Grid-Friendly Control Strategy for Offshore Wind Power Integration via Medium-Frequency MMC Transmission System

Offshore wind power in deep and far offshore areas is one of the important sources of power supply increment along the eastern coastal regions of China. However, with the gradual increase in the grid-connected renewable energy represented by offshore wind power, the trend of “hollowing out” in the power system has become more pronounced. In order to provide solid and reliable frequency support for the onshore main AC power grid, this paper innovatively proposes a grid-friendly control strategy based on the system where offshore wind power is transmitted through a medium-frequency MMC. This paper first introduces the system structure and basic principles, then proposes a communication-less main AC grid frequency support control strategy, and conducts simulation verification in PSCAD. The research results show that this strategy can significantly reduce the frequency deviation of the onshore power grid and enhance the stability and resilience of the grid.