The Experts below are selected from a list of 120 Experts worldwide ranked by ideXlab platform

Victor M. Edelstein - One of the best experts on this subject based on the ideXlab platform.

  • Magnetoelectric effect in polar superconductors
    Physical Review Letters, 1995
    Co-Authors: Victor M. Edelstein
    Abstract:

    The question of how the lack of spatial reflection symmetry can affect properties of a superconductor is investigated. A novel magnetoelectric effect is predicted: The supercurrent in a metal of polar symmetry must be accompanied by the spin polarization of the carriers. The relevance to some known pyro- and antipyroelectric superconductors including a High-Temperature System as well as the possibility of an experimental verification are briefly discussed.

Johann W. Kolar - One of the best experts on this subject based on the ideXlab platform.

  • A 120 °C Ambient Temperature Forced Air-Cooled Normally-off SiC JFET Automotive Inverter System
    IEEE Transactions on Power Electronics, 2014
    Co-Authors: Benjamin Wrzecionko, Dominik Bortis, Johann W. Kolar
    Abstract:

    The degree of integration of power electronic converters in current hybrid electric vehicles can be increased by mitigation of special requirements of these converters, especially those regarding ambient air and cooling fluid temperature levels. Today, converters have their own cooling circuit or are placed far away from hot spots caused by the internal combustion engine and its peripheral components. In this paper, it is shown, how the use of SiC power semiconductors and active control electronics cooling employing a Peltier cooler can help to build an air-cooled inverter System for 120 °C ambient temperature. First, a detailed analysis shows, how the optimum junction of this High-Temperature System can be calculated. Then, the operating temperature ranges of power semiconductors, thermal interface materials, capacitors, and control electronics are investigated, leading to a comprehensive analysis of mechanical concepts for the inverter System in order to show new ways to solve electrical and thermal tradeoffs. In particular, the operation of the signal electronics and the gate driver for power semiconductors with a junction temperature of 250 °C within the specified operating temperature range is ensured by appropriate placement and cooling methods, while taking the electrical requirements for limits on the wiring inductances and symmetry requirements into account. The analysis includes an accurate thermal model of the converter and an optimized active cooling of the signal electronics using a Peltier cooler. Finally, a hardware prototype with discrete power semiconductor devices and thus with a junction temperature limit of 175 °C driving high-speed electrical machines is shown to validate the theoretical considerations in a custom-designed High-Temperature test environment.

Benjamin Wrzecionko - One of the best experts on this subject based on the ideXlab platform.

  • A 120 °C Ambient Temperature Forced Air-Cooled Normally-off SiC JFET Automotive Inverter System
    IEEE Transactions on Power Electronics, 2014
    Co-Authors: Benjamin Wrzecionko, Dominik Bortis, Johann W. Kolar
    Abstract:

    The degree of integration of power electronic converters in current hybrid electric vehicles can be increased by mitigation of special requirements of these converters, especially those regarding ambient air and cooling fluid temperature levels. Today, converters have their own cooling circuit or are placed far away from hot spots caused by the internal combustion engine and its peripheral components. In this paper, it is shown, how the use of SiC power semiconductors and active control electronics cooling employing a Peltier cooler can help to build an air-cooled inverter System for 120 °C ambient temperature. First, a detailed analysis shows, how the optimum junction of this High-Temperature System can be calculated. Then, the operating temperature ranges of power semiconductors, thermal interface materials, capacitors, and control electronics are investigated, leading to a comprehensive analysis of mechanical concepts for the inverter System in order to show new ways to solve electrical and thermal tradeoffs. In particular, the operation of the signal electronics and the gate driver for power semiconductors with a junction temperature of 250 °C within the specified operating temperature range is ensured by appropriate placement and cooling methods, while taking the electrical requirements for limits on the wiring inductances and symmetry requirements into account. The analysis includes an accurate thermal model of the converter and an optimized active cooling of the signal electronics using a Peltier cooler. Finally, a hardware prototype with discrete power semiconductor devices and thus with a junction temperature limit of 175 °C driving high-speed electrical machines is shown to validate the theoretical considerations in a custom-designed High-Temperature test environment.

Bozena Kaminska - One of the best experts on this subject based on the ideXlab platform.

  • High temperature polymer capacitors for aerospace applications
    2010 Design Automation & Test in Europe Conference & Exhibition (DATE 2010), 2010
    Co-Authors: Clinton K. Landrock, Bozena Kaminska
    Abstract:

    Due to the need for reducing System size and weight while increasing performance, many military and commercial Systems today require High-Temperature electronics to run actuators, high-speed motors or generators. Of the many passive devices required to satisfy the needs for a complete high temperature System, none has been more problematic than the capacitor, particularly for larger devices requiring values of several micro- or milli-farads. Here we introduce a polymer metal composite we have recently developed that meets typical aerospace design constraints of high reliability, robustness, light-weight, as well as high temperature (up to 300°C) operation. Our recent discovery of the capacitive behaviour in perfluorinated sulfonic acid polymers sandwiched between metal electrodes has lead to the exciting development of high temperature capable high density passive storage components. These composites exhibit capacitance per unit planar area of ~1.0 mF cm-2 or 40 mF/g for a ~100 ¿m-thick polymer substrate, with only a small predictable decrease in capacitance immediately after heating to 100°C followed by constant capacitance up to 300°C. Here we report the design and testing of single step microfabrication of metal electrodes to these polymer composites sandwiched between two thin metal films along with their performance at high temperatures.

Zhijie Liao - One of the best experts on this subject based on the ideXlab platform.

  • Hydrothermal Convection Systems and Geothermal Energy in the Southwest China
    Thermal Springs and Geothermal Energy in the Qinghai-Tibetan Plateau and the Surroundings, 2018
    Co-Authors: Zhijie Liao
    Abstract:

    This chapter is the assessment of geothermal resources (high and intermediate temperature) of the Qingzang Plateau and its surroundings. Based on the average of SiO_2, Na–K, Na–K–Ca and K–Mg geothermometers, 107 High-Temperature hydrothermal convective Systems have been determined and then their installed capacity has been estimated. The definition of 559 intermediate temperature Systems relies upon SiO_2 geothermometer for help. The geothermoelectric potential of High-Temperature System is 3410 MW_30yr and the beneficial heat is 11.78 EJ in research area.

  • Warm Springs and Tepid Springs in the Southwest China
    Springer Hydrogeology, 2017
    Co-Authors: Zhijie Liao
    Abstract:

    This chapter will briefly introduce warm springs and tepid springs in research area by making use of tabulation. The items in table will show serial number, spa’s name, county, longitude and latitude, altitude, spa’s temperature, the SiO2 content and TDS values of spa’s water, and type of water. The table is marked “SiO2 concentration” that can distinguish type of hydrothermal convective System. The chemical content of some low-temperature springs is similar to that of High-Temperature System. The analysis results of its water sample will be fully revealed.