Modeling, Optimization And Control Of Distributed Energy System In The CCHP System

With the economical social development, the demand for energy is growing, the threat of energy depletion is increasingly becoming the focus of people’s concern. At present, Chinese energy structure is irrational. Because the coal is the dominant energy consumption, the most commonly used energy supply systems are centralized units, which consist of large power grids. But this kind of energy supply has the following several typical problems:single product; poor security; serious air pollution; increasing demand; mismatching development between the construction of power grid and demand for energy. To abandon the traditional way of production and promote the use of high energy utilization, the low pollution emission of new capacity is imperative. At the same time, in order to realize the scientific and sustainable development of social economy, the distributed energy system has become a hot research topic.One distributed energy system contains a variety of energy supplies among which the system combined cooling, heating and power (CCHP) is the one main way. The CCHP system’s main producting electric equipments rely on gas turbine or internal combustion engine. The gas turbine exhaust emissions of heat can be used directly for heating or absorptional refrigeration, when the CCHP system is running. The CCHP system operates with a typical energy cascade utilization characteristics. It can use different grades of energy, to provide users with electrical energy while providing cold, heat or other multiple forms of energy and increase energy utilization rate.A CCHP system is set up on the TRNSYS simulation platform based on a hotel’s electric load, heat load and cooling load data in one-year. The data, collected when the system running, is used to establish the fuzzy relation matrix model for each part of the system. A multi-objective optimization model, which contains economic costs, environmental costs, and the cost of configuring, is implemented based on the fuzzy relation matrix model. The improved fuzzy controller design is realized based on optimization objective. The main research contents are as follows:The first chapter reviews and analyzes the current energy distribution structure both domestic and abroad as well as the main modes of energy uses by studying literature. While, the composition, the utilization and the development status of energy of the CCHP system are introduced.A CCHP system is set up on the TRNSYS simulation platform based on a hotel’s electric load, heat load and cooling load data in one-year in the second chapter. The fuzzy relation matrix model for each part of the system is established based on the data collected when the system is running.The particle swarm optimization (PSO) algorithm is introduced in the third chapter. The performance index of the system is established. Objective function, which consists the minimum fuel cost, minimum system configuration costs and minimal environmental costs, is established based on the price of electricity in different time. The CCHP system’s optimal operation model is built.The design of the controller based on the improved fuzzy controller is realized in the multi-objective optimization index of the CCHP system. Each subsystem in the CCHP system is controlled to optimize operating power to achieve the most optimal results.In the fifth chapter, the achieved research results in this dissertation are summarized and analyzed. Besides, some deficiencies are put forward.