[Show abstract][Hide abstract] ABSTRACT: Supercapacitor aging is mainly related to thermal and voltage constraints. This aging causes degradation in the supercapacitor performances which can lead to the failure of this component. To avoid this failure, it is necessary to determine the supercapacitor state of health. The aim of this study is the supercapacitor diagnosis. In this paper, aging tests of supercapacitor subjected to calendar aging constraints are presented. The supercapacitor is aged at constant temperature and constant bias voltage. During the aging process, the variations of the supercapacitor equivalent series resistance (ESR) and equivalent capacitance (C) are measured and analyzed. For diagnosis, a least square algorithm is used. This algorithm is used for ESR and C identification during the supercapacitor operation. For vehicle applications, the supercapacitor is considered as aged when the capacitance loss is in order of 20% of its initial value, or if the value of the equivalent series resistance increases by a factor of 2.
[Show abstract][Hide abstract] ABSTRACT: In this paper, a new nonlinear control strategy for static boost type converters is proposed. This control law is an extension of the high gain control algorithm which takes into account the input model parameter uncertainties. Unlike traditional high gain approaches, the integral action is directly incorporated into the physical variables basis. This ensures constant performances even in presence of parametric uncertainties. In addition, the present control algorithm doesn't need the measurement of the battery voltage and the current load. These variables are estimated online with a nonlinear observer. The algorithm presented here is validated on a dedicated electric vehicle converter and experimental results are provided.
[Show abstract][Hide abstract] ABSTRACT: A new method of supercapacitor online health diagnosis based on an electric model and on experimental results obtained by calendar ageing tests is proposed.The calendar ageing of supercapacitor is mainly related to thermal and voltage constraints from the application. This ageing causes the degradation of supercapacitor performances which can finally lead to failures. In vehicle applications, the goal is to avoid these failures which may have serious consequences and high non-quality costs. The device survey and ageing state detection are a priority for anticipating the problems. This paper presents the case of calendar ageing tests on supercapacitors made of activated carbon and organic electrolyte. The ageing is performed at constant temperature (65 °C) under a 2.9 Vdc bias voltage. These tests permit to highlight online and in real-time the measurable external indicators of ageing.
Electric Power Systems Research 02/2013; 95:330–338. DOI:10.1016/j.epsr.2012.09.005 · 1.60 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: This paper deals with the effects of Co gamma irradiation on punch-through commercial insulated gate bipolar transistors turn-off switching behavior. The response of the threshold voltage, the gate-emitter leakage current, the collector leakage current, the collector-emitter breakdown voltage and the turn-off switching parameters under three different in situ gate biases are described. Charge trapping in the gate oxide causes the decrease of the threshold voltage. It is shown that the decrease of this parameter and the modifications in the Miller plateau level and width result in an increase of the turn-off delay time, the collector current fall-time, the collector-emitter voltage rise-time, and consequently an increase of the turn-off switching losses and a decrease of the turn-off overshoot collector-emitter voltage.
[Show abstract][Hide abstract] ABSTRACT: This paper presents supercapacitor ageing as a function of voltage, temperature and charge/discharge cycling solicitations. To investigate their effects, a test bench of accelerated supercapacitor calendar and cycling ageing was carried out. Experimental tests are performed at constant temperature when the supercapacitors are polarized at the maximum voltage in the case of calendar ageing. In the case of cycling test, supercapacitors are charged and discharged at constant current. It can be noted that when the supercapacitors are charged and discharged at constant current the temperature of the supercapacitor increases and that the average voltage is not zero. To quantify the supercapacitor ageing, the equivalent series resistance (ESR) and the equivalent capacitance (C) are measured.
[Show abstract][Hide abstract] ABSTRACT: This paper deals with the effects of 60Co gamma irradiation on punch-through commercial insulated gate bipolar transistor turn-on switching behaviour. The response of the threshold voltage and the turn-on switching parameters under three different in situ gate biases are described. Charge trapping in the gate oxide causes the decrease of the threshold voltage. It is shown that the decrease of this parameter and the decrease of the Miller plateau level result in a decrease of the collector current rise-time, the collector–emitter voltage fall-time, the turn-on switching energy and in an increase of the peak of the turn-on switching instantaneous power and of the turn-on overshoot collector current.
[Show abstract][Hide abstract] ABSTRACT: The ageing of power insulated gate bipolar transistor (IGBT) modules is mainly related to thermal and thermomechanical constraints applied to the device. This ageing causes degradation of the device performances and defects appearance which can lead to failures. To avoid these failures, the follow-up of the device operation and the detection of an ageing state remain a priority. This paper presents, at first, ageing tests of 1200V–30A IGBT module subjected to power cycling with the aim to highlight online and real-time measurable external indicators of ageing. Secondly, these indicators are used to develop a failure diagnosis method. The diagnosis is realized by artificial training methods based on pattern recognition.
[Show abstract][Hide abstract] ABSTRACT: The success of the high temperature power electronic applications depends on the power device reliability. The increasing thermal demands, like in hybrid electric cars, require power devices operating at junction temperatures above their common level of 125 °C. The thermal cycles generated in standard modules in such conditions induce several failure mechanisms in their package and chips. This article presents ageing tests of an EconoPIM IGBT module submitted to PWM power cycling at high ambient temperature. Several electrical and thermal parameters are monitored to detect failure onsets in the module components. Static and dynamic measurements are periodically made to reveal possible module characteristic drifts, and to better understand the effects of this kind of cycling test on the module static and switching behaviors. The follow-up of the dynamic parameter evolution represents the originality of this study.
[Show abstract][Hide abstract] ABSTRACT: This paper presents supercapacitor ageing according to the voltage, the temperature and thermal shock tests. To investigate this effect, a test bench of accelerated supercapacitor calendar ageing was carried out. Experimental tests are realized at constant temperature when the supercapacitors are polarized at the maximum voltage. To quantify the supercapacitor ageing, the equivalent series resistance (ESR) and the equivalent capacitance (C) are measured using the DC and AC characterization. To lead to the determination of the supercapacitor lifetime, Arrhenius law, that describes the effect of temperature on the velocity of a chemical reaction, is considered. Finally, experimental results of supercapacitor thermal shock are presented.
[Show abstract][Hide abstract] ABSTRACT: In this work we analyse the behavior of the Non Punch Through Trench Insulated Gate Bipolar Transistors submitted to High Temperature Gate Bias (HTGB) and High Temperature Reverse Bias (HTRB) stresses. The electric stress has been accomplished during 1200 hours at 140 °C with 0.8 VCEmax Collector - Emitter bias (HTRB) and with VGE = −20 V or +20 V Gate Bias (HTGB). The results show the evolution of the static parameters as threshold voltage and on-state voltage drop and of switching parameters. The aim is to constitute a database as complete as possible for the analysis and diagnosis of failure causes related to the switching devices in power conversion systems.
[Show abstract][Hide abstract] ABSTRACT: The work presented in this paper is concerned with the effects of a positive and of a negative gate bias stress on punch-through insulated gate bipolar transistors (PT-IGBT's). Two selections of PT IGBT's all of the same nominal range were gate biased at their positive and negative maximum gate-to-emitter voltage with drain and emitter short-circuited at 140 °C during 1200 hours. A particular interest was taken in the switching parameters. Experimental results on their evolution under the two types of stress are presented in a quantified way. Then, a qualitative analysis of the effects of the switching times shift, due to the IGBT's ageing, on a PWM inverter operation is presented.
Industrial Electronics, 2005. ISIE 2005. Proceedings of the IEEE International Symposium on; 07/2005
[Show abstract][Hide abstract] ABSTRACT: The work presented in this paper is concerned with the effects of a high temperature gate bias (HTGB) and a high temperature reverse bias (HTRB) stresses on non-punch-through IGBTs. The stresses were achieved during 1200 hours at 140degC. A particular interest was taken in the parameters related to the switching mode operation and experimental results on their evolution under the two types of stress are presented in a quantified way. A qualitative analysis of the switching times effects, due to the IGBTs ageing, on a pulse width modulation (PWM) inverter operation is presented
[Show abstract][Hide abstract] ABSTRACT: The work presented in this paper is concerned with the effects of a high temperature gate bias (HTGB) stress on punch-through (PT) and non-punch-through (NPT) insulated gate bipolar transistors (IGBTs). A selection of PT IGBTs and a selection of NPT IGBTs all of the same nominal range were gate biased at their maximum gate-to-emitter voltage with drain and emitter short circuited at 140 °C during 1200 hours. A particular interest was taken in the switching parameters. The turn-on delay time t<sub>don</sub> increases for the PT IGBTs while it decreases for the NPT IGBTs. The switching losses and the rise time increase for the two technologies. The turn-off delay time monotonically decreases for both the PT and NPT IGBTs. The fall time decreases for the PT IGBTs whereas it increases but in a less important way for the other technology. The on state voltage drop increases in both cases and in a more important way for the PT IGBTs. The gale threshold voltage is quiet insensitive to this type of stress for the NPT IGBTs whereas it increases during the first hundred hours of stress and remains unchanged thereafter for the PT IGBTs. The gate leakage current increases strongly for the two technologies while the collector leakage current, such as the threshold voltage, increases to remain constant after some hours of stress for the PT IGBTs.
Industrial Electronics, 2004 IEEE International Symposium on; 06/2004
[Show abstract][Hide abstract] ABSTRACT: Gate bias stress as well as hot-carrier stress are applied to polysilicon thin film transistors made from two types of channel-silicon dioxide interface. The transfer characteristics of the two types of TFTs were measured in the range of temperature from 90K up to 450K. Initially the material constituting the channel region is more defected in one type and TFTs made from this last type degrade more than the other. The degradation is observed from the increase of the substhreshold slope S, the shift of the threshold voltage V-T, and the increase of the defect density in the channel region.
[Show abstract][Hide abstract] ABSTRACT: Previous works on the study of the state creation under gate-bias stress in polysilicon thin film transistors (TFTs) are extended here by some measurements of the transfer characteristics in the temperature range from 90 to 400 K. Using two different qualities of the active layer polysilicon material, the analysis gives evidence of this state creation. Moreover, and surprisingly, the measurements show a nearly constant on-current at temperature lower than 300 K. So, the field effect mobility is nearly constant from 300 to 90 K and, due to the decrease of the off-current, the Ion/Ioff ratio increases from 107 at 300 K to 109 at 90 K. The density of states (DOS) is calculated assuming polycrystalline silicon as a spatially homogeneous material with a uniform distribution of the DOS in the bulk. Using the transconductance of the TFTs at different temperatures, we can check a wide region of the band-gap. The calculation gives a nearly constant DOS in a large part of the gap and very low extended band-tails. A bump, more important with the lower quality material, appears in the DOS after negative gate bias stress.
Thin Solid Films 03/2003; 427(1):340-344. DOI:10.1016/S0040-6090(02)01209-9 · 2.13 Impact Factor