| The capacitor commutated converter (CCC) is a new type of HVDC converter topology which shows promise for use in long distance transmission via cables. This technology is, thus, a potential candidate for use in HVDC transmission across large bodies of water. This thesis investigates the suitability of CCC in such applications using electromagnetic transient simulation.;An analytical formulation is first developed, which is used to investigate the steady-state behaviour of both the CCC and the conventional HVDC converter. The results indicate that the CCC is superior to the conventional in terms of stability margin when operated in power control.;Two new control strategies are developed because the traditional control strategy was found unsuitable in long cable HVDC-transmission. The suitability of the CCC-inverter in a long cable HVDC-scheme was examined for both control options.;Ac-filters at near-unity-power-factor converters, such as the CCC, require some mechanism of online tuning due to their sensitivity to detuning effects. An active filter, based on a voltage source converter, is developed to ensure satisfactory filtering performance.;Finally, the suitability of the CCC-inverter is investigated in a network configuration where two HVDC-links are feeding power into a common ac-network. The multi-infeed HVDC-scheme under study is a simplified representation of the existing and planned HVDC-connections in Norway. The results indicated that the presence of the CCC-inverter does not have an uniformly favourable impact on the multi-infeed HVDC scheme's performance. The scheme demonstrated, nevertheless, satisfactory transient performance regardless of the converter type employed at the inverter. |
