Based On FSBB Two-way DC Closed DC Electronic Load

With the rapid development of semiconductor and power electronics technology,the shipments and types of power supply products are constantly increasing.In order to meet the reliability and output stability of power supply equipment,it is necessary to carry out strict on-load and aging tests.The energy-fed electronic load with low energy consumption has gradually become a research hotspot.Aiming at the isolated DC/DC power supply,this paper takes the energy feedback type electronic load as the research object.Based on the design concepts of economy,high efficiency,simple structure,high precision tracking of load characteristics,and high efficiency feedback of test electric energy,this paper conducts in-depth research on the circuit topology,control strategy,hardware selection and design,and software algorithm implementation.A DC electronic load based on a four-switch Buck-Boost circuit(FSBB)is developed to form a DC closed test system together with the measured power supply.Finally,the experimental platform is built and the simulation and experimental research are carried out to demonstrate the feasibility of the scheme.In this paper,the basic structure of the energy feed type DC electronic load is analyzed.After comparison,the FSBB circuit is selected as the main power topology.The main working modes of the circuit are analyzed and discussed.The control strategy of monotone wave dual carrier and the solution of smooth transition problem when Buck mode Boost mode and Buck-Boost mode switch each other are proposed.Secondly,based on the function of electronic load simulation of various load characteristic curves,a battery model was established for constant voltage,constant current and battery simulation modes,and a double closed-loop control strategy based on current control was proposed to respond quickly and track the controlled object without static error on the input side of electronic load.Thirdly,according to the design index,the main circuit parameters are calculated in detail,the small signal model of the circuit is established based on the concept of state average,and the controller parameters of the system loop are optimized.Finally,Matlab/Simulink was used to verify the theoretical design.From the perspective of concrete implementation,hardware and software systems were designed,and an electronic load prototype with rated power of 6KW was built.Relevant experimental research was conducted,and the load simulation function was realized.