To solve regional voltage instability caused by large-scale wind farm active power fluctuations

this paper studies reactive power optimization model and algorithm for highly wind power penetrated regional grids. Besides

it proposes a reactive power control strategy considering both safety and economy.The strategy is divided into three layers:The monitoring layer utilizes WAMS and SCADA to monitor voltages

power flows and reactive source statuses in real time;The calculation layer is to calculate the reactive power upper and lower bounds of DFIGs on the basis of the monitoring layer information

and uses the quantum-behaved particle swarm optimization（QPSO）algorithm to solve the joint reactive power optimization model;The execution layer is responsible for issuing the calculation layer results to each reactive source. The strategy can fully utilize the DFIGs’ reactive power adjustment capability to improve the overall static voltage stability of the regional grid and reduce the power loss while ensuring the node voltage is within the control range. Case studies show that the proposed strategy is feasible and provides a reference value for highly wind power penetrated regional grids operation.