Research On Decentralized Dynamic Power Allocation Control Strategy Of Multi-source Hybrid Power System

With the increasing urgent demand for energy conservation and emission reduction in the transportation sector,fuel cell vehicle(FCV)have become an important direction for my country’s future development of new energy vehicles due to its long cruising range,high unit energy efficiency and almost zero emissions.However,most of the fuel cells(FC)currently in use have low power density,slow dynamic response and irrecoverable braking energy.In order to compensate for these shortcomings,this paper introduces battery and supercapacitor(SC)as auxiliary power units to form a multi-source hybrid power system(HPS)to supply power to the load.In order to realize the complementary advantages of different power sources and comprehensively improve HPS performance,rational design of system structure and control methods has great theoretical value and practical significance.For the FC/Battery/SC HPS,this paper analyzes and researches its topology and power control strategy in detail.The main research work is as follows:(1)Through the research background analysis and research status investigation,apply decentralized control strategies to a HPS composed of three types of power sources(FC,battery and SC),and the research object and research focus of this paper have been established.(2)Established the model of HPS,FC is connected to DC bus through unidirectional DC/DC converter,battery and SC are connected to DC bus through bidirectional DC/DC converter to supply power to load,which determined the overall system Topological structure.In addition,the three sources and the corresponding converter are selected,and the working principle of the converter is described in detail.(3)Based on the traditional droop control strategy,a new hybrid droop control strategy is proposed.Virtual inductance droop(VID),virtual resistance droop(VRD),and virtual capacitor droop(VCD)are applied to FC,battery,and SC units,so that the corresponding units bear low,medium and high frequency load power.And the droop parameters and controller parameters are optimized.(4)Based on the proposed control strategy,the impedance characteristics,stability,failure performance of power unit.and scalability of the HPS in this paper are analyzed in detail.The results prove that the system has good dynamic and steady-state performance.(5)Finally,a set of 50 k W multi-source HPS simulation model was established in Matlab/Simulink,and a 200 W experimental platform was built in the laboratory.The effectiveness and correctness of the proposed dynamic power allocation strategy are verified by simulation and experiment.