Studies Of Some Crucial Issues On Isolated Island Energy Production And Transmission

The development and utilization of islands is of great importance in line with national maritime strategy,while adequate energy supply is the necessary fundamental for this purpose.In terms of geographical position,all islands are isolated islands.If observing from the aspect of energy supply,most islands are also isolated islands except few of islands capable of being linked with the power systems in the mainland.For isolated islands,their traditional power supply mainly adopts local mode depending diesel generation,which obviously departs from the prevalent idea of energy supply and utilization in terms of green and high-efficiency.Indeed,most islands have abundant storage of renewable energy.If being developed reasonably,the green power supply mode can be formed by mean of taking renewable energy as the main source.By this means,it will be a successful practice of human society sustainable and green development.Meanwhile,it shall be a more reasonable mode of constructing island energy supply system for most islands much far away from mainland.Traditionally,they usually face many problems of energy replenishment such as inconvenience and very high cost.For the above novel island energy supply mode,there still exist various theoretical and technical problems to solve.The following crucial issues,including the combined sourcestorage device sizing for isolated island,how independent power generation system is involved in electricity market,how the dispatching strategy should be designed in terms of global optimization for the island group containing independent power generation system,and how to optimize the dispatching strategy by using idle movable energy storage vessel,are studied and investigated in this thesis.The main content includes:In the aspect of combined sizing for the power source and energy storage equipment of isolated island,a new non-cooperative game model of electric energy transaction for renewable energy generation system and energy storage system is proposed on the basis of fundamental of power supply system already having been established and the social entities being encouraged to be involved in construction of island energy supply.Further,the capacity allocation for each parts is studied.After proving the existence of Nash equilibrium,the most responsive analytical strategy is used to find out the Nash equilibrium of capacity allocation for each participant.Furthermore,the economic analysis of the income and expenditure of each participant is carried out at equilibrium point.It can be proven with extensive case studies that the proposed game model can improve penetration of renewable energy and solve the problem of unbalanced new energy generating units output and load demand to some extent,while ensuring the benefits of all parties and effectively increasing the construction enthusiasm of investors,accomplishing comprehensive highly-efficient utilization,which has great practical significance.In the aspect of independent power generation system being involved in electricity market,the rationality of constructing electricity market for isolated island energy supply system is firstly verified,meanwhile,the characters of power seller,power buyer,and ISO in the isolated island electricity market are clarified.In the next,the mode how the island containing abundant renewable resource without direct cable link with the island of load center shall be involved in the isolated island electricity market by combining multiple-function vessel operator is discussed.Based on this mode,a dual-level decision-making model,which enables the combined pricing of the island containing abundant renewable resource without direct cable link with the island of load center and multiple-function vessel operator,together with the unified market clearing model for the island of load center,is established.By solving the above models,the strategies of power generation and transmission are formed correspondingly.Finally,the feasibility of independent power generation system being involved in electricity market is verified with simulation case studies.In the aspect of how the dispatching strategy should be designed in terms of global optimization for the island group containing independent power generation system,the drawbacks on the aspects of crucial element modeling and global optimization of the island energy supply model only based on electricity market are analyzed in the first.Then,a novel island energy dispatch model capable of taking energy transmission independent of cable and achieving the global optimization is proposed.On this basis,the flaw of simply applying traditional power dispatching mode on the isolated power system containing independent power generation system is investigated.Furthermore,the idea of extending dispatching cycle to adapt to the various uncertain scenarios most taking advantage of the energy package of the most flexible power output characteristic is put forward,and the energy dispatching model considering the duration of low-energy-density production is proposed.Finally,the effectiveness of the proposed strategy is verified with extensive simulation studies.In the aspect of day-ahead dispatch of island power grid taking the participation of Shared Electric Vessel(SEV)into account,considering the characteristics of the reverse space distribution for source-load on pelagic islands,a day-ahead dispatching strategy for the power grid on islands that takes into account the participation of SEV is proposed.First of all,the concept of SEV is proposed to realize transferring inter-island energy by sharing the idle energy storage of electric travelling ships.Furthermore,based on the time-space transfer characteristics of the SEV,an accurate SEV model is established.On this basis,aiming at minimizing operating cost of the system,a day-ahead dispatching model of the power grid on islands,which takes into account the participation of SEV,is constructed,and the operational profits are rationally distributed between the SEV and the power grid on islands by the Shapley value method.The simulation results show that the SEV-based energy supply system on pelagic island realizes flexible consumption of new energy and support of load while meeting the passenger demand,and the system also realizes “win-win” by “sharing”.