| EPE 2015 - DS3i: Power Supplies | ||
| You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 2015 ECCE Europe - Conference > EPE 2015 - Topic 07: Power Supplies > EPE 2015 - DS3i: Power Supplies | ||
 | [return to parent folder] | |
 | A Modulation and Sampling Based Modeling Method for the Nonlinearities of Power Converters and its application analysis
By Xiaolong YUE | |
|
Abstract: Power electronic converters are single input multiple output (SIMO) systems in frequency domain. In distributed power system (DPS), one converter's switching frequency ripples are another converter's perturbations. However, traditional modeling methods only take the frequency of input perturbation into consideration and the power converters are simplified as linear models, which are inappropriate to analyze the high frequency interactions. This paper proposes a modulation and sampling based modeling method to describe SIMO frequency characteristic of power converters and to analyze the oscillations introduced by switching frequency ripples in DPS.
| ||
| | A Novel Single Stage Isolated AC-DC Converter with Zero Voltage Switching
By Shunsuke TAMADA | |
|
Abstract: In this paper, we propose new isolated AC-DC converters which have only one conversion stage; inaddition it can operate zero voltage switching in all switching devices. Moreover, we propose controlstrategy for these converters, and also confirmed it by experimentation or simulation using 100Wprototype.
| ||
| | Active Damping Control of Multi-Mode UPS for Power Quality Improvement
By Lorenzo GIUNTINI | |
|
Abstract: Double-conversion UPS provide top protection to critical loads, but limited efficiency. However, such UPS often support alternative high-efficiency operating modes (e.g. so-called ECO Mode). This paper discusses Active ECO Mode operation, introducing Active Damping Control for improving Power Quality with minimal losses. The system evolves into a Multi-Mode UPS, where the operating mode is selected for optimal trade-off between power conditioning and efficiency. Performance improvement is confirmed by experimental results and field experience.
| ||
| | An RCDD Snubber for a Bidirectional Flyback Converter
By Tahir LAGAP | |
|
Abstract: Increased usage of renewable energy sources has boosted the demand for power electronics converters.Indeed, the DC/DC flyback converter is nowadays frequently used in applications where isolation isrequired, due to its low component count, simple structure and high energy efficiency. One of the majorchallenges faced in a flyback converter is the excess voltage stress sensed by its semiconductor devices,because of the interrupted current flow through its transformer leakage inductances. In this paper, a high-efficient bidirectional flyback converter, operating in discontinuous conduction mode, is examined withan integrated RCDD snubber. Additionally, experimental comparison where the converter runs with atypical RCD and RCDD snubber network, is done. Experimental results on an IGBT-based bidirectionalflyback converter validate the applicability of the RCDD snubber demonstrating energy efficiency above90\%. Furthermore, the operation of the bidirectional converter with the employed snubber is thoroughlyanalysed and an appropriate mathematical analysis is conducted highlighting all the design specificationsof the proposed snubber.
| ||
| | Analysis and Design of a Cost Effective One Stage Topology for LED Lighting Applications
By Alexander PAWELLEK | |
|
Abstract: Light emitting diodes (LEDs) have great potential to replace existing light sources, like incandescent and fluorescent lamps due to their long life time and higher efficacy. Therefore, also the life time and efficiency of the LED ballast are important in order to improve the overall system. In addition, size and costs are relevant factors in the highly competitive LED market. The paper presents a very promising one stage topology for LED lighting applications. The highly efficient ballast convinces with its simplicity in structure and control and provides on the one hand a ripple-free LED current, while fulfilling the regulation for the line current harmonics on the other hand. The investigation and optimization is validated by a practical setup.
| ||
| | Architecture and Design of an Inductive Contactless Energy Transfer System with two Mobile Loads for Residential Applications
By Arash MOMENEH | |
|
Abstract: Inductive contactless energy transfer systems with multiple mobile loads are very complex systems. Main challenges of these systems are to propose a suitable architecture and to design their power components. These challenges are particularly more noticeable in residential areas where various types of consumers (loads) are expected. This paper introduces a new architecture and design guidelines for a high-frequency resonant transformer operating with frequency modulation. The design process includes the effects of 1) the resonant frequency, 2) the magnetizing inductance, and 3) the characteristic impedance. The excellent performance of the designed system is validated by simulation results.
| ||
| | Capacitor Voltage Balancing Control of a Flying Capacitor Based n-level DC-DC Converter
By Boran FAN | |
|
Abstract: A flying capacitor based n-level non-isolated DC-DC converter is researched in this paper. The converter features reduced flying capacitors, compact structure, adjustable output voltage and high-voltage high-power ability. Basic operating principle was analyzed and a mean value model is derived. A dual-loop capacitor voltage balancing method for n-level structure is proposed. A seven-level prototype was built up, both steady and dynamic experimental results are presented to verify this method.
| ||
| | Closed-Loop Control with Harmonic Based Phase-Shift Control for Inductively Coupled Power Transfer System
By Liming SHI | |
|
Abstract: The output power regulation and transfer efficiency are key issues in inductively coupled power transfer system (ICPT) systems. The harmonic based phase shift control (HPSC) is an effective method to improve system efficiency. However, due to the high frequency and harmonic components of the inverter output current within this method, general closed-loop control is not suitable. Meanwhile, in inductively coupled power transfer system of contactless power supply (CPS) system for rail transit, the output voltage and current on board cannot be sent directly to the controller by cable on ground. This paper propose a novel control method by using the inverter average current and secondary load voltage to adjust transferred power with lower switching losses. It is especially effective for light load condition. Both the simulation and experimental results verify effectiveness of the proposed control method.
| ||
| | Efficiency Study of Coaxial Contactless Power Transmission for Electric Railway
By Kenta MORIKI | |
|
Abstract: A novel contactless power supply system for electric trains is discussed based on structure of an airgapped coaxial transformer. Theoretical analysis, simulation results and verification experiments wereconducted and the results are shown in this paper. The 94.0 \% efficiency was observed with air gapcoaxial structure. Moreover, the power factor corrector (PFC) circuit are introduced to increase sendingpower. However, the efficiency drops to 86.8 \% for the internal resistance (ESR) of inserted parallelcapacitor Cp. In order to reduce the effect of ESR, parallelization of Cp are introduced. This methodachieves power transmission efficiency of 88.0 \%.
| ||
| | Floating High Step-Down Stacked dc-dc Converter Based on Buck-Boost Cells
By Gabriel TIBOLA | |
|
Abstract: In some high power dc-dc applications, where high voltage is present, a converter with high step-down ratio is required in order to provide an isolated low power auxiliary supply. This requirement represents a challenge and many topologies are currently being researched. The analysis of a non-isolated, unidirectional, high step-down voltage-ratio converter based on a stack of buck-boost converters is demonstrated. The converter is intended to be applied as a floating non-isolated power supply, which can be connected to one or more isolated converters. A design example is detailed and validated with simulations, and experimental results for a 200 W, 2.8 kV input voltage and 350 V output voltage converter.
| ||
| | Grid Voltage Emulation at the Secondary Side of a Contactless Power Supply
By Faical TURKI | |
|
Abstract: Conventional contactless power supply systems deliver in most of the cases a DC-voltage or a DC-current at their output. In case of a need for an AC- grid voltage on the secondary part to feed commongrid frequency loads, an inverter may be connected to the DC-output of the contactless system togenerate an AC- voltage emulating the voltage of the grid. However this solution requires high numberof components and has low system efficiency. A new rectifier topology for inductive power systemsable to emulate the grid voltage is presented and compared with the conventional inverter solution anda matrix inverter based solution.
| ||
| | High Voltage Pulse Speed Study for High Voltage DC-DC Power Supply Based on Voltage Multipliers
By Saijun MAO | |
|
Abstract: The high voltage (HV) pulse speed is investigated for voltage multiplier based HV power supply. The key factors which influence the HV pulse rise and decay response time for HV power supply such as switching frequency, load resistance, and voltage multiplier capacitance are studied. When the stage number of voltage multiplier is determined, the switching frequency is the key influence factor for the HV pulse rise time. High switching frequency will lead to short HV pulse rise time. From the voltage multiplier HV pulse rise time simulation results, assuming sufficient power supply power rating, the load resistance and filter capacitor have little influence for the HV pulse rise time. The high voltage pulse decay time is proportional to load resistance and multiplier capacitance. Though switching frequency has indirect relation to decay time, multiplier capacitance can be decreased with higher switching frequency. So higher switching frequency can effectively decrease the both high voltage pulse rise and decay time. The experimental results of a 2kV output HV power supply switching at 300 kHz with 2-stage half-wave series voltage multiplier prototype verify the analysis and simulation results. The practical design guidelines for achieving desired HV pulse rise & decay time is provided finally.
| ||
| | Influence of Inverse Coupled Inductors on Fault-Tolerant Operation of Two-Phase DC-DC Converters
By Michael GLEISSNER | |
|
Abstract: Multiphase DC-DC converters with coupled inductors are applied to increase the power density andefficiency. But coupling also creates an interference between still active and failed phases as well asinfluences the inductance characteristic. This paper investigates the fault-tolerance of multiphase DCDCconverters with focus on the behaviour of the total as well as phase current ripples and the inductorsaturation depending on duty cycle and coupling coefficient. Compared to non-coupled inductors, thetotal current ripple can be kept similar after loss of a converter phase if no saturation occurs. Moreover,the influence of the induced voltage due to coupling on the deactivated phase is analysed. Design hints forfault-tolerant strategies with coupled inductors are presented. Measurement results with various coupledinductors prove the theoretical considerations.
| ||
| | Key Construction Aspects of Low Frequency Wireless Power Transfer System Using Parallel Resonance
By Tomas KAVALIR | |
|
Abstract: The papers deals with the wireless power transfer (WPT) system using parallel resonance at low frequency. Twodifferent construction arrangements of two-coil resonant system - with and without impedance conversion - are presented. Impedance conversion is carried out via linkage autotransformer. Both systems are consequently measured and the theoretical presumptions are verified.
| ||
| | MULTIMODULAR, HIGH CURRENT, FAST RESPONSE IGBT INVERTER POWER SUPPLY OF SST-1 TOKAMAK
By Dinesh kumar SHARMA | |
|
Abstract: IGBT power supply is a single-phase H bridge inverter capable to provide current of ±12kA with 1MA/sec ramp rate. This paper describes performance requirements, ratings, inverter design calculations, multimodular topology, protections, fast control, symmetrical layout, bus bar engineering, and cooling requirement and test results.
| ||
| | New Inductive Contactless Energy Transfer System for Residential Distribution Networks with Multiple Mobile Loads
By Arash MOMENEH | |
|
Abstract: This paper proposes a novel inductive contactless energy transfer system for residential distribution networks. The system is based on a resonant inverter with sliding transformers, allowing high flexibility (the connection point of the loads is movable) and high safety (electrical shocks are avoided). A new resonant topology for driving the sliding transformers is proposed which behaves as an AC high-frequency voltage source. A very interesting feature of this voltage source is that the amplitude of the output voltages is nearly constant and independent of the load consumption. The paper presents a design procedure for calculating the components and parameters of the resonant circuit. The performance of the complete contactless system is evaluated, especially the efficiency and the transient response. The reported results show good performance validating the proposed topology.
| ||
| | Next generation of digital control power devices for medium to low power AC/DC SMPS applications
By Marc FAHLENKAMP | |
|
Abstract: A next generation of digital control power devices that provides software defined power competes to enter the medium to low power AC/DC SMPS applications in a broader scope. Based on a core approach, the new IC generation claims to fully exploit the opportunities given by a digital control implementation. The target power range can be mainly seen in consumer applications, which are extremely product and system cost driven. Furthermore there are requirements on low IC current consumption to support the energy saving standards. The on high performance optimized DSP and µC can't support the low bill of material in the application and are consuming too high currents compared to state of the art analog controllers. Therefore a dedicated IC architecture is necessary to enable properly the software defined power approach in this AC/DC consumer segment. This paper gives an insight on how system and product cost and current consumption can be specifically addressed by a corresponding IC hardware architecture.
| ||
| | Operation of Single-Chip MOSFET and IGBT Devices after failure due to repetitive avalanche
By Andrei BLINOV | |
|
Abstract: This paper presents analysis of post-failure behaviour of MOSFETs and IGBTs operating in a series connected string. The aim of this experimental study is to analyse the operation of devices in case of sudden loss of controllability, leading to repetitive avalanche conditions at relatively low current and subsequent failure due to overheat. For redundant designs it is important that the devices are locked in stable conducting state after the failure and the string continue its operation.
| ||
| | Power Decoupling with Autonomous Reference Generation for Single-Phase Differential Converters
By Wenli YAO | |
|
Abstract: The second-harmonic power ripple in single-phase inverter may introduce the issue of low reliability and lowpower density. In order to replace the bulky dc-link capacitor, an alternative approach is to use active powerdecoupling so that the ripple power can be diverted into other energy storages. However, the performance of existing active power decoupling methods depends heavily on certain control references, which unfortunately are parameter dependent. In this paper an autonomous reference generation technique is proposed for single phase differential inverter without relying on the system parameters. A unified average switching model is firstly derived for Buck, Buck-Boost and Boost differential inverter, which is apparently have nonlinear characteristics. Then, dual-loop cascading control and a feedback linearization method is employed to design the inner- and outer loop controllers, which are used for realizing an improved power decoupling control, capacitor voltage and inductor current regulation. By substituting the corresponding parameter into unified model, the proposed control loop can be applied to different inverter types (Buck, Buck-Boost and Boost). Finally, detailed laboratory prototype experimental results have been done to verify the effectiveness of this power decoupling method.
| ||
| | Primary-Controlled Constant Current LED driver with Extremely Low THD and Optimized Phase-Cut Dimming Compatibility
By Giovanni GRITTI | |
|
Abstract: This paper describes a novel control method for high-power-factor quasi-resonant (Hi-PF QR) flyback converters able to meet simultaneously three control objectives: a) performing constant-current control with primary sensing regulation (CC-PSR); b) achieving ideally no harmonic distortion of the ac input current; c) being fully compatible with real-world 'phase-cut' wall dimmers. Simulation results and experimental verification data are provided to validate the method, which has been implemented in a control IC targeting solid state lighting applications (LED drivers).
| ||
| | Reduction of Voltage Drop and Ripple in Voltage Multipliers
By Doron SHMILOVITZ | |
|
Abstract: In this paper we present a novel topology for high voltage generation based on the widelyused Half-Wave Cockcroft-Walton voltage multiplier. The proposed topology consists ofseveral voltage multiplying sections fed separately at their inputs and whose output voltagesare summated across the load. Using the proposed topology we can attain over m times highervoltage gain compared to the regular Half-Wave Cockcroft Walton voltage multiplier (mbeing the splitting level), while significantly reducing the output ripple. The theory issupported by simulations and experiments.
| ||
| | Switched-Capacitor Quasi-Resonant PWM Converters With Continuous Conversion Ratio
By Mert TURHAN | |
|
Abstract: Inherent disadvantages of conventional switched-capacitor converters (SCC) are their discrete conversion ratio and inefficient energy transfer. In order to soften these downsides, a step-down switched-capacitor quasi-resonant PWM converter is proposed. The operation modes and steady-state characteristics are described. Besides the theoretical analysis, experimental results for a step-down SCC (45V input voltage, 13-44V output voltage, 45W output power) are presented.
| ||
| | The load current sensing method in the multiple output high insulation voltage transformer
By Andrzej WYZGA | |
|
Abstract: Some power supplies do not require accurate current feedback to function properly. In many cases theinformation about the output current is only needed to make sure that the power supply is not overloaded.This paper describes a sensing method of individual secondary currents of a four channel power supplybuilt using a single core transformer, by sensing the currents flowing in separate primary windings. Eachsecondary current could be sensed on the primary side of the high insulation voltage transformer withsufficient accuracy to assure proper fault handling strategy for the power supply.
| ||
| | Thermal Impact Analysis of the Circulating Current in High Power Modular Online Uninterruptible Power Supply Applications
By CHI ZHANG | |
|
Abstract: In a modular uninterruptible power supplies (UPS), each DC/AC module was designed to work in a circular way considering the reliability and power stress issues of the whole system. Thus unsynchronized PWMs will occur if any of the DC/AC modules is plugged in or out of the system at any time. On the other hand, modular difference is another issue that will bring such kind of circulating current. In order to reduce system size and cost, each module shares the same DC and AC bus without any isolation or passive elements in the system. Consequently, potential zero-sequence current is possible to occur and should be paid specific attention. In this paper, a four-module online UPS system is designed. And thermal and loss distribution condition are investigated under different circulating current condition with conventional three phase H-bridge topology.
| ||
| | Tolerance Design of Ballast Resistance for Multi-string LED Driver
By JUN-YOUNG PARK | |
|
Abstract: This paper investigates a novel tolerance design method for a resistive light-emitting-diode (LED) driver with multi-string configuration in mass production. Considering a trade-off among the current uniformity, the current accuracy in LEDs, and the loss dissipation in the driver circuit, a bus voltage and a series resistor are identified as two design parameters regardless of production spreads both in the LED string voltage and in the ballast resistance. By combining discrete optimization technique with Monte-Carlo method, this paper proposes an effective algorithm to design the circuit parameters. Comparison with the conventional design by simulation and hardware tests shows that the suggested scheme provides more reliability and flexibility in practical situation. Moreover, utilizing only datasheet values eliminates the need for I-V curve extraction in the design process.
| ||