Key Technologies Research And Equipment Development Of High-power Multi-port Energy Router

With the wide application of new energy technology and energy storage devices and the access of new loads such as electric vehicles,the traditional power supply form is facing great challenges in terms of stability,efficiency and economy.In order to solve this challenge,the multi-port energy router concept emerged.There are two kinds of multi-port energy router used in low voltage occasion,integrated multi-port energy routers and common DC bus type multiport energy.The common DC bus type multi-port energy router has characters of high-power and low coupling degree,so it is not suitable for high-power industrial occasion.Herein,a highpower multi-port energy router based on common dc bus structure is proposed.Based on Yunnan Power Grid Project “Research on Key Technologies of Multi-Port Energy Router for New Energy Access” and National Natural Science Foundation Project “Research on Multi-Port Power Regulator for High-speed Railway and Its Collaborative Control for New Energy Access”,this thesis researches high-power multi-port energy router in these aspects,including theoretical study,simulation verification and physical platform construction.The major work of this thesis are as follows:(1)For AC port module of high-power multi-port energy router,the scheme based on T-type three-level converter is designed.The basic working principle and modulation strategy of the T-type three-level converter is introduced.What’s more,the main circuit parameters such as LCL filter is analyzed and designed in detail.Based on the mathematical model established in the stationary coordinate system,a double closed-loop control strategy is proposed.Futhermore,the inner loop is realized by applying capacitive current feedback,and the outer loop is realized by apply power supply side current feedback.A simulation model is built to verify the steadystate performance and dynamic performance of the T-type three-level converter.And the feasibility of the AC port scheme based on the T-type three-level converter is verified in the simulation level.(2)For DC port module of high-power multi-port energy router,the scheme based on cascaded Buck-Boost converter is designed.Two basic modes of operation are determined according to the basic working principle of cascaded Buck-Boost converter,including Buck mode and Boost mode.What’s more,the modulation strategy of cascaded Buck-Boost converter is given,and the dual carrier mode modulation strategy is analyzed in detail.The mathematical model of Buck-Boost converter in Buck mode and Boost mode is established respectively,as well as the proposed double closed loop control strategy.A simulation model is built to verify the steady-state performance and dynamic performance of the cascaded Buck-Boost converter.And the feasibility of the DC port scheme based on the cascaded Buck-Boost converter is verified in the simulation level.(3)Based on the basic port scheme,the overall system scheme of high-power multi-port energy router is designed.According to the project requirements,the system topology scheme is adjusted,and a port coordination control strategy with the energy storage port as the core is designed.The control strategy is realized by adjusting the working state of the energy storage port in the system’s steady state operation mode and dynamic operation mode.A simulation model is built to verify the different operating modes of the system.And the feasibility of the multi-port energy router system solution is verified in the simulation level.(4)A multi-port energy router device platform is built.The system architecture of the multiport energy router platform is introduced,and the bottom controller and the host computer platform are given.Based on Kingview software,the host computer monitoring platform is designed,and finally a high-power multi-port energy router platform is built,and the feasibility and value of the multi-port energy router system scheme are verified in the experimental level.