Showing papers on "Power module published in 2016"
TL;DR: In this paper, the authors provide a comprehensive review of active power decoupling circuit topologies and their development laws from the view of the dual principle, switch sharing, and differential connection.
Abstract: Active power decoupling methods are developed to deal with the inherent ripple power at twice the grid frequency in single-phase systems generally by adding active switches and energy storage units. They have obtained a wide range of applications, such as photovoltaic (PV) systems, light-emitting diodes (LEDs) drivers, fuel cell (FC) power systems, and electric vehicle (EV) battery chargers, etc. This paper provides a comprehensive review of active power decoupling circuit topologies. They are categorized into two groups in terms of the structure characteristics: independent and dependent decoupling circuit topologies. The former operates independently with the original converter, and the latter, however, shares the power semiconductor devices with the original converter partially and even completely. The development laws for the active power decoupling topologies are revealed from the view of “duality principle,” “switches sharing,” and “differential connection.” In addition, the exceptions and special cases are also briefly introduced. This paper is targeted to help researchers, engineers, and designers to construct some new decoupling circuit topologies and properly select existing ones according to the specific application.
395 citations
TL;DR: In this article, a comparative analysis of these high-power storage technologies in terms of power, energy, cost, life, and performance is carried out and the applications, advantages, and limitations of these technologies in a power grid and transportation system as well as critical and pulse loads are presented.
Abstract: Energy storage systems provide viable solutions for improving efficiency and power quality as well as reliability issues in dc/ac power systems including power grid with considerable penetrations of renewable energy. The storage systems are also essential for aircraft powertrains, shipboard power systems, electric vehicles, and hybrid electric vehicles to meet the peak load economically and improve the system’s reliability and efficiency. Significant development and research efforts have recently been made in high-power storage technologies such as supercapacitors, superconducting magnetic energy storage (SMES), and flywheels. These devices have a very high-power density and fast response time and are suitable for applications with rapid charge and discharge requirements. In this paper, the latest technological developments of these devices as well as advancements in the lithium-ion battery, the most power dense commercially available battery, are presented. Also, a comparative analysis of these high-power storage technologies in terms of power, energy, cost, life, and performance is carried out. This paper also presents the applications, advantages, and limitations of these technologies in a power grid and transportation system as well as critical and pulse loads.
278 citations
TL;DR: The rationally designed sandwich-structured polymer nanocomposites are capable of integrating the complementary properties of spatially organized multicomponents in a synergistic fashion to raise dielectric constant, and subsequently greatly improve discharged energy densities while retaining low loss and high charge–discharge efficiency at elevated temperatures.
Abstract: The demand for a new generation of high-temperature dielectric materials toward capacitive energy storage has been driven by the rise of high-power applications such as electric vehicles, aircraft, and pulsed power systems where the power electronics are exposed to elevated temperatures. Polymer dielectrics are characterized by being lightweight, and their scalability, mechanical flexibility, high dielectric strength, and great reliability, but they are limited to relatively low operating temperatures. The existing polymer nanocomposite-based dielectrics with a limited energy density at high temperatures also present a major barrier to achieving significant reductions in size and weight of energy devices. Here we report the sandwich structures as an efficient route to high-temperature dielectric polymer nanocomposites that simultaneously possess high dielectric constant and low dielectric loss. In contrast to the conventional single-layer configuration, the rationally designed sandwich-structured polymer nanocomposites are capable of integrating the complementary properties of spatially organized multicomponents in a synergistic fashion to raise dielectric constant, and subsequently greatly improve discharged energy densities while retaining low loss and high charge-discharge efficiency at elevated temperatures. At 150 °C and 200 MV m(-1), an operating condition toward electric vehicle applications, the sandwich-structured polymer nanocomposites outperform the state-of-the-art polymer-based dielectrics in terms of energy density, power density, charge-discharge efficiency, and cyclability. The excellent dielectric and capacitive properties of the polymer nanocomposites may pave a way for widespread applications in modern electronics and power modules where harsh operating conditions are present.
275 citations
TL;DR: In this paper, the authors proposed three zero-sequence injection methods for multilevel cascaded H-bridge converters for large-scale photovoltaic power plants, which allow direct connection to mediumvoltage distribution networks without the presence of bulky line frequency power transformers.
Abstract: Multilevel cascaded H-bridge converters are promising candidates for large-scale photovoltaic power plants. They allow direct connection to medium-voltage distribution networks without the presence of bulky line frequency power transformers. Owing to the stochastically variable nature of irradiance level, ambient temperature, and other factors, power levels in the three phases are expected to be unequal. The power imbalance condition creates unexpected problems with this topology, which was initially designed to operate under balanced power conditions. To deal with this issue, the paper proposes three novel zero-sequence injection methods as an expansion to the conventional zero-sequence injection method. Results obtained from simulations and a 430-V 8-kW three-phase seven-level cascaded H-bridge prototype are presented to verify the effectiveness and feasibility of the proposed methods.
261 citations
TL;DR: In this article, a typical power delivery architecture commonly found in computer supplies and data centers is presented, where the incoming universal ac grid power is converted by a power factor correction circuit to 400 V dc before it is stepped down to a lower voltage dc intermediate bus, such as 12 V, and then it powers the digital loads at voltages as low as 1 V by a point-of-load converter.
Abstract: The most important impact of power electronics on our society in the last 50 years has been the elimination of the 60-Hz ac power delivery system for consumer electronic products. Central to this achievement is the use of silicon (Si) power devices and pulsewidth modulation (PWM) techniques in delivering regulated ac and dc powers to low-voltage (LV) loads such as light-emitting diodes and computers. These solid-state power electronic converters have provided our society numerous benefits, including high-quality power and substantial energy savings. They also form the core technology for integrating renewable energies such as wind and solar into our power grid. Figure 1 shows a typical power delivery architecture commonly found in computer supplies and data centers. The incoming universal ac grid power is converted by a power factor correction circuit to 400 V dc before it is stepped down to a lower voltage dc intermediate bus, such as 12 V, and then it powers the digital loads at voltages as low as 1 V by a point-of-load converter. Si power metal-oxide-semiconductor field-effective transistor (MOSFET) transistors from 20 V to 700 V are almost exclusively used in this application with switching frequencies from tens of kilohertz to one megahertz. Emerging devices based on gallium nitride (GaN) heterojunction field effect transistors reduce the switching and conduction losses when compared with Si power MOSFETs and are, therefore, poised to compete in these applications, driven by the need for higher energy efficiency and higher power density.
206 citations
TL;DR: In this article, the influence of device and circuit mismatches on paralleling the silicon carbide (SiC) MOSFETs is investigated and experimentally evaluated for the first time.
Abstract: This paper addresses the influences of device and circuit mismatches on paralleling the silicon carbide (SiC) MOSFETs. Comprehensive theoretical analysis and experimental validation from paralleled discrete devices to paralleled dies in multichip power modules are first presented. Then, the influence of circuit mismatch on paralleling SiC MOSFETs is investigated and experimentally evaluated for the first time. It is found that the mismatch of the switching loop stray inductance can also lead to on-state current unbalance with inductive output current, in addition to the on-state resistance of the device. It further reveals that circuit mismatches and a current coupling among the paralleled dies exist in a SiC MOSFET multichip power module, which is critical for the transient current distribution in the power module. Thus, a power module layout with an auxiliary source connection is developed to reduce such a coupling effect. Finally, simulations and experimental tests are carried out to validate the analysis and effectiveness of the developed layout.
201 citations
TL;DR: In this paper, the capabilities and efficiencies of four micro-power harvesting methods including thermoelectric, thermo-photovoltaic, piezoelectrics, and microbial fuel cell renewable power generators are thoroughly reviewed and reported.
Abstract: Power harvesting devices which harness ambient surrounding energies to produce electricity could be a good solution for charging or powering electronic devices. The main advantages of such devices are that they are ecologically safe, portable, wireless, and cost effective and have smaller dimensions. Most of these power harvesting devices are realized by utilizing the microelectromechanical systems (MEMS) fabrication techniques. In this paper, the capabilities and efficiencies of four micro-power harvesting methods including thermoelectric, thermo-photovoltaic, piezoelectric, and microbial fuel cell renewable power generators are thoroughly reviewed and reported. These methods are discussed in terms of their benefits and applications as well as their challenges and constraints. In addition, a methodological performance analysis for the decade from 2005 to 2014 are surveyed in order to discover the methods that delivered high output power for each device. Moreover, the outstanding breakthrough performances of each of the aforementioned micro-power generators within this period are highlighted. From the studies conducted, a maximum energy conversion of 2500 mW cm −2 is reached by thermoelectric modules. Meanwhile, thermo-photovoltaic devices achieved a rise in system efficiency of up to 10.9%. Piezoelectricity is potentially able to reach a volumetric power density of up to 10,000 mW cm −3 . Significantly in microbial fuel cell systems, the highest power density obtained reached up to 6.86 W m −2 . Consequently, the miniaturized energy harvesters are proven to have credibility for the performance of autonomous power generation.
178 citations
TL;DR: In this paper, a multiport power electronic transformer (PET) topology with multiwinding medium-frequency transformer (MW-MFT) isolation along with the associated modeling analysis and control scheme is proposed.
Abstract: This paper proposes a multiport power electronic transformer (PET) topology with multiwinding medium-frequency transformer (MW-MFT) isolation along with the associated modeling analysis and control scheme. The power balance at different ports can be controlled using the multiwinding transformer's common flux linkage. The potential applications of the proposed multiport PET are high-power traction systems for locomotives and electric multiple units, marine propulsion, wind power generation, and utility grid distribution applications. The complementary polygon equivalent circuit modeling of an MW-MFT is presented. The current and power characteristics of the virtual circuit branches and the multiports with general-phase-shift control are described. The general current and power analysis for the multiple active bridge (MAB) isolation units is investigated. Power decoupling methods, including nonlinear solution for power balancing are proposed. The zero-voltage-switching conditions for the MAB are discussed. Control strategies including soft-switching-phase-shift control and voltage balancing control based on the power decoupling calculations are described. Simulations and experiments are presented to verify the performance of the proposed topology and control algorithms.
167 citations
TL;DR: In this article, the authors presented the Futoshiki puzzle pattern for the arrangement of the modules of a PV array under partial shading condition, ensuring the enhancement of the power generation with respect to totally crossed tired (TCT) structure.
Abstract: As per energy efficiency of a photovoltaic (PV) system is concerned, partial shading is an important issue. Under partial shading condition, the modules of a PV array receive different levels of solar irradiation, so the power generation of a PV system decreases. The power–voltage characteristic of a partially shaded PV array contains multiple local maxima, and the global maximum power point is one of them. The losses in a PV array depend on the shading pattern and the physical location of shaded modules. This paper presents the Futoshiki puzzle pattern for the arrangement of the modules of a PV array under partial shading condition, ensuring the enhancement of the power generation with respect to totally crossed tired (TCT) structure. In this method, the physical locations of modules in a TCT structure PV array are rearranged without changing the electrical connection of the modules. A comparison between the power generation in TCT and Futoshiki puzzle pattern configuration is presented. It is demonstrated that the power generated by a PV array in the Futoshiki configuration method is enhanced, and mismatch loss (ML) is minimized under different shading patterns by theoretical, simulation, and experimental results.
163 citations
TL;DR: In this article, a detailed statistical review of publications from 1994 to 2015 dealing with power cycling is presented, which reveals the principal trends in power electronic devices and highlights the main reliability issues for which an important lack of knowledge remains.
Abstract: Electronic devices using semiconductors such as insulated-gate bipolar transistors, metal–oxide–semiconductor field-effect transistors, and diodes are extensively used in electrical traction applications such as locomotive, elevators, subways, and cars. The long-term reliability of such power modules is then highly demanded, and their main reliability criterion is their power cycling capability. Thus, a power cycling test is the most important reliability test for power modules. This test consists in periodically applying a current to a device mounted onto a heat sink. This leads to power loss in the entire module and results in a rise in the semiconductor temperature. In this paper, the different kinds of semiconductors and power modules used for traction applications are described. Experimental and simulation methods employed for power cycling tests are presented. Modules' weak points and fatigue processes are pointed out. Then, a detailed statistical review of publications from 1994 to 2015 dealing with power cycling is presented. This review gives a clear overview of all studies dealing with power cycling that were carried out until now. It reveals the principal trends in power electronic devices and highlights the main reliability issues for which an important lack of knowledge remains.
158 citations
Patent•
15 Jan 2016
TL;DR: In this article, an electrical circuit for providing electrical power for use in powering electronic devices is described, which includes a primary power circuit and a secondary power circuit, where the primary circuit receives an alternating current (AC) input power signal from an electrical power source and generates an intermediate direct current (DC) power signal.
Abstract: An electrical circuit for providing electrical power for use in powering electronic devices is described herein. The electrical circuit includes a primary power circuit and a secondary power circuit. The primary power circuit receives an alternating current (AC) input power signal from an electrical power source and generates an intermediate direct current (DC) power signal. The intermediate DC power signal is generated at a first voltage level that is less than a voltage level of the AC input power signal. The secondary power circuit receives the intermediate DC power signal from the primary power circuit and delivers an output DC power signal to an electronic device. The output DC power signal is delivered at an output voltage level that is less than the first voltage level of the intermediate DC power signal.
TL;DR: In this paper, a 15kV silicon carbide (SiC) MOSFET gate drive is presented, which features high commonmode (CM) noise immunity, small size, light weight, and robust yet flexible protection functions.
Abstract: This paper presents a 15kV silicon carbide (SiC) MOSFET gate drive, which features high common-mode (CM) noise immunity, small size, light weight, and robust yet flexible protection functions. To enhance the gate-drive power reliability, a power over fiberbased isolated power supply is designed to replace the traditional design based on isolation transformer. It delivers the gate-drive power by laser light via optical fiber over a long distance (>1 m), so a high isolation voltage (>20 kV) is achieved, and the circuit size and weight are reduced. More importantly, it eliminates the parasitic CM capacitance coupling the power stage and control stage, and thus eradicates the control signal distortion caused by high dv/dt in switching transients of the high-voltage SiC devices. In addition, the gate-drive circuit design integrates comprehensive protection functions, including the overcurrent protection, undervoltage/overvoltage lockout, active miller clamping, soft turn off, and fault report. The overcurrent protection responds within 400 ns. The experimental results from a 15kV double-pulse tester are presented to validate the design.
TL;DR: A review of the state-of-the-art technology and future design guidelines for high efficiency power electronic converters are presented and a design example for an ultrahigh efficiency converter is presented.
Abstract: Thermal management is a key design aspect of power converters since it determines their reliability as well as their final performance and power density. Cooling technologies have been a research area in electronics since the 1940s and, in the last 15 years, the number of articles related to this field has grown significantly. At present, thermal management is essential in new disciplines and it is a critical enabling technology in the development of power electronic systems. This paper aims at presenting a review of the state-of-the-art technology and provides future design guidelines for high efficiency power electronic converters. The main design trends are focused on the need to develop cooling systems able to manage high local density heat fluxes due to two converging trends: higher power dissipation and smaller module size. Considering the latest advances in thermal management, as well as the huge improvement in power electronics in the last decades, a review and classification of the main thermal management techniques is presented. Besides, they are compared considering important parameters such as peak power dissipation, efficiency, cost/complexity, power density or technical maturity, and a design example for an ultrahigh efficiency converter is presented.
TL;DR: The effectiveness of common techniques of mitigating shoot-through, including bipolar gate drives, multiple gate resistance switching paths, and external gate-source and snubber capacitors, has been evaluated for both technologies at different temperatures and switching rates and shows that solutions are less effective for SiC-MOSFETs.
Abstract: The temperature and $dV/dt$ dependence of crosstalk has been analyzed for Si-IGBT and SiC-MOSFET power modules. Due to a smaller Miller capacitance resulting from a smaller die area, the SiC module exhibits smaller shoot-through currents compared with similarly rated Si-IGBT modules in spite of switching with a higher $dV/dt$ and with a lower threshold voltage. However, due to high voltage overshoots and ringing from the SiC Schottky diode, SiC modules exhibit higher shoot-through energy density and induce voltage oscillations in the dc link. Measurements show that the shoot-through current exhibits a positive temperature coefficient for both technologies, the magnitude of which is higher for the Si-IGBT, i.e., the shoot-through current and energy show better temperature stability in the SiC power module. The effectiveness of common techniques of mitigating shoot-through, including bipolar gate drives, multiple gate resistance switching paths, and external gate–source and snubber capacitors, has been evaluated for both technologies at different temperatures and switching rates. The results show that solutions are less effective for SiC-MOSFETs because of lower threshold voltages and smaller margins for negative gate bias on the SiC-MOSFET gate. Models for evaluating the parasitic voltage have also been developed for diagnostic and predictive purposes. These results are important for converter designers seeking to use SiC technology.
TL;DR: In this paper, a review of existing IMD technologies and their thermal effects on the IMD system is presented, along with potential converter topologies for an IMD like the matrix converter, two-level bridge, three-level neutral point clamped and multiphase full bridge converters.
Abstract: With increased need for high power density, high efficiency and high temperature capabilities in aerospace and automotive applications, integrated motor drives (IMD) offers a potential solution. However, close physical integration of the converter and the machine may also lead to an increase in components temperature. This requires careful mechanical, structural and thermal analysis; and design of the IMD system. This study reviews existing IMD technologies and their thermal effects on the IMD system. The effects of the power electronics position on the IMD system and its respective thermal management concepts are also investigated. The challenges faced in designing and manufacturing of an IMD along with the mechanical and structural impacts of close physical integration is also discussed and potential solutions are provided. Potential converter topologies for an IMD like the matrix converter, two-level bridge, three-level neutral point clamped and multiphase full bridge converters are also reviewed. Wide band gap devices like silicon carbide and gallium nitride and their packaging in power modules for IMDs are also discussed. Power modules components and packaging technologies are also presented.
TL;DR: A special three-stage startup strategy is designed to shorten the startup time and reduce the startup inrush current and an individual dc voltage balancing controller based on regulating the output power of each parallel LVPC is proposed to keep the dc-link voltages balanced.
Abstract: This paper presents the design and development of a three-phase 10-kV/400-V 500-kVA electronic power transformer (EPT). The power circuit is designed in a modular fashion, i.e., the main circuit consists of many identical ac–dc–dc–ac modules (abbreviated as power modules). Each power module consists of a high-voltage power cell, a low-voltage power cell (LVPC), a medium-frequency isolation transformer, and a filter. The corresponding control and protection system is developed. A special three-stage startup strategy is designed to shorten the startup time and reduce the startup inrush current. The negative-sequence current compensation is introduced in the input stage to handle the unbalanced loads. To keep the dc-link voltages balanced, an individual dc voltage balancing controller based on regulating the output power of each parallel LVPC is proposed. The detailed control hardware design and software implementation are discussed. The functions of this 10-kV EPT prototype are verified through the laboratory and field tests. The results are shown in this paper. Currently, the prototype is operating in the industrial power grid.
TL;DR: In this article, a novel hydrogen storage system for a RX60-30L 3-tonne electric forklift equipped with a GenDrive 1600-80A fuel cell power module (Plug Power) has been developed.
TL;DR: In this article, the lifetime evaluation of the MMC based on power cycling and thermal cycling, considering the mission profiles in the high-voltage direct current application for offshore wind power, was analyzed in order to better understand the loading characteristics of MMC.
Abstract: Due to a series of unique merits, modular multilevel converters (MMCs) have been developing dramatically in the last decade. However, in some applications, such as offshore power transmission, the MMC modules are subjected to a variety of tough temperature profiles with adverse working conditions, and all of these could lead to thermomechanical fatigues in the components and the joints of the power modules, thereby causing reliability challenge. This paper focuses on the lifetime evaluation of the MMC based on power cycling and thermal cycling, considering the mission profiles in the high-voltage direct current application for offshore wind power. The mission profiles as well as the topology of the MMC are first analyzed in order to better understand the loading characteristics of MMC. Then, the power loss calculation along with the electrothermal simulation is conducted to uncover the thermal loading of MMC. At last, the lifetime of MMC is studied based on rainflow counting and lifetime models for power semiconductors.
TL;DR: In this paper, the power module (PM) capacitor voltage balancing of a modular multilevel converter (MMC) has been studied and a low-switching frequency PM balancing method has been proposed by introducing the balancing adjusting number (BAN).
Abstract: This letter focuses on the power module (PM) capacitor voltage balancing of a $\pm 350$ -kV/1000-MW modular multilevel converter (MMC). For this MMC, the current flowing through the IGBTs will exceed the nominal current of the adopted commercial high-voltage (3.3 kV or higher) IGBT products, i.e., 1500 A. As for the PM voltage balancing of this MMC, the switching frequency must be kept low to reduce the losses and the accurate calculation of the PM switching frequency is of great importance to the design of the cooling system. This letter presented a low-switching frequency PM balancing method by introducing the balancing adjusting number (BAN). The PM switching frequency calculation method is also presented with different BANs. Computer simulation and the real-time control hardware in the loop test results based on RT-LAB show the effectiveness of the proposed PM balancing method and the accuracy of the switching frequency calculation method under the rated power.
TL;DR: A low-power, autonomous power management unit able to perform maximum power point tracking for dc-type renewable sources and allows power consumption decrease by reducing the gate driving losses associated with large pass transistor devices, and it enhances efficiency.
Abstract: Efforts towards energy-harvesting solutions are targeted for wireless sensor node applications and focus on performing maximum power extraction and storing power, yet efforts to deliver a regulated supply to voltage-sensitive blocks in power-limited applications has yet to be fully achieved. This paper presents a low-power, autonomous power management unit (PMU) able to perform maximum power point tracking for dc-type renewable sources. It includes a startup circuit fed directly from the renewable source. The PMU delivers a regulated output voltage through a digital LDO. The main step-up operation is performed through a dynamically controlled, power-aware, capacitive dc–dc converter that performs the required voltage gain procedure. Then, the digital LDO receives the EH source power density information from the dc–dc converter and provides regulation. Information about the source-power density availability is passed on to the digital LDO in order to select the best pass device size from a bank of three arrays. The PMU allows power consumption decrease by reducing the gate driving losses associated with large pass transistor devices, and it enhances efficiency. The system was fabricated in 180 nm CMOS process, and maximum end-to-end efficiency was measured at 57% with 1.75 mW of input power.
TL;DR: In this paper, a single-phase unified power quality conditioner (UPQC) based on the modular multilevel matrix converter (M3C) is presented to enhance the power quality in the medium/highvoltage distribution power systems.
Abstract: To enhance the power quality in the medium/high-voltage distribution power systems, a single-phase unified power quality conditioner (UPQC) based on the modular multilevel matrix converter (M3C) is presented in this paper. The M3C-UPQC is comprised of four identical multilevel converter arms and associated filtering inductors. According to the established equivalent circuit of M3C-UPQC, its operation principle and power balance of each arm are analyzed theoretically, and the parameters’ design for the arm inductance as well as submodule capacitance is studied. Then, an integrated control method for M3C-UPQC in which the dc circulating current is used to balance the instantaneous active power of each arm is proposed to prevent the capacitor voltages from divergence inter- and intra-arms, so as to achieve voltages balance of M3C-UPQC. Finally, the effectiveness of the proposed control method is verified by a prototype rated at 8 kVA.
TL;DR: In this paper, a degradation model investigating the electro-thermo-mechanical fatigue, experienced by insulated gate bipolar transistors modules, is presented, which is based on determining the thermally induced stress around the bond wire/substrate interface through multiphysics-based models.
Abstract: A degradation model investigating the electro-thermo-mechanical fatigue, experienced by insulated gate bipolar transistors modules, is presented. To illustrate the concept, a specific case of power modules subjected to active power cycling which induce failure through bond wire lift-off is considered. Bond wire lift-off is believed to be due to thermally induced stress arising from a mismatch in the coefficients of thermal expansion between the wires and the given substrate. Overall, the theoretical evaluation is based on determining the thermo-mechanical stress around the bond wire/substrate interface through multiphysics-based models. The simulation detail and included equations are specified according to the region of interest and their complexity. In common, however, is the use of the finite element method combined with empirical equations. The final result is a numerical approach to evaluate the damage accumulated by a given load which may be used for prediction of lifetime or optimization of work points and module geometry.
01 Nov 2016
TL;DR: In this paper, a 10 kV / 240 A silicon carbide (SiC) metal-oxide field effect transistor (MOSFET) power module design is presented.
Abstract: In this work, a novel high performance 10 kV / 240 A silicon carbide (SiC) metal-oxide field-effect transistor (MOSFET) power module design is presented. The key features for this power module include reworkability, low parasitic design, low thermal resistance design, equal current sharing of high voltage power MOSFETs, and low profile and small form factor. The design tradeoffs to achieve these characteristics will be discussed. In addition, the static and dynamic electric characteristics will be presented and compared to an off-the-shelf silicon (Si) counterpart.
TL;DR: In this article, a direct bonded copper (DBC) layout was proposed for mitigating the current imbalance among the paralleled SiC mosfet dies in multichip power modules.
Abstract: This letter proposes a novel direct bonded copper (DBC) layout for mitigating the current imbalance among the paralleled SiC mosfet dies in multichip power modules. Compared to the traditional layout, the proposed DBC layout significantly reduces the circuit mismatch and current coupling effect, which consequently improves the current sharing among the paralleled SiC mosfet dies in power module. Mathematic analysis and circuit model of the DBC layout are presented to elaborate the superior features of the proposed DBC layout. Simulation and experimental results further verify the theoretical analysis and current balancing performance of the proposed DBC layout.
TL;DR: In this paper, a flexible control technique for power electronics converters, which can function as an active power filter, as a local power supply interface, or perform both functions simultaneously, is presented.
Abstract: This paper presents a flexible control technique for power electronics converters, which can function as an active power filter, as a local power supply interface, or perform both functions simultaneously. Thus, it can compensate for current disturbances while simultaneously injecting active power into the electrical grid, transforming the power converter into a multifunctional device. The main objective is to use all the capacity available in the electronic power converter to maximize the benefits when it is installed in the electricity grid. This objective is achieved by using the orthogonal current decomposition of the conservative power theory. Each current component is weighted by compensation coefficients ( $k_i $ ), which are adjusted instantaneously and independently, in any percentage, by means of load conformity factors ( $\lambda _i $ ), thus providing online flexibility with respect to the objectives of compensation and injection of active power. Finally, simulated and experimental results are presented to validate the effectiveness and performance of the proposed approach.
TL;DR: This paper investigates the trade-off between the lifetime extension or de-rating and its cost due to the efficiency reduction and its method is validated on a laboratory setup, where active thermal control is implemented by adapting the switching frequency.
TL;DR: In this paper, the authors present test results of a commercial 3-tonne electric forklift equipped with a commercial fuel cell power module (Plug Power) and a MH hydrogen storage tank (HySA Systems and TF Design).
12 Jun 2016
TL;DR: In this article, a high power density DC/AC converter system, developed by a team of the ETH Zurich, the Fraunhofer Institute for Reliability and Microintegration (IZM) and the Fraza company, was described and further optimized.
Abstract: There is an ongoing demand for increased power density and efficiency along with lower costs of converter systems and shorter development time for specific applications in the field of power electronics. In order to expedite the technology development Google and IEEE initiated the Google Little Box Challenge (GLBC) including $1 million prize money. Aim of the GLBC was to build the worldwide smallest 2 kVA/400…450 VDC/230 VAC single-phase converter with η > 95% efficiency and an air-cooled case temperature of less than 60 °C by using latest semiconductor technology and innovative topological concepts. Out of 2000+ applications 18 finalists have been selected, whose converter systems exhibited power densities mostly in the range of 120…220 W/in3. With this, a clear performance increase compared to the state of the art (ρ < 50 W/in3) was achieved, but in the end it represented only a limited performance improvement. In this work, a high power density DC/AC converter system, developed by a team of the ETH Zurich, the Fraunhofer Institute for Reliability and Microintegration (IZM) and the Fraza company and presented at the GLBC finale in Golden, Colorado, will be described and further optimized. Given the converter system, it will be clarified which components and technologies are finally limiting an increase in performance. In a first step, the optimum solution will be identified by means of a ηρ-Pareto front obtained from a multi-objective optimization. The analysis will be based on detailed loss and volume models of the utilized GaN GIT power switches, inductors and capacitors as well as on component stresses, resulting for advanced modulation and control techniques. Thereafter, the models of the power semiconductors will be gradually idealized by means of reducing the switching and conduction losses. The resulting shift of the Pareto front reveals the sensitivity of the system performance with respect to the semiconductor technology and ultimately leads to an ‘absolute’ performance limit imposed by the passive components and the cooling system. It is shown that for fully idealized semiconductors a maximum possible performance increase of 50 % regarding power density or losses is feasible, whereby the switching frequencies are limited to & 1 MHz due to the losses in the magnetic components. Thus, for the realization of highly compact systems, high frequency core materials and winding concepts of the magnetic components, new heat management concepts and 3D-packaging will gain further importance in future along with the ongoing improvement of semiconductor technologies.
20 Mar 2016
TL;DR: In this paper, the gate power supply for medium voltage level applications has been investigated, and several isolation transformer designs have been investigated and optimum design with very low coupling capacitance ≈ 0.5 pF, has been identified and used in the gate driver design.
Abstract: The commercial gate drivers are available upto 6.5 kV IGBTs. With the advances in the SiC, power devices rated beyond 10 kV are being researched. These devices will have use on medium voltage power converters. Commercial gate drivers rated for such high voltages are not available. These power devices have very high dv/dts (30–100 kV/µs) at switching transitions. Such high dv/dts bring in challenges in the gate driver design. The isolation stage of the gate power supply needs to have very low coupling capacitance to limit the high frequency circulating currents from reaching the gate driver control circuits. Also, the isolation stage has to be designed with insulation several times higher than the peak system voltage level. In this paper, design, development and evaluation of the gate power supply for medium voltage level applications have been investigated. Several isolation transformer designs have been investigated and optimum design, with very low coupling capacitance ≈ 0.5 pF, has been identified and used in the gate driver design. Experimental characterization of the transformer has been done. The performance of the gate driver power supply has been evaluated in several MV power converters, using 10 kV SiC MOSFETs.