| Energy router is the key equipment in the energy Internet,which plays an important role in the energy Internet.On the one hand,it can be equipped with a variety of energy interfaces to achieve interconnection and integration with distributed generation and other devices;on the other hand,its most important function is to achieve energy conversion,which can make it control the internal energy flow in size and direction Convenient control.How to choose the topology of the energy router and how to schedule its internal energy reasonably is of great significance to the operation of microgrid.This paper studies the topology of energy router,the control strategy of AC / DC interface converter,and its application in energy Internet.First of all,most of the research on energy router is focused on single DC bus,but the traditional single bus connects all distributed generation and grid ports on the same bus,so the load is easily affected by voltage fluctuations.In this paper,through the study of a large number of literature,the dual DC bus is introduced into the energy router,which has the advantage of restraining the fluctuation of various distributed energy sources in the lowvoltage side,and can effectively alleviate the impact of power grid and high-voltage side load.Secondly,this paper studies the control strategy of energy router.Because the traditional droop control only introduces the frequency modulation characteristics of the power system,the overshoot is large and the support performance is insufficient.In contrast,in this paper,the virtual synchronous generator control is added to the grid connection port.By writing the mathematical model of the generator,the synchronous generator control algorithm is designed,the virtual governor and virtual exciter are designed,and the virtual resistance is added to the voltage and current inner loop,so that the AC interface inverter has inertia and damping characteristics,and the stability and anti disturbance of the system are enhanced.At the same time,simulation results show that VSG has better control performance than droop control;Then,in the study of its low-voltage bus control strategy,in view of the lack of inertia and low stability margin of traditional control,the virtual DC motor control is introduced into the energy storage interface based on the principle of DC generator,and the corresponding voltage and current control loop is designed to improve its inertia and damping characteristics.Compared with droop control,the bus voltage in the control process of DC virtual motor is more flexible and has better anti voltage disturbance ability,which is more conducive to the safe operation of power system.Finally,the overall control of the energy router is studied.According to the working mode of the energy router and the generation sequence of the distributed generation,the control method of each port and the coordinated control strategy of the energy router are established.The strategy takes the photovoltaic power generation system as the main output module,and the energy storage and intermediate converter jointly suppress the voltage and power fluctuations to achieve the orderly distribution of electric energy in the energy router.The effectiveness of energy management is verified by simulation. |
