Comprehensive Scheduling Models And Algorithm For Power Systems With Renewable Energy Integration Considering Transmission Network Topology Optimization And Demand Side Response

Power system optimal scheduling is an important process for the daily production and operation of electeic power industry.The research objects of conventional power system scheduling problem are generating units(ie,generating units scheduling),which is focused on the design of optimal economical operation plan through the scheduling.With the intelligent and informatized development process of power systems,it is possible to transform the topology of the transmission network(ie,transmission topology scheduling)and schedule the flexible loads on the demand side(ie,load scheduling).Meanwhile,the increasing penetration levels of uncertain renewable energy such as wind power and photovoltaics has brought severe challenges to power system scheduling.Therefore,taking into account the uncertainty of power output from renewable energy,establishing a power system comprehensive scheduling mechanism considering the scheduling process for generating unit,transmission topology and load so as to improve the economical performance of the power systems and the accommodation capability for renewable energy,has become major concerns for the national energy strategy development and operational decisions of power company.Supported in part by the National Science Fund for Distinguished Young Scholars(Project No.51725701),this thesis studies and explores the comprehensive scheduling of power systems considering generating units scheduling,transmission topology scheduling and load scheduling with renewable energy integration.The study of this thesis is mainly focused on transmission line switching and substation busbar splitting incorporated transmission topology scheduling,demand response incorporated load scheduling and renewable energy incorporated source-grid-load comprehensive scheduling problems.The meteorological conditions around the conductor have a great influence on the transmission capacity of the overhead transmission line,which in turn affects the optimal transmission line switching scheme in the power systems.To this end,based on the conductor heat balance equation,the dynamic transmission capacity evaluation model of overhead lines is obtained.Based on this model,the transmission capacity improvement rates of overhead lines under predicted meteorological conditions are calculated and then the dynamic transmission capacity of lines can be evaluated.Based on the dynamic transmission capacity and combined with the switchable transmission line recources,the power system optimal scheduling model considering transmission switching is established so as to realize the coordinated scheduling of line switching action and generating unit.The objective function of the model is to minimize the operating cost.The switching states of lines are characterized by binary variables and the dynamic transmission capacities are embedded in the line power flow constraints.Applying the model to the modified IEEE RTS-79 system,the results show that the dynamic transmission capacity assessment of overhead lines will affect the transmission swiching incorporated transmission topology scheduling scheme and will change the operational performance of power systems.Under favorable weather conditions,implementing the transmission switching incorporated power system transmission topology scheduling with dynamic transmission capacity of overhead lines can help improve the economical operation performance of power system and contribute to the accommodation of renewable energies.Through the substation bus splitting technology,the topology of the transmission network can be changed effectively.By analyzing the bus splitting ability of different configuration scheme of substations,the day-ahead optimal scheduling model of power system considering substation bus splitting technology and generating units can be established.The objective function of the model is to minimize the operating cost and the operational constraints of generating units and lines etc.are considered.Meanwhile,the connection relationship variables are unitized to symbolize the connectivity relationship between different busbars and between busbars and connected components including generating units,lines and loads.The collaborative scheduling of traditional generating units and transmission topology is realized in this model.Applying the model to the modified IEEE RTS-79 system,the results show that in the scenario without wind power integration and with large-scale wind power integration,the substation bus splitting technology can reduce the generation cost of day-ahead scheduling for the power system by 6.18% and 5.81%,respectively.The capability of power system to accommodate large-scale renewable energy is also improved.In order to explore the effect of demand response technology and emerging hydrogen storage technology with broad application prospects on the economical operation of power system,a power system load scheduling model with multiple demand response programs and hydrogen storage incorporated energy hub is established.In the model,from the consumer’s electricity comsumption behavior regulation by means of real-time electricity price and the direct control from power grid towards the dispatchable load,a load scheduling model considering price-based and incentive-based demand response is established with the scheduling characteristics of hydrogen storage integrated.The objective function of the model is to minimize the operating cost and constraints including demand response constraints,hydrogen storage constraints,traditional operational constraints etc.are considered.Applying the load scheduling model to the modified IEEE RTS-79 system,the results show that the established model can effectively formulate the daily electricity price,determine the scheduling scheme of incentive-based demand response program and hydrogen storage incorporated energy hub to improve the economical performance of power system and contribute to the accommodation of renewable energies.The flexible interaction of generation side,transmission side and load side resources is an effective way to improve the economical operation performance of power systems.This thesis establishes a stochastic comprehensive scheduling model of power system considering generating units,transmission topology and load side scheduling.The model aims to minimize the operating cost and it integrates concentrating solar power generation technology,transmission network topology scheduling technology,load side demand response technology and hydrogen energy storage technology,etc.,which can realize the deep interaction and coordinated scheduling of generation,transmission network and load side dispatchable resources.In the two-stage stochastic optimization model,at the first stage,the commitment scheme of traditional generating units,hydrogen storage incorporated energy hub and the concentrating solar plant,the transmission topology scheduling scheme and the day-ahead real time pricing are determined.At the second stage,under different uncertainty scenarios for renewable energy,the scheduling scheme of traditional generating units,the concentrating solar plant,hydrogen storage and incentive-based demand response program are determined.In the model,the scenario generation process is based on the Latin Hypercube Sampling method and the number of scenarios is reduced by K-means clustering method.Applying the model to the modified IEEE RTS-79 system,the case study shows that the power system comprehensive scheduling model proposed in this thesis can improve the operational performance and the renewable energy accommodation capability of the power system effectively.