Showing papers on "Power module published in 2019"

20-kW Zero-Voltage-Switching SiC- mosfet Grid Inverter With 300 kHz Switching Frequency

Abstract: Although SiC- mosfet has significant advantages on switching performance over traditional Si-IGBT, the switching loss of SiC- mosfet devices at hard switching rises quickly with the increment in the switching frequency. This has narrowed down further possibilities of improving efficiency and power density of the grid inverter. Zero-voltage-switching (ZVS) space-vector-modulation (SVM) technique is introduced to further push the power density of SiC- mosfet inverter. This paper focuses on the impact of applying the ZVS-SVM to three-phase two-level SiC- mosfet inverter. With the same efficiency requirement the ZVS-SVM SiC inverter can operate at a much higher switching frequency, which gives the opportunity to further reduce the size of passive components. The loss distributions, conversion efficiencies, and volumes of passive components of both a 20-kW SiC- mosfet hard-switching inverter and a 20-kW SiC- mosfet ZVS-SVM inverter have been compared under switching-frequency range from 50 to 300 kHz. Meanwhile, a new metric called “efficiency stiffness” is proposed to compare different inverters with respect to the efficiency performance against switching-frequency characteristics. In addition, high voltage overshoot of SiC- mosfet and high thermal stress of resonant inductor are the two critical issues in the SiC- mosfet ZVS-SVM inverter with high switching frequency. A power module including seven SiC- mosfet bare dies with low stray inductance is designed for ZVS-SVM inverter instead of the existing seven discrete TO-247 package SiC- mosfet s to reduce the voltage overshoots on the switches. Besides, to reduce the power loss of the resonant inductor caused by large amplitude of current at hundreds of kHz excitation frequency, design of the inductor with distributed air gap and optimal winding thickness are studied. A 20-kW SiC- mosfet ZVS-SVM grid inverter prototype is built to verify the proposed design.

Power module electronics in HEV/EV applications: New trends in wide-bandgap semiconductor technologies and design aspects

Abstract: A large number of factors such as the increasingly stringent pollutant emission policies, fossil fuel scarcity and their price volatility have increased the interest towards the partial or total electrification of current vehicular technologies. These transition of the vehicle fleet into electric is being carried out progressively. In the last decades, several technological milestones have been achieved, which range from the development of basic components to the current integrated electric drives made of silicon (Si) based power modules. In this context, the automotive industry and political and social agents are forcing the current technology of electric drives to its limits. For example, the U.S Department of Energy’s goals for 2020 include the development of power converter technologies with power densities higher than 14.1 kW/kg and efficiencies greater than 98%. Additionally, target price of power converters has been set below $3.3/kW. Thus, these goals could be only achieved by using advanced semiconductor technologies. Wide-bandgap (WBG) semiconductors, and, most notably, silicon carbide (SiC) based power electronic devices, have been proposed as the most promising alternative to Si devices due to their superior material properties. As the power module is one of the most significant component of the traction power converter, this work focuses on an in-deep review of the state of the art concerning such element, identifying the electrical requirements for the modules and the power conversion topologies that will best suit future drives. Additionally, current WBG technology is reviewed and, after a market analysis, the most suitable power semiconductor devices are highlighted. Finally, this work focuses on practical design aspects of the module, such as the layout of the module and optimum WBG based die parallelization, placement and Direct Bonded Copper (DBC) routing.

Electrical Performance Advancement in SiC Power Module Package Design With Kelvin Drain Connection and Low Parasitic Inductance

Abstract: Silicon carbide (SiC) power modules are promising for high-power applications because of the high breakdown voltage, high operation temperature, low ON-resistance, and fast switching speed However, the large parasitic inductance in existing package designs results in compromised performance, ie, long blanking time in the desaturation protection scheme and large overvoltage spikes during the switching transient Consequently, the benefits of SiC devices are often not fully utilized in practical applications This paper deals with these two issues and aims at improving the electrical performance of the existing SiC module package Specifically, a package design with Kelvin drain-to-source connection is first proposed to minimize the blanking time More than 99% reduction of blanking time is achieved experimentally compared to the conventional package design Second, a low parasitic inductance package with double-side cooling is proposed to allow the fast switching speed of SiC devices without sacrificing the thermal performance A power loop inductance of 163 nH is realized from Q3D simulation Verified by the experiment, more than 60% reduction of power loop inductance is achieved in comparison to a previously designed baseline module At 0- $\Omega $ external gate resistance, the turn-off voltage spike is less than 9% of the dc-link voltage under the rated load condition

A Fast-Switching Integrated Full-Bridge Power Module Based on GaN eHEMT Devices

Abstract: New packaging solutions and power module structures are required to fully utilize the benefits of emerging commercially available wide bandgap semiconductor devices. Conventional packaging solutions for power levels of a few kilowatt are bulky, meaning important gate driver and measurement circuitry are not properly integrated. This paper presents a fast-switching integrated power module based on gallium nitride enhancement-mode high-electron-mobility transistors, which is easier to manufacture compared with other hybrid structures. The structure of the proposed power module is presented, and the design of its gate driver circuit and board layout structure is discussed. The thermal characteristics of the designed power module are evaluated using COMSOL Multiphysics. An ANSYS Q3D Extractor is used to extract the parasitics of the designed power module, and is included in simulation models of various complexities. The simulation model includes the SPICE model of the gallium nitride devices, and parasitics of components are included by experimentally characterizing them up to 2 GHz. Finally, the designed power module is tested experimentally, and its switching characteristics cohere with the results of the simulation model. The experimental results show a maximum achieved switching transient of 64 V/ns and verify the power loop inductance of 2.65 nH.

Mission-Profile-Based Lifetime Prediction for a SiC mosfet Power Module Using a Multi-Step Condition-Mapping Simulation Strategy

Abstract: The reliability analysis and lifetime prediction for SiC-based power modules is crucial in order to fulfill the design specifications for next-generation power converters. This paper presents a fast mission-profile-based simulation strategy for a commercial 1.2-kV all-SiC power module used in a photovoltaic inverter topology. The approach relies on a fast condition-mapping simulation structure and the detailed electro-thermal modeling of the module topology and devices. Both parasitic electrical elements and thermal impedance network are extracted from the finite-element analysis of the module geometry. The use of operating conditions mapping and look-up tables enables the simulation of very long timescales in only a few minutes, preserving at the same time the accuracy of circuit-based simulations. The accumulated damage related to thermo-mechanical stress on the module is determined analytically, and a simple consumed lifetime calculation is performed for two different mission profiles and compared in different operating conditions.

Comparison of the Heat Transfer Capabilities of Conventional Single- and Two-Phase Cooling Systems for an Electric Vehicle IGBT Power Module

Abstract: This paper presents a comparison of conventional single-phase water/glycol liquid and innovative two-phase cooling technology for thermal management of high-power electronics automotive insulated-gate bipolar transistor modules during a full drive cycle. The proposed two-phase cooling system is built using conventional automotive air conditioning components (a condenser, an expansion valve, a compressor, and vapor and liquid lines) and a conventional cold plate as used for single-phase cooling; thus, the design does not require the development of new technology for its implementation. Three-dimensional numerical simulation in COMSOL and experimental results of two-phase cooling have been obtained on a prototype and compared to conventional water/glycol cooling high-power electronics modules, with a considerable improvement on working temperature, power transfer capacity, and equalization of die temperatures during a full driving cycle. These results suggest that two-phase cooling using the same cold plates as in single-phase cooling can be used to substantially improve the performance and reliability of electric vehicle power converters without major changes.

Flexible PCB-Based 3-D Integrated SiC Half-Bridge Power Module With Three-Sided Cooling Using Ultralow Inductive Hybrid Packaging Structure

Abstract: Silicon carbide (SiC) devices are capable of high switching speeds and also enable high switching frequency in power electronic converters. However, this feature poses substantial challenges to packaging, especially limiting the loop inductance. The traditional wire-bonding packaged power module has large parasitic inductance, which will cause voltage overshoot, oscillation, parasitic turn-on, and EMI issues. In order to reduce the parasitic inductance, this paper proposes a flexible printed circuit board (FPCB) based full SiC half-bridge power module with a novel low inductive hybrid packaging structure and three-dimensional (3-D) integration method. This hybrid packaging structure has an ultrathin FPCB substrate stacked on a direct bonding copper (DBC) substrate, which forms a multilayer 3-D power loop. The SiC chips are soldered on the DBC substrate for good thermal dissipation through a cavity in the FPCB substrate. After power loop optimization, the power loop inductance of a 1200-V/120-A SiC power module is only 0.79 nH. The power module consists of three submodules, which are connected by the bendable FPCB substrate. The bendable power module enables maximum utilization of 3-D space. The gate drive, decoupling capacitors, and dc-link capacitors are also integrated and 3D-structured using rigid-flexible PCBs. Moreover, the cooling system is a high-efficiency three-sided cooling structure for the bendable power module. The simulation results show that the three-sided cooling structure reduces the heatsink volume by 50%. Applying this method, the converter can be designed as a system-in-package and a 3D-structured compact system. The power density of a 20-kW three-phase inverter will reach 19.3 kW/L based on this power module. In this paper, the 1200-V/120-A power module fabrication and assembly processes are given. Finally, the static and dynamic experimental comparisons are done for a commercial power module and the proposed power module. The experiment results show that the voltage overshoot of the proposed module reduces about 5.8 times and are consistent with the simulation results. Meanwhile, the proposed power module switching speed is 1.8 times faster than the commercial module under zero external gate resistors and the switching loss can reduce by about 60%.

Methodology for Active Thermal Cycle Reduction of Power Electronic Modules

Abstract: This paper proposes a methodology for active thermal control of power electronic modules in ac applications, which includes a loss manipulation unit, a thermal observer structure, and an active thermal cycle reduction algorithm. It aims to reduce the thermo-mechanical strain in the inter-connects of the module in order to enhance its reliability and lifetime. The loss manipulation unit operates in a minimally invasive manner by manipulating adaptive gate resistances and the pulsewidth modulation frequency. This allows the individual thermal control of multiple devices within a power module, which has not been achieved in prior work. A thermal observer structure that estimates averaged junction temperatures by combination of a thermal model and sensor information is introduced. The observer technology makes this paper the first to realize closed-loop control of averaged temperatures achieving an increased robustness and insensitivity to modeling errors. A key element of the active thermal cycle reduction algorithm is the virtual heat sink that derives feasible and stress-relieving thermal trajectories. The trajectories are applied with a unique thermal feedback control that smoothly manipulates the averaged junction temperature of the power module even in the presence of loss manipulation limits. The active thermal control methodology is evaluated experimentally with a state-of-the-art insulated-gate bipolar transistor (IGBT) power module.

PowerSynth: A Power Module Layout Generation Tool

Abstract: PowerSynth is a multiobjective optimization tool for rapid design and verification of power semiconductor modules. By using reduced order models for the calculation of electrical parasitics of the layout and thermal coupling between devices, optimal trace layout and die placement can be simultaneously achieved orders of magnitude faster than conventional finite element analysis (FEA) techniques. An overview of the tool, its modeling methods, model validation, and module layout optimization are presented. The electrical and thermal models are validated against FEA simulations and physical measurements of built modules generated from the tool. The FEA comparisons are performed with FastHenry and ANSYS Icepak to evaluate electrical parasitics and thermal behavior, respectively. A sample hardware prototype based on a half-bridge circuit topology is chosen for testing. Excellent agreement between the FEA simulations, experimental measurements, and PowerSynth predictions are demonstrated. Additionally, when compared with conventional simulation runtime and workflow, PowerSynth takes considerably less computation and user time to produce several candidate layout solutions from which a designer may easily balance selected tradeoffs.

Layout-Dominated Dynamic Current Imbalance in Multichip Power Module: Mechanism Modeling and Comparative Evaluation

Abstract: The multichip power module is an irreplaceable component for high-capacity industrial converters. Dynamic current imbalance among parallel chips challenges the electrothermal stability and limits the maximum current rating of the power module. In this paper, general mechanism models are proposed to reveal the layout-dominated dynamic current imbalance in the multichip power module. The influence of the layout on the current sharing is comparatively evaluated by power modules with and without Kelvin connections. Focusing on the dynamic current imbalance, based on a commercial multichip power module, finite-element analysis and equivalent electric circuit are utilized to illustrate the impact of Kelvin connection. General mathematical and graphical models are created to address the current sharing of parallel chips affected by networked parasitic impedances. Based on the fabricated power module prototypes, extensive experiments and detailed analyses are presented concerning the current sharing, transient time, and switching loss. It is demonstrated that the Kelvin connection can elevate switching speed and reduce switching loss of parallel chips, while its functionality to eliminate dynamic current imbalance depends on the parasitic impedances. Some general design guidelines of the multichip power module are presented for current sharing. To achieve satisfactory current sharing, advanced packaging layout by using the optimized chip arrangement and wire interconnection is further needed for the multichip power module.

Monitoring 3-D Temperature Distributions and Device Losses in Power Electronic Modules

Abstract: This paper presents a methodology for real-time monitoring of 3-D temperature distributions and device losses within power electronic modules. It allows precise thermal management, empirical lifetime prognosis, and detection of critical degradation of the power module. By effective combination of thermal 3-D finite difference modeling, parametric loss models, and model truncation techniques, a compact thermal real-time model is derived. It enables the computation of device losses and temperatures at critical locations within a power module, e.g., at the devices, solder interfaces or the base plate, on a conventional digital signal processor. The real-time model as well as real-time junction temperature information are combined in a new Luenberger-style observer structure. Applying bandwidth partitioning, the observer estimates the temperatures throughout the power module every switching period and averaged over one excitation period with nearly zero lag, even if the junction temperature measurement exhibits delays and has noisy signals. Furthermore, it estimates errors in the loss prediction process that can be tracked over the lifetime of the power module to detect degradation of the devices or the power module. The observer and its features are experimentally evaluated under realistic operating conditions on a load emulator using a state-of-the-art automotive power module.

Asymmetrical Reactive Power Capability of Modular Multilevel Cascade Converter Based STATCOMs for Offshore Wind Farm

Abstract: Modular multilevel cascade converters (MMCCs) are becoming attractive solutions as high-voltage Static Synchronous Compensators (STATCOMs) for power plants in renewable energy generation, in order to satisfy the strict grid codes under both normal and grid fault conditions. This paper investigates the performances of four potentially used configurations of the MMCC family for the STATCOM in large-scale offshore wind power plants, with special focus on asymmetrical low-voltage ride through capability under grid faults. The specifications and the sizing of components of each type of practical 80-MVar/33-kV-scaled MMCC-STATCOM are carefully designed and compared. The total cost and volume are compared based on the total power semiconductor chip area and the total energy stored in the passive components. Asymmetrical reactive power delivering operation of the MMCC family considering the dc-link capacitor voltage-balancing method is solved mathematically in order to quantitatively understand the performance limitations and behaviors. The electrothermal stress of the power modules used in each type of the MMCC for a practical 80-MVar/33-kV-scaled STATCOM is analyzed. The asymmetrical reactive power capability of the MMCC solutions is compared under different scenarios of grid faults, while considering the device temperature limits as well as voltage saturation. It is found that the MMCC configuration with double-star bridge cells becomes the most attractive circuit configuration for the STATCOM application based on the obtained results.

Investigation of heat transfer and thermal stresses of novel thermal management system integrated with vapour chamber for IGBT power module

Abstract: Thermal stress in IGBT power module can lead to sever thermal reliability problems such as module deformation, performance degradation and even permanent damage. So, it is important to develop innovative and efficient IGBT cooling technologies. In this paper, a novel thermal management system is developed for cooling IGBT power module. The module is integrated with a vapour chamber-based heat sink to reduce thermal resistance and improve temperature uniformity significantly. 3D FEM modelling is conducted to investigate the effect of vapour chamber on temperature distribution, thermal stress, energy strain dissipation density and lifetime under power cycle. The simulation results show that the proposed thermal management system is superior to traditional cooling solution regarding cooling capacity, thermal stress, creep and plastic strain energy dissipation and thermal fatigue life. The study of failure mechanism of solder layer under power cycling suggests that creep causes the main is damage in the power cycling and cracks induced by thermal loading can be expected to initiate at the edge.

Gate–Emitter Pre-threshold Voltage as a Health-Sensitive Parameter for IGBT Chip Failure Monitoring in High-Voltage Multichip IGBT Power Modules

Abstract: This paper proposes a novel health-sensitive parameter, called the gate–emitter pre-threshold voltage V GE(pre-th), for detecting IGBT chip failures in multichip IGBT power modules. The proposed method has been applied in an IGBT gate driver and measures the V GE at a fixed time instant of the V GE transient before the threshold voltage occurs. To validate the proposed method, theoretical analysis and practical results for a 16-chip IGBT power module are presented in the paper. The results show a 500 mV average shift in the measured V GE(pre-th) for each IGBT chip failure.

Thermal Concept Design of MOSFET Power Modules in Inverter Subsystems for Electric Vehicles

Abstract: The most important key in the thermal management of power electronic devices is the cooling system design. One of the most promising cooling techniques is indirect liquid cooling using cold plates. This paper studies the performance of a liquid cooling system on the junction temperature of a high-power inverter drive utilizing three legs of half-bridge modules (CAS120M12BM2 Silicon Carbide CREE MOSFET). One of the primary objectives is to compare the effect of different geometries and boundary conditions on the thermal performances regarded as maximum junction temperature. Based on the analysis of the liquid cooling, different boundary conditions are proposed and a comparison of the main case study is made against the case of different geometries and boundary conditions. Furthermore, the concept of varying the distance between three half-bridge MOSFETs in an inverter drive is introduced. According to the simulation results, in the best combination, the maximum junction temperature of the module is decreased to 82.2°C when the thermal paste and NX100 materials are selected for the thermal interface material and the heat sink, respectively. In addition, Simulation results show that the best distance between each of the modules in the inverter drive is 10mm spacing.

Wear-Out Condition Monitoring of IGBT and mosfet Power Modules in Inverter Operation

Abstract: In this article, a condition monitoring system for the degradation assessment of power semiconductor modules under switching conditions is presented. The proposed monitoring system is based on the online measurement of two damage indicators: the on -state voltage of the semiconductor and the voltage drop in the bond wires. The on-state voltage of a semiconductor can be employed for temperature estimation, in order to anticipate failures in the solder joints that increase the thermal resistance of the cooling path. Moreover, by measuring the voltage drop in the bond wires, the degradation of the bond wires can be detected. The described monitoring system has been implemented in an inverter prototype, and tests have been performed in different scenarios to verify its capabilities in healthy and degraded states. Furthermore, a monitoring routine has been proposed in order to perform the required measurements in high switching frequency applications.

Reliability Improvement of a Double-Sided IGBT Module by Lowering Stress Gradient Using Molybdenum Buffers

Abstract: A double-sided 1200-V/600-A multichip half-bridge insulated gate bipolar transistor (IGBT) module was fabricated utilizing molybdenum as stress-relief buffer and sintered nanosilver as die-attachment. By using the double-sided packaging, the volume, parasitic inductance, and junction temperature were decreased significantly, and thus the higher power density could be achieved. However, the thermomechanical stress was also increased. In this paper, molybdenum instead of the most common copper was used as a stress-relief buffer between chips and substrate, and thus the thermomechanical stress decreased greatly without significantly increasing the junction temperature. Specifically, by using molybdenum instead of copper as the buffer material, the simulation results showed that the IGBT junction temperature at total power loss of 200 W only increased by 5.2% (2.22 °C), but the corresponding thermomechanical stress decreased by 9.8% (5.58 MPa), and the sintering residual stress decreased by 20.1% (48.88 MPa). Thermal performance, static and dynamic electrical performance, and reliability via power cycling test of the double-sided module were also characterized experimentally. No degradation of the power devices proved that the way to double-sided packaging power devices could be used for future manufacturing of high-power density power module.

Reliability Evaluation of SiC Power Module With Sintered Ag Die Attach and Stress-Relaxation Structure

Abstract: Silicon carbide (SiC) power modules with Ag sinter-bonding die attach were designed on the basis of thermal stress analysis for reliable high-temperature operations. Both the finite-element analysis (FEA) simulations and preliminary experiments confirmed that inserting the direct-bonded-copper (DBC) substrates can effectively reduce the maximum thermal stress in the module. A prototype SiC power module using sintered Ag die attach with a DBC substrate was designed and fabricated. The modules exhibited excellent durability in power cycling between 65 °C and 250 °C up to 20 000 cycles. FEA calculations of cumulative thermal strain and stress distributions adequately predicted the initial cracking position in the specimens after prolonged power cycles, observed by scanning electron microscopy.

DAVIC: A New Distributed Adaptive Virtual Impedance Control for Parallel-Connected Voltage Source Inverters in Modular UPS System

Abstract: In this paper, an average active power sharing control strategy based on the distributed concept for the parallel operation of voltage source inverters is proposed to be applied to the modular uninterruptible power supply (UPS) systems The presented method is named distributed adaptive virtual impedance control (DAVIC), which is coordinated with the droop control method Low bandwidth CAN-based communication is used for the requirement of data sharing of the proposed method in the real modular UPS system Unlike the conventional virtual impedance control techniques, the virtual impedance of a converter module is adjusted automatically by using global information when DAVIC is applied, further to tune the output impedance of the power modules The adaptive virtual impedance is calculated by using the difference between the active power of a local module and the average active power of all the modules in a modular UPS The DAVIC overcomes the drawback of the conventional virtual impedance control since an accurate value of the real output impedances of different converter modules is not required Simulations using PLECS and experiments on a real commercial modular UPS are developed to verify the effectiveness of the proposed control methodology These results shown a superior power sharing performance is obtained when using the proposed method

An Integrated SiC CMOS Gate Driver for Power Module Integration

Abstract: With high-temperature power devices available, the support circuitry required for efficient operation, such as a gate driver, is needed as part of a complete high-temperature solution. The design of an integrated silicon carbide (SiC) gate driver using a 1.2-μm complementary metal–oxide–semiconductor (CMOS) process is presented. Adjustable drive strength is added to facilitate a minimal external component requirement for high-temperature power modules and lays the groundwork for dynamic adjustment of drive strength. The adjustable drive strength feature demonstrates a capability of reducing overshoot and controlling dv / dt dynamically. Measurement of the gate driver was performed driving a power mosfet gate over temperature, exceeding 500 °C. High-speed and high-voltage room temperature evaluation is provided, demonstrating a system capable of high performance over temperature. The driver accomplishes better than 75 ns of rise and fall time driving the Cree CPM3-0900-0065B from room temperature to over 500 °C indicating that it will be ideal for integration into an all-SiC power module where driver, protection circuits, and power devices are fabricated in SiC.

Design and Evaluation of A 150 kVA SiC MOSFET Based Three Level TNPC Phase-leg PEBB for Aircraft Motor Driving Application

Abstract: This paper presents the design and evaluation of a phase-leg of power electronic building block (PEBB) with 150-kVA rated power by using 3-level T-type neutral-point-clamped (3L-TNPC) inverter for high-speed motor drives. Model-based pre-design evaluations and power module selections are first introduced to evaluate the design feasibility and improve efficiency. Based on the selected power modules, a novel busbar structure is proposed with a stray inductance of 11.2 nH. Besides these, a novel non-metallic cold plate is designed and evaluated. It shows less weight and improved common-mode noise than the traditional aluminum-cast cold plate. In the end of the paper, continuous tests are carried out to demonstrate the performance of the designed PEBB system. The measured peak efficiency is 99.45% with 30 kHz switching frequency and the measured specific power is 35.36 kW/kg.

Compact Thermal Models of Semiconductor Devices – a Review

Abstract: In the paper the problem of modelling thermal properties of semiconductor devices with the use of compact models is presented. This class of models is defined and their development over the past dozens of years is described. Possibilities of modelling thermal phenomena both in discrete semiconductor devices, monolithic integrated circuits, power modules and selected electronic circuits are presented. The problem of the usefulness range of compact thermal models in the analysis of electronic elements and circuits is discussed on the basis of investigations performed in Gdynia Maritime University.

Intelligent power module and air conditioner

Abstract: The invention discloses an intelligent power module and an air conditioner. The intelligent power module comprises a high-voltage side driving circuit, a low-voltage side driving circuit, a dead zonegeneration interlocking circuit and a bootstrap circuit, the bootstrap circuit comprises a bootstrap control unit, an N-MOS transistor and a bootstrap resistor, a positive electrode input terminal ofthe bootstrap control unit is connected with a positive terminal of a power supply, a negative electrode input terminal of the bootstrap control unit is connected with a negative terminal of the powersupply, a first controlled terminal of the bootstrap control unit is connected with a first output terminal of the dead zone generation interlocking circuit, a second controlled terminal of the bootstrap control unit is connected with a second output terminal of the dead zone generation interlocking circuit, an output terminal of the bootstrap control unit is connected with a grid electrodes of the N-MOS transistor, a source electrode and the grid electrode of the N-MOS transistor are in short circuit connection, a drain electrode of the N-MOS transistor is connected with a first terminal ofthe bootstrap resistor, and a second terminal of the bootstrap resistor is connected with a high-voltage side output terminal. According to the intelligent power module and the air conditioner, problems that the bootstrap circuit formed by discrete devices is not good for the layout of a PCB and increases the area of an electric control board are solved.

New 40kV / 300kVA Quasi-2-Level Operated 5-Level Flying Capacitor SiC “Super-Switch” IPM

Abstract: Emerging applications, e.g., traction systems and utility scale renewable energy systems, demand for Medium Voltage (MV)power electronic switches with blocking capabilities above 20kV, which cannot be provided with today's 10kV or 15kV SiC power semiconductors. Therefore, this work investigates different concepts for the realization of a MV half-bridge, i.e., a series connection of 10kV SiC MOSFETs, a JFET Super Cascode arrangement, and Modular Multilevel Converter (MMCs)and Flying Capacitor Converter (FCCs)topologies. The FCC topology features several advantages such as reduced switching losses, reduced chip area, lower $\mathrm{d}v/\mathrm{d}t$ of the switching transitions, and robust voltage balancing. Moreover, the volume of the flying capacitors can be reduced with Quasi-2-Level (Q2L) operation of the half-bridge, where the intermediate voltage levels are only used during very short time intervals, i.e., during the switching transitions. This paper analyzes the design, the switching behavior, and the voltage balancing of the Q2L-FCC bridge-leg and confirms its suitability as a versatile MV switch. Finally, the integration of a complete bridge-leg, including gate drivers, isolated cooling interfaces, measurements, and Q2L control into a 300 kVA/40 kV SiC Super-Switch Intelligent Power Module (SiC-SS-IPM)is presented.

A 50-kW Air-Cooled SiC Inverter With 3-D Printing Enabled Power Module Packaging Structure and Genetic Algorithm Optimized Heatsinks

Abstract: This article presents a systematic power stage design approach for a high-power density air-cooled inverter, which involves the utilization of emerging 1.7 kV silicon carbide (SiC) mosfet bare die engineering samples, heatsinks optimized with genetic algorithm, and built using three-dimensional printing technology and integrated power modules with a novel packaging structure. The developed air-cooled inverter assembly is mainly composed of the SiC mosfet phase leg modules with split high-side and low-side switch submodules, which are attached to two separate heatsinks for increased heat dissipation area and reduced thermal resistance. The heatsink is designed using a co-simulation environment with finite element analysis in COMSOL and genetic algorithm in MATLAB. The primary design procedure, including bare die device characterization, loss calculation, thermal evaluation, and power module development, is elaborated. The proposed design approach is verified and validated through experiments at each stage of development. The experimental results show that the inverter California Energy Commission efficiency is 98.4%, and a power density of 75 W/in3 is achieved with a sufficient junction temperature margin for semiconductor long-term reliability.

The Effect of Type of Voltage (Sinusoidal and Square Waveform) and the Frequency on the Performance of Nonlinear Field-Dependent Conductivity Coatings for Electric Field Control in Power Electronic Modules

Abstract: In this paper, it is shown that nonlinear field-dependent conductivity (FDC) material as a coating layer applied to the high electric field regions in combination with two geometrical techniques known as 1) stacked substrate, and 2) protruding substrate, can result in significant electric field reduction within next-generation high voltage high power density wide bandgap power modules. The studies by using the models developed in COMSOL Multiphysics are carried out under DC, 60 Hz sinusoidal, and square waveform voltages. The influence of frequency is also studied.

Partial Discharge Analysis under High-Frequency, Fast-Rise Square Wave Voltages in Silicone Gel: A Modeling Approach

Abstract: Wide bandgap (WBG) power modules able to tolerate high voltages and currents are the most promising solution to reduce the size and weight of the power management and conversion systems. These systems are envisioned to be widely used in the power grid and the next generation of more (and possibly all) electric aircraft, ships, and vehicles. However, accelerated aging of silicone gel when being exposed to high frequency, fast rise-time voltage pulses that can offset or even be an obstacle for using WBG-based systems. Silicone gel is used to insulate conductor parts in the module and encapsulate the module. It has less electrical insulation strength than the substrate and is susceptible to partial discharges (PDs). PDs often occur in the cavities located close to high electric field regions around the sharp edges of metallization in the gel. The vulnerability of silicone gel to PDs occurred in the cavities under repetitive pulses with a high slew rate investigated in this paper. The objective mentioned above is achieved by developing a Finite-Element Analysis (FEA) PD model for fast, repetitive voltage pulses. This work has been done for the first time to the best of our knowledge. By using the model, the influence of frequency and slew rate on the magnitude and rate of PD events is studied.

Wearable textile power module based on flexible ferroelectret and supercapacitor

Abstract: The rapid development of electronic textiles imposes a challenge on the power supply devices that, unlike conventional rigid batteries, ideally should be compatible with the mechanical properties. It would be highly advantageous if the power supply was integrated within the same textile as the system it is powering. This communication presents for the first time a textile power module that combines a ferroelectret biomechanical energy harvester and solid‐state supercapacitor energy storage fabricated in a single woven cotton textile layer. The textile power module is highly flexible and the fluorinated ethylene propylene (FEP) based ferroelectret can generate electric energy with an instantaneous output voltage of ∼10 V and power density of ∼2.5 µW cm−2. The activated carbon and non‐toxic gel electrolyte based solid‐state supercapacitor demonstrates a capacitance of 5.55 mF cm‐2 and excellent stability after mechanically straining the textile. The textile power module can be charged to around 0.45 V in 3600 s with a compressive cyclical for of 350 N applied at 1 Hz. This work demonstrates a promising combination of materials and devices for achieving a self contained integrated power supply for e‐textile applications.

High Frequency Conducted EMI Investigation on Packaging and Modulation for a SiC-Based High Frequency Converter

Abstract: Silicon carbide (SiC) devices have the advantages of high switching speed and high switching frequency, which can increase the power density, but electromagnetic interference (EMI) will increase along with higher switching frequency thus it can become a challenge for high-frequency converters. In order to clarify the influence factors of EMI noise in SiC converters and find the suppressing method, this paper investigated the conducted EMI in SiC-based high power density electronic systems from two aspects: packaging structures and modulation methods. For packaging investigation, this paper introduced parasitic parameters of power module into EMI analytical model, then defined transfer functions of EMI noise to analyze the influence of parasitic parameters on noise propagation path and further studied the impact of parasitic parameters on noise source by analyzing switching transient and frequency spectrum. Analysis and simulation are carried out based on a hybrid structure SiC power module and discrete SiC devices to verify the analysis. The influence of modulation on EMI is studied by analyzing and comparing two modulations: continuous current modulation (CCM) and triangle current modulation (TCM). To certify the analysis study, two 1.6-kW, 300-kHz switching-frequency synchronous buck converters are designed and tested. One is based on the hybrid packaging power module and the other is based on TO-247 packaged SiC devices, respectively. The result shows that the hybrid packaging module can suppress the common mode (CM) EMI by 10 dB, and has a suppression on differential mode (DM) EMI between 10 and 20 MHz. Moreover, TCM can increase DM EMI in low-frequency range but suppress it in the high-frequency range.