特高压直流保护高仿真度建模和动作行为评价

High fidelity modeling and action behavior evaluation of UHV DC protection

研究特高压直流线路保护动作评价,可以帮助运行人员快速处理故障,防止故障范围进一步扩大,对于提高电力系统的安全稳定运行具有重要作用。为了准确地模拟特高压直流线路保护动作行为,基于PSCAD/EMTDC仿真平台搭建了±800 kV特高压直流输电系统高仿真精度模型。整个模型主要由2大部分组成,即一次系统模型和二次控制保护模型。一次系统模型参数完全采用工程设计参数,使其外部特性与特高压直流换流站一次设备高度一致。通过移植并转换现场运行的控制保护装置的程序源码,实现了直流二次控制保护的高仿真度建模。仿真和试验的结果表明该模型的二次控保逻辑与实际现场完全一致,可准确模拟导致控保系统异常动作的因素。使用该模型仿真了多种故障情况下的直流线路保护动作行为,并评价了线路保护动作行为。

The research on protection action evaluation of the ultra-high voltage(UHV)direct current(DC)line can help operators deal with faults quickly and prevent the further expansion of fault range.It plays an important role in improving the safe and stable operation of power system.In order to accurately simulate the protection action behavior of UHV DC line,a high fidelity model of a ±800 kV UHV DC transmission system is developed based on PSCAD/EMTDC simulation platform.This model consists of two parts:the primary system model and the control and protection model.The primary system model parameters completely adopt the engineering design parameters to make its external characteristics highly consistent with the primary equipment of UHV DC converter station.The high fidelity modeling of the DC secondary control and protection is realized by transplanting and converting the program source code of the practical control and protection device running in the field.The simulation and test results show that the secondary control and protection logic of the model is completely consistent with the field test,and the model can accurately simulate the factors leading to the abnormal action of the control and protection system.The DC line protection action under various faults is simulated by using the model.Finally,the line protection action is evaluated.