In recent years, DC-DC converters have been widely used and promoted in renewable energy power generation systems, electric vehicles, and aviation power supplies. However, the output DC voltage of renewable energy sources is low. Increasing the duty cycle can improve the high gain but brings problems such as high voltage spikes across semiconductors, high losses, and low efficiency. A high step-up and high-efficiency DC-DC converter is necessary, which can be achieved by busing switched-inductor, switched-capacitor, coupled inductor, and other techniques. Simultaneously, the practical application has imposed stringent requirements on DC-DC converters, including miniaturization and lightweight design. Using magnetic integration technology can partially fulfill the developmental needs of the converter.
Based on the quadratic Boost converter, the switched capacitor and clamping branch combination is simplified using device multiplexing. Subsequently, the coupled inductor is integrated with decoupled magnetic technology, effectively reducing the volume and number of magnetic components. Therefore, a high step-up quadratic converter is achieved with a dual-coupled inductor’s magnetic and switched capacitor. The working principle of the proposed converter is analyzed, the parameters are derived, the calculation methods for loss and efficiency are provided, and the related diagrams depicting loss proportion and efficiency analysis are generated. The structure and parameters of the integrated magnetic component are designed and simulated. The volume of the integrated magnetic component is reduced by about 13.4% compared with the discrete magnetic component. Finally, an experimental prototype is built, and the feasibility of the topology is validated.
The proposed converter’s input voltage is 12 V, switching frequency is 50 kHz, turn ratio is 1, output voltage is 185 V, output power is 200 W, and load is 170 Ω. Different output power can be obtained by adjusting the load size. When the output power is 140, 160, 180, 200, 220 and 240 W, the corresponding efficiency is 91.6%, 91.9%, 92.4%, 93%, 93.3%, and 92.7%, respectively. Under the load of 200 W, the experimental efficiency reaches 93%.
The proposed converter has the following characteristics: (1) the dual-coupled inductors improve the voltage gain. The duty cycle and turn ratio can be adjusted to obtain high voltage gain, and the switch has low voltage stress. When the duty cycle is 0.5 and the turn ratio is 1, the voltage stress is about 25% of the output voltage, and the voltage gain is 16 times. (2) The clamping structure can absorb the leakage inductor of the coupled inductor, which effectively alleviates the voltage spike on the switch. (3) The diodes experience low voltage stress, ranging from 16% to 66% of the output voltage, allowing for the selection of diodes with a low withstand voltage. (4) The decoupled magnetic integration technology is adopted, which reduces the number and volume of magnetic components.
| 科 Family | 属数 Number of genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) | 属 Genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) |
|---|---|---|---|---|---|---|
| 鹅膏菌科Amanitaceae | 2 | 11 | 5.26 | 鹅膏菌属 Amanita | 10 | 4.78 |
| 小菇科 Mycenaceae | 2 | 12 | 5.74 | 丝盖伞属 Inocybe | 5 | 2.39 |
| 多孔菌科 Polyporaceae | 8 | 14 | 6.70 | 蜡蘑属 Laccaria | 5 | 2.39 |
| 红菇科 Russulaceae | 3 | 23 | 11.00 | 小皮伞属 Marasmius | 6 | 2.87 |
| 小菇属 Mycena | 11 | 5.26 | ||||
| 光柄菇属 Pluteus | 5 | 2.39 | ||||
| 红菇属 Russula | 17 | 8.13 | ||||
| 栓菌属 Trametes | 5 | 2.39 |