Performance of Electromagnetic Oil Circuit Breakers Under Hyperbaric Conditions

Abstract

AbstractUnderstanding the influence of ambient hydrostatic pressure in the electric circuit breaking performance of pressure-compensated (PC) electromagnetically actuated oil circuit breakers is essential for the design of reliable deep ocean power systems. Experiments are conducted using an industry-standard 300-V direct current PC power contactor in a hyperbaric chamber. It is identified that at 150-bar pressure, the circuit breaking duration and arc energy reduce fivefold and threefold, respectively, compared to their performance at 1-bar conditions. At pressures greater than 200 bar, the circuit breaker opening duration increases due to the increase in the viscosity of the dielectric PC oil. This leads to increased arc energy and formation of larger carbon conglomerations due to the breakdown of dielectric oil. During the hyperbaric experiments, the pressure-induced viscosity increase was offset by increasing the oil temperature.