Back-to-back Converter Control of Grid-connected Wind Turbine to Mitigate Voltage Drop Caused by Faults
For wind turbine operators and grid operators, this work addresses voltage drop mitigation during faults, but the approach is incremental as it applies known converter control strategies to a specific scenario.
This paper investigates back-to-back converter control for a PMSG wind turbine to mitigate voltage drops caused by grid faults, while injecting maximum active power and regulating DC link voltage. Simulation results demonstrate improved voltage support during faults.
Power electronic converters enable wind turbines, operating at variable speed, to generate electricity more efficiently. Among variable speed operating turbine generators, permanent magnetic synchronous generator (PMSG) has got more attentions due to low cost and maintenance requirements. In addition, the converter in a wind turbine with PMSG decouples the turbine from the power grid, which favors them for grid codes. In this paper, the performance of back-to-back (B2B) converter control of a wind turbine system with PMSG is investigated on a faulty grid. The switching strategy of the grid side converter is designed to improve voltage drop caused by the fault in the grid while the maximum available active power of wind turbine system is injected to the grid and the DC link voltage in the converter is regulated. The methodology of the converter control is elaborated in details and its performance on a sample faulty grid is assessed through simulation.