Improved high step-up DC-DC converter based on active clamp coupled inductor with voltage double cells

In this paper, an improved active clamp coupled inductor and switched capacitor based converter is proposed for high step-up applications for photovoltaic power generation systems. The topology of the proposed circuit is based on coupled inductor technology, and two voltage double cells are added to extend the voltage gain and reduce the voltage stress of diodes. Then, the switch has an extremely low voltage stress compared with the output voltage, and an active clamp circuit is added to suppress the switch voltage stress. Therefore, low voltage rated and low on-resistance switches can be used to reduce the on-state losses. Furthermore, zero voltage switching turn-on is achieved to reduce the switching losses. Finally, a prototype is built to verify the theoretical analysis.