Tow-step inertia provision with consideration of load type in an islanded wind turbine with grid-supporting voltage control

The modern power system encounters difficulties in increasing the share of renewables as they are not participating in the total power system inertia, which endangers the strength of the power system against faults. As conventional generation with inherent inertia provision ability are being replaced by converter-based generation, they have to perform this role. Therefore, it is important that the control method of wind turbines seamlessly estimate frequency variation and be designed to make the inertia power command to smooth it. Hence, in this paper, inertia provision in an islanding scenario in a power system by a wind turbine will be studied. The inertia is provided via rotating masses or auxiliary power source, or together in a two-step inertia power injection. The power and energy limitations will also be considered in the comparison of inertia provision in different scenarios. The time is important for the injected inertia power to catch the frequency from falling into a very low nadir and make a different stability border for the share of renewables. In this study, the effect of converter-fed loads will also be investigated.