| Due to this geographical condition,it is generally difficult to supply energy to such isolated islands.The conventional power-supply mode of a typical large power-grid can often not be adapted adequately.Hence,currently,many isolated islands mainly rely on fossil energy,which is expensive,unstable,and harmful to the environment.This means,an economically viable,stable,and effective energy-supply system is essential to ensure both the human well-being and economic development of local residents.With the continuous development of multi-energy complementary energy supply systems such as distributed energy systems and microgrids,the use of renewable energy to establish multi-energy complementary systems is one of the effective ways to solve the problem of energy supply in isolated islands.As a typical isolated island,Yongxing island in the South China Sea has high temperature and humidity all year round.It is very uncomfortable for residents if the temperature is not regulated by air conditioning.Unfortunately,air-conditioning also increases the energy consumption substantially.Due to the long distance from the mainland,there is no connection to the large power grid and the island mainly relies on diesel engines for energy-supply.With the continuous increase in oil prices,fossil energy does not work in Yongxing island.In this study,Yongxing island in the South China Sea was considered as the research area,and a multi-energy complementary system suitable for residential buildings was established.Since the multi-energy complementary system adopts renewable energy sources,such as wind energy and solar energy,which are greatly affected by natural factors.The power output of the corresponding equipment also shows intermittent and random characteristics,which undoubtedly increases the instability of system.Therefore,the purpose of this study is to optimize the multi-energy complementary system of residential buildings on Yongxing island in the South China Sea,and obtain the power generation configuration schemes with considering energy supply stability and economy.The research content mainly includes the following aspects: 1.Through the assessment of the renewable energy forms and levels in Yongxing island,the structure of the multi-energy complementary system has been determined.2.EnergyPlus was used to simulate the energy consumption of a residential building on Yongxing island;the support vector machine prediction model was established to predict the wind and solar data.3.Copula Stochastic Programming and Inexact Rough Interval Linear Programming are used to establish the multi-energy complementary system optimization model with the minimum total cost as the objective function.By setting two constraint violation levels,the 24 energy supply scenarios are generated under 4 renewable energy scarcity levels.4.Solve the model and obtain the system power generation configuration schemes under different scenarios.The following shows some results:(1)As the level of renewable energy increases,the total cost of the multi-energy complementary system decreases;Compared with a 100% diesel generator system,under the optimal energy supply scenario,the diesel generators in the system account for only 2.3% of the power generation,which greatly reduces the use of fossil energy.(2)As the level of renewable energy increases,the proportion of electricity generated by photovoltaic modules increases.In the optimal power output configuration schemes,the photovoltaic module power generation accounted for more than 60%,indicating that the use of solar power in the system has good economic performance.This provides valuable suggestions for the establishment of a renewable energy supply system in the region.(3)The stability of the system is closely related to the power output of solar and wind energy.Increasing solar power generation can enhance the stability of the system.(4)The detailed monthly power generation configuration schemes can provide reference for system operation strategy.By referring to the power output of diesel generators,an early warning can be provided for energy supply in this area. |
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