Fault Ride Through Capability of Fixed Speed Induction Generators Connecting to Full Converter Wind Generation System within Weak Network

Abstract

Current grid codes request the wind turbines (WTs) to have a decent level of fault ride through (FRT) capability and also participate in recovering the network stability following contingencies. Modern WTs are mostly equipped with power converters that allow them to control the output power under various operating conditions. However, there are some Fixed Speed Induction Generators (FSIGs) still operating. FSIGs have simple and economic construction. But under fault, they are very susceptible to rotor overspeed that may lead to disconnection from the grid. For variable speed WTs, application of power converters can improve the controllability of the turbines but modifications in their PQ capability are needed to meet the network requirements. This paper is aimed to investigate the impacts of connecting full converter wind generators (FCWGs) to improve FRT capability of FSIGs within a weak network. The implemented reactive power supports set in Danish and Australian Grid Codes will be assessed based on their influences on the FRT capability of FSIGs. Impacts of FCWGs locations as reactive power providers and fault durations on the FRT capability of FSIGs will also be discussed. Results confirm that FRT capability of FSIGs can be improved in accordance with enhanced capability of FCWGs.