Auto-tuned, discrete PID controller for DC-DC converter for fast transient response

Ziegler-Nichols tuned PID controller´s performances usually are not acceptable for applications requiring precise control. In this paper an improved discrete auto-tuning PID scheme is developed for DC-DC converters where large load changes are expected or the need for fast response time. The algorithm developed in this paper is used for the tuning discrete PID controller to obtain its parameters with a minimum computing complexity and is applied to Synchronous buck converter to improve its performance. To improve the transient response and rise time of the Converter, the controller parameters are continuously modified based on the current process trend. For its implementation a synchronous buck converter is designed and its MATLAB/Simulink model with non-linear parameters is developed and considered. Also, the non-linear effects such as S/H, quantization, delay, and saturation are considered in the close loop model. The simulation results demonstrate the effectiveness of the developed algorithms.