Research On Operation Optimization Technology Of Energy Router Connected To Grid

The large amount of various distributed energy sources and new types of loads have brought new challenges to the operation and control in distribution network.The power flow has been multi-directional,and voltage control has been affected by more factors.The traditional control mode is difficult to adapt.As a new type of equipment that combines power electronics technology and communication technology,the energy router can provide AC and DC interfaces,transform voltage and current,collect various electrical quantities in operation,actively control power flow,and contain communication functions.It will play a key role in the future grid energy management and power control,and become the foundation of the energy Internet.Because of the characteristics of energy internet infrastructure,in practical applications,energy routers will be large-scale grid-connected in a distributed manner.In this process,it is necessary to reasonably allocate energy routers and various types of new resources to ensure the power system operation stability and economy.The optimization control of the energy router itself and the various types of new resources connected to it,as well as the cluster coordination control of the energy routers connected to the power grid on a large scale,are critical issues that need to be researched urgently.Therefore,this thesis takes the multi-energy routers connected to grid as research objects.In the two scenarios of the distribution network and the island micro-grid,research is conducted on optimized operation control strategies and placement planning methods.Aiming at the local control of the energy router on the user side of the distribution network,an optimized control strategy that comprehensively considers the time scale of the day ahead and intra day is proposed.The day aheadh strategy optimizes scheduling with the goal of operating economy,and the intra day strategy uses the model prediction algorithm for rolling optimization to eliminate operating errors caused by differences between forecast data and actual data.For the optimization strategies,simulation example is established,and their effects are verified by calculation examples.Aiming at the coordination and optimization of energy router clusters in the distribution network,firstly,a node voltage-power linear relationship model is established according to the characteristics of the radial distribution network.On this basis,an energy router placement planning method is proposed based on the voltage sensitivity evaluation index.Finally,a hierarchical control model of multi-energy routers in the distribution network is established.At the upper layer,the goal of maintaining the voltage level of the entire network is optimized to obtain the operating boundary of each energy router.At the lower layer,the operating boundary is the constraint condition.The energy router performs local control.And simulation example is established to verify its effect.Aiming at the distributed control technology of energy routers in the independent microgrid,a hierarchical control strategy based on SOC consensus is proposed.In the lower layer,droop control is adapt for intial power distribution;in the upper layer,the power distribution in the working process is dynamically adjusted to reduce the SOC difference to ensure the sustainable operation of the entire system by the weak communication network between energy routers.Finally,a simulation model is established to verify the effectiveness of the control strategy for SOC equilibrium and fault tolerance under communication failure.