Research on Multi-frequency Damping Control Method of Energy Storage for New Energy Station

With the large-scale access of new energy sources such as wind power and photovoltaic, the interaction between new energy sites composed of many power electronic equipment and the power grid is increasing, which is easy to induce multi-frequency oscillation phenomenon in the power grid. In order to understand the multi-frequency oscillation between new energy and power grid, a new energy station system model including wind power, photovoltaic and thermal power generation units is established in this paper. Then, the oscillation characteristics of the power grid under different operating conditions are analyzed, and the characteristic frequencies of different frequency bands are aggregated and divided into low frequency oscillation, sub-synchronous oscillation and high frequency oscillation in turn by eigenvalue analysis. Then, with the help of the fast response characteristics of energy storage, a multi-band oscillation suppression system of power grid is constructed. By dividing the frequency bands of power grid frequency and voltage oscillation, the damping effect of different frequency bands is improved to realize the effective suppression of multi-band oscillation. Finally, the effectiveness of the proposed control strategy is verified by simulation.