Cascode GaN/SiC: A Wide-Bandgap Heterogenous Power Device for High-Frequency Applications

Silicon carbide (SiC) devices can exhibit simultaneously high electro-thermal conductivity and extremely fast switching. To perform optimal designs showing the benefits of SiC in achieving efficiency, size, weight, and cost objectives for electric converters design, it is necessary to establish better models for calculating device losses and an efficient thermal model that can be calibrated to consider the nuances of measurement based thermal equivalent circuits. This work's outputs can be used in a power converter multi-objective optimization process or real-time temperature prediction of drives to improve reliability and maximize performance.The proposed modified loss calculation and thermal model demonstrate the SiC power module's advantages to reduce peak junction temperature and power cycling effects. A detailed power loss calculation and thermal model is developed and tested on a 480 V, 186 A, 150 HP variable frequency drive (VFD) with SiC modules. A comparison between the SiC module and an equivalent rated Si module demonstrates the reduction in power cycling effects, particularly at low-speed operation. Infrared (IR) imaging results and analytical explanations of the phenomenon is provided. Power cycle tests show that higher thermal conductivity is not the only reason contributing to the lower temperature ripple in low-speed operation.

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“…The instantaneous junction temperatures T D and T M can be found from (1). Equation ( 1) is based on Fig.…”

Section: Derivation Of Thermal Modelmentioning

confidence: 99%

“…Various aspects of SiC-MOSFETs have been discussed comparing with IGBT, such as reducing the converter size and improving power density [1] through increased switching frequency and efficiency. However, the full benefits of SiC MOSFETs to motor drives have not, to date, been adequately identified in the literature.…”

Section: Introductionmentioning

confidence: 99%

Thermal Characterization of SiC Modules for Variable Frequency Drives

Karami

Tallam

et al. 2021

IEEE Open J. Power Electron.

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“…2 Gallium nitride (GaN) devices have also been reported as prominent solutions for low-voltage and high-frequency applications rated at megahertz. 3 However, it is worth mentioning that wide-bandgap materials such as SiC and GaN still present higher manufacturing cost when compared with pure Si.…”

Section: Introductionmentioning

confidence: 99%

“…Besides, it is expected that SiC power metal‐oxide semiconductor field‐effect transistors (MOSFETs) are supposed to replace Si insulated gate bipolar transistors (IGBTs) in medium‐voltage applications in a near future 2 . Gallium nitride (GaN) devices have also been reported as prominent solutions for low‐voltage and high‐frequency applications rated at megahertz 3 . However, it is worth mentioning that wide‐bandgap materials such as SiC and GaN still present higher manufacturing cost when compared with pure Si.…”

Section: Introductionmentioning

confidence: 99%

In‐depth analysis of an RCD snubber applied to a DC‐DC boost converter

Vaz

Tofoli

2020

Circuit Theory & Apps

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Resistor-capacitor-diode (RCD) snubbers are traditionally used in practice aiming to maintain the stresses on semiconductors within safe operating limits. However, a serious drawback is the power lost in the resistor, which may affect the converter efficiency significantly. In this context, this work proposes a detailed procedure for the accurate design of an RCD snubber based on two additional key parameters that are not considered in typical guidelines provided in didactic books, that is, the forward recovery time of the main diode and the inductor current ripple. The impact of the maximum additional voltage spike on the switch is first assessed considering that it influences both the power dissipated in the snubber resistor and the current stresses on all semiconductors. A systematic optimization of the design is presented later on, considering that proper tradeoffs can be made among the type of main diode used in the converter, the maximum voltage spike on the switch, and the inductor current ripple as demonstrated mathematically. A dc-dc boost converter operating in continuous conduction mode (CCM) is thoroughly analyzed so that is possible to derive a consistent methodology comprising all power stage elements. This study intends to shed new light on an old research topic, as well to investigate the snubber impact on the converter operation and overall performance. The effectiveness of the proposed approach is demonstrated experimentally employing a laboratory prototype rated at 200 W. The results clearly show that is possible to optimize the design as desired, with good overall performance over a wide load range considering all aforementioned aspects.

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“…De acordo com Xu et al (2020), semicondutores GaN são frequentemente utilizados em aplicações de baixas tensões e altas frequências de chaveamento devido a baixas capacitâncias de entrada e saída, enquanto semicondutores SiC são mais utilizados em aplicações de mais alta tensão e menores frequências de chaveamento, devido a suas maiores tensões de bloqueio e maiores cargas de gatilho.…”

Section: Introductionunclassified

Análise de Perdas em Semicondutores SIC e GaN Utilizados em Conversor DAB Multinível Aplicado em Carregador de Veículo Elétrico

Oliveira

Barreto

2020

Anais Do Congresso Brasileiro De Automática 2020

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Neste trabalho faz-se a comparação, por simulação, entre as perdas por condução e comutação geradas em semicondutores de banda larga (SiC e GaN) aplicados em um conversor DAB (Dual Active Bridge) multinível monofásico projetado para aplicação no estágio CC-CC de protótipo de um carregador de veículo elétrico. As simulações foram realizadas por meio do software PSIM, sendo consideradas apenas as perdas em regime permanente. A topologia do conversor aplicado é caracterizada por um conversor full-bridge no primário e um braço NPC (Neutral Point Clamped) de três níveis no secundário. É utilizada a modulação Phase-Shifted Modulation (PSM), com possibilidade de variação na razão cíclica do primário e secundário e variação do ângulo entre as tensões na ponte completa do primário e no braço NPC do secundário. O conversor é simulado em dois pontos de operação, 4,8 kW e 833,3 W, com 600 V e 250 V na porta 2, com frequência de comutação de 500 kHz. Maior eficiência é obtida na simulação com aplicação de 600 V na porta 2 do conversor e com a utilização de chaves GaN, obtendo-se uma redução de 2,037% de eficiência em comparação à 2,705% com aplicação das chaves SiC.

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Cascode GaN/SiC: A Wide-Bandgap Heterogenous Power Device for High-Frequency Applications

Cited by 49 publications

References 26 publications

Thermal Characterization of SiC Modules for Variable Frequency Drives

Thermal Characterization of SiC Modules for Variable Frequency Drives

In‐depth analysis of an RCD snubber applied to a DC‐DC boost converter

Análise de Perdas em Semicondutores SIC e GaN Utilizados em Conversor DAB Multinível Aplicado em Carregador de Veículo Elétrico

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