As power semiconductor devices are the key components of hybrid DC circuit breakers (HCBs), how to select suitable devices is critical for the whole HCB design. First, this paper compared the general characteristics of press pack insulated gate bipolar transistor (IGBT), injection-enhanced gate transistor (IEGT), and integrated gate commutated thyristor (IGCT). Then working conditions of devices were analyzed from the perspective of HCBs. According to these, vital features of devices including maximum turn-off current, on-state voltage, conduction ability, and robustness of power semiconductor devices were carefully analyzed and compared. Related experiments were implemented to compare maximum turn-off capability, and the 4.5 kV/3 kA IGBT/IEGT was able to turn off 19 and 22 kA respectively after 5-ms current conduction. Analysis and experiments indicated that IGCT was suitable for natural commutation low-voltage and low-current hybrid circuit breakers, due to its low on-state voltage and huge surge current conduction ability. Comparatively, IGBT and IEGT were more suitable for very high current interruption, and IEGT was the superior selection among available commercial devices. However, the interference should be considered in applications.

Analysis and Experiments for IGBT, IEGT, and IGCT in Hybrid DC Circuit Breaker

Medium-voltage (MV) silicon carbide (SiC) devices have opened up new areas of applications which were previously dominated by silicon-based IGBTs From the perspective of a power converter design, the development of MV SiC devices eliminates the need for series connected architectures, control of multilevel converter topologies which are necessary for MV applications, and the inherent reliability issues associated with it However, when SiC devices are used in these applications, they are exposed to a high peak stress (5–10 kV) and a very high $dv/dt$ (10–100 kV/ $\mu$ s) Using these devices calls for a gate driver with a dc–dc isolation stage that has ultralow coupling capacitance in addition to be able to withstand the high isolation voltage This paper presents a new MV gate driver design to address these issues while maintaining a minimal footprint for the gate driver An MV isolation transformer is designed with a low interwinding capacitance, while maintaining the clearance, creepage, as well as insulation standards A dc isolation test has been performed to validate the integrity of the insulating material The key features include low input common mode current, and a short-circuit protection scheme specifically designed for 10 kV SiC mosfet s The performance of the gate driver is evaluated using double pulse tests and continuous tests Experimental results validate the advantages of the gate driver and its application for MV SiC devices exhibiting very high $dv/dt$  The proposed gate driver concept is aimed at providing an efficient and reliable method to drive MV SiC devices

Design Considerations and Development of an Innovative Gate Driver for Medium-Voltage Power Devices With High $dv/dt$

Driving solutions for power semiconductor devices are experiencing new challenges since the emerging wide bandgap power devices, such as silicon carbide (SiC), with superior performance become commercially available. Generally, high switching speed is desired due to the lower switching loss, yet high $dv/dt$ and $di/dt$ can result in elevated electromagnetic interference (EMI) emission, false-triggering, and other detrimental effects during switching transients. Active gate drivers (AGDs) have been proposed to balance the switching losses and the switching speed of each switching transient. The review of the in-existence AGD methodologies for SiC devices has not been reported yet. This review starts with the essence of the slew rate control and its significance. Then, a comprehensive review categorizing the state-of-the-art AGD methodologies is presented. It is followed by a summary of the AGDs control and timing strategies. In this work, using AGD to reduce the EMI noise of a 10-kV SiC MOSFET system is reported. This work also highlights other capabilities of AGDs, including reliability enhancement of power devices and rebalancing the mismatched electrical parameters of parallel- and series-connected devices. These application scenarios of AGDs are validated via simulation and experimental results.

A Review of Switching Slew Rate Control for Silicon Carbide Devices Using Active Gate Drivers

High di/dt and dv/dt of SiC MOSFET cause a considerable amount of overshoot in device voltage and current during switching transients in the presence of inverter layout parasitic inductance and load parasitic capacitance. The excessive overshoots in device voltage and current cause failure of the device. Moreover, these uncontrolled overshoots increase the switching loss in the inverter. It is difficult to reduce parasitic inductance beyond a certain point. This paper proposes an active gate driving technique, which allows inverter to operate with moderate amount of layout parasitic inductance and load parasitic capacitance. The proposed technique dramatically reduces switching loss of the SiC MOSFET with the help of existing parasitic elements. The proposed switching loss reduction technique is termed as quasi zero switching . The developed active gate driver has been tested in a double pulse test setup and a 10 kW two-level voltage source inverter driving an induction motor.

Parasitic Inductance and Capacitance-Assisted Active Gate Driving Technique to Minimize Switching Loss of SiC MOSFET

Along with the increasing maturity for the material and process of the wide bandgap semiconductor silicon carbide (SiC), the insulated gate bipolar transistor (IGBT) representing the top level of power devices could be fabricated by SiC successfully This article presents a thorough review of development of SiC IGBT in the past 30 years The progresses of models, structure design, and performance in SiC IGBT are summarized The challenges resulting from fabrication process and switching characteristics are discussed and analyzed in detail The experimental results and existing problems in SiC IGBT-based applications are summarized in the end

A Review of SiC IGBT: Models, Fabrications, Characteristics, and Applications

This paper presents an Intelligent Medium-voltage Gate Driver (IMGD) for 15kV SiC IGBT and 10kV SiC MOSFET devices. The high voltage-magnitude and high dv/dt(> 30kV/µs) of these MV SiC devices, pose design challenge in form of isolation and EMI. This problem is solved by development of a < 1pF isolation capacitance power-supply. But due to applied high stress, smaller short-circuit withstand time and the criticality of the application, these devices need to be monitored, well protected, active gate-driven and safely shut-down. This paper presents an EMI hardened IMGD built around a CPLD, sensing and optical interfacing unit. It provides advanced gate-driving, added protection and optically isolated state-monitoring features. The device operating conditions such as module temperature and Vds(on) can be data-logged. They can be used for diagnosis/prognosis purposes such as to predict failure and safely shut-down the system. This paper describes the functionality of different building blocks. The 15kV SiC IGBT has higher second switching slope above its punch-through level which is moderated without increasing losses by using digitally controlled active gate-driving. The shoot-through protection time can be reduced below withstand time by advanced gate driving. Soft turn-on and over-current triggered gate-voltage reduction helps reducing blanking time and quick turn-off reduces the protection response time. In this paper, the IMGD is high side tested at 5kV with device state monitoring on. The active gate-driving is tested at 6kV.

Akshat Yadav

Papers

A MV intelligent gate driver for 15kV SiC IGBT and 10kV SiC MOSFET