抑制变压器直流偏磁的电容隔直装置优化配置  

Optimal Configuration of Capacitor Blocking Devices for Suppressing DC Bias in Transformers

作　　者：刘春明[1] 黄彩臣 潘明明[1,2] 杨嘉楠 闫旭东[1] 

机构地区：[1]华北电力大学电气与电子工程学院,北京102206 [2]中国电力科学研究院,北京100192

出　　处：《高电压技术》2016年第7期2308-2314,共7页High Voltage Engineering

基　　金：国家自然科学基金(51177045);国家高技术研究发展计划(863计划)(2012AA121005);国家电网公司科技项目(521820140017)~~

摘　　要：高压直流输电单极运行时产生的接地极电流会导致其附近变压器出现直流偏磁,影响交流电网的安全运行。由于偏磁电流在电网中存在多条流通路径,在某变压器中性点安装电容隔直装置虽能明显抑制该变压器中的直流电流,但往往引起相邻变压器偏磁直流增大。为此,考虑自耦变压器接线特点和电网拓扑结构,引入有效偏磁电流来描述直流接地极电流对变压器的影响,提出以所有变压器的有效偏磁电流都小于允许限值为约束条件,以隔直装置的安装数量最少为优化目标的优化模型,应用基于改进轮盘赌选择法的遗传算法求解电容隔直装置的优化配置问题。以溪浙直流输电工程金丝接地极附近的受端电网为例,求解了不同有效偏磁电流限值下电容隔直装置的优化安装方案,与未优化的安装方案相比较,所需安装装置的数量可减少50%以上。The ground current during monopole operation of HVDC transmission system can lead to DC bias in the transformers near the grounding pole, which affect the safe operation of AC power grid. Due to the multiple flow paths of the bias current in the power grid, the DC blocking device installed in the neutral point of a transformer may cause more severe DC bias in the other adjacent transformers while obviously suppressing the DC current in one transformer. We introduced the transformer effective bias current to describe the effect of the grounding current in the transformers after considering the wiring characteristic of auto-transformers and the topology of the power networks,and proposed an optimization method to find the least quantity of DC blocking devices which satisfied the constraint conditions that effective bias current of all transformers was less than the allowed limiting value.Moreover, we applied a genetic algorithm based on improved roulette selection method to solve the optimal configuration problem. Using the test case of Xizhe HVDC transmission receiving-end grid near the Jinsi grounding pole, we calculated the optimal quantity and installed location of capacitor blocking devices under different effective bias current limiting values. The results in comparison with the un-optimized method show that the required quantity of the blocking devices can be reduced by 50% or more.

关 键 词：直流偏磁 电容隔直装置 有效偏磁电流 遗传算法 优化配置 

分 类 号：TM721.1[电气工程—电力系统及自动化]