±1100kV直流换流站避雷器布置、参数和设备绝缘水平的选择  

Selection of Arresters Arrangement, Parameters and Apparatuses Insulation Levels for ±1100 kV DC Converter Station

作　　者：周沛洪[1] 何慧雯[1] 戴敏[1] 万磊[1] 

机构地区：[1]中国电力科学研究院,武汉430074

出　　处：《高电压技术》2014年第9期2871-2884,共14页High Voltage Engineering

基　　金：国家电网公司科技项目(SG11069;EPRIGYKJ3184)~~

摘　　要：为了合理确定±1 100 kV直流换流站避雷器布置、参数和换流站设备的绝缘水平,在分析和比较±800 kV直流输电工程换流站避雷器布置和参数的基础上,推导了6脉动换流器绝对最大理想空载直流电压与换流变的短路阻抗成正比关系的公式,提出了换流变的短路阻抗大小基本确定了整流站直流侧阀厅内设备的绝缘水平,因此需尽可能减小该阻抗值。给出了阀厅内直流避雷器伏安特性、荷电率、持续运行电压峰值(CCOV)、包括换相过冲的持续运行电压最高峰值(PCOV)、直流参考电压和直流偏置电压的选择方法和影响因素。在换流变短路阻抗不大于24%和采用A2避雷器直接保护高端Y/Y换流变阀侧方案的条件下,高端Y/Y换流变阀侧的额定操作冲击耐受电压(SIWV)可选为2 030 kV,低于采用M2+V3避雷器串联保护方案的2 191 kV。针对整流站和逆变站交流侧分别接入750 kV和1 000 kV交流特高压方案,提出了降低交流避雷器额定电压的建议。提出的绝缘水平为换流变、换流阀、极母线和中性母线等±1 100 kV直流设备的样机制造和交流设备选型以及交、直流场的设计提供了技术支撑。In order to reasonably determine the arrangement and parameters of arresters and the apparatuses insulation levels for ±1 100 kV DC converter stations, by analyzing and comparing the arrangement and parameters of arresters applied in ±800 kV DC converter stations, we derived equations showing the proportional relationship between the maximum absolute ideal no-load direct voltage of per 6-pulse converter and the short circuit impedance of converter transformer. According to the equations, it is concluded that the converter transformer＇s short-circuit impedance basically determines the insulation levels of the apparatuses in valve hall, so the impedance should be reduced as much as possible. The selection methods of U-I characteristics, charge rate, crest value of continuous operation voltage（CCOV）, peak value of continuous operation voltage（PCOV）, DC reference voltage, and the DC offset voltage for the DC arresters installed in valve hall, as well as the influencing factors, are introduced. Under the conditions that the converter transformer short-circuit impedance is no more than 24% and the A2 arrester is used to directly protect the valve side of high-level Y / Y converter transformer, the rated switching impulse withstand voltage （SIWV） of the valve side of high-level Y / Y con- verter transformer is suggested to be 2 030 kV, which is lower than 2 191 kV, the value of protecting the valve side with the M2 and V3 arresters connected in series. We also suggested reducing the rated voltage of AC arresters when the rec- tifier and the inverter converter station are connected to 750 kV AC and 1 000 kV AC systems, respectively. The proposed insulation levels can be applied to aid the prototype manufacture of ±1 100 kV DC apparatuses, such as converter trans- former, converter valve tower, pole and neutral bus device etc., as well as the design of AC and DC converter stations.

关 键 词：±1 100 kV直流输电 整流站 避雷器布置 避雷器特性参数 换流变短路阻抗 绝缘配合 绝缘水平 

分 类 号：TM862[电气工程—高电压与绝缘技术]