中文摘要：

电力电缆敷设时常采用三段换位的方法以降低护层电压，但电力电缆线路改造时容易造成换位的电缆三段不等长，从而引起护层电压不平衡，产生护层环流。为解决此问题，通过对电缆护层电压的理论分析，推导了电缆单回路和双回路任意排列方式下的护层感应电压的计算模型；提出了在电缆终端加补偿装置（实际上为补偿电感器）的方法来平衡护层电压，抑制护层电流。其基本原理是将该补偿装置套装于电缆上，电缆中通过电流时。补偿装置产生感应电动势，利用该感应电势来抵消电缆护层电压。补偿电感的仿真计算表明，该法可有效减小电缆护层的感应电压，从而减小护层环流，大大减小电缆损耗。

英文摘要：

In order to reduce the induced voltage of the metal shield in power cable, the method of three segments conversion is often adopted. But the unequal length of three segments will make the induced voltage of the metal shield unbalanced, and produce the circulating current in the metal shield when the power cable is renovated. According to analysis, the induced voltage models of the metal shield of power cable are deduced in this paper, these models include any arrangement way of the cable at single circuit and two-circuit. The method of adding compensating unit （in fact ,compensating inductance device） at the end of the metal shield of power cable is presented, which ean restrain eireulating eurrent. Its basle prineiple is that the eompensating unit is set around the power eable, when eurrent flows through the power eable, the indueed voltage arises in eompensating unit, the indueed voltage is used to eounteraet the indueed voltage of the metal shield. The ealeulation model of eompensating induetanee is derived, and emulation ealeulation are made. Researeh shows that the method proposed in this paper ean reduee the indueed voltage of the metal shield effieiently, reduee the eireulating eurrent in the metal shield, and deerease the loss of power eable greatly.