The Design Of Energy-feedback Electric Load Based On PWM

In the field of electronic applications,it usually test the switching power supply,linear power supply,battery,charger and other electronic equipment,the traditional test methods in general use resistance,sliding rheostat resistance box,such as electronic load^[4],the electronic load is mainly through the load side with high power resistance to consume energy,energy to all in the form of heat consumption,with electronic equipment unceasing renewal,the traditional load can not meet the test requirements,so the design has very important significance to a new type of electronic load.This paper designed a energy feedback electronic load based on PWM,which can accurately simulate the actual resistance load characteristics,but also to achieve the renewable energy use,energy saving and environmental protection.This paper describes the structure,principle and control strategy of AC and DC energy recycling electronic load briefly.The principle and control strategy of the PWM rectifier are studied in-depth.This paper introduces the design that can work principle of electronic load,and Research on topology and control method of electronic load.The hardware design of this subject mainly includes the following four parts:processor module design,sampling circuit design,PWM regulation circuit design,step-up circuit design and protection circuit design.The internal structure and working principle of the PWM rectifier chip which mainly affect the performance of the system are introduced in detail.The voltage and current double closed loop regulation and the protection circuit design based on chip turn off function are also introduced.The software part mainly includes AD digital module acquisition module,software delay module and initialization module.Through debugging,this design can meet the test requirements of 0-300W load,while90%of the energy can be fed back to the power supply,effectively reducing the input power of the power supply.