| In the future,distribution system will become the Energy Internet,which have multiple energies hybrid power generation and a bidirectional relationship of power supply and demand.The Power Router is the necessary power conversion device in the Energy Internet.In terms of energy control,the Power Router not only needs to satisfy the demand of output power quality,but also controls the power reasonable delivery.The three-port converter(TPC)has broad development prospects for power distribution systems due to its high power density,power easy to realize bidirectional delivery and ability to dispose different energy synchronously.Therefore,the three-port converter and its application in the power distribution system are studied in this paper.In this paper,firstly,the working principle and power delivery equation of dual active bridge converter and TPC are described and deduced respectively.The hardware decoupled condition of the TPC is obtained according to the power delivery equation,and a hardware decoupled TPC is constructed.Secondly,to solve the coupling and interaction of power delivery among the different ports in TPC,the feedforward decoupling control method and the linear active disturbance rejection control(LADRC)method are used.The virtual resistor is introduced to avoid the oscillation of current caused by the three-port system input LC filter.The simulation based on MATLAB and experiment results shown that the stability of the control system is improved by introducing the virtual resistors and the input current resonance phenomenon is effectively suppressed.Meanwhile,the decoupling effects of two methods are compared.Compared with the feedforward decoupling method,the three-port system has better dynamic performance by using the LADRC method.The DAB converter and the hardware decoupled TPC are applied to the DC power distribution system.They are used as the control nodes of the two systems respectively,and corresponding energy management strategies are proposed.In this control strategy,multiple parallel control loops perform operations at the same time and the final control signal is selected by taking a logic judgment.When the mode is changed,the soft switching of this system is realized.According to the different operating conditions of the system,the bus voltage of each power distribution zone are stabilized within the set range by controlling the power delivery among three ports.So the stable operation of each power distribution zone in this system is ensured and the fault tolerance of this system is improved.Two power distribution system simulation models are built in MATLAB.These energy management strategies correctness and effectiveness are verified by the simulation results.The experiment platform of DC distribution system based on DAB converter is built and it verifies the proposed energy management strategy. |
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