摘要 |
A power transmission system and method for transmitting power over a three-phase power system on a multi-conductor power cable between a surface and a sub-surface location are provided. A surface system includes a power supply providing a direct current (DC) power signal to the power cable. A sub-surface system includes a downhole system coupled to a Y-point of a downhole motor. The downhole system is configured to be powered by (i) the DC power signal provided by the surface system, (ii) alternating current (AC) power drawn from the Y-point, and (iii) a combination of the DC power and the AC power. The downhole system is powered by the DC power when the power cable does not have an insulation fault, and the downhole system is powered by the AC power or the combination of the DC power and the AC power when the power cable has an insulation fault. |