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In battery applications, a DC contactor is usually used in series with a current-limiting fuse to clear respectively low and high fault currents. However, classic protection devices have operation limits due to maximum and minimum breaking capacities of each device. In this paper, the self-triggered pyrofuse (Xp-ST) based on conventional fuses and pyroswitch is introduced. This protection solution can be installed as a standalone device. The Xp-ST has an advantage of selectivity. The selectivity is more easily tunable by using a low voltage fuse for the trigger fuse. As an experimental result under the DC condition of 1000 V with 15.6 kA fault current, the proposed self-triggered pyrofuse cleared the fault in 1.5 ms and has limited the current to 7 kA. Furthermore, reliability of the Xp-ST is validated by simulations and aging tests for cycling performances. The cycling performances of the Xp-ST can satisfy the requirements from the EV application with up to 1000 V.

This paper presents the performances expected by SiC MOSFETs for high temperature applications. A complete static and dynamic electrical characterization of SiC MOSFETs have been tested under varying temperature from 25°C to 250°C using suitable packaging materials. To go further, aging tests have been performed to evaluate lifetime of SiC MOSFET under switching condition up to 300°C.

9 pages; International audience; Silicon carbide (SiC) JFETs are attractive devices, but they might suffer from thermal instability. An analysis shows that two mechanisms could lead to their failure: the loss of gate control, which can easily be avoided, and a thermal runaway caused by the conduction losses. Destructive experimental tests performed on a dedicated system show that the latter mechanism is more severe than initially expected. A low thermal resistance and gate driver equipped with protections systems are thus required to ensure safe operation of the SiC JFETs.

International audience; Silicon Carbide (SiC) Junction-Field Effect Transistors (JFETs) are attractive devices for power electronics. Their high temperature capability should allow them to operate with a reduced cooling system. However, experiments described in this paper conclude to the existence of runaway conditions in which these transistors will reach destructive temperatures.

Fuses and Circuit Breakers play an important safety role in electrical transportation systems. Challenging new applications, especially in DC grids, have brought conventional current limiting devices to their limits. Indeed, mechanical circuit breakers may be too slow to open for networks with large DC fault currents. On the other hand, fuses may be too slow to open with very low DC fault currents. For AC applications, the natural zero crossing will help clear fault currents. In DC applications, the no natural zero crossing makes clearing faults by conventional current limiting technologies difficult. This paper presents a new solution to protect DC transportation using a fuse and pyroswitch hybrid system. This will apply to PV generation, energy storage, Electric Vehicles.

Fuses and Circuit Breakers play an important safety role in electrical transportation systems. Challenging new applications, especially in DC, have brought conventional current limiting devices to their limits. Indeed, mechanical circuit breakers may be too slow to open for networks with large DC fault currents. On the other hand, fuses may be too slow to open with very low DC fault currents. For AC applications, the natural zero crossing will help clear fault currents. In DC applications, the no natural zero crossing makes clearing faults by conventional current limiting technologies difficult. This paper presents a new solution to protect DC transportation using a fuse and pyroswitch hybrid system. This will apply to PV generation, energy storage, Electric Vehicles.

Fuses and Circuit Breakers play an important safety role in electrical distribution systems. New challenging applications, especially in DC applications, have brought conventional current limiting devices to their limits. Indeed, mechanical circuit breakers may be too slow to open for novel DC networks with large DC fault current. As well, fuses may be too slow to open for new DC networks with very low DC fault current. For AC applications, the natural zero crossing will help clear fault current. In DC applications, the no natural crossing is challenging fault clearing by conventional current limiting technologies. This paper presents the latest development in current limiting devices as well as new solutions using hybrid and/or full static current limiting devices. This will apply to PV generation, energy storage, DC grid.

International audience; Under realistic switching conditions, SiC MOSFETs reliability issues remain as a challenge that requires further investigation. In this letter, a specific aging test has been developed to monitor and characterize the electrical parameters of the SiC MOSFET. This allows estimations of the health state and predictions of the remaining lifetime prior to its failure. The gate leakage current seems to be a relevant runaway parameter just before failure. This leakage indicates deterioration of the gate structure. This hypothesis has been validated through analysis of scanning electron microscopy pictures, with a focused ion beam cut showing cracks within the polysilicon.

8 pages; International audience; Although they can operate at elevated junction temperature, silicon carbide power devices can in some cases fail, even at low ambient temperature. This destruction mechanism, called the thermal run-away, is described in the paper. Then, the sensitivity of normally-on SiC JFETs (SiCED) to this mechanism is evaluated using a model based on experimental measurements performed over a wide temperature range (from -50°C to 300°C). It is shown that above a certain current level, run-away can occur. An experimental test bench is used to validate the modelling and explore the safe-operating area of these devices. The measurements confirm the sensitivity of the device to thermal run-away. Mitigation techniques are discussed.

International audience; SiC JFETs are experimentally tested to verify their robustness against Lightning induced strokes. The experimental set-up is fully described. A lightning surge generator is built and a SiC JFET is stressed. The full thermal response of the SiC JFET internal temperature is obtained from a specific temperature estimation technique at different time steps during the surge test. This short time thermal response is compared and validated by a conventional 1-D thermal model. This work shows that for a moderate lightning stroke, according to standards [1], the JFET temperature rise is less than 60°C, which is acceptable in most circumstances.

International audience; The aim of this paper is to investigate the ability of a vertical structure JFET to operate in an inverter leg without any internal or external diode. The JFET is characterized to show the reverse conduction capability while the gate-to-source voltage is lower than the threshold voltage. An inverter leg is tested at 540 V /5 A and 50 kHz. A specific test board is implemented to assess a safe operation over a period of time.