Tracking-differentiator-based dynamic virtual inertial control of offshore wind power plant for frequency regulation

The increasing penetration of electronic-converter-interfaced wind generations remarkably declines the inertia of the power grid, which deteriorates the grid frequency stability. In this regard, various virtual inertial control (VIC) techniques have been developed. Among them, the proportional-derivative (PD) VIC is currently considered a standard solution. However, the problem with the PD-type VIC is that its structure amplifies the measurement noise and other high-frequency disturbances. This disadvantage greatly limits the overall quality of energy generation. Motivated by this practical problem, in this paper, a tracking-differentiator-based dynamic VIC is proposed for primary frequency regulation in offshore wind power plant. The idea is to derive the derivative of the frequency deviation, which canbe used to reject the adverse effect of noise amplification. This method can also help to avoid frequent adjustments of wind turbines, thus decreasing both damage and maintenance costs. In order to further enhance the control system anti-disturbance capability, a linear active disturbance rejection controller is designed to robustify the secondary frequency regulation. A single area modern power system including wind power and thermal power is simulated to verify the effectiveness of the proposed control strategy.