Abstract:In order to evaluate the frequency recovery capability of AC/DC hybrid power grid after fault accurately and quantitatively, a frequency resilience evaluation method for receiving-end power grid with multi-high voltage direct current (HVDC) feed-in is proposed. Firstly, electromechanical transient simulations are carried out under different HVDC blocking faults so that the frequency variation of power grid is obtained. Then, the area between the frequency change curve and the constant frequency curve during the primary frequency regulation is calculated to evaluate the frequency resilience of the power grid. In this way, the mapping relationship between various DC blocking faults and frequency resilience index is established successfully. Proposed method not only can evaluate the frequency resilience of multi-HVDC feed-in power grid, but also can analyze the effect of different measures on improving frequency stability. In the end, taking the actual East China power grid as an example. The adaptability of the proposed index to evaluate the frequency stability of power grid is analyzed. The stability improvement effect of various measures such as increasing gas turbine is quantitatively tested. The results show that the proposed frequency resilience evaluation method is effective and correct, which can effectively guide the planning and operation of the actual power grid.