Effect of the Surge Arrester Configuration
in MMC-HVDC Systems under DC and Converter Fault Conditions
Different surge arrester configurations are studied for a modular multilevel converter (MMC) in a symmetrical monopole configuration. Each configuration is analyzed under fault conditions including DC side faults and faults inside the converter station. The configurations considered are compared in terms of overvoltages, current levels and energy dissipation. It is found that the selection of the surge arrester parameters does not only depend on the overvoltage levels of the equipment, but also on the surge arrester configuration considered. The action of the surge arresters could result in higher longitudinal withstand voltage requirements of the arm reactors. Furthermore, special attention shall also be given to the possible low inductance loops created by the conduction of the arresters during a transient event.
N. Manduley, S. Touré, A. Xémard, B. Raison, S. Poullain