CSI-fed subsea cable transmission for motor drive applications

To supply speed-variable motor drives in subsea stations, a cable transmission system fed by a standard type of current source inverter (CSI) is proposed. Detailed theoretical investigations concentrated on the effects of current resonance phenomenas show an advantageous characteristic of the CSI, to reduce significantly the emitted current harmonics dose to the resonance frequency. This 'self-regulating' effect of a CSI-fed cable transmission result into a sufficient operating performance even in the ease, that converter current harmonics are exiting the resonance frequency. Comparing field test measurements confirm the validity of the investigations as well as the practical feasibility of the proposed application of a six-pulse CSI up to a cable length of about 20 km.