适用于继电保护整定计算的双馈风电机组等效模型

随着双馈风电机组并网容量的不断增加,风电机组的接入对电网继电保护的影响逐渐增强,研究适用于继电保护整定计算的双馈风电机组短路电流计算方法尤为重要。为了解决这一问题,并考虑到继电保护整定计算的实用性,建立了一种适用于继电保护整定计算的双馈风电机组等效模型。通过对双馈风电机组基本关系式的推导,得到了双馈风电机组的简化等效电路。通过对简化等效电路以及双馈风电机组发生短路故障时的暂态过程进行研究,推导出等效电动势的表达式,并进一步推导出了双馈风电机组的短路电流计算公式。最后通过仿真验证了等效电路和短路电流计算公式的准确性,为双馈风电机组的继电保护整定计算提供了一种新的等效模型。

Equivalent model of DFIG for relay protection setting calculation

With the increase of DFIG capacity and the influence that the wind turbine to power grid relay protection gradually increased, the research which applies to relay protection of DFIG setting short-circuit current calculation method is particularly important. In order to solve this problem and consider the practicability of setting calculation of relay protection, this paper establishes a protection setting calculation of DFIG equivalent model for the relay. Through the derivation of the doubly fed wind turbine basic formula, the simplified equivalent circuit of DFIG is got. By studying the simplified equivalent circuit and the transient process of DFIG with short circuit fault, the expression of equivalent electromotive force is derived, and the formula of short circuit current of DFIG is derived. Finally, the accuracy of equivalent circuit and short-circuit current calculation formula is verified by simulation. It provides a new equivalent model for relay protection calculation of DFIG. This work is supported by National High-tech R & D Program of China (863 Program) (No. 2015AA050101).