Research On The Optimal Allocation Of Solar-Thermal Power Station Capacity In Wind-Solar New Energy Base

In the context of the rapid development of new energy sources in China,the problems of randomness in the operation of the power system,the anti-peaking characteristics and the voltage stability of the ultra-high voltage direct current(UHVDC)transmission lines have become increasingly prominent.New energy generation is often limited by its own characteristics and generation technology,but concentrating solar-thermal power(CSP)generation is one of the most promising new energy generation technologies at present because it has the advantages of good adjustability and peak regulation flexibility while maintaining clean power generation,which can improve the system’s peak regulation stability and capacity.However,CSP generation technology is flexible and versatile,but there are also some uncertainties,CSP plants are composed of many sub-modules,and its different capacity configuration ratios are related to the economic performance of the CSP plant or even the whole system,and it is difficult to find its equivalent power generation model from the existing optimization operation model.The following research work was carried out in this thesis to optimize the capacity configuration of CSP plants for wind power and photovoltaic new energy bases.(1)Based on the analysis of the development status of new energy generation technologies represented by wind power and photovoltaic,explaining its advantages and disadvantages of CSP generation technology and summarizing the operation model,installed capacity configuration status and thermal storage capacity configuration status of CSP plants.(2)On the basis of the analysis of the basic composition and operation principle of the CSP plants,studying the working state of each component module,proposing five working modes of its operation,studying the main energy flow patterns of CSP plants,and establishing the simplified energy flow model as well as the operation model of CSP plants.(3)For the long-distance,large-capacity UHVDC outgoing system cannot meet the DC outgoing demand and the transient voltage stability problem is prominent.Based on the opportunity constraint planning theory,this thesis proposes an optimal allocation model for the installed capacity of CSP plants considering transient voltage stability.Considering the uncertainty and fluctuation of scenery output,the uncertainty modeling of photovoltaic and wind power is carried out,and the scenario reduction is carried out by the K-Medoids clustering algorithm.On this basis,establishing the optimal configuration model of installed capacity of CSP plants with the objective function of the strongest transient voltage stability and the lowest comprehensive operating cost,and the operating constraints of CSP power plant,DC outgoing contact line constraints and system operating constraints as constraints.The simulation analysis is carried out by a new energy base improvement calculation in Gansu,and using the CPLEX solver to solve it.According to the transient voltage recovery index(TVRI),analyzing the impact on the transient voltage stability of a new energy base with different capacities of CSP plants,and using the peak-to-valley difference and cumulative climbing volume to analyze the peak regulation effect of the CSP plants after its addition,which verifies the feasibility of the proposed model.(4)Studying the problem of optimal allocation of thermal storage capacity of CSP plants considering unit reliability.Establishing the reliability models of conventional units,wind turbines,photovoltaic units and CSP units considering the unit reliability.This thesis,proposing a model for optimal allocation of thermal storage capacity based on a time-series production simulation method,which takes the maximum capacity confidence and the lowest comprehensive operating cost of CSP plants as the objective function,explores the balanced relationship between the reliability index and economic factors of the thermal storage system,and using the non-dominated sorting genetic algorithm-II(NSGA-II)to solve the optimal thermal storage capacity.Finally,the optimal configuration of thermal storage capacity is given based on the simulation calculation of a new energy base in Gansu.The optimization results show that the reasonable allocation of thermal storage capacity can effectively reduce the peaking cost,reduce the wind power curtailment rate and photovoltaic curtailment rate,increase the capacity confidence of CSP plants,achieve the best economic benefits,improve the reliability of system operation and promote the consumption of new energy.