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  • 1.
    Colmenares, Juan
    et al.
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Peftitsis, Dimosthenis
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Rabkowski, Jacek
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Nee, Hans-Peter
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Dual-function gate driver for a power module with SiC junction field transistors2013Inngår i: 2013 IEEE ECCE Asia Downunder - 5th IEEE Annual International Energy Conversion Congress and Exhibition, IEEE ECCE Asia 2013, IEEE , 2013, s. 245-250Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Driving a high-power module which is populated with several parallel-connected silicon carbide junction field-effect transistor chips must be done appropriately. Parasitic elements may give rise to oscillations during turn-on and turn-off. Fast and oscillation-free switching performance is desired in order to achieve a high efficiency. The key-issue in order to fulfill these two requirements is the design of a sophisticated gate driver. This paper proposes a dual-function gate-drive unit which is able to switch the module with an acceptable speed without letting the current and voltage suffer from significant oscillations. It is experimentally shown that turn-on and turn-off switching times of approximately 140 ns and 165 ns respectively can be reached, while the magnitude of the current oscillations is kept at an acceptable level. Moreover, using the proposed gate driver an efficiency of approximately 99.6% is expected for a three-phase converter rated at 125 kVA and having a switching frequency of 2 kHz.

  • 2.
    Colmenares, Juan
    et al.
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Peftitsis, Dimosthenis
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Rabkowski, Jacek
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling. Warsaw University of Technology, Poland .
    Sadik, Diane-Perle
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Nee, Hans-Peter
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Dual-Function Gate Driver for a Power Module With SiC Junction Field-Effect Transistors2014Inngår i: IEEE transactions on power electronics, ISSN 0885-8993, E-ISSN 1941-0107, Vol. 29, nr 5, s. 2367-2379Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Silicon Carbide high-power modules populated with several parallel-connected junction field-effect transistors must be driven properly. Parasitic elements could act as drawbacks in order to achieve fast and oscillation-free switching performance, which are the main goals. These two requirements are related closely to the design of the gate-drive unit, and they must be kept under certain limits when high efficiencies are targeted. This paper deeply investigates several versions of gate-drive units and proposes a dual-function gate-drive unit which is able to switch the module with an acceptable speed without letting the current suffer from significant oscillations. It is experimentally shown that turn-on and turn-off switching times of approximately 130 and 185 ns respectively can be reached, while the magnitude of the current oscillations is kept at an adequate level. Moreover, using the proposed gate driver an efficiency of approximately 99.7% is expected for a three-phase converter rated at 125 kVA and having a switching frequency of 2 kHz.

  • 3.
    Colmenares, Juan
    et al.
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Peftitsis, Dimosthenis
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Tolstoy, Georg
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Sadik, Diane-Perle
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Nee, Hans-Peter
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Rabkowski, Jacek
    High-efficiency three-phase inverter with SiC MOSFET power modules for motor-drive applications2014Konferansepaper (Fagfellevurdert)
    Abstract [en]

    This paper presents the design process of a 312 kVA three-phase silicon carbide inverter using ten parallel-connected metal-oxide-semiconductor field-effect-transistor power modules in each phase-leg. The design processes of the gate-drive circuits with short-circuit protection and the power circuit layout are also presented. Electrical measurements in order to evaluate the performance of the gate-drive circuits have been performed using a double-pulse setup. Experimental results showing the electrical performance during steady-state operation of the power converter are also shown. Taking into account measured data, an efficiency of approximately 99.3% at the rated power has been estimated for the inverter.

  • 4.
    Kostov, Konstantin
    et al.
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Rabkowski, Jacek
    Warsaw University of Technology, Poland .
    Nee, Hans-Peter
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Conducted EMI from SiC BJT boost converter and its dependence on the output voltage, current, and heatsink connection2013Inngår i: 2013 IEEE ECCE Asia Downunder - 5th IEEE Annual International Energy Conversion Congress and Exhibition, IEEE ECCE Asia 2013, IEEE , 2013, s. 1125-1130Konferansepaper (Fagfellevurdert)
    Abstract [en]

    In comparison to their Silicon (Si) counterparts, the Silicon Carbide (SiC) power transistors have lower on-state resistance and higher switching speed, power and temperature ratings. These advantages make it possible to build smaller, lighter and more efficient power converters. Unfortunately, all these benefits come at the price of higher conducted and radiated electromagnetic interference (EMI). This paper investigates the conducted disturbances from a 6 kW boost converter with SiC bipolar junction transistors (BJTs). The results show that the conducted emissions at the input of the converter are approximately proportional to the output voltage, but almost independent on the load current. The effect of the heatsink on the conducted EMI was studied as well. It was found that using separate heatsinks for the diode and the BJT did not affect the level of conducted emissions significantly, but the way of connecting the heatsink does. A floating heatsink is bad from an EMI point of view, and in many cases it may not be allowed for safety reasons. When the heatsink is grounded, alone or together with the negative terminal, the common-mode noise increases the EMI measured at the positive line and decreases the EMI on the negative line. However, this appears only in the lower frequency range. At higher frequencies, connecting the heatsink in any way is better than letting it float. Therefore, the best option is to connect the heatsink to the negative line of the boost converter, and if grounding is required, it may be grounded as well. This may not be possible in systems where the negative voltage bus is at non-zero potential.

  • 5.
    Lim, Jang-Kwon
    et al.
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Peftitsis, Dimosthenis
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Rabkowski, Jacek
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Bakowski, Mietek
    Nee, Hans-Peter
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Analysis and Experimental Verification of the Influence of Fabrication Process Tolerances and Circuit Parasitics on Transient Current Sharing of Parallel-Connected SiC JFETs2014Inngår i: IEEE transactions on power electronics, ISSN 0885-8993, E-ISSN 1941-0107, Vol. 29, nr 5, s. 2180-2191Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Operation of parallel-connected 4H-SiC vertical junction field effect transistors (VJFETs) from SemiSouth is modeled using numerical simulations and experimentally verified. The unbalanced current waveforms of parallel-connected VJFETs are investigated with respect to the spread in the critical parameters of the device structure and to the influence of the parasitic inductances in the measurement circuit. The device structures are reconstructed based on scanning electron microscopy (SEM) analysis, electrical characterization, and device simulations. The doping concentration and profile depth of a p-grid formed by angular implantation are studied as main contributors that influence the variation of the on-state characteristics, and the threshold voltage of the experimental devices. It has been shown elsewhere that similar differences in p-grid also lead to differences in gate-source breakdown voltage. The switching performance of the parallel-connected JFETs is measured using single and double gate drivers in a double-pulse test and compared with simulations. The switched current and voltage waveforms from measurements are reproduced in simulation by introducing the parasitics. From the analysis, it is found that reasonable differences in doping levels and profiles of the p-grid give rise to significant differences in device parameters. However, even with these parameter differences and circuit asymmetries, it is possible to successfully operate parallel-connected VJFETs of this type.

  • 6.
    Lim, Jang-Kwon
    et al.
    Acreo.
    Peftitsis, Dimosthenis
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Rabkowski, Jacek
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Bakowski, Mietek
    Acreo.
    Nee, Hans-Peter
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Modeling of the impact of parameter spread on the switching performance of parallel-connected SiC VJFETs2013Inngår i: Materials Science Forum, Trans Tech Publications Inc., 2013, s. 1098-1102Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Operation of parallel-connected 4H-SiC VJFETs from SemiSouth was measured and modeled using numerical simulations. The unbalanced current waveforms in parallel-connected VJFETs were related to spread in the critical parameters of the device structure and to the influence of the parasitic inductances in the measurement circuit. The physical device structure was reconstructed based on SEM analysis, electrical characterization, and device simulations. The two hypothetical critical design parameters that were studied with respect to spread were the p-gate doping profile (Case 1) and the emitter doping (Case 2). Variation in both parameters could be related to variation in the emitter breakdown voltage, the on-state characteristics, and the threshold voltage of the experimental devices. The switching performance of the parallel-connected JFETs was measured using a single gate driver in a double pulse test and compared with simulations. In both investigated cases a very good agreement between measurements and simulations was obtained. The modeling of the transient performance relies on good reproduction of transfer characteristics and circuit parasitics.

  • 7.
    Lim, Jang-Kwon
    et al.
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling. Acreo Swedish ICT AB, Sweden.
    Reshanov, Sergey
    Kaplan, W.
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Zhang, A.
    Hjort, T.
    Schöner, A.
    Bakowski, M.
    Nee, Hans-Peter
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Temperature-Dependent Characteristics of 4H-SiC Buried Grid JBS Diodes2015Inngår i: Materials Science Forum, ISSN 0255-5476, E-ISSN 1662-9752, Vol. 821/823, s. 600-603Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    4H-SiC Schottky Barrier Diodes (SBD) have been developed using p-type buried grids (BGs) formed by Al implantation. In order to reduce on-state resistance and improve forward conduction, the doping concentration of the channel region between the buried grids was increased. The fabricated diodes were encapsulated with TO-254 packages and electrically evaluated. Experimental forward and reverse characteristics were measured in the temperature range from 25 °C to 250 °C. On bare die level, the forward voltage drop was reduced from 5.36 V to 3.90 V at 20 A as the channel doping concentration was increased, which introduced a low channel resistance. By the encapsulation in TO-254 package, the forward voltage drop was decreased approximately 10% due to a lower contact resistance. The on-state resistance of the identical device measured on bare die and in TO-254 package increased with increasing temperature due to the decreased electron mobility in the drift region resulting in higher resistance. The incremental contact resistances of the bare dies were larger than in the packaged devices. One key issue associated with conventional Junction Barrier Schottky (JBS) diodes is a high leakage current at high temperature operation over 200 °C. The developed Buried Grid JBS (BG JBS) diode has significantly reduced leakage current due to a better field shielding at the Schottky contact. The leakage current of the packaged BG JBS diodes is compared to pure SBD and commercial JBS diodes.

  • 8.
    Lim, Jang-Kwon
    et al.
    KTH, Skolan för elektro- och systemteknik (EES), Elektriska maskiner och effektelektronik (stängd 20110930).
    Tolstoy, Georg
    KTH, Skolan för elektro- och systemteknik (EES), Elektriska maskiner och effektelektronik (stängd 20110930).
    Peftitsis, Dimosthenis
    KTH, Skolan för elektro- och systemteknik (EES), Elektriska maskiner och effektelektronik (stängd 20110930).
    Rabkowski, Jacek
    KTH, Skolan för elektro- och systemteknik (EES), Elektriska maskiner och effektelektronik (stängd 20110930).
    Bakowski, Mietek
    Acreo, Kista.
    Nee, Hans-Peter
    KTH, Skolan för elektro- och systemteknik (EES), Elektriska maskiner och effektelektronik (stängd 20110930).
    Comparison of total losses of 1.2 kV SiC JFET and BJT in DC-DC converter including gate driver2011Inngår i: Materials Science Forum, ISSN 0255-5476, E-ISSN 1662-9752, Vol. 679/680, s. 649-652Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The 1.2 kV SiC JFET and BJT devices have been investigated and compared with respect to total losses including the gate driver losses in a DC-DC converter configuration. The buried grid, Normally-on JFET devices with threshold voltage of -50 V and -10V are compared to BJT devices with ideal semiconductor and passivating insulator interface and an interface with surface recombination velocity of 4.5·104 cm/s yielding agreement to the reported experimental current gain values. The conduction losses of both types of devices are independent of the switching frequency while the switching losses are proportional to the switching frequency. The driver losses are proportional to the switching frequency in the JFET case but to a large extent independent of the switching frequency in the BJT case. The passivation of the emitter junction modeled here by surface recombination velocity has a significant impact on conduction losses and gate driver losses in the investigated BJT devices.

  • 9.
    Nee, Hans-Peter
    et al.
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Kolar, Johann W.
    Friedrichs, Peter
    Rabkowski, Jacek
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Special Issue on Wide Bandgap Power Devices and Their Applications, 20142014Inngår i: IEEE transactions on power electronics, ISSN 0885-8993, E-ISSN 1941-0107, Vol. 29, nr 5, s. 2153-2154Artikkel i tidsskrift (Fagfellevurdert)
  • 10.
    Nee, Hans-Peter
    et al.
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Rabkowski, Jacek
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Peftitsis, Dimosthenis
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Tolstoy, Georg
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Colmenares, Juan
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Sadik, Diane
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Bakowski, Mietek
    Acreo Swedish ICT AB, Sweden.
    Lim, Jang-Kwon
    Acreo AB, Kista.
    Antonopoulos, Antonios
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Ängquist, Lennart
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Zdanowski, Mariusz
    Warsaw University of Technology.
    High-Efficiency Power Conversion Using Silicon Carbide Power Electronics2013Inngår i: Proc. of International Conference on silicon carbide and related materials (ICSCRM) 2013, Miyazaki, Japan, Sept. 29–Oct. 4, 2013, Trans Tech Publications Inc., 2013, s. 1083-1088Konferansepaper (Fagfellevurdert)
    Abstract [en]

    The message of this paper is that the silicon carbide power transistors of today are good enough to design converters with efficiencies and switching speeds beyond comparison with corresponding technology in silicon. This is the time to act. Only in the highest power range the devices are missing. Another important step towards high powers is to find new solutions for multi-chip circuit designs that are adapted to the high possible switching speeds of unipolar silicon carbide power transistors.

  • 11.
    Peftitsis, Dimosthenis
    et al.
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Baburske, R.
    Rabkowski, Jacek
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Lutz, J.
    Tolstoy, Georg
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Nee, Hans-Peter
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Challenges regarding parallel connection of SiC JFETs2013Inngår i: IEEE transactions on power electronics, ISSN 0885-8993, E-ISSN 1941-0107, Vol. 28, nr 3, s. 1449-1463Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    State-of-the-art silicon carbide switches have current ratings that are not sufficiently high to be used in high-power converters. It is, therefore, necessary to connect several switches in parallel in order to reach sufficient current capabilities. An investigation of parallel-connected normally ON silicon carbide JFETs is presented in this paper. The device parameters that play the most important role for the parallel connection are the pinch-off voltage, the gate-source reverse breakdown voltage, the spread in the on-state resistances, and the variations in static transfer characteristics of the devices. Moreover, it is experimentally shown that a fifth factor affecting the parallel connection of the devices is the parasitic inductances of the circuit layout. The temperature dependence of the gate-source reverse breakdown voltages is analyzed for two different designs of silicon carbide JFETs. If the spread in the pinch-off and gate-source reverse breakdown voltages is sufficiently large, there might be no possibility for a stable off-state operation of a pair of transistors without forcing one of the gate voltages to exceed the breakdown voltage. A solution to this problem using individual gate circuits for the JFETs is given. The switching performance of two pairs of parallel-connected devices with different combinations of parameters is compared employing two different gate-driver configurations. Three different circuit layouts are considered and the effect of the parasitic inductances is experimentally investigated. It is found that using a single gate circuit for the two mismatched JFETs may improve the switching performance and therefore the distribution of the switching losses significantly. Based on the measured switching losses, it is also clear that regardless of the design of the gate drivers, the lowest total switching losses for the devices are obtained when they are symmetrically placed.

  • 12.
    Peftitsis, Dimosthenis
    et al.
    KTH, Skolan för elektro- och systemteknik (EES), Elektriska maskiner och effektelektronik (stängd 20110930).
    Baburske, Roman
    Technische Universität Chemnitz.
    Rabkowski, Jacek
    KTH, Skolan för elektro- och systemteknik (EES), Elektriska maskiner och effektelektronik (stängd 20110930).
    Lutz, Josef
    Technische Universität Chemnitz.
    Tolstoy, Georg
    KTH, Skolan för elektro- och systemteknik (EES), Elektriska maskiner och effektelektronik (stängd 20110930).
    Nee, Hans-Peter
    KTH, Skolan för elektro- och systemteknik (EES), Elektriska maskiner och effektelektronik (stängd 20110930).
    Challenges regarding parallel-connection of SiC JFETs2011Inngår i: IEEE 8th International Conference on Power Electronics and ECCE Asia (ICPE & ECCE), 2011: 'Green World with Power Electronics' / [ed] IEEE, 2011, s. 1095-1101Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Considering the present development of the available Silicon Carbide switches, their current ratings are so low that they cannot be used for high-power converters. It is therefore necessary to connect several switches in parallel in order to obtain sufficient current ratings. An investigation of parallel-connected normally-on Silicon Carbide Junction Field Effect Transistors is presented in this paper. The parameters that play the most important role for the parallel connection are the pinch-off and the gate-source breakdown voltages. The temperature dependency of those two voltages is analyzed based on the pnp structure of the device. If the spread in these parameters is sufficiently large there might be no possibility for a stable off-state operation of a pair of transistors without forcing one of the gate voltages to exceed the breakdown voltage, especially at high temperatures. A solution to this problem is given. The switching performance of two pairs of parallel-connected devices is compared with respect to their pinch-off voltages, and it is found that differences of approximately 25% in switching losses could result from a difference in the pinch-off voltage of 0.5 V.

  • 13.
    Peftitsis, Dimosthenis
    et al.
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Lim, Jang-Kwon
    Acreo AB.
    Rabkowski, Jacek
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Tolstoy, Georg
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Nee, Hans-Peter
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Experimental Comparison of Different Gate-Driver Configurations for Parallel-Connection of Normally-ON SiC JFETs2012Inngår i: 7th International Power Electronics and Motion Control Conference (IPEMC), 2012, IEEE conference proceedings, 2012, s. 16-22Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Due to the low current ratings of the currently available silicon carbide (SiC) switches they cannot be employed in high-power converters. Thus, it is necessary to parallel-connect several switches in order to reach higher current ratings. This paper presents an investigation of parallel-connected normally-on SiC junction field effect transistors. There are four crucial parameters affecting the effectiveness of the parallel-connected switches. However, the pinch-off voltage and the reverse breakdown voltage of the gates seem to be the most important parameters which affect the switching performance of the devices. In particular, the spread in these two parameters might affect the stable off-state operation of the switches. The switching performance and the switching losses of a pair of parallel-connected devices having different reverse breakdown voltages of the gates is investigated by employing three different gate-driver configurations. It is experimentally shown that using a single gate-driver circuit the switching performance of the parallel-connected devices is almost identical, while the total switching losses are lower compared to the other two configurations.

    Fulltekst (pdf)
    fulltext
  • 14.
    Peftitsis, Dimosthenis
    et al.
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Rabkowski, Jacek
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Nee, Hans-Peter
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Design Considerations for a Self-Powered Gate Driver for Normally-ON SiC Junction Field-Effect Transistors2013Inngår i: 2013 IEEE ECCE Asia Downunder - 5th IEEE Annual International Energy Conversion Congress and Exhibition, IEEE ECCE Asia 2013, IEEE conference proceedings, 2013, s. 251-257Konferansepaper (Fagfellevurdert)
    Abstract [en]

    The very low on-state resistance, the voltagecontrolledgate, and the relative simplicity of fabrication of thenormally-ON silicon carbide junction field effect transistor makethis device the most important player among all state-of-theartsilicon carbide transistors. However, the normally-ON naturecounts as the main factor which keeps this device far frombeing considered as an alternative to the silicon insulated-gatebipolar transistor. A self-powered gate driver without externalpower supply for normally-ON silicon carbide junction field effecttransistors is presented in this paper. The proposed circuit isable to handle the shoot-through current when the devices aresubjected to the dc-link voltage by utilizing the energy associatedwith this current. On the other hand it supplies the necessarynegative gate-source voltage during the steady-state operation. Adetailed description of the operating states of the proposed circuitalong with various design considerations are presented. Fromexperiments which were performed in a half-bridge converter, itis shown that the shoot-through current can be turned off withinapproximately 15 s. Moreover, it is shown that the proposedgate driver can properly switch the devices.

    Fulltekst (pdf)
    fulltext
  • 15.
    Peftitsis, Dimosthenis
    et al.
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Rabkowski, Jacek
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Nee, Hans-Peter
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Self-powered gate driver for normally on silicon carbide junction field-effect transistors without external power supply2013Inngår i: IEEE transactions on power electronics, ISSN 0885-8993, E-ISSN 1941-0107, Vol. 28, nr 3, s. 1488-1501Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The very low on-state resistance, the voltage-controlled gate, and the relative simplicity of fabrication of the normally ON silicon carbide junction field-effect transistor (JFET) make this device the most important player among all state-of-the-art silicon carbide transistors. However, the normally ON nature counts as the main factor which keeps this device far from being considered as an alternative to the silicon insulated-gate bipolar transistor. A self-powered gate driver without external power supply for normally ON silicon carbide JFETs is presented in this paper. The proposed circuit is able to handle the short-circuit currents when the devices are subjected to the dc-link voltage by utilizing the energy associated with this current. On the other hand, it supplies the necessary negative gate-source voltage during the steady-state operation. A detailed description of the operating states in conjunction with a theoretical analysis of the proposed self-powered gate driver is presented. The first part of the experimental investigation has been performed when the proposed circuit is connected to a device which is directly subjected to the dc-link voltage. The second set of measurements were recorded when the self-powered gate-driver was employed as the driver of normally ON components in a half-bridge converter. From the experimental results, it is shown that the short-circuit current is cleared within approximately 20μs after the dc-link voltage is applied, while the power consumption when all devices are kept in the OFF state equals 0.37W. Moreover, it is experimentally shown that the proposed gate driver can properly switch when it is employed in a half-bridge converter. Finally, limitations regarding the range of the applications where the self-powered gate drive can efficiently operate are also discussed.

  • 16.
    Peftitsis, Dimosthenis
    et al.
    KTH, Skolan för elektro- och systemteknik (EES), Elektriska maskiner och effektelektronik (stängd 20110930).
    Rabkowski, Jacek
    KTH, Skolan för elektro- och systemteknik (EES), Elektriska maskiner och effektelektronik (stängd 20110930).
    Tolstoy, Georg
    KTH, Skolan för elektro- och systemteknik (EES), Elektriska maskiner och effektelektronik (stängd 20110930).
    Nee, Hans-Peter
    KTH, Skolan för elektro- och systemteknik (EES), Elektriska maskiner och effektelektronik (stängd 20110930).
    Experimental comparison of dc-dc boost converters with SiC JFETs and SiC bipolar transistors2011Inngår i: Proceedings of the 2011-14th European Conference on Power Electronics and Applications (EPE 2011) / [ed] EPE Association, 2011Konferansepaper (Fagfellevurdert)
    Abstract [en]

    An experimental performance comparison between SiC JFET and SiC BJT switches which are used as the main switch for a 2 kW dc/dc converter is presented. In order to perform a fair comparison and due to the different chip areas of these two SiC devices, they both operate under the same on-state losses. Moreover, the switching speeds of the gate and base drivers are approximately equal. It is experimentally shown that the SiC BJT is switching slightly faster than the SiC JFET under the same circuit conditions, while the driver loss for the SiC BJT is higher than for the JFET, especially at relatively low switching frequencies. Various experimental results dealing with the switching performance of the SiC devices and the power losses at different switching frequencies are presented. It is found that the BJT converter has a higher efficiency (99.0% measured at 50 kHz) that the JFET converter.

  • 17.
    Peftitsis, Dimosthenis
    et al.
    KTH, Skolan för elektro- och systemteknik (EES).
    Tolstoy, Georg
    KTH, Skolan för elektro- och systemteknik (EES).
    Antonopoulos, Antonios
    KTH, Skolan för elektro- och systemteknik (EES).
    Rabkowski, Jacek
    KTH, Skolan för elektro- och systemteknik (EES).
    Lim, Jang-Kwon
    Acreo, Kista.
    Bakowski, Mietek
    Acreo, Kista.
    Ängquist, Lennart
    KTH, Skolan för elektro- och systemteknik (EES).
    Nee, Hans-Peter
    KTH, Skolan för elektro- och systemteknik (EES).
    High-power modular multilevel converters with SiC JFETs2010Inngår i: 2010 IEEE Energy Conversion Congress and Exposition (ECCE) / [ed] IEEE, IEEE , 2010, s. 2148-2155Konferansepaper (Fagfellevurdert)
    Abstract [en]

    This paper studies the possibility of building a Modular Multilevel Converter (M2C) using Silicon Carbide (SiC) switches. The main focus is on a theoretical investigation of the conduction losses of such a converter and a comparison to a corresponding converter with silicon insulated gate bipolar transistors. Both SiC BJTs and JFETs are considered and compared in order to choose the most suitable technology. One of the sub-modules of a down-scaled 10 kVA prototype M2C is replaced with a sub-module with SiC JFETs without anti-parallel diodes. It is shown that diode-less operation is possible with the JFETs conducting in the negative direction, leaving the possibility to use the body diode during the switching transients. Experimental waveforms for the SiC sub-module verify the feasibility during normal steady-state operation. The loss estimation shows that a 300 MW M2C for high-voltage direct current transmission would potentially have an efficiency of approximately 99,8 % if equipped with future 3.3 kV 1.2 kA SiC JFETs.

  • 18.
    Peftitsis, Dimosthenis
    et al.
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Tolstoy, Georg
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Antonopoulos, Antonios
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Rabkowski, Jacek
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Lim, Jang-Kwon
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Bakowski, Mietek
    Acreo AB.
    Ängquist, Lennart
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Nee, Hans-Peter
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    High-Power Modular Multilevel Converters With SiC JFETs2012Inngår i: IEEE transactions on power electronics, ISSN 0885-8993, E-ISSN 1941-0107, Vol. 27, nr 1, s. 28-36Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    This paper studies the possibility of building a modular multilevel converter (M2C) using silicon carbide (SiC) switches. The main focus is on a theoretical investigation of the conduction losses of such a converter and a comparison to a corresponding converter with silicon-insulated gate bipolar transistors. Both SiC BJTs and JFETs are considered and compared in order to choose the most suitable technology. One of the submodules of a down-scaled 3 kVA prototype M2C is replaced with a submodule with SiC JFETs without antiparallel diodes. It is shown that the diode-less operation is possible with the JFETs conducting in the negative direction, leaving the possibility to use the body diode during the switching transients. Experimental waveforms for the SiC submodule verify the feasibility during normal steady-state operation. The loss estimation shows that a 300 MW M2C for high-voltage direct current transmission would potentially have an efficiency of approximately 99.8% if equipped with future 3.3 kV 1.2 kA SiC JFETs.

    Fulltekst (pdf)
    fulltext
  • 19.
    Rabkowski, Jacek
    et al.
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Mariusz, Zdanowski
    Warsaw Institute of Technology.
    Peftitsis, Dimosthenis
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Nee, Hans-Peter
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    A Simple High-Performance Low-Loss Current-Source Driver for SiC Bipolar Transistors2012Inngår i: 7th International Power Electronics and Motion Control Conference (IPEMC), 2012, IEEE conference proceedings, 2012, s. 222-228Konferansepaper (Fagfellevurdert)
    Abstract [en]

    The paper proposes a novel topology of a simple base drive unit for silicon carbide bipolar junction transistors (BJTs) based on the current-source principle. Energy stored in a small, air-cored inductor is employed to generate a current peak forcing the BJT to turn-on (10–20ns) very rapidly. The driver enables very high switching performance and very low switching losses of the driven BJT. Both the current source and the unit delivering the steady-state current to the base are supplied from the same low-voltage source in order to limit power consumption. Operation principles as well as selected design issues are discussed in the paper and illustrated by experiments. The 1200V/6A SiC BJT driven by the proposed circuit shows a very fast switching speed.

    Fulltekst (pdf)
    fulltext
  • 20.
    Rabkowski, Jacek
    et al.
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Peftitsis, Dimosthenis
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Bakowski, Mietek
    Acreo.
    Nee, Hans-Peter
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Evaluation of the drive circuit for a dual gate trench SiC JFET2013Inngår i: SILICON CARBIDE AND RELATED MATERIALS 2012, 2013, s. 946-949Konferansepaper (Fagfellevurdert)
    Abstract [en]

    The paper discusses the switching performance of the dual gate trench SiC JFET. In applications such as dc/dc converters, when fast switching is expected the standard totem-pole driver is not sufficient. The reason for this is that both the internal resistance and the parasitic capacitances of this device are significantly higher than for other designs. Instead, the gate driver with a dynamic current source is proposed in this paper to speed-up the switching process. Performed double-pulse measurements show improved dynamic performance of the tested DGTJFET with the new driver.

  • 21.
    Rabkowski, Jacek
    et al.
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Peftitsis, Dimosthenis
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Mariusz, Zdanowski
    Warsaw Institute of Technology.
    Nee, Hans-Peter
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    A 6kW, 200kHz boost converter with parallel-connected SiC bipolar transistors2013Inngår i: 2013 Twenty-Eighth Annual IEEE Applied Power Electronics Conference And Exposition (APEC 2013), IEEE Press, 2013, s. 1991-1998Konferansepaper (Fagfellevurdert)
    Abstract [en]

    This paper describes issues related to design,construction and experimental verification of a 6 kW, 200 kHzboost converter (300 V/600 V) built with four parallel-connectedSiC bipolar transistors. The main focus is on parallel-connectionof the SiC BJTs: crucial device parameters and influence of theparasitics are discussed. A special solution for the base-driveunit, based on the dual-source driver concept, is also presentedin this paper. Experimental verification of the boost converterwith special attention to power loss measurement and thermalperformance of the parallel-connected transistors is also shown.The peak efficiency measured at nominal conditions wasapproximately 98.5% where the base-drive unit causes around 10% of the total losses.

    Fulltekst (pdf)
    fulltext
  • 22.
    Rabkowski, Jacek
    et al.
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Peftitsis, Dimosthenis
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Nee, Hans-Peter
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Design Steps Toward a 40-kVA SiC JFET Inverter With Natural-Convection Cooling and an Efficiency Exceeding 99.5%2013Inngår i: IEEE transactions on industry applications, ISSN 0093-9994, E-ISSN 1939-9367, Vol. 49, nr 4, s. 1589-1598Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    This paper describes the concept, design, construction, and experimental investigation of a 40-kVA inverter with silicon carbide junction field-effect transistors (JFETs). The inverter was designed to reach an efficiency exceeding 99.5%. The size of the heat sink is significantly reduced in comparison to silicon insulated-gate bipolar transistor designs, and the high efficiency makes it possible to use free-convection cooling. This could potentially increase reliability compared with solutions with fans. A very low conduction loss has been achieved by parallel connecting ten 85-m Omega normally-ON JFETs in each switch position. A special gate-drive solution was applied, forcing the transistors to switch very fast (approximately 10 kV/mu s), resulting in very low switching losses. As output power is almost equal to input power, special effort was done to precisely determine the amount of semiconductor power losses via comparative thermal measurements. A detailed analysis of the measurements shows that the efficiency of the inverter is close to 99.7% at 40 kVA.

    Fulltekst (pdf)
    fulltext
  • 23.
    Rabkowski, Jacek
    et al.
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Peftitsis, Dimosthenis
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Nee, Hans-Peter
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Design steps towards a 40-kVA SiC inverter with an efficiency exceeding 99.5%2012Inngår i: Conference Proceedings - IEEE Applied Power Electronics Conference and Exposition - APEC, IEEE , 2012, s. 1536-1543Konferansepaper (Fagfellevurdert)
    Abstract [en]

    This paper describes the concept, the design, the construction, and experimental investigation of a 40 kVA inverter with Silicon Carbide Junction Field Effect Transistors. The inverter was designed to have an efficiency exceeding 99.5%. Due to the low losses free convection cooling could be used. Since no fans are used the reliability can be increased compared to solutions with fans. A very low conduction loss has been achieved by parallel connecting ten 85 mΩ normally-on JFETs in each switch position. A special gate-drive solution was applied forcing the transistors to switch very fast (approx. 20 kV/μs) resulting in very low switching losses. As the output power is almost equal to the input power a special effort was done to precisely determine the amount of semiconductor power losses via comparative thermal measurements. A detailed analysis of the measurements shows that the efficiency of the inverter is approximately 99.7% at 40 kVA.

  • 24.
    Rabkowski, Jacek
    et al.
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Peftitsis, Dimosthenis
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Nee, Hans-Peter
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Parallel-Operation of Discrete SiC BJTs in a 6-kW/250-kHz DC/DC Boost Converter2014Inngår i: IEEE transactions on power electronics, ISSN 0885-8993, E-ISSN 1941-0107, Vol. 29, nr 5, s. 2482-2491Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    This paper describes issues related to parallel connection of SiC bipolar junction transistors (BJTs) in discrete packages. The devices are applied in a high-frequency dc/dc boost converter where the switching losses significantly exceed the conduction losses. The design and construction of the converter is discussed-with special emphasis on successful parallel-operation of the discrete BJTs. All considerations are experimentally illustrated by a 6-kW, 250-kHz boost converter (300 V/600 V). A special solution for the base-drive unit, based on the dual-source driver concept, is also shown in this paper. The performance of this driver and the current sharing of the BJTs are both presented. The power losses and thermal performance of the parallel-connected transistors have been determined experimentally for different powers and switching frequencies. An efficiency of 98.23% (+/- 0.02%) was measured using a calorimetric setup, while the maximum temperature difference among the four devices is 12 degrees C.

  • 25.
    Rabkowski, Jacek
    et al.
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling. Warsaw University of Technology, Poland .
    Peftitsis, Dimosthenis
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Nee, Hans-Peter
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Recent Advances in Power Semiconductor Technology2014Inngår i: Power Electronics for Renewable Energy Systems, Transportation and Industrial Applications, Wiley-Blackwell, 2014, s. 69-106Kapittel i bok, del av antologi (Annet vitenskapelig)
    Abstract [en]

    This chapter presents recent advances in power semiconductors technology with special attention on wide bandgap (WBG) transistors. A short introduction to the state-of-the-art Silicon power devices is given, and the characteristics of the various SiC power switches are also described. Design considerations of gate and base-drive circuits for various SiC power switches along with experimental results of their switching performance are presented in details. Moreover, a section on applications of SiC power devices is also included, where the three design directions (high-efficiency, high switching frequency and high-temperature) that might be followed using SiC technology are shown. Last but not least, a short overview of Gallium Nitride transistors is presented in the last section of this chapter.

  • 26.
    Rabkowski, Jacek
    et al.
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Peftitsis, Dimosthenis
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Nee, Hans-Peter
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Silicon Carbide Power Transistors: A New Era in Power Electronics Is Initiated2012Inngår i: IEEE Industrial Electronics Magazine, ISSN 1932-4529, E-ISSN 1941-0115, Vol. 6, nr 2, s. 17-26Artikkel i tidsskrift (Fagfellevurdert)
  • 27.
    Rabkowski, Jacek
    et al.
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Tolstoy, Georg
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Peftitsis, Dimosthenis
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Nee, Hans-Peter
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Low-Loss High-Performance Base-Drive Unit for SiC BJTs2012Inngår i: IEEE transactions on power electronics, ISSN 0885-8993, E-ISSN 1941-0107, Vol. 27, nr 5, s. 2633-2643Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Driving a silicon carbide bipolar junction transistor is not a trivial issue, if low drive power consumption and short-switching times are desired. A dual-source base-drive unit with a speed-up capacitor consisting of a low-and a high-voltage source is, therefore, proposed in this paper. As a significant base current is required during the conduction state, the driver power consumption is higher than for other semiconductor switches. In the presented solution, the steady-state base current is provided by a low-voltage source and is optimized for lowpower losses. On the contrary, a second source with a higher voltage and speed-up capacitor is used in order to improve the switching performance of the device. The proposed driver has experimentally been compared to other standard driver solutions by using a double-pulse circuit and a 2-kW dc/dc boost converter. Switching times of 20 ns at turn-ON and 35 ns at turn-OFF were recorded. Finally, the efficiency of the converter was determined experimentally at various switching frequencies. From power loss measurements at 100-kHz switching frequency using the proposed driver in a 2-kW dc/dc boost converter, it was found that the efficiency was approximately 99.0%. In the same operating point, the driver power consumption was only 0.08% of the rated power.

  • 28.
    Rabkowski, Jacek
    et al.
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Zdanowski, Mariusz
    Barlik, Roman
    Gate drive units for silicon carbide power transistors - solutions overview2012Inngår i: Przeglad Elektrotechniczny, ISSN 0033-2097, E-ISSN 2449-9544, Vol. 88, nr 4B, s. 187-192Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The paper presents an overview of the gate drive units for Silicon Carbide power transistors. Solutions for two types of Junction Field Effect Transistors: normally-on and normally-off as well as base drive units for bipolar transistors (BJTs) are described. Experimental results - waveforms of the currents and voltages recorded during double-pulse tests are presented in order to illustrate switching behavior of discussed transistors.

  • 29.
    Sadik, Diane-Perle
    et al.
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Colmenares, Juan
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Peftitsis, Dimosthenis
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Lim, Jang-Kwon
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Rabkowski, Jacek
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Nee, Hans-Peter
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Experimental investigations of static and transient current sharing of parallel-connected silicon carbide MOSFETs2013Inngår i: 2013 15th European Conference on Power Electronics and Applications, EPE 2013, 2013Konferansepaper (Fagfellevurdert)
    Abstract [en]

    An Experimental performance analysis of a parallel connection of two 1200/80 MΩ silicon carbide SiC MOSFETs is presented. Static parallel connection was found to be unproblematic. The switching performance of several pairs of parallel-connected MOSFETs is shown employing a common simple totem-pole driver. Good transient current sharing and high-speed switching waveforms with small oscillations are presented. To conclude this analysis, a dc/dc boost converter using parallel-connected SiC MOSFETs is designed for stepping up a voltage from 50 V to 560 V. It has been found that at high frequencies, a mismatch in switching losses results in thermal unbalance between the devices.

  • 30.
    Sadik, Diane-Perle
    et al.
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Colmenares, Juan
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Peftitsis, Dimosthenis
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Tolstoy, Georg
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Rabkowski, Jacek
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Nee, Hans-Peter
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Analysis of short-circuit conditions for silicon carbide power transistors and suggestions for protection2014Inngår i: 2014 16th European Conference on Power Electronics and Applications, EPE-ECCE Europe 2014, IEEE , 2014, s. 6910789-Konferansepaper (Fagfellevurdert)
    Abstract [en]

    An experimental analysis of the behavior under short-circuit conditions of three different Silicon Carbide (SiC) 1200 V power devices is presented. It is found that all devices take up a substantial voltage, which is favorable for detection of short-circuits. A suitable method for short-circuit detection without any comparator is demonstrated. A SiC JFET driver with an integrated short-circuit protection (SCP) is presented where a short-circuit detection is added to a conventional driver design in a simple way. Experimental tests of the SCP driver operating under short-circuit condition and under normal operation are performed successfully.

  • 31.
    Sadik, Diane-Perle
    et al.
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Colmenares, Juan
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Tolstoy, Georg
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Peftitsis, Dimosthenis
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Bakowski, Mietek
    Rabkowski, Jacek
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Nee, Hans-Peter
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Short-Circuit Protection Circuits for Silicon Carbide Power Transistors2016Inngår i: IEEE transactions on industrial electronics (1982. Print), ISSN 0278-0046, E-ISSN 1557-9948, ISSN 0278-0046, Vol. 63, nr 4, s. 1995-2004, artikkel-id ITIEDArtikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    An experimental analysis of the behavior under short-circuit conditions of three different siliconcarbide (SiC) 1200-V power devices is presented. It is found that all devices take up a substantial voltage, which is favorable for detection of short circuits. A transient thermal device simulation was performed to determine the temperature stress on the die during a short-circuit event, for the SiC MOSFET. It was found that, for reliability reasons, the short-circuit time should be limited to values well below Si IGBT tolerances. Guidelines toward a rugged design for short-circuit protection (SCP) are presented with an emphasis on improving the reliability and availability of the overall system. A SiC device driver with an integrated SCP is presented for each device-type, respectively, where a shortcircuit detection is added to a conventional driver design in a simple way. The SCP driver was experimentally evaluated with a detection time of 180 ns. For all devices, short-circuit times well below 1 µs were achieved.

  • 32. Schöner, A.
    et al.
    Bakowski, M.
    Malhan, R. K.
    Takeuchi, Y.
    Sugiyama, N.
    Rabkowski, Jacek
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Peftitsis, Dimosthenis
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Ranstad, P.
    Nee, H. P.
    Fabrication of a SiC double gate vertical channel jfet and it's application in power electronics2012Inngår i: Gallium nitride and silicon carbide power technologies 2, Electrochemical Society, 2012, nr 3, s. 45-52Konferansepaper (Fagfellevurdert)
    Abstract [en]

    The fabrication process of an innovative epitaxial trench JFET with vertical channel and double gate control is reviewed. Due to the excellent doping and thickness control of the epitaxial regrowth techniques, the sub-micron channel can be tailored for normally-on and -off operation. Due to the vertical channel design the epitaxial trench JFETs have narrow cell pitch for high-density power integration and high saturation current capabilities. The excellent performance of these fabricated and packaged JFET devices is demonstrated with on-wafer measurements and power switching tests. High current conduction tests are performed at room temperature and elevated temperatures of 125°C with switching frequencies of 30 kHz and 200 kHz.

  • 33.
    Tolstoy, Georg
    et al.
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Peftitsis, Dimosthenis
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Rabkowski, Jacek
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Nee, Hans-Peter
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Palmer, P. R.
    A discretized proportional base driver for Silicon Carbide Bipolar Junction Transistors2013Inngår i: 2013 IEEE ECCE Asia Downunder - 5th IEEE Annual International Energy Conversion Congress and Exhibition, IEEE ECCE Asia 2013, IEEE , 2013, s. 728-735Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Silicon Carbide Bipolar Junction Transistors require a continuous base current in the on-state. This base current is usually made constant and is corresponding to the maximum collector current and maximum junction temperature that is foreseen in a certain application. In this paper, a discretized proportional base driver is proposed which will reduce, for the right application, the steady-state power consumption of the base driver. The operation of the proposed base driver has been verified experimentally, driving a 1200V/40A SiC BJT in a DC-DC boost converter. In order to determine the potential reduction of the power consumption of the base driver, a case with a dc-dc converter in an ideal electric vehicle driving the new European drive cycle has been investigated. It is found that the steady-state power consumption of the base driver can be reduced by approximately 63 %. The total reduction of the driver consumption is 2816 J during the drive cycle, which is slightly more than the total on-state losses for the SiC BJTs used in the converter.

  • 34.
    Tolstoy, Georg
    et al.
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Peftitsis, Dimosthenis
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Rabkowski, Jacek
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Palmer, Patrick R.
    Nee, Hans-Peter
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    A Discretized Proportional Base Driver for Silicon Carbide Bipolar Junction Transistors2014Inngår i: IEEE transactions on power electronics, ISSN 0885-8993, E-ISSN 1941-0107, Vol. 29, nr 5, s. 2408-2417Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Silicon carbide (SiC) bipolar junction transistors (BJTs) require a continuous base current in the on-state. This base current is usually made constant and is corresponding to the maximum collector current and maximum junction temperature that is foreseen in a certain application. In this paper, a discretized proportional base driver is proposed which will reduce, for the right application, the steady-state power consumption of the base driver. The operation of the proposed base driver has been verified experimentally, driving a 1200-V/40-A SiC BJT in a dc-dc boost converter. In order to determine the potential reduction of the power consumption of the base driver, a case with a dc-dc converter in an ideal electric vehicle driving the new European drive cycle has been investigated. It is found that the steady-state power consumption of the base driver can be reduced by approximately 60%. The total reduction of the driver consumption is 3459 J during the drive cycle, which is slightly more than the total on-state losses for the SiC BJTs used in the converter.

  • 35.
    Tolstoy, Georg
    et al.
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Ranstad, Per
    Colmenares, Juan
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Giezendanner, Florian
    Rabkowski, Jacek
    Warsaw University of Technology, Poland.
    Nee, Hans-Peter
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    An experimental analysis on how the dead-time of SiC BJT and SiC MOSFET impacts the losses in a high-frequency resonant converter2014Inngår i: 2014 16th European Conference on Power Electronics and Applications, EPE-ECCE Europe 2014, IEEE conference proceedings, 2014, s. 6911042-Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Active control of the dead-time in a SLR converter is in this paper shown to be of great importance. The efficiency of the full-bridge will increase if the dead-time control is made in the right way. Different control algorithms are shown to work well for different power switches. For the SiC MOSFET and the SiC BJT the control algorithms are tested experimentally.

  • 36.
    Tolstoy, Georg
    et al.
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Ranstad, Per
    Colmenares, Juan
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Peftitsis, Dimosthenis
    Giezendanner, Florian
    Rabkowski, Jacek
    Warsaw University of Technology, Poland.
    Nee, Hans-Peter
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    An experimental analysis on how the dead-time of SiC BJT and SiC MOSFET impacts the losses in a high-frequency resonant converterManuskript (preprint) (Annet vitenskapelig)
  • 37.
    Zdanowski, M.
    et al.
    Warsaw Univ Technol, Inst Control & Ind Elect, Warsaw, Poland..
    Rabkowski, Jacek
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Kostov, Konstantin
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Barlik, R.
    Warsaw Univ Technol, Inst Control & Ind Elect, Warsaw, Poland..
    Nee, Hans-Peter
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Design and Evaluation of Reduced Self-Capacitance Inductor for Fast-Switching SiC BJT dc/dc Converters2012Inngår i: 2012 15TH INTERNATIONAL POWER ELECTRONICS AND MOTION CONTROL CONFERENCE (EPE/PEMC), IEEE , 2012Konferansepaper (Fagfellevurdert)
    Abstract [en]

    The paper presents design, measurements and evaluation of the inductor with reduced self-capacitance. As an reference inductor with the same parameters but non-optimized self-capacitance is chosen. Differences in the parasitic capacitance of the inductor are validated by four measurement methods and experimentally confirmed on a 2 kW, 100 kHz dc/dc converter with silicon carbide BJTs. When the low-capacitance inductor is applied the switching performance is better, especially high-frequency resonances are limited. Additionally, it was found that the power losses were reduced by approximately 20%.

  • 38. Zdanowski, Mariusz
    et al.
    Kostov, Konstantin
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Rabkowski, Jacek
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Barlik, Roman
    Nee, Hans-Peter
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Design and Evaluation of Reduced Self-Capacitance Inductor in DC/DC Converters with Fast-Switching SiC Transistors2014Inngår i: IEEE transactions on power electronics, ISSN 0885-8993, E-ISSN 1941-0107, Vol. 29, nr 5, s. 2492-2499Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The paper presents an inductor with reduced self-capacitance, designed and evaluated with fast-switching SiC transistors in dc-dc converters. A conventional inductor with the same core and number of turns was also build for comparison. The two inductors are tested experimentally on two different 2 kW, 100 kHz dc-dc converters with silicon carbide switches-one with a junction field-effect transistor (JFET) and the other with a bipolar junction transistor (BJT). Replacing the conventional inductor with the one that has lower self-capacitance improved the switching performance of the converter and reduced its electromagnetic emissions. Furthermore, the efficiency of the converter is improved-in the case of the JFET boost converter the power losses were reduced by 16% and by 20% in the case of BJT.

  • 39.
    Zdanowski, Mariusz
    et al.
    Warsaw University of Technlogy.
    Rabkowski, Jacek
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Kostov, Konstantin
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Barlik, R.
    Nee, Hans-Peter
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Design and Evaluation of Reduced Self-Capacitance Inductor for Fast-Switching SiC BJTdc/dc Converters2012Inngår i: Power Electronics and Motion Control Conference (EPE/PEMC), 2012 15th International, IEEE , 2012, s. DS1a.41-DS1a.47Konferansepaper (Fagfellevurdert)
    Abstract [en]

    The paper presents design, measurements and evaluation of the inductor with reduced self-capacitance. As an reference inductor with the same parameters but non-optimized self-capacitance is chosen. Differences in the parasitic capacitance of the inductor are validated by four measurement methods and experimentally confirmed on a 2 kW, 100 kHz dc/dc converter with silicon carbide BJTs. When the low-capacitance inductor is applied the switching performance is better, especially high-frequency resonances are limited. Additionally, it was found that the power losses were reduced by approximately 20%.

  • 40.
    Zdanowski, Mariusz
    et al.
    Warsaw University of Technlogy.
    Rabkowski, Jacek
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Kostov, Konstantin
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    Nee, Hans-Peter
    KTH, Skolan för elektro- och systemteknik (EES), Elektrisk energiomvandling.
    The Role of the Parasitic Capacitance of the Inductorin Boost Converters with Normally-On SiC JFETs2012Inngår i: 2012 7th International Power Electronics and Motion Control Conference (IPEMC), IEEE conference proceedings, 2012, s. 1842-1847Konferansepaper (Fagfellevurdert)
    Abstract [en]

    In this paper the impact of the parasitic capacitance ofthe inductor on the performance of a fast-switching boostconverters with SiC JFETs is discussed. Two inductor designs,one conventional and another with a space between the windinglayers, are investigated and their parasitic capacitances aremeasured by different methods. The air-gap between the windinglayers reduced the inductor self-capacitance more than 8 times.The two inductors were used in a 2 kW, 100 kHz boost converterwith a normally-on SiC JFET and their performance wascompared. When the inductor with a low self-capacitance wasused, there were fewer oscillations during the switchingtransients and the losses were reduced about 16 %.

1 - 40 of 40
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