| Energy and environment is the foundation of human survival, in order to realize the sustainable development of energy and environment, a large-scale and high-efficiency usage of clean energy oriented revolution is taking place all around the world. Microgrid, as a kind of important clean energy consumption technology, has great value to the transformation of traditional energy structure to clean energy. Microgrid changed the energy consumption way in social production and life. The four key links:traditional grid vast power generation, transmission, distribution and utilization of energy, has realized the high degree of concentration by microgrid. Microgrid is a source, dual nature of active load, through the optimization of flexible control, can realize the interaction between power generation and consumption, so as to promote the efficient usage of clean energy and the development of extensive energy society and resources saving society.This dissertation is supported by state 863 projects "Key technology research and integrated demonstration of smart microgrid on the user side based on distributed energy" and natural science funds "Synergy mechanism and optimization method of electric car and renewable energy in microgrid". Five aspects, multi-type renewable energy microgrid capacity optimization configuration, microgrid autonomous optimization operation method, multi-microgrid connectivity analysis, distribution network reconfiguration containing multiple microgrid and multiple microgrid cooperation to participate in the distribution network coordination, are studied in this dissertation. This dissertation provides theoretical support and engineering reference for microgrid demonstration and promotion. The main innovation of this dissertation is as follows:1) The related optimal allocation methods are proposed for microgrid containing multiple type of energy from in grid and off-grid. A multi-objective optimal allocation model and solution method are proposed targeted typical off-grid microgrid:island microgrid containing diesel-wind-solar-battery and sea water desalination, which consider three types of controllable resources:water desalination, storage battery, and diesel generator, and system power allocation strategy is proposed. An optimal allocation method of energy storage capacity considering essential load is proposed. This method is targeted in-grid microgrid:industrial PV microgrid. The operating characteristics and the impact of starting feature of industry sensitive loads in the PV microgrid for industries are analyzed. Energy storage system charging and discharging control strategy based on industry TOU (Time of use electricity price) mechanism which is applicable to industrial PV microgrid is proposed. Multi-objective including retained profits and PV consumption rate maximizing optimization model is proposed.2) A microgrid optimization controlling strategy based on load classification is proposed. Load of microgrid can be divided into baseline load, shiftable load and schedulable load, and electricity characteristic model is built respectively, so the load optimization control constraints is formed. Based on the real-time electricity price and load classification constraints, combining two rival goal:the user electricity cost and user dissatisfaction rate. Objective function of user preferences to adjust ability is formed.3) A method analyzing multi-microgrid interconnected feasibility from interconnected system frequency stability and adjust ability is proposed. By analyzing the frequency characteristic of non-difference FM micro source, difference FM micro source and load, microgrid composite frequency characteristic containing different type of energy is proposed. According to the microgrid integrated frequency characteristic, lowest frequency points of active power can be calculated, the power is the critical power frequency stability. According to the spare capacity of controllable battery and energy storage in microgrid system, standby time and standby power whether meet the requirements is calculated from the perspective of renewable energy power different drop quantity adjustment.4) A two phase reconstruction model in real time for distribution network containing multi-microgrid is proposed. The model consider renewable energy sources and random uncertainty of load. In the first phase, the topology of the distribution network is optimized, in the second stage, the model focus on the optimization of power output of diesel generators and charge-discharge of energy storage, and power exchange with external power grid power, to reduce the economic risk of power distribution network real-time operation. Multi-cutting plane decoupling generalized genders is used to solve the two phase reconstruction model. The model is tested on RBTS Bus 5 system containing 3 microgrid.5) For coordination problems of multi-microgrid in local distribution network, the electric power market environment cooperative game method of is proposed. First of all, based on adaptive robust optimization, single microgrid day-ahead scheduling model is proposed, and energy and standby sharing between the multi-microgrids is achieved. Secondly, using convex game theory, collaborative benefits of multi-microgrids are effectively allocated to each microgrid, and theory stability of multi-microgrids benefit distribution mechanism is proved. |
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