A new double mode control strategy for power router with very wide DC voltage range

In household applications, the power router is a cost-effective device for AC/DC power conversion. To make it compatible with various types of DC loads without introducing extra power conversion stages, it is important that the power router can work in an extremely wide DC voltage range. However, this poses great challenges for the controller design. To address this concern, a double mode control scheme is proposed. The high frequency resonant DC/DC converter is employed together with a DC/AC converter to form the power router. Its circuit features on voltage gain and active power ratio are presented to guide the accurate controller design. Mode I is designed to ensure the high efficiency DC/DC conversion while the desired output DC voltage of power router is tracked by a DC/AC converter. For mode II, the phase shift scheme is triggered to eliminate the loss induced by the reactive power, and the desired output DC voltage is adjusted by DC/DC converter. Mode I and II cooperate to guarantee the wide DC voltage range to satisfy different load requirements. The experimental validation in a lab-scale power router prototype shows that the proposed scheme not only provides extremely wide voltage range, but also guarantees high efficiency by effectively tracking the resonant frequency.