Testbed to Study the Surface Charge Distribution along DC Standoff Insulators for All-Electric Ships

Future all-electric ships will likely be based on a medium voltage direct current (MVDC) architecture to distribute power to its electrical loads. It is essential to investigate the different conditions from conventional terrestrial power systems under which such power systems operate: (a) DC voltage, (b) ungrounded operation, (c) spectrum of power electronic switching harmonics, (d) environmental conditions and type of pollution, as well as (e) required level of resiliency and reliability. The testbed is designed to operate at up to 60 kV DC voltage, ungrounded, with a superimposed ripple voltage, and enable to study the effect of various degrees of surface pollution and the impact of ground faults. The impact of the above-listed factors as preliminary result is studied experimentally through the testbed. Recommendations for new standards for creepage distance specific to MVDC shipboard power system are provided.