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Research On Energy Router For AC/DC Microgrid Cluster Based On Cascaded H-Bridge

Posted on:2018-08-17Degree:MasterType:Thesis
Country:ChinaCandidate:Y MengFull Text:PDF
GTID:2322330542456769Subject:Electrical engineering
Abstract/Summary:PDF Full Text Request
With the gradual depletion of fossil fuels and the worse of environment,it is widely recognized all over the world that traditional power generation is supposed to be replaced with renewable energy generation for the sustainable development of human environment and resources.As the development of energy internet and the presentation of a variety of energy interoperability strategies,power grid as one of the core network of energy internet has become the vital focus which is confronted with many problems on the increase of renewable energy generation.In order to reduce the transient influence of distributed renewable energy to traditional power grid,it is an effective method that renewable energy is consumed locally in the form of microgrid to improve the utilization rate of renewable energy and enhance the stability of power grid.With increasing microgrids,energy coordination and control strategies in microgrid cluster are becoming the vital techbology of microgrid stability.The"energy router" is the core content of this paper.A novel energy router topology is proposed in this paper,and some research on this topology has been done from following aspects.Firstly,the development and basic working principle of energy router are introduced.An energy router suitable for energy coordination and energy control in microgrid cluster is proposed.The working principle is presented iin detail and its mathematical model is deduced.The control strategy in power balance condition is meticulously studied.On the condition that DC capacitor voltage in cascaded H-bridge circuit in energy router is balanced,a simplified voltage sorting algorithm is presented to reduce the consumption of the digital control system resources and realize the simple and fast control of the DC voltages.Aiming at the power limitations of balance control in energy router,a control strategy is proposed based on power unbalance theory.By computing unbalanced power flow in each H-bridge,the DC voltage can be regulated timely to change the unbalanced power limitation of each DC side.The DC voltage reference regulator in energy router is designed to realize a rapid and accurate control of energy and DC voltage in energy router when the power flow is unbalanced in each level.For the faster and precicer DC voltage control on power fluctuation,a vector modulation control strategy in energy router is presented.A novel DC voltage reference regutator is researched by quantitative and detailed analysis among DC voltage,vectors in AC side of H-bridge and active power flow in each level.This regulator can realize precise control of DC capacitor voltage and power coordination by the accurate relation between power fluctuation and DC voltage increment.Finally,the validity and effectiveness of the two kinds of strategies and the energy route function of the energy router for AC/DC microgrid cluster based on cascaded H-bridge is demonstrated by the simulations and experimental prototype results.
Keywords/Search Tags:Energy internet, energy router, cascaded H-bridge rectifier, unbalanced power control, vector modulation
PDF Full Text Request
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