Optimal reactive power dispatch of permanent magnet synchronous generator-based wind farm considering levelised production cost minimisation

As wind power penetration increases, large wind farms (WFs) need to provide reactive power according to modern grid codes. Permanent magnet synchronous generator-based wind turbines (WTs) can generate reactive power, by assigning the appropriate reactive power to each WT to meet the reactive power requirements of the grid. This is a more economical method than setting up additional reactive power compensation equipment. This study proposes an optimal reactive power dispatch strategy for minimising a levelised production cost, and is implemented in two ways: minimising the power loss of a WF, and maximising the lifetime of WTs. The reactive power references of each WT are chosen as the optimisation variables, and a particle swarm optimisation algorithm is adopted to solve the optimisation problem. The proposed and traditional reactive power dispatch strategies are demonstrated and compared on a WF with 25 WTs to validate the effectiveness of the proposed approach.