220kV主变压器中性点加装隔直电容对零序电量的影响  

Influence of 220kV Transformer Neutral Point Accessing DC Blocking Capacitor on Zero-sequence Electric Quantities

作　　者：李晓华[1] 傅龙辉[1] 罗龙波[1] 晏寒婷[1] 张波[1] 邱建[2] 

机构地区：[1]华南理工大学电力学院,广东省广州市510640 [2]广东电网公司电力调度控制中心,广东省广州市510600

出　　处：《电力系统自动化》2014年第1期121-126,共6页Automation of Electric Power Systems

基　　金：国家自然科学基金资助项目(51377059);广东省自然科学基金资助项目(S2013010012885)~~

摘　　要：变压器中性点加装隔直电容是抑制直流偏磁的有效措施,但加装隔直电容后系统零序参数将发生改变,且大规模加装隔直电容后对零序电量的影响是否存在叠加效应未有明确定论。文中建立了220kV复杂系统环形等值模型,考虑不同运行工况进行计算仿真,采用继电保护智能整定计算软件进行全网故障计算,验证大规模加装隔直电容时系统所受的影响情况。研究结果表明,加装隔直电容后对线路保护安装处零序电流及电压保护影响很小,对加装站点变压器中性点零序电流的影响最大,大规模加装隔直电容时存在叠加效应,但叠加后对相关零序保护的影响基本可以忽略。The neutral point of transformer accessing direct current（DC）blocking capacitor is an effective measure to restrain DC bias.But accessing the DC blocking capacitor will bring changes to the zero-sequence parameters of the system.At the same time, it is still unknown whether there exists the superimposed effect after widely accessing the DC blocking capacitor.A ring-shaped system equivalent model based on the 220kV transformer is developed for calculation and simulation, while making quantitative calculation with the computer-aided coordination for relay in the whole power system in different kinds of circumstances and fault types.The research results show that accessing the DC blocking capacitor has little effect on the line zero-sequence current and voltage, but exerts the greatest effect on the zero-sequence current of transformer neutral point in the accessing substation.The superimposed effect does exist when widely accessing the DC blocking capacitor in the neutral point of transformers.But the effect of the zero-sequence protection is basically negligible after the superposition.

关 键 词：直流偏磁 中性点接地 隔直电容 零序电量 叠加效应 

分 类 号：TM41[电气工程—电器]