Short Circuit Current Contribution for Different Wind Turbine Generator Types

An important aspect of wind power plant (WPP) impact studies is to evaluate the short circuit (SC) current contribution of the plant into the transmission network under different fault conditions. This task can be challenging to protection engineers due to the topology differences between different types of wind turbine generators (WTGs) and the conventional generating units. This paper presents simulation results for SC current contribution for different types of WTGs obtained through transient analysis using generic WTG models. The obtained waveforms are analyzed to explain the behavior, such as peak values and rate of decay, of the WTG. The effect of fault types and location, and the effect of the control algorithms of power converters on SC current contribution are also investigated. We show that the response of the WPP to faults will vary based on the type of the installed WTGs. While in Type 1 and Type 2 WTGs, SC current will be determined by the physical characteristics of the induction generator, the contribution of Type 3 and Type 4 WTG will be mostly characterized by the power converter's control algorithms, which are usually considered proprietary information by the wind turbine manufacturers.