Electromagnetic Transient Modeling and Frequency Response Analysis of The Large-Scale Renewable Energy Base

China's wind and solar resources are centrally distributed in the west and north of the country, with the advancing renewable energy industry witnessing the development of large-scale and remote projects. Simultaneously, large-scale renewable energy bases often utilize LCC-HVDC power transmission to connect with the receiving grid. In such cases, relying on traditional AC networking to access the sending grid may lead to insufficient resistance to frequency and voltage disturbances. This paper firstly constructed a full electromagnetic transient model of the renewable energy LCC-HVDC feeder system based on the MMC-HVDC connection, which contains the sending grid, MMC-HVDC, large-scale renewable energy base, LCC-HVDC and receiving grid. Then, the frequency regulation control of the renewable energy unit and MMC-HVDC is designed based on steady-state control. Through the software integration of RT-LAB and HYPERsim as well as the hardware integration of CPU and FPGA, combined with model decoupling, the parallel heterogeneous simulation of the system is realized, which greatly improves the simulation efficiency. Simulation results under load disturbance demonstrate that the frequency regulation control of renewable energy units and MMC-HVDC can effectively enhance the frequency safety level of large-scale renewable energy bases.