The Research And Design Of Intelligent Fast Charging Technology

With the rapid development of Mobile Internet,the functions of portable electronic products are becoming more powerful and more frequently used,and the overall power consumption is getting faster and faster.Battery endurance of the electronic products has become an urgent problem to be solved.At present,fast charging technology is a key technology to solve the battery endurance problem.With the continuous emergence of various fast charging protocols,fast charging products supporting multi-protocol charging are in urgent demand.This article,based on the study of fast charging technology,designs a fast charger for charging portable electronic products such as mobile phones,which supports automatic identification of various fast charging protocols,combined with adaptive fuzzy PID control algorithm and through microprocessor to improve the charging performance of the products and have a wealth of extended functions.The fast charging circuit hardware designed in this paper consists of two pails:the main circuit and the controller circuit.The main circuit mainly includes DC-DC step-down conversion circuit,fast charge protocol identification circuit signal detection feedback circuit and other modules.The controller circuit includes a microprocessor control circuit and an OLED display circuit.In the DC-DC converter circuit designed the stop-and-charge control circuit,which is used to control the circuit to stop charging and recharging at the end of charging.This design has two points.First,it can reduce power consumption.Second,it is beneficial to prevent the safety hazard caused by constant charging.The microprocessor control circuit uses STM32 as the main control chip,and the circuit can be controlled by using the minimum system.The chip is powerful and beneficial to expand the intelligent functions.In addition to controlling the DC-DC conversion circuit to adjust the output voltage,it can also be used to control the OLED display circuit to display data,such as input and output voltage,output current,charging time,and current date and so on.The software design is based on STM32 main control chip,and the adaptive fuzzy PID algorithm is used as the core control algorithm.The control circuit program of each module is designed in this part.In controlling the output voltage of the DC-DC converter,the circuit combined with the adaptive fuzzy PID control algorithm,the output voltage of the fast charging circuit is adjusted according to the signal detection value,and the output signal of the circuit is accurately controlled to ensure the stability of the charging circuit and improve the charging efficiency.The simulation results of MATLAB/Simulink show that the application of adaptive fuzzy PID control algorithm to fast charging circuit can not only adapt to different output voltage values,but also effectively improve the stability of fast charging circuit charging voltage.Finally,the fast charger physical test shows that the fast charger designed in this paper supports automatic identification of 7 fast charging protocols,and can automatically adjust the output voltage according to the fast charging protocol.The maximum output voltage is 12V,and the output voltage error is less than 1.5%.The output voltage ripple coefficient is less than 1%,and the input and output signal parameters of the circuit meet the design requirements,which verifies the rationality of the circuit design.