Electric Energy Router Interconnection System And Its Energy Management

Electric energy router(EER)is a new intelligent power electronic device that combines power electronic conversion technology and information technology,which is considered to be one of the core devices of the future energy Internet.EER has many superior functions,making it can play an important role in promoting the transformation of energy structure and the upgrading of power system architecture.If multiple EERs are further interconnected to form an EER interconnection system,the application potential of EER can be fully tapped so that EER can play a more powerful role.Meanwhile,it can help promote the popularization and application of EER in the future distribution network.This thesis focuses on the EER interconnection system and conducts research on its basic architecture and control,energy management and related prototype development.Firstly,according to the two occasions of single power user and multiple power users,this thesis classifies the EER interconnection system into two types: single user type and multiple users type.The basic architectures of single user type EER interconnection system and multiple users type EER interconnection system are proposed respectively,and their characteristics summary and operation state classification are given.The control models of EER interconnection system in grid-connected state and off-grid state are established respectively.A grid-connected/off-grid state seamless switching strategy considering advance compensation is proposed,which can realize the seamless switching process of EER interconnection system between grid-connected state and off-grid state.Simulation results verify the effectiveness of the proposed grid-connected/off-grid state seamless switching strategy.Aiming at the application scenarios where the system prediction data can be obtained,a day-ahead optimal scheduling scheme based on the non-dominated sorting genetic algorithm-Ⅱ(NSGA-Ⅱ)is proposed for multiple users type EER interconnection system.An internal price trading mechanism based on the supply-demand ratio is proposed to ensure the fairness and equality of each power user in the process of peer-to-peer energy trading.Based on the internal price trading mechanism,the day-ahead optimal scheduling problem is analyzed and modeled in detail,and the solution to the day-ahead optimal scheduling problem is given by using NSGA-Ⅱ and multi-attribute decision making method.Simulation results verify the effectiveness and superiority of the proposed day-ahead optimal scheduling scheme,showing that the system has been improved in lots of evaluation indicators after adopting this scheme.Aiming at the application scenarios where the system prediction data cannot be obtained,real-time energy management schemes based on fuzzy control are proposed for single user type EER interconnection system and multiple users type EER interconnection system,respectively.Through analysis,the energy management objectives to be considered in the real-time energy management scheme are given,and the design processes of the realtime energy management scheme are expounded in detail.In the real-time energy management scheme proposed for single user type EER interconnection system,a novel fuzzy controller considering the unit-time electricity charge is designed,which can simplify the rule design and real-time calculation of the fuzzy controller.In the real-time energy management scheme proposed for multiple users type EER interconnection system,a novel design idea of realizing the supply-demand balance adjustment process of the system through fuzzy controllers is adopted,which can guide the power supply-demand level of the system to approach the self-sufficiency state in real time.Simulation results verify the effectiveness of the proposed real-time energy management scheme,showing that the system can achieve multiple energy management objectives at the same time without prediction data after adopting this scheme.Finally,the related experimental prototypes are developed for single user type EER interconnection system and multiple users type EER interconnection system,respectively.The design processes of the prototypes are expounded in detail,including the design of main circuit topology and key parameter,the basic control strategy,and the implementation of control system.Several tests have been carried out on the developed prototypes,and the test results verify the effectiveness and feasibility of the aforementioned grid-connected/off-grid state seamless switching strategy,day-ahead optimal scheduling scheme and real-time energy management scheme.The development and test of the above-mentioned prototypes have laid a foundation for promoting the practical application of EER interconnection system.