云广特高压直流输电系统中换流变压器铁心饱和不稳定分析

Analysis on Converter Transformer Core Saturation Instability in UHVDC Power Transmission System from Yunnan to Guangdong

高压直流换流器和换流变压器的饱和特性之间的相互作用可以导致换流变压器铁心饱和不稳定现象的发生。文章研究了变压器铁心饱和不稳定的产生机理,给出了饱和稳定因子(saturation stability factor,SSF)的定义,提出了采用仿真方法求取换流器两侧谐波关系的矩阵参数和SSF。基于南方电网2010年数据,采用PSCAD/EMTDC对云广±800kV特高压直流输电系统建立了详细的电磁暂态仿真模型,对三相接地故障激发的铁心饱和不稳定现象进行了仿真研究,验证了SSF判断法的有效性。

The interaction of HVDC converter with the saturation characteristic of converter transformer can lead to core saturation instability of converter transformer, The authors research the generation mechanism of transformer core saturation instability, give the definition of saturation stability factor （SSF）, and propose that by use of simulation method to obtain the matrix and SSF that describe the harmonic relation between both sides of converter. Based on the data of China Southern Power Grid in the year of 2010, a detailed electromagnetic transient simulation model for ±800 kV DC power transmission system from Yunnan to Guangdong is built by use of software package PSCAD/EMTDC, and the core saturation instability caused by three-phase earth fault is researched. Simulation results verify the effectiveness of SSF based judgment method.