Optimum Design of Power Converter Current Controllers in Large-Scale Power Electronics Based Power Systems

In a large-scale power electronic system such as a wind farm, the mutual interactions between the power converter controllers and passive components may lead to instability problems or undesired dynamic response. This paper presents an optimum parameter design procedure for the power converter controllers in a power electronic system in order to guarantee a stable operation and to guarantee an acceptable dynamic response. In the approach, first, all oscillatory modes are calculated by a multi-input multi-output (MIMO) transfer function matrix of the power system; then, a multi-objective optimization procedure based on the genetic algorithm (GA) is presented to place the modes in the desired locations in order to increase the stability margin and to improve the dynamic response. Time-domain simulations of a 400-MW wind farm in the PSCAD/EMTDC environment confirms the effectiveness of the presented design approach.