Analysis of Induced Voltage in Metal Shield of Power Cable and Research on Its Compensating Device

摘要

Three segments transposition is often made use of to decrease the induced voltage in metal shield of high voltage power cable, but when the power cable is rebuilt, the length of the three segments will be unequal, which will make the induced voltage in metal shield unbalanced, and produce the circulating current in metal shield. Based on the theoretical analysis, mathematic models of the induced voltage in metal shield under several main arrangement ways of power cable were deduced in this paper. The compensating method of induced voltage in metal shield of power cable was put forward. Based on these methods, the computing software package of compensating unit was developed, and by means of emulation the compensating unit was developed. By changing air gap and turn number of the compensating unit, it can compensate the induced voltage and reduce the synthesis induced voltage in the metal shield efficiently, reduce the circulating current in the metal shield, then decrease the loss of power cable and increase the transmission capacity greatly.