Research On New Distributed PV Storage System Based On Virtual Synchronous Generator

The distributed power supply to the low-voltage distribution network can alleviate the voltage used during heavy load and improve the robustness and reliability of the grid.The main research contents of this paper are as follows:Firstly,a virtual synchronous generator model is established.The simulation of the power frequency characteristics and excitation characteristics of the generator is realized by the active power-frequency control strategy and the reactive power-voltage control strategy.Second,the PV storage virtual synchronous machine system was designed.In steady state,it outputs power or stores energy according to a given power.In the transient state,it has the inertia characteristics of the synchronous generator and actively participates in the frequency regulation process of the power grid.The PV storage virtual synchronous machine system can stably operate in the dual mode of the outputting/storage mode,and has the bidirectional frequency regulation capability and the inertia characteristic to meet the requirements of the autonomous power system.Finally,the feasibility of the proposed system was verified by synchronous equivalent grid model.Then,a control method for grid-connected photovoltaic inverters with the characteristics of governor failure zone is proposed.The introduction of new energy frequency regulation delay improves the adaptability of the inverter to renewable energy penetration.The DC bus voltage was stabilized through the DC voltage loop to resist the voltage fluctuation of the system.The dynamic balance between resisting fluctuation,participating in frequency modulation and response scheduling was achieved through the design of dispatching interface and power enabling link.Finally,the article was summarized and forecasted.