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Power Electronics, IEEE Transactions on

Issue 7 • Date July 2010

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Displaying Results 1 - 25 of 31
  • [Front cover]

    Page(s): C1
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    Freely Available from IEEE
  • IEEE Transactions on Power Electronics publication information

    Page(s): C2
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  • Table of contents

    Page(s): 1665 - 1666
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  • A Lab-Scale Alternative Interconnection Solution of Semiconductor Dice Compatible with Power Modules 3-D Integration

    Page(s): 1667 - 1670
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (311 KB) |  | HTML iconHTML  

    Increase in the power density of power modules requires an interconnection technology alternative to wire-bonding technology. Emerging interconnection technologies allow a 3-D packaging of power modules. A proposal of interconnection solution for the power semiconductor dice is presented here; it is based on copper microposts that are electroplated on topside of the die. The die with its microposts is then attached to a top direct-bonding copper (DBC) substrate using a copper/tin transient liquid phase technique. The assembly of the backside of the die to a bottom DBC substrate is processed concurrently using the same transient liquid phase technique. The benefits or limitations of the substrate on the assembly are not discussed in this letter. Manufacturing and electrical characterization of a power semiconductor die with the microposts interconnection is presented in detail. View full abstract»

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  • Efficiency-Oriented Design of ZVS Half-Bridge Series Resonant Inverter With Variable Frequency Duty Cycle Control

    Page(s): 1671 - 1674
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    The efficiency of zero voltage switching half-bridge series resonant inverter can be decreased under certain load conditions due to the high switching frequencies required. The proposed variable frequency duty cycle (VFDC) control is intended to improve the efficiency in the medium and low output power levels because of the decreased switching frequencies. The study performed in this letter includes, in a first step, a theoretical analysis of power balance as a function of control parameters. In addition, restrictions due to snubber capacitors and deadtime, and variability of the loads have been considered. Afterward, an efficiency analysis has been carried out to determine the optimum operation point. Switching and conduction losses have been calculated to examine the overall efficiency improvement. VFDC strategy efficiency improvement is achieved by means of a switching-frequency reduction, mainly at low-medium power range, and with low-quality factor loads. Domestic induction heating application is suitable for the use of VFDC strategy due to its special load characteristics. For this reason, the simulation results have been validated using an induction heating inverter with a specially designed load. View full abstract»

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  • High-Power Pulse Generator With Flexible Output Pattern

    Page(s): 1675 - 1684
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1111 KB) |  | HTML iconHTML  

    This paper presents a high-voltage bipolar rectangular pulse generator using a solid-state boosting front-end and an H-bridge output stage. The topology generates rectangular pulses with fast enough rise time and allows easy step-up input voltage. In addition, the circuit is able to adjust positive or negative pulsewidth, dead time between two pulses, and operating frequency. The topology can also be controlled to produce unipolar pulses and other pulse patterns without changing its configuration. With an appropriate dc source, the output voltage can also be adjusted to requirements of different applications. The intended application for such a circuit is algal cell membrane rupture for oil extraction, although additional applications, include biotechnology and plasma sciences, medicine, and food industry. A 1 kV/200 A bipolar solid-state pulse generator was fabricated to validate the theoretical analysis presented in this paper. In addition, to validate the analysis with simulations and prototype tests, biological test were conducted in order to examine the technical value of the proposed circuit. These evaluations seem to suggest that oil production rate from bipolar pulses may double that of an equivalent process with unipolar pulses. View full abstract»

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  • Hot-Carrier Reliability of Power SOI EDNMOS

    Page(s): 1685 - 1691
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    In this paper, hot-carrier-induced degradation test is performed on the 100 V power silicon-on-insulator n-type extended drain MOSFET with shallow trench isolation structure at the maximum substrate current condition under dc bias stress. Double reduced surface field design is employed to make sure the capability of the device is over 100 V. The degradation parameters including drain current, maximum transconductance, threshold voltage and the peak value of the substrate current are investigated, according to Joint Electron Devices Engineering Council Standard. Abnormal degradation of the linear and less than perfect linear degradation of the saturation are observed and they are attributed to the presence of two different hot-carrier injection sites in the device. Technology computer-aided design simulation tool is employed to provide the explanations in this paper. View full abstract»

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  • Effects of Discretization Methods on the Performance of Resonant Controllers

    Page(s): 1692 - 1712
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    Resonant controllers have gained significant importance in recent years in multiple applications. Because of their high selectivity, their performance is very dependent on the accuracy of the resonant frequency. An exhaustive study about different discrete-time implementations is contributed in this paper. Some methods, such as the popular ones based on two integrators, cause that the resonant peaks differ from expected. Such inaccuracies result in significant loss of performance, especially for tracking high-frequency signals, since infinite gain at the expected frequency is not achieved, and therefore, zero steady-state error is not assured. Other discretization techniques are demonstrated to be more reliable. The effect on zeros is also analyzed, establishing the influence of each method on the stability. Finally, the study is extended to the discretization of the schemes with delay compensation, which is also proved to be of great importance in relation with their performance. A single-phase active power filter laboratory prototype has been implemented and tested. Experimental results provide a real-time comparison among discretization strategies, which validate the theoretical analysis. The optimum discrete-time implementation alternatives are assessed and summarized. View full abstract»

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  • Sub-1 V Input Single-Inductor Dual-Output (SIDO) DC–DC Converter With Adaptive Load-Tracking Control (ALTC) for Single-Cell-Powered Systems

    Page(s): 1713 - 1724
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    In this paper, a sub-1 V input single-inductor dual-output (SIDO) dc-dc converter with an adaptive load-tracking control (ALTC) technology is proposed for single-cell-powered portable devices. Having a minimal number of switches and an optimum current sequence, the proposed ALTC technique adaptively and accurately adjusts storage energy in the form of inductor current according to the actual load condition, without wasting surplus charge and without increasing cross regulation. Moreover, a current-mode ring oscillator with a self-bias current source circuit, in place of the conventional start-up ring oscillator, is proposed to produce a nearly constant system clock for the requirement of sub-1 V start-up procedure. Because the proposed current-mode ring oscillator operates between the start-up process and steady state of the SIDO dc-dc converter, its simplified design efficiently addresses the high switching frequency losses at sub-1 V start-up procedure, reducing chip area and power consumption. The proposed sub-1 V input SIDO dc-dc converter was fabricated via Taiwan Semiconductor Manufacturing Company 0.25 μm 2.5 V/5 V Bipolar-CMOS-DMOS process, and the experimental results show high efficiency of 92% with a good cross regulation smaller than 10 mV. View full abstract»

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  • A Passive Lossless Snubber Cell With Minimum Stress and Wide Soft-Switching Range

    Page(s): 1725 - 1738
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1164 KB) |  | HTML iconHTML  

    A passive lossless snubber cell and its dual structure for reducing the switching loss of a range of switching converters are presented. The proposed snubber cell has several advantages over existing snubbering techniques. First, it provides zero-current-switching and zero-voltage-switching conditions for turning on and off, respectively, the switch over a wide load range. Second, it does not introduce extra voltage stress on the switch. Third, by taking the ripple current through the switch into account, the peak switch current during the snubber resonance period is designed to be less than the designed switch current without the snubber. Hence, the proposed snubber does not introduce extra current stress on the switch. The operating principle, procedure of designing the values of the components, and soft-switching range of the snubber will be given. The connections of the snubber cells to different switching converters will be illustrated. A performance comparison among the proposed snubber and a prior-art snubber will be addressed. The proposed snubber has been successfully applied to an example of a 200-W, 380-V/24-V, 100-kHz two-switch flyback converter. Experimental results are in good agreement with the theoretical predictions. View full abstract»

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  • Circuit Analysis and Modeling of a Phase-Shifted Pulsewidth modulation Full-Bridge-Inverter-Fed Ozone Generator With Constant Applied Electrode Voltage

    Page(s): 1739 - 1752
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    This paper proposes a circuit analysis and system modeling of an ozone generator using a phase-shifted pulsewidth modulation full-bridge inverter connected to two electrodes via a step-up transformer. The circuit operation of the inverter is fully described. Approximate models of the high-frequency transformer and the ozone-generating tube are given. Model parameter values are obtained from electrical characteristic measurement in conjunction with physical dimension calculation. In order to ensure that a zero-voltage soft-switching mode always operates over a certain range of a frequency variation, a series compensated resonant inductor is included. The advantage of the proposed system is a capability of varying ozone gas production quantity by varying the frequency of the inverter while the applied electrode voltage is kept constant, in order to overcome a high-frequency effect on the transformer voltage regulation. As a consequence, the absolute ozone production affected by the frequency is possibly achieved. The correctness and validity of the proposed system are verified by both simulation and experimental results. View full abstract»

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  • Power flow control in networks using controllable network transformers

    Page(s): 1753 - 1760
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (355 KB) |  | HTML iconHTML  

    The drive for higher reliability has motivated many utilities to move toward a more meshed system. Two control areas are often connected together with tie-lines. Power flow through the tie-lines connecting two control areas is difficult to control. This lack of controllability of power flow is one of the major issues in the modern grid. It causes asymmetric stress on the grid assets. This makes some grid assets more vulnerable to failure than others, and therefore, decreases the overall system reliability. Presently utilities can achieve very limited power flow control using devices like load tap-changing transformers and phase-shifting transformers. Controllable network transformers (CNTs) were introduced as a simple, low-cost solution to the power flow problem. This paper develops a theoretical analysis for the operation of CNT in a meshed network. It also shows the various possible applications of the CNT. Experimental validation of the working principle of a small-scale prototype CNT is also provided. View full abstract»

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  • A Soft Switching Scheme for Multiphase DC/Pulsating-DC Converter for Three-Phase High-Frequency-Link Pulsewidth Modulation (PWM) Inverter

    Page(s): 1761 - 1774
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    This paper outlines a switching scheme to improve the energy efficiency for an isolated high-frequency multiphase dc/pulsating-dc converter, which is the front end of a three-phase rectifier-type high-frequency-link inverter. Without using any auxiliary circuit, the proposed switching scheme achieves zero-current or zero-voltage switching for the power switches on the front-end multiphase dc/pulsating-dc converter. Moreover, on the back-end pulsating-dc/ac converter, the proposed soft-switching scheme reduces the switching frequency requirements for the associated switchers, which need high-frequency switching. In conjunction with the back-end pulsating-dc/ac converter, operating with a patent-filed hybrid modulation scheme, the proposed switching scheme leads to reduced overall switching loss as compared with other existing schemes. It is more suitable for isolated low-voltage dc to three-phase high-voltage ac applications from the standpoints of cost, efficiency, and footprint. View full abstract»

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  • A High Efficiency Flyback Converter With New Active Clamp Technique

    Page(s): 1775 - 1785
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    This paper proposes a flyback converter with a new noncomplementary active clamp control method. With the proposed control method, the energy in the leakage inductance can be fully recycled. The soft switching can be achieved for the main switch and the absorbed leakage energy is transferred to the output and input side. Compared to the conventional active clamp technique, the proposed methods can achieve high efficiency both for heavy-load and light-load condition, and the efficiency is almost not affected by the leakage inductance. The detailed operation principle and design considerations are presented. Performance of the proposed circuit is validated by the experimental results from a 16 V/4 A prototype. View full abstract»

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  • A Medium-Voltage Motor Drive With a Modular Multilevel PWM Inverter

    Page(s): 1786 - 1799
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    This paper describes the control and operating performance of a modular multilevel PWM inverter for a transformerless medium-voltage motor drive. The inverter is prominent in the modular arm structure consisting of a cascaded stack of multiple bidirectional chopper-cells. The dominant ac-voltage fluctuation with the same frequency as the motor (inverter) frequency occurs across the dc capacitor of each chopper-cell. The magnitude of the voltage fluctuation is inversely proportional to the motor frequency. This paper achieves theoretical analysis on the voltage fluctuation, leading to system design. A downscaled model rated at 400 V and 15 kW is designed and built up to confirm the validity and effectiveness of the nine-level (17-level in line-to-line) PWM inverter for a medium-voltage motor drive. View full abstract»

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  • Design of a Plug-In Repetitive Control Scheme for Eliminating Supply-Side Current Harmonics of Three-Phase PWM Boost Rectifiers Under Generalized Supply Voltage Conditions

    Page(s): 1800 - 1810
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (578 KB) |  | HTML iconHTML  

    This paper presents a digital repetitive control (RC) scheme to minimize the even-order harmonics at the dc link voltage and odd-order harmonics in the line-side currents under distorted and unbalanced supply voltage conditions. The proposed current control scheme consists of a conventional PI and a plug-in repetitive controller. On the basis of the mathematical model of the three-phase pulsewidth-modulated (PWM) boost rectifier under the generalized supply voltage conditions, the control task is divided into: 1) dc-link voltage harmonics control and 2) line-side current harmonics control . In the voltage harmonics control scheme, a reference current calculation algorithm has been derived accordingly to ensure that the dc link voltage is maintained constant at the demanded value and the supply-side power factor is kept close to unity. In the line-side current harmonics control scheme, a plug-in repetitive controller is designed to achieve low total harmonic distortion (THD) line-side currents of the three-phase PWM boost rectifier. The experimental test results obtained from a 1.6-kVA laboratory-based PWM rectifier confirm that the proposed control scheme can reduce the line-side current THD from 16.63% to 4.70%, and improve the dc-link voltage tracking accuracy substantially over the conventional PI-based controller. View full abstract»

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  • Low-Cost Integrable Tuning-Free Converter for Piezoelectric Energy Harvesting Optimization

    Page(s): 1811 - 1819
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    The future in terms of autonomous devices is about to experience an important breakthrough because of the development of energy-harvesting systems. This paper presents a new vibration energy-harvesting electrical interface for optimizing the power extracted from piezoelectric elements. Based on piezoelectric energy-harvesting properties, the proposed circuit allows an optimization of the extracted energy independently from the structure's parameters and without any tuning required. Contrary to classical converter topologies (for instance, step-down or buck-boost), the proposed architecture does not require large inductors, allowing a high-integration potential, while requiring a very little power consumption. View full abstract»

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  • A Novel Symmetrical Rectifier Configuration With Low Voltage Stress and Ultralow Output-Current Ripple

    Page(s): 1820 - 1831
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    The dc-dc topologies with capacitive output filter are going to be widely used especially for high-output current applications because of its inherent advantages in the lower voltage stress on rectifiers and the smaller occupied printed circuit board layout area at the secondary side. However, the parasitic resonance between the equivalent leakage inductance of the power transformer and the equivalent output junction capacitance of the rectifier still practically exists in the center-tapped rectification configuration, which leads to considerable voltage ringing on the rectifier and then results in the utilization of the rectifier with much higher breakdown voltage rate and the decrease of conversion efficiency. Moreover, the relatively larger output-current ripple induces the both larger conduction loss in the secondary-side windings of the power transformer and the capacitive output filter. In this paper, a novel symmetrical rectifier configuration is proposed, which can effectively clamp the practical voltage stress on the rectifier without any parasitical voltage spike and reduce the output-current ripple due to the bypass effect of the auxiliary flying-balancing capacitors. The leakage inductance and the output filter capacitor can be treated as an inherent small LC filter to reduce the output voltage ripple further. Based on the theoretical analysis and the optimal design considerations, a 300-W lab-made LLC resonant dc-dc converter with this proposed configuration is built up to verify its advantages in high conversion efficiency. View full abstract»

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  • Generalized Gyrator Theory

    Page(s): 1832 - 1837
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    In this paper, the gyrator theory is generalized so that it can be applied to multiple-input multiple-output energy systems. A multiport gyrator is defined as a system that follows the same power flow characteristics as a conventional gyrator, and with the use of superposition theorem, the equations describing its behavior are developed. Then, a multiport version of the dual active bridge is analyzed in order to validate the proposed equations. Finally, the network transformation properties of multiport gyrators are explored. View full abstract»

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  • Analysis of Output Current-Ripple RMS in Multiphase Drives Using Polygon Approach

    Page(s): 1838 - 1849
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (564 KB) |  | HTML iconHTML  

    Multiphase variable-speed drives, supplied from two-level voltage-source inverters (VSIs), are currently considered for a number of industrial applications. Although various multiphase pulsewidth-modulated (PWM) schemes had been recently developed, very little has been reported with regard to the impact of these schemes on harmonic losses (current ripple). This paper presents a general analytical analysis and comparison of harmonic losses of two basic continuous PWM (CPWM) schemes aimed at sinusoidal output-voltage generation. The analysis utilizes the concept of multiple polygon connections, which exist for multiphase systems, and covers all multiphase topologies with an odd phase number and single neutral connection. General harmonic distortion factors (HDFs) of sinusoidal PWM (SPWM) and harmonic injection PWM (HIPWM) are determined and compared for various phase numbers. Theoretical findings are verified by means of simulations and experimentally using a five-phase induction motor drive. View full abstract»

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  • Analysis and Design of a High-Efficiency Full-Bridge Single-Stage Converter With Reduced Auxiliary Components

    Page(s): 1850 - 1862
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    This paper presents a single-stage circuit topology consisting of the association of a full-bridge isolated dc-dc converter and two input inductors and two input diodes connected to the mains network, in order to obtain an isolated ac/dc switch mode power supply, with sinusoidal input current. The proposed topology does not use an input bridge rectifier, common in similar applications. The current in the two input inductors can, therefore, flow in both directions. Consequently, the proposed topology equally distributes the current by the four-bridge transistors that provide four input parallel boost power factor correctors (PFCs). The use of the four-bridge transistors to obtain the PFC function and regulate the output voltage with galvanic isolation is a new technique that makes this topology unique, which also contributes to improve the converter efficiency. The definition of appropriate control strategies permitting the accurate simultaneous regulation of output voltage and input current is hereby described. The interdependency between these two conversion processes is completely analysed, allowing for useful design rules. Experimental results were obtained in a 650-W laboratory prototype to verify the theoretical study. A maximum efficiency of 94% was obtained. View full abstract»

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  • Discontinuous-Current-Source Drivers for High-Frequency Power MOSFETs

    Page(s): 1863 - 1876
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1954 KB) |  | HTML iconHTML  

    This paper proposes a new current-source driver (CSD) with discontinuous inductor current. Compared to other CSDs proposed in the previous work, the most important advantage of the proposed CSD is the small inductance (typically, 20 nH at 1 MHz switching frequency). This translates into the footprint reduction of as much as 90% compared with the continuous CSDs. Other features of the proposed CSD includes: 1) fast switching speed and reduced switching loss; 2) discontinuous inductor current with low circulating loss; 3) gate energy recovery; and 4) wide range of duty cycle and switching frequency. The experimental results verified the functionality of the proposed CSD. At 12 V input, 1.3 V output, and 1 MHz switching frequency, the new CSD improves the efficiency from 80.7% using a conventional driver to 85.7% at 25 A output, and at 30 A output, from 77.9% to 84.4%. View full abstract»

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  • An Integrated Four-Port DC/DC Converter for Renewable Energy Applications

    Page(s): 1877 - 1887
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    This paper proposes a novel converter topology that interfaces four power ports: two sources, one bidirectional storage port, and one isolated load port. The proposed four-port dc/dc converter is derived by simply adding two switches and two diodes to the traditional half-bridge topology. Zero-voltage switching is realized for all four main switches. Three of the four ports can be tightly regulated by adjusting their independent duty-cycle values, while the fourth port is left unregulated to maintain the power balance for the system. Circuit analysis and design considerations are presented; the dynamic modeling and close-loop design guidance are given as well. Experimental results verify the proposed topology and confirm its ability to achieve tight independent control over three power-processing paths. This topology promises significant savings in component count and losses for renewable energy power-harvesting systems. View full abstract»

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  • A Digitally Controlled Unity Power Factor Compensator for Pulse-Burst-Modulated Loads

    Page(s): 1888 - 1893
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    Pulse-burst-modulated (PBM) loads cause line losses that are significant when compared with equivalent loads that are compensated to operate with sinusoidal line currents. This study details the conceptual design of a system meant to compensate the power factor of a load power conditioned by means of PBM. The compensator controller is a digital controller that monitors the line current and voltage and adjusts the compensation current accordingly. Simulations of the proposed method confirm the effectiveness of such a compensator maintaining a nearly sinusoidal line current, even in the presence of an inductive load. View full abstract»

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  • Control of Solid-State Lamps Using a Multiphase Pulsewidth Modulation Technique

    Page(s): 1894 - 1904
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (859 KB) |  | HTML iconHTML  

    This paper describes a multiphase pulsewidth modulation (MPWM) technique used for controlling the luminance of a solid-state lamp (SSL). For a SSL consisting of multiple high-brightness LEDs (HBLEDs) that are electrically connected as a series-parallel network, the desired output luminance is obtained by modulating the average current through each parallel HBLED string. In conventional pulsewidth modulation (PWM) and pulse code modulation techniques, the average HBLED string current is controlled by simultaneously varying the “on” time duration of each current regulator circuit, resulting in large current transients and pulsating light output. The proposed MPWM technique operates by uniformly time-shifting the individual on/off control signal pulses, thus avoiding large current transients. When compared to conventional PWM dimming, MPWM dimming reduces the risk of visible flicker and lowers the magnitude of audible noise. The reduced magnitude of output current transients results in lower electromagnetic interference and enables optimization of the size of passive components. In this paper, the operation of the MPWM technique is explained in detail. Experimental results are presented for a 27 W boost converter powering 64 HBLEDs with digital MPWM and digital voltage loop implemented using a Virtex-4 field programmable gate arrays. View full abstract»

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Aims & Scope

IEEE Transactions on Power Electronics covers fundamental technologies used in the control and conversion of electric power.

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