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Research On Control Strategy Of Hybrid Energy Storage Feedback System

Posted on:2020-02-12Degree:MasterType:Thesis
Country:ChinaCandidate:S WangFull Text:PDF
GTID:2382330575974024Subject:Electrical engineering field
Abstract/Summary:PDF Full Text Request
Urban rail transit has the advantages of punctuality,large capacity and environmental protection.In recent years,it has developed rapidly.When the train adopts electric braking to decelerate or stop,the motor works in the power generation state,converting the kinetic energy of the train into electric energy,which is fed back to the DC bus.Compared with the energy consumption resistance,the energy storage system can store the braking energy of the train and then when the train is towed.Secondary utilization.Because of the large inertia of the train,the energy returned by the electric brake has the characteristics of large total amount and high power in a short time.Therefore,it is of practical significance to study the hybrid energy storage and feedback system composed of the supercapacitor of power-type energy storage element and the lithium-ion battery of energy-type energy storage element.In this paper,the control strategy of hybrid energy storage feedback system is studied by using the theory of automatic control.Firstly,the characteristics of each component of the power supply system of urban rail transit with hybrid energy storage are analyzed in detail,and their equivalent circuit models are established respectively.The small signal model of the bidirectional Buck/Boost converter used in the hybrid energy storage system is established.Combined with the actual parameters of Guangzhou Metro Line 4,the influence of the departure workshop and bilateral power supply on train energy consumption and feedback is considered.The capacity of surface hybrid energy storage system should be allocated reasonably.On this basis,the control strategy simulation platform of ground hybrid energy storage system is built by using MATLAB/SIMULINK.The control strategy of double closed-loop hybrid energy storage system using first-order low-pass filter power allocation method is simulated.Combining with the simulation results,the reasons of insufficient speed of voltage outer-loop threshold control in the charging stage of hybrid energy storage system are analyzed,and the variable with no-load voltage as reference is proposed.At the same time,aiming at the problem that the filter allocation method will cause power cycle in the hybrid energy storage system in the stage of power demand attenuation,an improved filter allocation method is proposed to improve the utilization rate of the capacity of the hybrid energy storage system,reduce the system loss,and prolong the service life of the energy storage components.The proposed method is preliminarily verified by comparative simulation.The superiority of the control strategy.In order to better study the control strategy of ground hybrid energy storage feedback system,based on the existing laboratory conditions,an experimental platform of hybrid energy storage feedback system with rated power of 300 W was designed and built.The proposed control strategy was verified by experiments using TMS320F28335 as the core controller,which further proved the rationality and superiority of the proposed control strategy.
Keywords/Search Tags:Hybrid Energy Storage System, energy feedback, Control Strategy, Super Capacitor, Lithium Ion Battery, Power Distribution
PDF Full Text Request
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