Provision of a synchronising power characteristic on DFIG-based wind farms

Abstract

The significant increase in wind penetration expected in the near future imposes the requirement that the bulk addition of wind farms to the network should not be detrimental to the overall network-operating characteristics. One way of ensuring this is to aim to provide a wind farm with a dynamic characteristic that is similar to that of a conventional synchronous-generator-based power station. A control strategy is presented that provides a DFIG-based wind farm with a power-response characteristic to network disturbances that dynamically resembles that of a synchronous generator. The DFIG controller is aimed at minimising the effect on network operation that the replacement of a conventional generator by a DFIG-based wind farm will have. A simple but realistic test network that combines synchronous and wind-farm generation has been modelled and used to assess dynamic performance. Simulation results are presented and discussed that demonstrate the capabilities of the new DFIG controller, although these are gained at the expense of losing some of the damping provided by conventional DFIG operation.