Research On The Structure And Control Of The Input Parallel Output Series DC Electronic Load System

Electronic load is a new type of power electronic system which can simulate the electrical load characteristics in the real environment.It plays an important role in the design and development of power supply equipment.The focus of research on the load test of low voltage and large current communication power supply at home and abroad is mainly divided into two aspects,the structure and strategy of input current tracking and output energy processing.Most scholars only pay attention to one of them,and few research can take both large input current simulation and low output voltage energy feedback at the same time,this paper proposes a DC electronic load based on the input interleaving parallel technology and output group series technology in view of the present disadvantages.Firstly,on the load side,the proposed DC electronic load system is composed of many cascaded current simulation units,each unit is based on the combination structure of buck and boost converter.The PI controller is used as a load current tracking control strategy,and a good shutdown characteris tic of the buck converter is utilized.It can not only simulate the continuous dynamic and steady load current,but also simulate the impulse load current.The interleaving parallel technology is dedicated to achieving accurate simulation of large load currents.Redundant hot back-up and dynamic current tracking,it can guarantee the accuracy and rapidity of simulation at the same time.This paper selects the parallel input parallel output combination and the current control strategy based on interleaving is applied to the electronic load.Furthermore,the input current sharing is achieved by current closed-loop control.This system realize the test of large current power supply,expand the power range of the power supply test,and increase the flexibility.At the same time,the redundancy and reliability of the system are increased,the switch frequency and the volume of the inductor is reduced.Secondly,for the low-voltage and large current communication power,this paper proposes a strategy based on group series technology,which connects the output voltages of each module in series to realize energy feedback.It is possible to test the low-voltage and large current communication power without complex battery-series,voltage-sharing technology and high boost ratio converters.Improve energy efficiency,and realize energy feedback through multi-level inverters.This circuit can achieve higher voltage level energy conversion by using low-voltage power switching devices,more inverter levels,less voltage harmonic and lower switching loss.It realizes the independent control of each current simulation unit,and achieves multi-module energy feedback through carrier phase-shifting technology.Then the feasibility of this design is verified by simulation and experiment.Finally,it introduces the designation and implementation of the interleaving DC electronic load of hardware circuit,the selection of components and the system software design of each function,and build the simulation experimental platform,and analysis the experimental waveform and data.To verify the feasibility of the DC electronic load system.