In the background of Tibet Cuoqin multi-energy complementary isolated microgrid demonstration power plant project

the microgrid characteristics are presented together with the system scale and composition consisting of wind turbines

photovoltaic

diesel generator

battery energy storage and hydropower. The operating characteristics of hydroelectric generating units as well as the voltage source inverter based on virtual synchronous generator(VSG)are analyzed. Besides

both the synchronization device and the zero-initial voltage boosting time of VSG are optimized to guarantee seamless switching in different system operation modes. Additionally

the power supply modes and operation process of the multi-microgrid system are demonstrated in detail. Finally

field tested results of the microgrid are utilized to confirm the feasibility and effectiveness of the proposed control strategy. This work is supported by National High Technology Research and Development Program of China(863 Program)(No. 2015AA050607)and National Key Technologies R&D Program(No. 2014BAA04B02).