Interleaved quartic high gain DC-DC converter

Area of Science:

• Electrical Engineering
• Power Electronics
• Renewable Energy Systems

Background:

• Traditional DC-DC converters face limitations in achieving ultra-high voltage gains required for applications like photovoltaic systems.
• Interleaved Boost Converters (IBCs) offer advantages but often require complex structures for significant voltage multiplication.

Purpose of the Study:

• To propose and validate a novel high-gain DC-DC converter with ultra-step-up voltage gain capability.
• To enhance voltage gain through a hybrid approach combining existing topologies and novel gain extension cells.
• To demonstrate the converter's performance, efficiency, and stability under various operating conditions.

Main Methods:

• Synthesizing a new converter topology from a two-phase Interleaved Boost Converter (IBC) and incorporating a voltage lift capacitor.
• Implementing a floating capacitor-based gain extension cell to further boost the voltage gain.
• Cascading these stages to achieve a quartic (4th power) voltage gain enhancement.
• Validating the design through experimental testing of a 16V to 400V, 150W prototype.

Main Results:

• The prototype converter achieved a 150W output at 400V with 92.7% full-load efficiency.
• The converter demonstrated stable output regulation under dynamic input voltage and load variations with negligible overshoot/undershoot.
• The hybrid voltage gain extension technique resulted in low voltage stress on semiconductor devices and ripple-free input current.
• Maximum voltage gain reached 37 at a reduced input voltage of 10.8V while maintaining safe duty ratios.

Conclusions:

• The proposed converter effectively achieves ultra-high step-up voltage gain with high efficiency and stable performance.
• The hybrid gain extension technique offers a significant advantage in voltage multiplication compared to conventional converters.
• The converter's features, including common-ground connection and ripple-free input current, make it highly suitable for photovoltaic (PV) applications.