中文摘要：

金属护层中产生感应电压是电力电缆的普遍现象,电缆敷设时常采用三段换位的方法以降低护层电压,但随着城市建设发展的加快,电缆线路的改造也越来越多,电力电缆线路改造时往往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。文中通过对电缆护层电压的理论分析,推导了电缆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。导出了补偿电感的计算模型,根据模型进行仿真计算,研制了电缆护层电压补偿装置,并在电力公司进行大量的现场实测,其实测结果与仿真计算基本一致。结果表明,基于所提出的方法可以有效地减小电缆护层的感应电压,从而减小护层环流,显著减小电缆损耗。

英文摘要：

The occurrence of the induced voltage is a universal phenomenon with the metal shield in the power cable, the method of three segments conversion being often adopted to lower the induced voltage when laying down the cable. With the development of urban construction, renovation of the power cable is becoming increasingly frequent, which often causes the length of three segments to be unequal, bringing about unbalanced induced voltage in the metal shield and the circulating current in the metal shield. Several main induced voltage models for the metal shield of power cable are deduced based on a sound analysis. The methods that add compensating unit to the end of the metal shield of power cable are then presented, which can balance the induced voltage and restrain the circulating current. Its basic principle is to sheathe the power cable in the compensating unit. When current flows through the cable, the compensating device will generate the induced electromotive force in the compensating unit. This induced electromotive force is used to offset the induced voltage of the metal shield. The calculation model of compensating inductance is obtained, and the compensating unit has been developed. Results of tests at Nanjing Power Supply Company are in agreement with those of simulation calculation. Research shows that the method proposed can effectively reduce the induced voltage and the circulating current of the metal shield as well as greatly reduce the loss of power cable.