中文摘要：

为检测电容器内部元件的损坏故障，高压直流输电（high voltage DC transmission，HVDC）I程中交直流滤波器的高压电容器通常采用H形接线或分支接线形式，进而配置电容器不平衡保护作为反映该类故障的主保护。然而一些HVDC工程中电容器不平衡保护仍存在隐患。为此分别针对上述2种接线形式的电容器，定量推导了单个支路电容器的故障发展过程中及2个支路电容器均有电容元件击穿时的不平衡电流及相应过电压倍数。分别对2种接线的电容器不平衡保护提出了实用的判据，并探讨了相应的整定计算原则及动作策略。

英文摘要：

To detect the failure of a component inside capacitors, the H-shaped or branch wirings are generally adopted for high voltage capacitors in AC/DC filters of HVDC transmission projects, and then as the main protection of this kind of faults the unbalance protection for capacitors are equipped. However, there are hidden troubles in the unbalance protection for capacitors of HVDC transmission projects. For this reason, for above-mentioned two wiring forms the unbalanced current during fault progression of single branch capacitor and the unbalanced current while the breakdown of capacitor components in both branches occurred as well as corresponding overvoltage multiples under the two conditions are quantitatively derived. On this basis practicable criteria of unbalance protection for capacitors using above-mentioned two wiring forms are proposed, and corresponding principle of setting calculation and action strategy for different failure conditions are discussed.