Recent advancements in renewable energy have created a need for both high step-up and high-efficiency DC-DC converters. These needs have typically been addressed with converters using high-frequency transformers to achieve the desired gain. The transformer design, however, is challenging. This paper presents a high step-up current fed converter based on the classical Cockcroft-Walton (CW) multiplier. The capacitor ladder allows for high voltage gains without a transformer. The cascaded structure limits the voltage stresses in the converter stages, even for high gains. Being current-fed, the converter (unlike traditional CW multipliers) allows the output voltage to be efficiently controlled. In addition, the converter supports multiple input operation without modifying the topology. This makes the converter especially suitable for photovoltaic applications where high gain, high efficiency, small converter size, and maximum power point tracking are required. Design equations, a dynamic model, and possible control algorithms are presented. The converter operation was verified using digital simulation and a 450-W prototype converter.
- Algorithms,
- Cascade Control Systems,
- Electric Inverters,
- Frequency Multiplying Circuits,
- High Frequency Transformers,
- HVDC Power Transmission,
- Maximum Power Point Trackers,
- Power Converters,
- Cascaded Structure,
- Current-Fed Converter,
- Digital Simulation,
- Maximum Power Point Tracking,
- Photovoltaic Applications,
- Prototype Converter,
- Renewable Energies,
- Transformer Design,
- DC-DC Converters
Available at: http://works.bepress.com/jonathan-kimball/58/