Study on Method of Digital/Analog Hybrid Simulation for the Ultra-High Voltage Grid

For the feasibility study of planning UHV (Ultra-High Voltage) AC/DC hybrid grid, real time simulation test using digital/analog hybrid simulator should be implemented other than offline simulation. The digital/analog hybrid simulator includes digital models, analog simulator, and interface devices. Limited by the testing equipment, dynamic-equivalent should be accomplished first for the grid to be studied. After the parameter proportion between simulation system and real system has been confirmed, the digital/analog hybrid simulation models should be built in term of the reduced grid, then the study on the characteristic and mechanism of AC/DC hybrid grid can be implemented. Exampled by the project of "real-time simulation research on the UHVDC feasibility of Jinshajiang phase I and Jinping power transmission", the digital/analog hybrid simulation model of the planed UHV, AC/DC hybrid grid will be introduced, then the conclusion of the test will be given. With the development of modern computer and information technology, full-digital real time simulation technology has great development. Limited by the simulation speed and precision for HVDC system, the full-digital real time simulator can not fully replace digital/analog simulator. So the improved digital/analog hybrid method was brought forward. To integrate the full-digital real time simulation technology and HVDC analog simulation technology, new hybrid interface should be developed, which will enhance the ability for the study of big scale AC/DC hybrid network.