A step-Up DC-DC converter for non-isolated on-line UPS applications

A new non-isolated boost converter with high voltage gain is proposed in this work. This converter is suitable for nonisolated on-line UPS systems, with common neutral connection, that improves bypass circuit installation. The adopted control strategy uses a hybrid control that implements both analog and digital controllers, that implements the average current mode control. It presents characteristics of continuous input current through the batteries that improve its lifetime, the maximum voltage across the controlled switches is equal to half of the total output voltage, and voltage equalization across the dc-link capacitors is intrinsic. In order to verify the feasibility of this topology; principle of operation, theoretical analysis, and experimental waveforms are shown for a 1.55 kW assembled prototype.