A Cascoded High Step-Up DC-DC Converter with Coupled Inductor and Switched Capacitor

In this paper, a high step-up DC-DC converter is proposed. This topology reduces the current spike on the main switch capacitor and solve reverse recovery problem of the diode. The coupled inductor and switched capacitor techniques are used to not only increases voltage gain, but also decreases input current ripple. The steady-state operating principle of continuous conduction modes, and key parameters design are discussed in detail. Finally, the digital signal processor, TMS320F28335 is used to realize the switching control and laboratory prototype with input voltage 24 – 38 V, output voltage 400 V, and rated output power 300 W was built and demonstrated. According to experimental results, the efficiency is 89.7% of full load at input voltage is 24 V, the efficiency is 91% of full load at input voltage is 38 V, and the highest efficiency is 94% at input voltage is 38 V.