Two stage power conversion architecture suitable for wide range input voltage
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The document discusses a two-stage power conversion architecture designed to enhance LED driver circuits, emphasizing improvements in energy consumption and power density. It critiques existing commercial LED drivers for their low efficiency and power factor, while proposing a new system that combines switched-capacitor and magnetic regulation stages to achieve higher performance. The paper highlights the advantages such as increased switching frequencies, high efficiency, and low device stress, positioning the architecture for robust LED driver applications.
Two stage power conversion architecture suitable for wide range input voltage
- 1. Do Your Projects With Domain Experts… Copyright © 2015 LeMeniz Infotech. All rights reserved LeMeniz Infotech 36, 100 Feet Road, Natesan Nagar, Near Indira Gandhi Statue, Pondicherry-605 005. Call: 0413-4205444, +91 9566355386, 99625 88976. Web : www.lemenizinfotech.com / www.ieeemaster.com Mail : projects@lemenizinfotech.com Two-Stage Power Conversion Architecture Suitable for Wide Range Input Voltage Abstract Introduction: In this paper, we explore improved design in this voltage and power range, with a focus on LED driver circuits as an important application in this space. Light emitting diode devices promise unprecedented reductions in energy consumption in comparison to incandescent and fluorescent lights, but come with an as-yet unmet demand for high power density, high efficiency, and high-power-factor LED driver circuitry. An examination of commercial LED drivers illustrates this: considering a group of commercial line interfaced (120 Vac ) LED drivers in the 3–12 W output power range, and power factors of 0.73–0.93, with no systems achieving both high efficiency and high power factor. The switching frequencies of these drivers were in the range of 57–104 kHz, with all having correspondingly low power densities below 5 W/in3. Recently published academic designs are harder to fully evaluate and compare because of large variation on LED output configurations (e.g., separation to multiple LED loads or diverse LED voltage specifications), but appear to provide generally
- 2. Do Your Projects With Domain Experts… Copyright © 2015 LeMeniz Infotech. All rights reserved LeMeniz Infotech 36, 100 Feet Road, Natesan Nagar, Near Indira Gandhi Statue, Pondicherry-605 005. Call: 0413-4205444, +91 9566355386, 99625 88976. Web : www.lemenizinfotech.com / www.ieeemaster.com Mail : projects@lemenizinfotech.com similar performance with moderate improvements in individual aspects. Overall, the volume of the converters was uniformly dominated by magnetic components, and in each case the driver circuit represented a major contribution to the LED system size. These examinations indicate that power electronics continues to be a significant limitation in solid-state lighting and that there is a need for major improvements in miniaturization and performance in this voltage and power range. Existing system: The converter architecture is well-suited to the available devices in such a process: The SC transformation stage can achieve a large voltage step-down, and can be designed for very high power density and efficiency using slow, moderate-voltage devices at relatively low switching frequency. The unregulated voltage, Vunreg is low so that the regulating stage can utilize fast, low-voltage devices operating at a high switching frequency to provide high-bandwidth regulation and a small additional voltage step-down. Since the regulation stage operates at a high frequency, the size of its passive components can be made small. By separating the transformation and regulation stage in this manner, the benefits typically associated with SC converters (i.e. high efficiency, high power density) can be
- 3. Do Your Projects With Domain Experts… Copyright © 2015 LeMeniz Infotech. All rights reserved LeMeniz Infotech 36, 100 Feet Road, Natesan Nagar, Near Indira Gandhi Statue, Pondicherry-605 005. Call: 0413-4205444, +91 9566355386, 99625 88976. Web : www.lemenizinfotech.com / www.ieeemaster.com Mail : projects@lemenizinfotech.com preserved, while the main drawback (poor regulation) is done away with by the use of a separate magnetic regulation stage. Proposed system: The first stage is a variable-topology SC circuit operating at moderate switching frequencies (e.g., tens to hundreds of kilohertz). The SC circuit can achieve high power density and efficiency at these frequencies because it employs only switches and capacitors and incorporates soft-charging operation. However, the SC converter alone cannot efficiently provide the fine voltage regulation capability needed in this application. Instead, this stage serves both to reduce the voltage range over which the second stage needs to operate, and to reduce the maximum voltage level (and hence impedance level) for which the second stage must be designed, in keeping with the design considerations described in the previous section. The second stage is a magnetic-based stage that provides both additional voltage transformation and fine voltage regulation, and is operated at high frequency (e.g., HF, 3–30 MHz) in order to minimize magnetic component size. High- frequency operation is more readily achieved with high efficiency in the second stage because it operates at lower voltages and smaller voltage range with voltage transformation of the SC first stage.
- 4. Do Your Projects With Domain Experts… Copyright © 2015 LeMeniz Infotech. All rights reserved LeMeniz Infotech 36, 100 Feet Road, Natesan Nagar, Near Indira Gandhi Statue, Pondicherry-605 005. Call: 0413-4205444, +91 9566355386, 99625 88976. Web : www.lemenizinfotech.com / www.ieeemaster.com Mail : projects@lemenizinfotech.com Block diagram: HF ZVS RESONANT INVERTED BUCK CONVERTER SWITCHED CAPACITOR PRE REGULATOR UNIT 5V DC 12V DC PIC CONTROLLER WITH BUFFER THREE PHASE DRIVER CIRCUIT LOADFILTERINPUT DC SUPPLY
- 5. Do Your Projects With Domain Experts… Copyright © 2015 LeMeniz Infotech. All rights reserved LeMeniz Infotech 36, 100 Feet Road, Natesan Nagar, Near Indira Gandhi Statue, Pondicherry-605 005. Call: 0413-4205444, +91 9566355386, 99625 88976. Web : www.lemenizinfotech.com / www.ieeemaster.com Mail : projects@lemenizinfotech.com Advantages: Increases in switching frequency. Low device stress, high efficiency, high power density, and high power factor. Applications: LED driver applications. Tools and software used: MPLAB – microcontroller programming. ORCAD – circuit layout. MATLAB/Simulink – Simulation.