DSP-based digitally controlled bi-directional DC-DC converter

This article presents an analysis of voltage and current control mode of DC-DC converter and proposes a multipurpose controller working in constant voltage/constant current/constant power states alterable. Also discussed here are determination of sampling rate, bits of AD conversion, DPWM resolution and the principle of switch frequency. Meanwhile, an asynchronous sampling method is proposed to ensure the precision of feedback signal, such as output voltage and current. Furthermore, aim at the nonlinear, parameter-changing and time-variant high-frequency switch system, a new type of PID regulator are used to improve the system´s stability and dynamic performance. Finally, a 5 kW bi-directional DC-DC converter is built with the DSP-TI320F243. Experiment with it showed that the system has excellent properties and can be used in areas like EV.