An Optimal Preventive Maintenance Method for MMC based VSC-HVDC

With the wide application of MMC in power system, its maintenance strategy has become an important issue. As time went by, traditional periodical maintenance will put the inverter at risk of downtime, the maintenance cycle of the condition-based-maintenance strategy of MMC will be greatly shortened, which will increase the maintenance cost. The maintenance strategy proposed in this paper finds the optimal cost of each maintenance cycle. Detailed numerical simulations verified the proposed maintenance strategy.