the proposed model nonlinearity factors like generation rate constraint and governor dead band are added.