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The Construction Of Microgrid Platform And Optimal Energy Management For Microgrid

Posted on:2016-05-16Degree:MasterType:Thesis
Country:ChinaCandidate:X H YinFull Text:PDF
GTID:2272330470951921Subject:Electrical engineering
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With the development of world economy, the demand for energy has risensharply. It is urgent to develop distributed renewable energy sources such aswind and solar energy. Microgrid combining modern electronic technology withdistributed generation technology, can not only adequately take advantages ofdistributed generation and improve power supply reliability and power quality,but also is advantageous to the construction of a conservation-minded societyand develop rapidly. As a small and isolated power grid, on the one hand, it canreal-timely balance internal load power through coordination of powergeneration units and energy storage equipments, on the other hand, microgridcan realize connected or isolated operate controlled by some electronic devices.Optimal energy management for microgrid is the guarantee to realize themicrogrid safe, reliable, economic, environmental, efficient operation.(1) The platform microgrid structure is given, and characteristics of thephotovoltaic, wind power generation are studied, fuel cell operationmaintenance and sewage treatment cost functions are established. Comparedvarious energy storage ways, decide to use lead-acid battery as the energystorage device. The paper discusses the factors that affect its life cycle, and thelife loss function is established. According to the platform voltage and capacityrequirements, storage battery connection is presented. On this basis, through theoverall design of the hardware system, the network environment parameters andelectric parameters are collected. The microgrid monitoring system based onLabVIEW is developed, to carry out the analysis of the signal processing, preservation and display functions.(2) Real-time optimal energy management for grid-connected microgrid isproposed. Firstly, it previously divides the24hours in a day into peak time,normal time and valley time. Considering controllable power supply and batteryrelated constraints, three optimization models of economic operation areestablished, discharge power penalty function considered SOC and dischargepower was designed in the whole time in model1. Model2on the basis ofmodel1, charging compensation function considered charge power wasdesigned at normal time and valley time, charging penalty function consideredSOC and charge power was designed at peak time. Model3based on model2,manage the load side. Secondly, a optimization model which environmentalpollution compensation cost minimum is considered as the objective function isestablished. Thirdly, for the multi-objective optimization problem consideringthe economic operation cost and environmental pollution compensation cost, onthe basis of single objective satisfaction degree and comprehensive evaluationfunctions, the multi-objective optimization problem is transformed to asingle-objective optimization problem and an interactive multi-objectiveoptimization model is built at last.(3) In view of the isolated microgrid, the optimal energy management isdivided into two phases, day-ahead scheduling and real-time dispatch. In theday-ahead optimization phase, take all day operation cost minimum as the goal,to optimize on/off states of controllable micro-sources and transfer out time,transfer in time and transfer amount of transferable load. Real-time dispatch ison the basis of day-ahead scheduling, SOC of battery is divided into fiveintervals, determine the operation interval based on the calculated real-time SOC.Different scheduling policies are adopted according to the SOC interval ofbattery, system power net load power and the capacity of each controllablepower unit.(4) On the basis of theoretical research, relying on the building microgrid platform, connected and isolated operate energy is optimized.Results show thatconnected operate, model2economic operation cost is decreased by11.2%thanthat of model1, model3is decreased by16.8%than model2, by26.1%thanmodel1. Economic benefit is remarkable and correctness and effectiveness ofthe models are verified. In model2, the interactive optimization method is used,the multi-objective optimization of the economic operation cost than theeconomic operating cost corresponding to pollution of the environment costminimum low3.97%, multi-objective optimization of environment pollutioncost than environmental pollution cost corresponding to economic operation costminimum low cost8.8%. when isolated operate, the microgrid optimal energymanagement ways can not only ensure microgrid economic, reliable andcontinuous operation, but also reduce the capacity configuration of batteries in amicrogrid.
Keywords/Search Tags:microgrid, monitoring systems, optimal energy management, grid-connected, grid-isolated
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