스위치드 인덕터 셀 기반의 고이득 승압형 DC-DC 컨버터에 관한 연구

Abstract

The renewable energies such as solar cells, fuel cells, photovoltaic have a low voltage and variable, the renewable energies are dependent on the weather conditions, and not stability. To connect them to the industrial application, many high boost DC-DC converters have been presented and investigated to convert low DC voltage into a high DC bus voltage. The positive and negative output voltages with respect to input ground can be generated by both of these switching methods. Converters in which switching control is performed by PWM are classified in non-isolated dc–dc converters such as buck, boost, buck–boost, Cuk, and SEPIC converters, and isolated dc–dc converters such as fly-back, forward, half-bridge, full-bridge, and push–pull [3], [4]. Non-isolated converters do not include a high-frequency transformer in their structure. The voltage-lift was introduced for boost converter with high voltage gain application. Using voltage-lift technique, the high output voltage is produced from low input voltage by using the energy storage feature elements includes passive components (capacitor and inductor). In this technique, capacitors as the series of voltage sources injected current to the circuit and inductors in addition to storing the energy, limit the current stress in switches and diodes. High efficiency, simple structure, high power density and cheapness in comparison with other techniques, small output voltage ripple, especially for high-voltage levels, the minimum number of switches are of these technique features. A suggested high boost DC-DC converter based on the switched-inductor cell (SL-cell) is presented. The suggested converter can provide a high boost gain is higher than 6, the voltage gain can be increased easily by extending a SL cell or a modular voltage boost stage. This paper shows the main waveforms, the operating principles at the continuous conduction mode (CCM), a comparison between the suggested converter and the other non-isolated converters is discussed. Moreover, the extension of the suggested converter is presented. A converter with PID controller was defined to confirm the stabilize respond of the suggested converter. The simulation and experiment results reconfirm the theoretical analysis. Finally, the accuracy performance of the suggested converter is reconfirmed through simulation and experimental results. A tested prototype has been established with the voltage gains are 6 and 12. To verify the operating principle, the input voltage of 10 to 20 V, the output voltage of 120 V, the resistor load of 150 to 300 Ω and the switching frequency of 12 kHz were used to verify. In here, the inductors capacitor are 1 mH - 2 mH, and 220 µF/ 200 V - 330 µF/ 200 V, the STTH3002C diodes and IXTR48P20P MOSFETs were used. The Digital Signal Processor of Texas Instrument TMS320F28027 for controlling. The testing PID controller was constructed with the input voltage changed from 5 V to 20 V, the output voltages are 120 V and 200 V, and the output power was changed from 72 W to 144 W. As a result, they have less size and low cost and are easier to control. This topology will use for hybrid electric vehicles, renewable energy source such as solar cells, and fuel cells. In which the high voltage gains are required.