计及直流控制特性的多送出直流电网故障分析方法

利用直流换流器开关函数模型,结合直流控制系统的故障响应特性,建立了适用于送端交流系统故障分析的直流系统简化等值模型;利用该简化模型结合送端电网的网络方程及其不对称故障的边界条件,提出了一种含多直流送出的交流电网故障分析计算方法。利用PSCAD/EMTDC搭建了基于CIGRE标准测试系统的含三回直流送出的交流电网模型,对本文所提方法进行了大量的仿真验证,结果表明所提方法计算简单,且有较好的收敛性及较高的计算精度,为含多直流送出交流电网故障分析及其继电保护的整定配合等提供了定量分析依据。

Fault Analysis Method for Multi-send HVDC System by Considering DC Control Characteristics

With a comprehensive consideration of the switching function model of convertor and the fault response characteristics of rectifier DC control system under various fault type, a simplified DC system model is established for fault calculation in sending end AC system. Based on the simplified model, combined with the sending power network equations and the fault boundary conditions of asymmetric fault, a multi send HVDC system fault calculation method is proposed. Based on CIGRE HVDC benchmark model, the PSCAD/EMTDC simulation model of a three send HVDC system is built to testify the proposed method fully. The results show that the proposed method is of simplicity, rapid convergence and more accuracy, and provides the analysis basis of protection setting and cooperation in multi send HVDC system.