| The randomness and intermittency of photovoltaic(PV)power output make it unable to be directly received and utilized by the power grid,which has a greater impact on the power supply reliability of the power grid.When the concentrating solar power(CSP)plant and the PV plant form a combined power generation system and operate independently,in order to effectively realize energy complementarity,it is necessary to reasonably allocate the thermal storage capacity of the CSP plant in the system,so as to adjust the output of the PV plant and ensure stable and reliable operation of the system.The reasonable allocation of the thermal storage capacity of the CSP plant is the core work in the research of the independent operation of the CSP-PV power generation,which aims to improve the operating benefit and energy utilization of the entire power generation system on the premise of satisfying the power supply reliability.Therefore,it is of great theoretical significance and practical value to carry out research on the reliability of the CSP-PV power generation system and its application in capacity optimization configuration.This thesis mainly focuses on the optimal allocation of the CSP-PV power generation considering the regulation demand.Starting from the operating characteristics of the CSP-PV power generation and its reliability evaluation model,the concept of system regulation demand is introduced,and it runs through optimal allocation of the CSP storage capacity during the entire system planning stage.Based on this research idea,the work completed in this thesis mainly includes the following aspects:(1)In order to establish an accurate and reliable evaluation model,the output characteristics of the CSP-PV power generation system are analyzed.First of all,taking the tower solar CSP as an example,the basic composition and working principle of the CSP plant are introduced,and five working modes of the CSP operation are analyzed according to different working conditions,thus the energy flow model of the CSP plant is established.Second,according to the working principle of the PV cells,the influencing factors of the PV output are analyzed,and then a random time series probability model of the PV power plant is established.Finally,based on the output characteristics of the CSP-PV power generation system,from the two dimensions of energy balance and climbing rate matching,the principle of energy complementary that the CSP plant adjusts the output of the CSP-PV power generation system through the thermal storage device is analyzed.(2)Aiming at the problem of how to coordinate allocation of thermal storage capacity of the CSP plant during the operation of the CSP-PV power generation system,and effectively improve the reliability of load power supply in the system,a reliability evaluation algorithm based on time-series simulation is proposed.First,based on the basic structure of the system,a corresponding reliability model is established,and on the basis of analyzing the reliability evaluation characteristics of the system,the reliability evaluation index is defined.Second,a load reduction strategy is applyed to ensure continuous power supply of key loads,and by comparing power output and load demand of system,an operation strategy of the energy storage system of the CSP plant under independent operation mode is analyzed.Finally,a Monte Carlo method is used to simulate the time-series operation state of system,and then the power supply reliability of system is evaluated.The effectiveness of the reliability assessment method is verified by the simulation results.(3)On the premise of ensuring the reliability of power supply,based on the definition of regulation demand and its relationship with reliability,the evaluation indexs of regulation demand are quantitatively analyzed.Simultaneously,from the perspective of the CSP-PV power generation system to maximize consumption of the PV power generation,considering the flexible regulation demand of random sources such as intermittent the PV power generation and load,taking the CSP plant as a flexible adjustment source,with the objectives of minimizing the loss of power supply probability of system load,minimizing investment and operating costs,and maximizing penetration of the PV power generation,an multi-objective optimal allocation model for the capacity of the CSP thermal storage systems is established,and the non-dominated sorting genetic algorithm(NSGA-II)with an elite strategy is used for solving.The simulation results verify the effectiveness and rationality of the optimal allocation scheme proposed in this thesis,which takes into account regulation demand. |
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