A PV-Ess Power Routing System Based On Partial Power Conversion And Its High Voltage Ride Through Scheme

With the development of renewable energy technology,distributed power supply mode with multi energy and multi-directional power flow including utility grid,renewable energy and energy storage unit has gradually become a research hotspot.An AC/DC hybrid multiport power routing(MPPR)system which based on dual DC buses is proposed in this paper,partial power conversion(PPC)and high voltage ride-through(HVRT)scheme are deeply analyzed and studied.Firstly of all,this paper designs a multi-port power routing system,which is composed of photovoltaic unit,battery energy storage unit,interconnected converter unit and load unit.The functions of each port,bus and module in the system are described,and the working principles of PPC and HVRT are analyzed in detail.The mathematical model and output characteristics of photovoltaic cells are introduced,the battery energy storage and power electronic converter in the system are optimized and selected,and the mathematical models of bidirectional double half bridge DC/DC converter and three-phase LCL filter are established.Secondly,the control strategies of PPC and HVRT are designed for the multi-port power routing system.The control schemes of half-bridge Boost converter,dual half bridge(DHB)bidirectional DC/DC converter and three-phase grid-connected converter are analyzed in detail,including the corresponding parameters design,controller design and modeling process.At the same time,the energy flow relationship between buses and ports under five different operating modes is studied and analyzed.Finally,each module of the system is simulated by MATLAB,and then five operating modes of the overall system are simulated and analyzed.The simulation results of the system under different operating modes are given to verify the feasibility of the control strategy and energy management scheme.The overall experimental platform including photovoltaic converter,DHB bidirectional DC/DC converter and bidirectional Buck/Boost converter in the system is built.The effectiveness of PPC and HVRT control strategy used in the system is verified through experiments.