输电网故障时新能源并网点电压跌落及影响范围计算方法

Calculating Method of the Voltage Sag at Point of Interconnection and Affected Range of Renewable Energy Under the Faults in Transmission Network

为了应对当前电网安全稳定分析无法评估输电网故障对新能源影响的问题,提出一种输电网故障时新能源并网点电压跌落及影响范围计算方法。以220 kV节点为界,考虑新能源电流输出特性的影响,完善故障计算模型,并计算220 kV节点故障电压。基于计算结果,提取新能源接入中低压电网的典型场景,并细化分析计算故障时刻新能源并网点电压及其与故障点的电气距离。最后,基于修正的39节点标准测试系统,通过与传统故障计算和时域仿真结果对比分析对所提方法进行验证,研究结果表明:采用所提方法的故障电压计算偏差范围为-4.82%~0.6%,能够准确地评估输电网故障对新能源的影响,可以进一步为新能源运行规划和控制策略优化提供指导。

In order to solve the issue of inability to evaluate the impact of power grid faults on renewable energy using the current power grid security and stability analysis,a method of calculating the voltage sag at point of interconnection(POI)and affected range of renewable energy under the faults in transmission network is proposed.Bounded by 220 kV nodes,fault voltage of 220 kV nodes is calculated by the improved fault calculation model considering the influence of current output characteristics of renewable energy.Based on the results,voltage at POI of renewable energy and the electrical distance between POI and fault point are calculated in typical scenarios for renewable energy integration into power grid.Finally,the proposed method is verified in the modified 39-node simulation system by comparison with traditional meth-od and time domain simulation.The results show that,the deviation of fault voltage calculated by the proposed method is within-4.82%~0.6%,so the proposed method can accurately evaluate the influence of faults in transmission network on re-newable energy.It can provide guidance for the optimization of renewable energy operation planning and control strategies.