High precision constant voltage DC power supply is a fundamental core equipment in the fields of electronic equipment research and development, precision testing, and industrial control. Its output accuracy, dynamic response, and anti-interference ability directly determine the performance of subsequent systems. Traditional analog power supplies and switch mode power supplies based on fixed parameter PID control have problems such as slow regulation speed, large overshoot, or insufficient steady-state accuracy when dealing with wide range load transients, input voltage fluctuations, and nonlinear factors. This article designs and implements a Buck type switching power supply based on digital signal processor (DSP) control, and proposes an adaptive PID control algorithm combined with online parameter self-tuning. This algorithm dynamically adjusts the proportional, integral, and derivative coefficients of the PID controller by monitoring the system error and its rate of change in real time to cope with different operating conditions. The main circuit of the system hardware adopts synchronous rectification Buck topology, with TI’s TMS320F28335 DSP as the core controller, to achieve high-precision ADC sampling, digital PID control, and PWM signal generation. The experimental results show that, under the input voltage of 18-30V DC and the output rated of 12V/5A conditions, compared with the traditional fixed-parameter PID and fuzzy PID controllers, the adaptive PID controller designed in this paper optimizes the maximum transient drop/overshoot of the voltage during the load step change (1A ↔ 5A) from 320mV/280mV and 210mV/190mV to within 150mV, and shortens the recovery time to below 200μs. The steady-state voltage accuracy over a wide load range is better than ± 0.1%. This design effectively improves the dynamic quality and robustness of the power supply, providing a reliable solution for high-precision and fast response power systems.
Ren et al. (Thu,) studied this question.