Experimental Study on Electromagnetic Interference on control cable from two unbalanced 10 kV Power Cables

Abstract

The occurrence of unpredicted and sudden failures in power cables seriously threatened the nearby control cables. Two cases of unbalance in the three-phase current load originate from a high horsepower pump and a sudden power off in an MW pump, resulting in an error signal detected in the adjacent control cable. However, these two cases just occurred once during the plant operation; no more history records can be a reference. In this paper, a typical power cable and control cable structure was constructed, typical accidents in power cables were considered, and electromagnetic interference was considered. The results show that the unbalance of the three-phase load results in a fold increase in interference current. Compared with the two-phase unbalance, the one-phase would bring a higher current. In other words, power off in a sudden situation brought a higher current than three-phase unbalance, especially a faster drop in current load. Finally, more attention should be given to the power cable operation, including unbalance in the power cable and an urgent power off.