Multi-machine cooperative transient voltage support control method for large-scale renewable energy

The large-scale new energy grid connected scenario is receiving widespread attention. The output current of different renewable energy units during fault will affect the voltage support ability of other stations. The existing research is limited to the single-machine scenario, and lacks the limited utilization of reactive power resources of each unit during fault. In this paper, a multi-machine cooperative transient voltage support control method is proposed. By analyzing the voltage support interaction of the output current of each new energy unit during the fault, the principle of reactive power cooperative injection during the fault of the new energy unit is clarified. By solving the optimal voltage support, the current limit and power fluctuation limit of each unit are taken into account, and the current command value is given during the fault. A simulation example is built in PSCAD. The results show that the proposed method has greatly improved the voltage increase compared with the existing control methods.