Design of digital PID controller for voltage mode control of DC-DC converters

DC/DC converters are massively used for switchmode regulated power supply, renewable energy conversion systems and electrical drives. Conventionally analog methods were popular for control of these converters. This paper elucidates a digital controller using digital filter architecture, which supports fixed-point algorithm. Digital controller application to DC/DC converters has always been considered because of their superiority over analog controller. In digital controller, the control strategy can be altered or reprogrammed without the need of significant hardware changes. The digital controller improves response of DC-DC converter by varying loop-gain, cross-over frequency and phase margin. Closed loop digital control of buck and boost converter is presented and the results are obtained for varying operating conditions and verified using MATLAB/Simulink.