Design Of Fast Response Digital DC-DC Converter Based On Improved PID Control

The importance of the power supply as a device to ensure the normal operation of electronic products is self-evident.In recent years,digitally controlled power supplies have gradually replaced analog power supplies in the market due to their programmability and higher reliability.However,the digital control method adds analog-to-digital and digital-to-analog conversion parts than the analog control method,which makes it difficult for the digital control system to achieve the timeliness of the analog system.Therefore,in order to fully demonstrate the superiority of the digital control power supply,it is particularly important to improve the dynamic performance of the system by the digital control module.This thesis takes Buck DC-DC switching power supply as an example to study,and aims to design a digital compensation algorithm to improve its dynamic response performance.This thesis proposes a PID control algorithm incorporating non-linear thinking to improve the dynamic performance of the system at the moment of system startup and sudden load change.In order to prove the superiority of the proposed algorithm,this thesis compares it with the simulation results of the original PID control algorithm and the adaptive PID control algorithm through the Matlab platform.The output results show that the response time at system startup is reduced by 50% and 33%,and the response time at load suddenness is reduced by 78% and50%,which fully verifies the fast response index it achieves.Finally,this thesis verifies this algorithm based on the FPGA platform.The proposed improved PID control algorithm is implemented as the core control algorithm in the XC6SLX9-2FTG256 C development board.And a DLL-based delay line pulse width modulator structure with a compensation module is proposed as well.A complete digital DC-DC system is designed to verify the simulation results through experiments.The results prove that the algorithm introduced in this thesis has fast dynamic response and good stability.The response time when the load current changes from 100 m A to 300 m A is 150μs,and the load adjustment rate is 50μV/ m A.