Voltage stability study of micro-grid with asynchronous wind turbine in islanding mode

In islanding mode, the surge current during startup and shutdown of asynchronous wind turbine and its power fluctuations can be a significant challenge to the stable operation of micro-grid. Energy storage based micro-grid stability controller has been proved effective for micro-grid control. This paper analyses the performance of the micro-grid stability controller considering its capacity, the control strategy and the line impedance. The minimum necessary capacity of the energy storage and maximum line impedance limitation for micro-grid voltage stability are presented theoretically and verified by simulation. Finally, the transient process of grid-connection and disconnection of asynchronous wind turbine are studied with the developed micro-grid stability controller by field experiment.