Study on the dynamic reactive power characteristics of MMC-MTDC for wind farm integration

The modular multilevel converter-multi-terminal high-voltage direct current (MMC-MTDC) system is a superior alternative applied to the integration of large-scale renewable energy due to its technical advantages compared with the conventional high-voltage direct current. Based on power systems computer aided design/electro magnetic transient in DC system (PSCAD/EMTDC), a four-terminal MMC-MTDC transmission system for a wind farm integration model is built and then several scenarios, simulation results and corresponding analyses about the dynamic reactive power characteristics are presented. The result shows that MMC-MTDC has a rapid and independent alternating current (AC) voltage regulation ability and effective dynamic reactive power reserves, which has a positive effect under wind power stochastic fluctuations and AC fault conditions.