Christina DiMarino

High-temperature characterization and comparison of 1.2 kV SiC power MOSFETs

The aim of this work is to characterize and compare the high-temperature performances of the latest generation 1.2 kV Silicon Carbide (SiC) MOSFETs from three well-known manufacturers: Cree, ROHM, and GE. A complete static characterization is performed from 25 °C to 200 °C, including threshold voltage, specific on-resistance, leakage current, junction capacitances, and internal gate resistance. The dynamic performance of each device is evaluated through double-pulse tests conducted from 25 °C to 200 °C. From these double-pulse tests, the switching losses are computed.

High-temperature silicon carbide: characterization of state-of-the-art silicon carbide power transistors

For several decades, silicon (Si) has been the primary semiconductor choice for power electronic devices. During this time, the development and fabrication of Si devices has been optimized, which, in combination with the large abundance of material, has resulted in high manufacturing capability and extremely low costs. However, Si is approaching its limits in power conversion [1], [2]; improved efficiency, reduced size, and lower overall system cost can now be achieved by replacing Si devices with wide-bandgap (WBG) semiconductors [1]?[3].

Characterization and comparison of 1.2 kV SiC power semiconductor devices

This paper seeks to provide insight into state-of-the-art 1.2 kV Silicon Carbide (SiC) power semiconductor devices, including the MOSFET, BJT, SJT, and normally-on and normally-off JFET. Both commercial and sample devices from the semiconductor industrys well-known manufacturers; namely Cree, GE, ROHM, Fairchild, GeneSiC, Infineon, and SemiSouth, are evaluated in this study. To carry out this work, static characterization of each device is performed under increasing temperatures (25-200 °C). Dynamic characterization is also conducted through double-pulse tests. Accordingly, the paper describes the experimental setup used and the different measurements conducted, which comprise: threshold voltage, current gain, specific on-resistance, and the turn on and turn off switching energies. For the latter, the driving method used for each device is described in detail. Furthermore, for the devices that require on-state dc currents, driver losses are also taken into consideration. Key trends and observations are reported in an unbiased manner throughout the paper and summarized in the conclusion.

Modular scalable medium-voltage impedance measurement unit using 10 kV SiC MOSFET PEBBs

This paper describes the design and implementation of the first functional medium-voltage impedance measurement unit capable of characterizing in-situ source and load impedances of dc- and ac-networks (4160 V ac, 6000 V dc, 300 A, 2.2 MVA) in the frequency range from 0.1 Hz-1 kHz. It comprises three power electronics building blocks, each built using SiC MOSFET H-bridges, features great reconfigurability, and allows both series and shunt perturbation injection in order to achieve accurate impedance characterization of the Navys shipboard power systems. With extraordinary advantages featured by the power electronics building block modular concept, and unconventional power processing benefits offered by SiC semiconductors, development of the unit shown in this paper unquestionably enables both, improvement of the existing, and design of the future, stable and reliable electrical Navy shipboard platforms with advanced electrical energy generation and modern distribution architecture.

Gate driver design for 1.7kV SiC MOSFET module with Rogowski current sensor for shortcircuit protection

This paper shows a gate driver design for 1.7 kV SiC MOSFET module as well a Rogowski-coil based current sensor for effective short circuit protection. The design begins with the power architecture selection for better common-mode noise immunity as the driver is subjected to high dv/dt due to the very high switching speed of the SiC MOSFET modules. The selection of the most appropriate gate driver IC is made to ensure the best performance and full functionalities of the driver, followed by the circuitry designs of paralleled external current booster, Soft Turn-Off, and Miller Clamp. In addition to desaturation, a high bandwidth PCB-based Rogowski current sensor is proposed to serve as a more effective method for the short circuit protection for the high-cost SiC MOSFET modules.

Test environment for a novel medium voltage impedance measurement unit

Small signal stability of converter-based power distribution systems can be evaluated with the help of impedance characterization, which provides a means to predict the effect of interactions. These techniques have great Navy relevance as future ships may be based on medium voltage distribution networks of interconnected feedback-controlled switching power converters. These networks will be subject to converter interactions and potential instability. This paper summarizes work done to prepare full scale testing of the first medium voltage, MW scale impedance measurement unit which was recently developed using SiC technology.

Medium-Voltage Impedance Measurement Unit for Assessing the System Stability of Electric Ships

This paper describes the design and implementation of the first medium-voltage impedance measurement unit (IMU) capable of characterizing in situ source and load impedances of dc and ac networks (4160 V ac, 6000 V dc, 300 A, 2.2 MVA) in the frequency range of 0.1 Hz–1 kHz. The IMU comprises three power electronics building blocks (PEBBs), each built using 10-kV SiC MOSFET H-bridges. The modularity of the PEBBs allows for both series and shunt perturbation injection modes to be realized, as both injection modes are needed to accurately predict the stability of the electrical system. The effectiveness of the proposed impedance identification approach is experimentally verified on medium voltage power grid.

Design of a modular and scalable small-signal dq impedance measurement unit for grid applications utilizing 10 kV SiC MOSFETs

Not only that tremendously increased employment of power electronics in the energy production, transfer, and consumption enables a sustainable future, it undoubtedly brings major energy savings and stimulating improvements in peoples quality of life. But not for “free”. This trend is considerably changing the nature of the sources and the loads in the electrical grid, altering their mild properties, and inflicting low-frequency dynamic interactions that did not exist in the conventional power system before. To be able to understand, analyze, design, and dynamically control the existing and future power systems, it is unarguably required to develop concepts and tools that offer better insights into the system-level behavior and stability of the grid. This paper presents the impedance measurement unit that can undoubtedly address some of the listed needs by characterizing in-situ source and load impedances of the sub-transmission medium-voltage networks (up to 69 kV). In addition to describing the design, this paper shows the experimental results obtained with the impedance measurement unit prototype built for 4.16 kV, capable of characterizing medium-voltage distribution systems of up to 2.2 MVA.

High-Temperature Characterization and Comparison of 1.2 kV SiC Power Semiconductor Devices

Focused on high-temperature (200 °C) operation, this paper seeks to provide insight into state-of-the-art 1.2 kV Silicon Carbide (SiC) power semiconductor devices; namely the MOSFET, BJT, SJT, and normally-off JFET. This is accomplished by characterizing and comparing the latest generation of these wide bandgap devices from various manufacturers (Cree, GE, Rohm, Fairchild, GeneSiC, and SemiSouth). To carry out this study, the static and dynamic characterization of each device is performed under increasing temperatures (25–200 °C). Accordingly, this paper describes the experimental setup used and the different measurements conducted, which include: threshold voltage, current gain, specific on-resistance, and the turn-on and turn-off switching energies of the devices. The driving method used for each device is also detailed. Key trends and observations are reported in an unbiased manner throughout the paper and summarized in the conclusion.

Static and dynamic characterization of a GaN-on-GaN 600 V, 2 a vertical transistor

Vertical GaN power semiconductors promise higher power with faster switching speeds but the development of this technology has been slowed. This is due to the expense and lack of familiarity with GaN substrates. This paper will detail the functionality of HRLs cutting-edge vertical GaN transistor which is mounted onto a specially made PCB and tested. The testing consists of a static characterization which shows a breakdown voltage of 600 V, as well as the transfer characteristics, output characteristics, and the on-state resistance with respect to current. The device is then switched at various voltages and currents with voltage switching speeds up to 97 V/ns. The device is successfully switched up to 450 V under a 2 A load current.