Impact of long-term use of direct current on the electrical characteristics and physical properties of power cable

The interest in DC power supplies for efficiency in data centers, communication buildings, and microgrids has been increasing in recent years. The authors focus on wire and cable facilities and report experimental investigation of the effects of DC power on cable. The study is divided into verification of the permissible current of cable, comparison of the results for AC current and DC current, and verification of cable degradation under long-term DC use. It was confirmed that the permissible current for single-core cable is from 1% to 3% higher under DC operation than under AC operation. Tests of the lifetime of cable subjected to long-term use confirmed that cable that has be used for DC operation for five years exhibited no degradation. These results confirm that DC power has no practical effect on cable.