| Under the new situation of promoting energy production and consumption revolution,intensifying energy conservation and emission reduction efforts and controlling haze,Increasing energy efficiency and reducing pollutant emissions has become a consensus among governments,enterprises and the public.Micro energy-grid contains four kinds of energy forms: cold, heat, electricity and gas, which schedules the rich kinds of energy supply and storage equipment to achieve the goal of optimizing the energy supply to regional hot, cold and electric load and enhancing the energy efficiency by using the Internet of Things technology and information technology. As a typical representative of Micro energy-grid, CCHP systems has become an important means to achieve energy production and consumption transformation, improve energy efficiency and solve energy and environmental problems by its efficient energy efficiency, flexible and reliable energy supply mode.This dissertation mainly researches on the CCHP systems, breaks the traditional regional power grid’s optimization process limit to the electricity optimization by considering the hot and cold energy with the electricity together. This dissertation integrates hot and cold resources into the optimization process to achieve the efficient use of energy of the entire region. In this dissertation, the energy consumption characteristics of hot and cold energy in the region are studied, at the same time the mathematical model of a variety of energy supply equipment and energy storage equipment are established in CCHP systems.Optimized economic dispatching model of the CCHP System is established according to the model. Then, consider a variety of operational objectives, the multi-objective operation optimization scheme of CCHP systems is proposed. Finally, based on the real-time operation requirements of CCHP systems, considering the possible deviation of energy supply and demand forecasting, the real-time optimal scheduling scheme of CCHP systems is proposed. The researches proposed in the dissertation are summarised as follows:1. Taking the area of Animation Park in Sino-Singapore Tianjin Eco-City as reference,an energy supply framework of Micro energy-grid is built according to the expanding of the area’s energy supply structure. The energy supply structure of the Micro energy-grid and the main energy supply and energy storage equipment components in the Micro energy-grid are studied.The relationship between power generation, waste heat utilization efficiency and the change of load rate of microturbine system in the Micro energy-grid is analyzed, then the corresponding energy supply mathematical models are established for microturbine, waste heat boiler and absorption refrigeration unit. The static output characteristics of auxiliary energy supply equipment in the Micro energy-grid are analyzed, then the corresponding energy supply and energy storage mathematical models are established respectively for chillers, energy storage devices, household air conditioning systems, electric storage boilers,gas boilers and photovoltaic power generation system.2. Taking a building-type CCHP system in Sino-Singapore Tianjin Eco-City as an example, the centralized energy supply structure of the building-type CCHP system is established, and then the operation scenarios and operational constraints of the system are given. Afterwards discussions of the two kinds of scheduling methods of "Following Electricity Strategy" and "Following Thermal Strategy" are carried out in several aspects,including typical application scenarios of scheduling methods, implementation process,effect of scheduling method on the configuration of energy equipment in the system, energy equipment utilization and the economics of the scheduling methods.3. An energy supply infrastructure for the CCHP System based on centralized and interconnected energy exchange network is proposed. Loads are subdivided into pure electric load, hot water load, space heating load, refrigeration load and space cooling load.Optimized economic dispatching model of the CCHP System is established according to the infrastructure. The model is solved by the interior point method with Hessian matrix iteration. The testing case shows that the dispatching method can achieve the destination of optimized economic operation of the CCHP system by reducing the operation cost remarkably, which is realized through controlling the operation mode and output of the energy supply and storage equipment.4. Considering the importance of optimizing the operation of CCHP systems in reducing system operating costs and controlling pollutant emissions, the environmental objectives of CCHP systems is added to the optimization objective, and the multi-objective optimization model for CCHP systems is established on the basis of day-ahead optimized economic dispatching model. According to the characteristics of the model, a multi-objective hierarchical progressive parallel algorithm based on improved NSGA-II is proposed. The algorithm improves the non-dominating layer sorting algorithm and introduces the goal attain method to accelerated convergence by changing the convergence criteria. The dissertation introduces parallel computing technology according to algorithm characteristics, which accelerates the convergence speed of the algorithm under the premise of ensuring the diversity of the solution searched by the algorithm. After analyzing the operation optimization application scenarios of CCHP systems under multiple objectives,the multi-objective operation optimization model of CCHP systems is solved, the typical daily operation results are given and the Pareto solutions are explained. The algorithm proposed in this dissertation is compared with the traditional weighting algorithm and NSGA-II algorithm in terms of solution diversity and solution time, which proves that the algorithm proposed in this dissertation has better effect in the diversity of solution searched,iteration time and convergence. In practical engineering applications, the optimal operation scheme can be chosen according to the needs of users, thus achieving the goal of multi-objective operation optimization of CCHP systems.5. After analyzing and learning from the real-time optimization scheduling scheme of traditional power system and microgrid, this dissertation modifies the scheduling method according to the characteristics of CCHP systems, then a real-time operation correction model for CCHP systems is proposed. The real-time correction model modifies the day-ahead operation scheme of CCHP systems in real time to offset the impact of forecasting errors, thus ensuring the safe, stable, reliable and economical operation of CCHP systems. On the basis of real-time correction model, a real-time rolling optimization model of CCHP systems is proposed to update the planned operating point of all kinds of energy supply equipment at the next time interval. By executing the scheduling results of real-time correction model and real-time running rolling optimization model, the system can achieve the balance of real-time energy supply and demand in the event of taking the day-ahead scheduling plan into account, thus achieve the goal of real-time operation optimization and scheduling and real-time energy optimization management. |
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