Calculation and Control of Reactive Power Support Capacity of DFIG Based on Cloud Model

Abstract

With the construction of the new power system, the installed proportion of the traditional synchronous generator continues to decline, and the stability of the grid voltage is greatly challenged. The participation of wind power in the emergency reactive power control after grid failure is faced with an urgent need. Aiming at the problem that it is difficult to take into account both the ontology constraint and the active power uncertainty constraint when the doubly-fed induction generator participates in the emergency reactive power control of the power grid, the influence mechanism of different reactive power output modes of the DFIG on the system reactive voltage sensitivity is analyzed, and the emergency reactive power support capacity of the wind power is divided into two levels: the turbine ontology constraint and the active power uncertainty constraint, The cloud model entropy is used to quantitatively describe the probability and uncertainty of wind farm output power, so as to determine the limit of reactive power support capacity of wind farm in real time. When the power grid is subject to voltage disturbance, the maximum reactive voltage support can be implemented to reduce the system transient overvoltage or low voltage without affecting the consumption of clean energy. It is verified by the simulation of the actual power grid.