Research On Optimal Scheduling Method Of Combined Heat And Power System For Wind Power Accommodation

China is rich in wind power resources,and the penetration rate of wind power is increasing day by day.However,the problem of wind abandonment in heating period is still prominent in North China.This is mainly due to the large proportion of combined heating and power units in the northern region of China,and the combined heating and power units occupy the grid space of wind power in the operation mode of ’heat-set’.In order to solve this problem,this thesis starts with the optimal scheduling of the combined electric and heating system.On the’source’ side,a scheduling strategy of the combined electric and heating system based on the additional heat source to absorb waste wind is proposed.On the ’load’ side,a demand response mechanism is established to enable the user side resources to participate in the optimal scheduling of the combined electric and heating system.An improved shuffled frog leaping algorithm is proposed and applied to the optimal scheduling problem of the combined electric and heating system to obtain an effective optimization effect,so as to provide more space for the wind power grid,and bring economic benefits to the combined electric heating system.Firstly,this thesis analyzes the overall structure of the combined electric and heating system,and establishes wind power output model,thermal power unit model,combined heating and power unit model,electric boiler model and heat storage tank model.According to the wind speed data and the annual average wind speed data of a certain wind farm,the uncertainty of wind speed and the error of wind speed Weibull distribution are explained.The simulation results show that the heat storage tank can promote the wind power accommodation.Secondly,the principle of using additional heat source to release the flexibility of combined heating and power unit to absorb waste wind is analyzed in detail,and puts forward the scheduling strategy of combined electric and heating system based on the principle.The strategy describes the steps of coordination among heat storage tank,electric boiler,combined heating and power unit and thermal power unit,and establishes the scheduling model of combined electric heating system based on the strategy.The simulation results verifiy the beneficial effect of the proposed strategy on promoting wind power accommodation.Finally,the demand response model is established on the ’load’ side,which considers load transfer and load conversion,and guides users to participate in the scheduling of the combined electric and heating system through the Time-of-use electricity price mechanism;considering the error of the Weibull distribution of wind speed,the wind power output scenario is established,so that the predicted output power of wind power participates in the scheduling in the form of the wind power output scenario,which can best fit the randomness of wind power output.A two-level scheduling model is established,which aims at the lowest electricity consumption cost of users and the lowest generation cost of the system.In view of the shortage of the shuffled frog leaping algorithm,an improved shuffled frog leaping algorithm is proposed,and its allocation mode and update strategy are improved,and it is applied to the optimal scheduling problem of the combined electric and heating system.The simulation results show that the improved shuffled frog leaping algorithm proposed in this thesis has superior performance.At the same time,it is shown that user-side resource participation in the user side resource participating in the optimal scheduling can further promote the wind power accommodation,reduce the user electricity cost and the generation cost of the combined electric and heating system,and improve the system operation economy.