| 摘要 |
A system which allows transmission of data on the same electrical cable which is used to transmit power to an electrical load, such as an Electrical Submersible Pump (ESP), is described. This is achieved, in one embodiment, by using the cable insulation as the dielectric of capacitors whose electrodes are the cable current-carrying conductors and external conducting sheaths. This obviates the need for direct contact or special high voltage connections with the current-carrying conductors which makes it especially advantageous in systems like oil well ESPs where high reliability of the system is essential. The system can be single-phase or three-phase. In a preferred arrangement two such capacitors are used to connect to two separate power cables lines to complete a circuit to allow bidirectional data transmission and the data, when transmitted across two such capacitors, avoids the need for an earth connection and this further improves the reliability and permits routine insulation testing. Various embodiments of the invention are described. |
