Study on cooperative reactive voltage sensitivity control strategy of AVC substations in clustered offshore wind farm

In recent years, more and more East coastal areas in China have formed large-scale renewable power generation clusters, compared with the form of long-distance radial-wiring integration to the power grid, offshore wind farms usually connect with each other near their landing point and then access to the main grid alongside. Applying the traditional single wind farm access system reactive voltage sensitivity way to respond to the automatic voltage control (AVC) main station voltage command regulation is easily triggered by abnormal fluctuations in local grid voltage. This paper proposes a cooperative reactive voltage sensitivity control strategy for clustered wind power AVC substations. Considering the interaction relationship between wind farms, the calculation method of reactive voltage sensitivity of AVC substations is derived, and the decoupled cooperative control strategy of reactive voltage sensitivity of AVC substations is proposed. Furthermore, the power loss under different reactive power output distribution methods is specifically analyzed. Three typical wind power clustering integrated systems are involved and examined to verify the effectiveness of the proposed algorithms based on MATLAB/MATPOWER platform. The example results show that compared with the traditional reactive voltage sensitivity algorithm, the proposed algorithm can regulate reactive power output of clustered wind farms to smoothly and effectively respond to the voltage regulation, and can better realize voltage control of grid-connected points of AVC substations under the conditions of the change of voltage deviation, the change of the topology structure and the different levels of wind power output, so as to maintain stable operation of the power grid voltage.