含换流器型分布式电源配电网的不对称短路电流计算方法

为了满足配电网不对称短路计算的通用性要求，针对换流器型分布式电源(inverter based distributed generation, IBDG)不对称短路特征的多样性，研究含IBDG配电网的不对称短路电流计算方法。该方法从通用计算模型出发，根据IBDG不对称短路的正负序电流控制原理及在不同控制目标下的短路电流输出特性，结合低电压穿越和限流控制对IBDG输出不对称短路电流的具体要求，建立一种通用的、适用于多种控制目标的IBDG不对称短路正负序等效模型。基于该模型建立含IBDG配电网通用的不对称短路等效电路和计算方程，得到一种适用于多种IBDG控制目标的、配电网任意节点发生任意不对称短路的短路电流通用计算流程。最后，在一个配电网算例中对所提计算方法进行验证，结果表明了所提方法的正确性和有效性。

Asymmetric short-circuit current calculation of a distribution network withinverter-based distributed generation

To meet the general requirements for asymmetric short-circuit calculation in distribution networks, a study is conducted on the calculation method with inverter-based distributed generation (IBDG), considering the diverse characteristics of asymmetrical short-circuits caused by IBDG. This method establishes a universal model that is applicable to the equivalent of IBDG asymmetric short-circuit positive and negative sequences with various control objectives. The establishment of this model is based on the principle of positive and negative sequence current control with IBDG asymmetric short-circuit and the short-circuit current output characteristics with different control objectives, as well as the specific requirements of low voltage ride-through and current limiting control for IBDG output asymmetric short-circuit current. Based on this model, a universal asymmetric short-circuit equivalent circuit and calculation equation are established, and a general calculation process for short-circuit current occurring at any node of the distribution network with any asymmetric short-circuit for multiple IBDG control objectives is obtained. Finally, the proposed method is verified in a distribution network example, and the results show that the proposed method is correct and effective.