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Research On Energy Management And Control In A Combined Heat And Power Microgrid

Posted on:2019-08-18Degree:MasterType:Thesis
Country:ChinaCandidate:J X ShiFull Text:PDF
GTID:2392330590967294Subject:Electrical engineering
Abstract/Summary:PDF Full Text Request
Characteristics of the power system is generally planned and operated separately such as active distribution networks and microgrids.There exists a lack of synergy and interaction between electricity,heat and gas networks.The renewable energy consumption,the multi-energy coupled control and the energy flow optimization cannot be realized.With the popularization and the application of the renewable energy,distributed energy supply systems such as wind power,photovoltaic and heat pumps are integrated on demand side.It finally forms a combined heat and power microgrid which takes end-users as the main body.The combined heat and power microgrid is designed to meet the energy demands of electricity and heat.It takes the cogeneration system as the construction core,and meets the renewable energy consumption,microgrid fluctuation suppression as well as the energy management optimization at the same time.Coordinated control of electricity and heat is the key operating characteristics of this kind of microgrid.The power network is coupled with the heat network based on the electric heating technology and the power cogeneration technology.The power storage capacity is optimized and the overall microgrid investment is reduced.Meanwhile,it improves the consumptive ability of the distributed renewable energy,suppressing the power fluctuation of the microgrid tie-line and realizing the coordinated supply and cascade of various energies.In this paper,we focus on the energy management and control in the combined heat and power microgrid.A method of the power fluctuation suppression under the short time scale and an energy management optimization method under the long time scale are studied in this microgrid.The specific achievements are presented as follows:(1)Based on the control flexibility of heat pumps,the power fluctuation suppression of the distributed renewable energy in the combined heat and power microgrid is analyzed.Considering the charging state of batteries and super-capacitors and the real-time operating characteristics of heat pumps,heat pumps as well as the electric energy storage hybrid systems are coordinated and controlled under the regulation of the energy management centre.Finally the power smoothing of renewable energy output is realized.Heat pump are applied to the multi-energy complementary integrated systems,which reduces the capacity and investment of the batteries,increases the service life of the electric energy storage,and realizes the stabilization of the power fluctuation in the microgrid.(2)Considering the coupling group control of heat pumps and the charge/ discharge characteristics of the energy storage system,the tie-line power fluctuation is suppressed in the combined heat and power microgrid.The energy management centre analyses signals of the distributed power output,the end-users' demand signals,the operating signals of heat pumps and the operating signals of microgrid tie-line,heat pumps are used as the core equipment of electric heating conversion.The on-off state model of heat pump group is established.By analysing the control algorithm of the onoff state model of heat pumps,the real-time heat pump on-off state sequence is calculated.Based on the output penalty of heat pumps and batteries,the fluctuating power is allocated between them.Finally the outputs of heat pumps and batteries are obtained.(3)Based on the energy management constraints corresponding to different prices in peak,flat and valley periods,the energy management and optimization method is obtained to match the end-users' heat demand.The method achieves the efficient energy management model as well as the peak cutting efficiency.Meanwhile,it realizes the economic operation of microgrid.The water tank has a large and long-time peak cutting effect.As a result,the system is able to cut the peak power to a great extent.For the operation and control of the combined heat and power microgrid,the system has a strong electrothermal coupling control function.Finally,the work of the whole paper is summarized,and prospect of further research is proposed.
Keywords/Search Tags:combined heat and power microgrid, power fluctuation suppression, energy management optimization, heat pump, hybrid energy storage system, fuzzy control
PDF Full Text Request
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