Research On The Regional Energy-Water-Emissions Nexus Coupling Model Based On The Electric Power System Planning

The low-carbon,clean and efficient development of regional power system is an important guarantee to achieve the "3060" emission reduction target on the premise of ensuring the security of power supply.As the highest proportion of power generation in China,thermal power generation is mainly distributed in the central and western provinces.Although these provinces have sufficient coal resources,water resources are relatively scarce,and the task of carbon emission reduction and air pollutant emission reduction is heavy and difficult.Because these provinces generally undertake the important task of power transmission from the west to the east,the contradiction of energy,water and drainage in the regional power system is intensified.How to achieve the task of carbon emission reduction in the new era and under the new background at the same time,effectively realize the optimization of energy supply structure,save water consumption of power generation,that is to realize the coordinated optimization of energy water drainage of regional power system has important theoretical and practical significance.Based on the current situation of regional power system in northern China,this paper takes the hierarchical model as the basic model framework,takes four selected typical northern regions as the research cases,and studies the optimization and adjustment scheme of power supply structure in these regions under different environmental constraints through multi model combination and different scenario settings,so as to realize the collaborative optimization of energy water drainage relationship of regional power system.The main contents of this paper are as follows:(1)In this paper,the coupling theory of energy system and the coupling research of energy water drainage in energy system are systematically investigated and combed,and the research scope of regional power system is defined.Firstly,this paper reviews the research status and progress of energy,water and emission coupling in energy system at home and abroad,and summarizes the problems in the research process;At the same time,combined with the current development situation and future development trend of China's power system,the necessity and feasibility of energy water drainage coupling optimization of regional power system in China are demonstrated.Secondly,it systematically combs the theoretical framework of hierarchical model,and demonstrates the feasibility and effectiveness of using hierarchical model to implement energy water drainage coupling optimization.Finally,the paper summarizes the possible types of uncertainty in the process of energy water drainage coupling optimization of regional power system and its potential impact on the optimization process,and combs the potential uncertainty control methods and strategies.(2)Based on multiple prediction method,the power demand,random unit output and utilization hours are predicted and simulated.In the process of carrying out the research on the coupling of energy,water and drainage in regional power system,because the prediction terms are the leading factors affecting the power structure,and also the potential preconditions to realize the optimization of the coupling of energy,water and drainage,improving the prediction accuracy of the medium and long-term power demand,the output of random units and their utilization hours of the regional power system will directly affect the reliability of the optimization results.In this paper,the traditional composite prediction model,Monte Carlo stochastic simulation,support vector machine(SVM),random forest(RF)and other prediction methods are comprehensively applied.Combined with different prediction scenarios,the parameters in the system are predicted,and through the comparison between different methods,the prediction accuracy of each prediction item is effectively improved,Thus,a good condition is created for the improvement of the overall optimization accuracy of energy water drainage system.(3)The energy water drainage coupling optimization model based on the mixed integer bilevel programming model is constructed.Aiming at the problems existing in the traditional single objective or multi-objective model in the process of optimization modeling,such as the single objective model is difficult to effectively reflect the collaborative optimization relationship of multi-element problems,and the multi-obj ective optimization model is difficult to effectively describe the primary and secondary relationship between different elements,this paper uses the mixed integer bilevel programming model as the basic model framework,Different coupling factors,including power structure adjustment strategy,power generation water resource consumption optimization strategy,carbon emission and air pollutant emission reduction strategy,are incorporated into the optimization framework at the same time.By setting different optimization factors in different target layers,the primary and secondary optimization order of different objectives is achieved,and then combined with the priority order of different optimization objectives,The corresponding optimization results are obtained;Through the adjustment of different target levels,the results of different optimization elements in different optimization levels are compared and analyzed.Through the fuzzy satisfaction algorithm,we can effectively quantify the overall satisfaction level of the system under the condition of different target priorities,so as to obtain the optimal feasible solution.In this paper,based on Hebei,Inner Mongolia and Shanxi three energy,water,drainage contradictions in the main northern region of double optimization modeling.Firstly,based on the scale of power plant level optimization,taking 15 existing large thermal power plants in Hebei Province as research cases,the low-carbon transformation scheme is studied,and the energy water drainage collaborative optimization path is found;Secondly,the power plant level optimization is extended to the regional level optimization.Based on the advantages of new energy resources in Inner Mongolia,the low-carbon power structure adjustment path is found to achieve the maximum consumption of new energy in Inner Mongolia under the constraint of carbon peak,and the energy water platoon coordination is optimized;Finally,combined with the clean power structure adjustment plan of Shanxi Province,the uncertain factors in the clean power structure adjustment process are fully considered,so as to achieve the energy water drainage coordination optimization goal under the uncertain conditions.(4)A multi-layer optimization model of regional energy water drainage coupling considering the accounting of virtual and real materials in the process of trans regional power transmission is constructed.On the basis of the framework of the two-layer energy water drainage coupling optimization model,this paper further extends it.By decomposing the lower objectives,a multi-layer optimization model with the upper objectives as the main guide layer is obtained.This model can express all the research elements in the process of energy water drainage coupling research in the form of objective function.In the process of building the model,by introducing the importance analysis theory and the improved gravity model,the virtual water resources and atmospheric emissions from different power supply areas in the process of trans regional power transmission can be quantitatively measured and differentiated,so as to provide feasible policy support for further defining the pollution responsibility in the process of trans regional power transmission.In addition,through the introduction of chance constrained programming method,the model also focuses on the power supply security of the study area,and gives the optimization and adjustment scheme of power supply structure under different power supply security levels.(5)Multi risk control strategy based on multi uncertainty control method.In the process of energy water drainage coupling research,there are many uncertain factors,such as power demand uncertainty,wind and light output uncertainty,different unit utilization hours uncertainty and environmental policy uncertainty.These uncertainties will eventually lead to the uncertainty of the input parameters of the model,and then affect the energy water drainage coupling optimization results.In this paper,through the combination of hierarchical model and interval parameter programming method,two-stage stochastic optimization method,chance constrained programming and other uncertainty methods,further effectively realize the quantification and control of uncertainty factors in the process of system optimization,so as to maximize the uncertainty control in the process of multi factor coupling optimization modeling.