储能电站逆变端短路电流分析与建模

Short Circuit Characteristics Analysis and Modeling on Inverter End of Energy Storage Power Station

随着电网负荷的日内峰谷差进一步扩大,为了满足电网调峰等需求,大量储能电站已投入运行。与传统电源相比,故障后其逆变端短路电流输出特征发生了较大的改变,目前较多采用稳态故障模型进行分析计算,但准确性不高。在介绍低电压穿越状态下储能电站逆变端控制策略的基础上,构建故障仿真平台,对比分析了3个主要因素对暂态短路输出特性的影响,并提出了一种基于电压跌落的短路电流非机理模型。根据电压跌落不同程度,对短路电流分段建模,并采用一定算法进行参数辨识。最后,通过仿真对比验证了所建模型的准确性。

As the intra-day peak-valley difference of grid load has further expanded,a large number of energy storage power stations have been put into operation in order to meet the needs of grid peak shaving and other requirements.Compared with the traditional power supply,the short-circuit current output characteristics of the inverter terminal have changed greatly after the fault.At present,steady-state fault models are often used for analysis and calculation,but the accuracy is not high.This paper introduces the control strategy of the inverter end of the energy storage power station under the low voltage ridethrough state,and builds a fault simulation platform.The impact of three main factors on the transient short-circuit output characteristics is compared and analyzed,and then a short-circuit current mechanism model based on voltage drop is proposed.According to the different degrees of voltage drop,the short-circuit current is modeled segmentally,and a certain algorithm is used for parameter identification.Finally,the accuracy of the built model is verified by simulation comparison.