Research On Optimal Day-ahead Economic Dispatching Strategy For Microgrid Considering P2G And Multi-source Energy Storage System

The installations of PV and wind turbine are increasing while grid construction is not synchronized.At the same time the outputs of wind turbine and PV are with obvious intermittence.So the power curtailments in the wind or PV plants are usually emerging in some regions,which causes the energy and economy loss.To avoid such problems and to improve the utilization of renewable energy turns more and more important.Integrated energy system is a possible solution to improve the utilization of renewable energy.And,microgrid is a typical integrated energy system at the customer side.It consists of electrical grid,gas-distribution network and heating network.The utilization of renewable energy can be improved by the optimization of electricity,gas and thermal in the microgrid.Besides,storages of electricity,gas and heat in integrated energy system can be combined together to improve the system performance and to decrease the renewable energy curtailment.An interesting technique is Power to Gas(P2G),which can convert the surplus electricity yielded by wind or PV into gas and gas can be stored more easily.In this thesis,an optimal day-ahead economic dispatching strategy for microgrid considering P2 G and multi-source energy storage system is proposed.The main work is as following.(1)Energy Hub is adapted to model the user side integrated energy system so as to analyze the conversion,storage and distribution of various energies.In this way,the interaction,coupling,conversion of different energies can be described.(2)In order to improve the utilization of renewable energy in the microgrid,P2 G equipment is introduced to convert the surplus electricity into natural or hydrogen gas during the peak of power output.Then the gas can be stored in the natural gas network or storage,which can be reconverted into electricity or heat if necessary.In this way,the penetration of the renewable energy in the microgrid can be increased.At the same time,system stability can be enhanced.(3)Based on the energy hub model,three microgrid scenarios are designed.Economic dispatching model is then established.Interior point method is used to find its optimal solution.The research results show that introduction of P2 G can improve the penetration of renewable energy and enhance the system stability.