Study Of Optimal Design Of Distributed Energy Resource Systems Under Uncertainty

Distributed energy resource system is an energy supply system that is set up close to end users,generates electricity and combines cooling and heating.It has a series of advantages such as good economy,good environmental performance,and high overall energy efficiency,and has attracted more and more research and applications.In the entire operating cycle of the distributed energy resource system,there are many uncertain factors.The lack of consideration of these factors may make the design of the system unreasonable,making the advantages of the distributed energy resource system not fully utilized,and the economy of the entire system deteriorate.Aiming at above problems,this paper studied and determined the key influencing factors of the distributed energy resource system,built an optimal design model of distributed energy resource system based on multiple uncertain optimization methods,and carried out research on the optimal design of the distributed energy resource systems under uncertainties.The main works of this paper are as follows:(1)A deterministic optimal design model of the distributed energy resource system with efficient solution was developed.The model takes into account the discreteness of available equipment capacity,variable operating conditions of equipment.The model has the advantages of short calculating time and concise program.By storing the data in an external database,the data and the procedures are separated,and the universality and independence of the model are improved.This part of the work lays the foundation for carrying out the study of optimal design of the distributed energy resource system under uncertainties.(2)A sensitivity analysis of the distributed energy resource system was carried out.The effects of electricity prices,equipment operating efficiency,equipment initial investment costs,natural gas prices and load demand on the system configuration were studied.Research shows that among these factors,electricity prices,natural gas prices and load demands have the greatest impact.These factors are identified as the key influencing factors in the subsequent uncertainty optimization research of this paper.(3)An uncertainty optimal design model of distributed energy resource system based on decision-making theory was constructed.Considering the uncertainties of load demand,energy prices and renewable energy intensity,five decision-making methods are used to select alternatives using optimistic criterion,pessimistic criterion,Hurwicz criterion,Laplace criterion and minimax regret criterion.Research shows that the installed capacity of equipment in the plan selected by optimistic criterion is small,and the installed capacity of equipment in the plan selected by pessimistic criterion is relatively large.Plans selected by the Laplace criterion and minimax regret criterion can achieve good economic performance operating in various scenarios.Decision-making theory helps decision makers choose the optimal system plan that reflects their risk attitude.(4)An uncertainty optimal design model of distributed energy supply system based on two-stage robust optimization method was constructed.Considering the uncertainty of load demand,energy price and renewable energy intensity,the uncertainty of parameters is described by box,ellipse and convex-hull uncertainty set.The results show that the uncertainty of energy prices and load demand has a great impact on the system configuration,mainly affecting the installed capacity of gas boilers,absorption chillers and storages;In order to improve the accuracy of the solution and reduce the conservativeness of the solution,it is very important to choose a suitable uncertainty set.The optimal system obtained by two-stage robust optimization is relatively conservative,but is reliable under uncertain conditions and has good economic performance under deterministic conditions.(5)An uncertainty optimal design model of distributed energy resource system based on interval optimization method was constructed.Considering the uncertainty of load demand,energy price and renewable energy intensity,using the probability degree and order relationship of interval numbers,the uncertain optimization problem is transformed into a deterministic optimization problem and then calculated and solved.Research shows that the uncertainty of energy prices and load demand has a significant impact on the configuration and economy of the system,mainly affecting the installation capacity of gas boilers,energy storage devices,and the selection of solar power generation devices;the possibility degree and the objective function coefficient can adjust the average performance of objective function value,the robustness and reliability of the optimization result.The interval solution obtained by interval optimization reflects the interval of the objective function value and the sensitivity of the objective function to uncertainties.The optimal design methods and models under uncertainty developed in this paper can effectively cope with various uncertainties in the system and reduce the operation risks of distributed energy resource systems.