Research on Voltage Control Strategy Between DFIG and STATCOM in Large-Scale Wind Farm Integration During Transient Voltage Disturbance

Under the large-scale grid-connected new energy, the problem of reduced regional voltage compliance is becoming more and more significant, which is mainly due to the instability of the new energy itself and the control strategy that needs to be improved. Firstly, with the objective of improving the accuracy and stability of regional voltage, a thorough calculation is conducted to determine the reactive power capability of the wind turbine units, taking into account the overcurrent factor, and further adjusting the lower limit of DFIG reactive power. Next, the control structure of the DFIG units is enhanced by incorporating the reactive power capacity of the grid-side converter (GSC) into the reactive power compensation of the wind turbine units. This allows the wind farm to maximize active power generation while effectively harnessing the reactive power potential and improving the reactive power compensation capability of the wind farm. And a coordinated control strategy is designed by combining with STATCOM, which can not only retain the flexible compensation ability of STATCOM, but also provide reactive power support for wind farm and share the compensation burden of STATCOM. Finally, the regional reactive power deployment strategy is designed to further improve the voltage refinement control strategy, and the whole set of control theory is verified by the two-region grid-connected system.