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关键词： IGBT   Online monitoring   Reliability   Reliability Temperature fluctuation  

摘要： The IGBT chip temperature is an important index affecting device reliability. Due to the existence of packaging, the temperature data of the IGBT chip is difficult to obtain directly. Because the large IGBT switching frequency, the temperature changes quickly. The chip junction temperature fluctuation is too difficult to measure. Based on the Cauer electrothermal coupling model, this paper deduces the calculation formula of the IGBT chip temperature fluctuation. Through the on-stage voltage, collector current, thermal resistance, thermal capacitance, on time and off time that can be directly monitored, the chip temperature fluctuation inside the package can be calculated. Then the accuracy of the calculation formula of temperature fluctuation is verified by experimental method, and the experimental results confirm the feasibility of this method. The chip temperature fluctuation monitored by this method is the premise for the lifetime prediction and reliability research of the IGBT, which plays a great role in the engineering field.

关键词： fault-tolerant control   modular multilevel matrix converter (M3C)   open-circuit failure   Fault detection  

摘要： The modular multilevel matrix converter (M3C) is a topology that can realize direct ac-to-ac power conversion. To increase the reliability of the M3C, submodule (SM) fault ride-through capability is required to avoid unscheduled shutdown caused by the failures of power components in its SMs, such as the open-circuit fault of insulated gate bipolar transistors. Although this kind of fault has been widely studied for the regular dc-ac modular multilevel converter (MMC), the existing fault diagnosis criteria and fault-tolerant control processes are not directly applicable to the M3C. To solve this problem, this article analyzes the behavior of the M3C under open-circuit faults and proposes a suitable fault detection criterion for the M3C by transferring the observation errors of circulating currents into specific values. Meanwhile, since the observers can only identify two types of faults but not accurately locate the faulty device in a full-bridge SM, a modified fault tolerance process is proposed. Moreover, this article proposes a method to obtain the actual maximum intrinsic errors (AMIEs) of the observers to determine fault diagnosis thresholds under different load conditions. A downscaled M3C prototype with 27 SMs is built, and experimental results are presented to validate the effectiveness of the proposed fault detection criterion, the fault-tolerant control process, and the AMIE-obtaining method.

关键词： Insulated gate bipolar transistor (IGBT)   Health state prediction   Unscented particle filter   Thermal resistance   Genetic algorithm  

摘要： Insulated gate bipolar transistor (IGBT), as the most critical and vulnerable power electronic component in the field of rail transportation, its reliability has become a research hotspot in recent years. To improve the safe and reliable operation of rail transportation and to reduce the maintenance cost by rationalizing system maintenance, it is critical to monitor the health of the traction converter IGBTs. This paper first reviews the failure mechanism of the IGBT, then analyzes the health state characterization parameters of the IGBT by the accelerated aging test, selects thermal resistance as the health state characterization parameter of the IGBT, and establishes the degradation model of the IGBT. On this basis, a health state prediction method of IGBT based on the genetic algorithm unscented particle filter (GA-UPF) is proposed. This method uses an unscented Kalman filter to generate important proposal density distribution for each particle, estimates, and updates the parameters of the degradation model, alleviates the particle degradation problem, and uses a genetic algorithm to solve the particle impoverishment problem introduced by the traditional resampling method, which improves the particle diversity and prediction accuracy. Mahalanobis distance is used to monitor the abnormal state of the thermal resistance. After the abnormal occurs, the value of the thermal resistance is predicted according to the degradation model and updated parameters. The degradation trend of the thermal resistance is predicted to reflect the health state of the IGBT. Experiments on IGBT degradation data show that the proposed method can provide higher health state prediction accuracy than the traditional particle filter method.

关键词： Inverter   IGBT   Fault diagnosis   Open-circuit   Wavelet packet analysis   VMD   Variance   Average  

摘要： It is critical to accurately detect IGBT (Insulated Gate Bipolar Transistor) switch faults in order to ensure the reliability and robustness of three-phase inverters. In this work, a new approach for the enhancement of the IGBTs open-circuit faults of a three-phase diagnosis inverter is proposed. This approach is based on an Enhanced version of the Variational Mode Decomposition algorithm (EVMD) combined with wavelet packet analysis (WPA) and scalar indicators such as the average and variance value. Firstly, the three-phase current signals are denoised using an improved version of the denoising technique based on a WPA. Secondly, the denoised current signals are decomposed by EVMD algorithm into Band Limited Intrinsic Mode Functions (BLIMFs). Thirdly, BLIMFs that have the highest correlation coefficients with current signals are selected as useful modes. Fourthly, the variance of the BLIMFs that have the highest correlation coefficient among those selected is calculated in order to detect the faulty phase and, consequently, the faulty arm. Finally, the average of the BLIMF that has the lowest correlation coefficient among those selected for the faulty phase is calculated to localize the fault position in either the upper or the lower IGBTs of the faulty arm. The proposed approach is applied to experimental signals and the results obtained show well the efficiency of the performance of the proposed approach in the diagnosis of open-circuit faults.

关键词： RC-IGBT   Single -event burnout   Snapback  

摘要： This paper proposes a reverse conducting insulated gate bipolar transistors (RC-IGBT) structure with a raised N -buffer layer (RNB-IGBT) to improve the single-event burnout (SEB) robustness. The electrical and radiation properties of the structure were verified by TCAD simulations. At the same snapback voltage of 0.22 V and the liner energy transfer (LET) of 60 MeVcm2/mg conditions, the SEB threshold of RNB-IGBT is improved by 52 % compared to that of conventional RC-IGBT. This result indicates that the raised N-buffer layer of the RNB-IGBT can effectively reduce impact ionization, so it can suppress excessive heat concentration and avoid induce SEB.

关键词： current balance   interleaved   IGBT   two-phase boost converter  

摘要： A zero-current-transition (ZCT) strategy is proposed herein. This strategy is applied to a two-phase boost converter with isolated gate bipolar transistors (IGBTs) used as main switches. However, IGBTs have a current tail during the switch-off interval. Consequently, the proposed constant-frequency ZCT strategy along with common-ground auxiliary switches is employed to decrease the switching loss generated by the current tail. Furthermore, the light-load efficiency can be upgraded by regulating the switch-off instants and switch-on times of the two auxiliary switches. Moreover, two phases are interleaved with one phase having a phase difference of 180 degrees from the other phase, and controlled by a current-sharing controller so that the input current can be distributed between the two phases as evenly as possible. Moreover, only one current sensing circuit is required to obtain information on currents in the two main switches. Above all, the number of phases can be extended with easy control of the ZCT and current balance.

关键词： Multi -chip IGBT module   Thermal analysis   Solder layer aging   Thermal diffusion angle   Thermal coupling   Junction temperature estimation  

摘要： With the continuous increase in the scale of new energy grid-connected, high-power converter IGBT modules are widely used in wind, solar, and other new energy power generation systems. The safe and reliable operation of IGBT modules with parallel chips is becoming more and more important. In the multi-chip module, uneven solder aging will increase the thermal resistance of some chips, which will lead to an inaccurate estimation of the junction temperature of the multi-chip IGBT power module. To this end, this paper proposes to use the recon-structed thermal impedance matrix to modify the multi-chip thermal network model and estimate the junction temperature. By analyzing the nonlinear accelerated deterioration law between the aging degree of the solder layer and the self-thermal impedance and coupled thermal impedance of the IGBT module, the influence mechanism of different solder layer aging degrees inside the module on the thermal conduction radius and thermal diffusion angle is clarified. The thermal impedance matrix is reconstructed with the modified thermal diffusion angle, thus realizing the optimization of the thermal network model of the multi-chip IGBT module. The experimental results show that the junction temperature calculation results of the improved multi-chip IGBT module thermal network model are more in line with the finite element simulation than the traditional unim-proved method, thus verifying the validity and accuracy of the model, and laying a solid foundation for the large-scale integrated multi-chip thermal analysis. Theoretical basis.

关键词： IGBT modeling   parameter extraction  

摘要： Extracting gate-drain overlap oxide capacitance (C-oxd) is a necessary step for almost all kinds of insulated-gate bipolar transistor (IGBT) compact models. There are two datasheet-driven methods that are universally accepted, one is based on reverse capacitance voltage characteristics (C-V method), and the other uses gate charge characteristics (Q-V method). This letter is to reveal the underlying mechanism of these two methods. It is found that the C-V method has an inescapable shortcoming which will mistake the turn-OFF delay time forecasted by IGBT models. In this letter, the internal capacitance system of IGBT is modeled and demonstrated completely. Based on this model, the accuracy and feasibility of the C-V and Q-V methods are analyzed. Moreover, the effect of C-oxd on IGBT compact models is studied and further verified by experiments and circuit simulations.

关键词： IGBT   Dielectric barrier discharge   Drive circuit   Inverter power supply   Protection circuit  

摘要： Purpose This paper aims to improve the general circuit of driving and protection based on insulated gate bipolar transistor (IGBT) in dielectric barrier discharge power supply by designing a novel half-bridge inverter circuit with discrete components. Design/methodology/approach With one SG3524 chip, the structure based on discrete components is used to design the IGBT drive circuit. The driving waveform is isolated and sent out by photo-coupler 6N137. The protection circuit is realized by Hall sensor directly detecting the main circuit current, supplemented by a few components, including diodes, resistors, capacitors and triodes. It improves the reliability of the protection circuit. Findings In the driving circuit, the phase difference of signals from two channels are 180 degrees. Moreover, when the duty cycle is set at 40%, it can ensure sufficient pulse width modulation response time. In the protection circuit, when over-current occurs, an intermittent output signal is automatically sent out. Furthermore, the over-current response time can be controlled independently. The peak voltage can be adjusted continuously from 0 to 30 kV with its frequency from 8 to 25 kHz and the power output up to 150 W. Originality/value The novel circuit of driving and protection makes not only its structure simpler and easier to be realized but also key parameters, such as frequency, the duty cycle and the driving voltage, continuously adjustable. Moreover, the power supply is suitable for other discharges such as corona discharge and jet discharge.

关键词： Insulated gate bipolar transistors   Sensors   Temperature measurement   Temperature sensors   Temperature distribution   Fiber gratings   Junctions   Fiber Bragg grating (FBG) head size   FBG sensor   insulated gate bipolar transistor (IGBT)   junction temperature   on-chip thermal sensing   thermal distribution  

摘要： This article studies the influence of fiber Bragg grating (FBG) head length on insulated gate bipolar transistor (IGBT) direct on-chip thermal sensing performance of FBG sensors. To this end, the surface of a commercial IGBT chip is thermally simulated and experimentally characterized. Uniform FBG sensors with three head sizes are then tested in two promising thermal sensing locations. The study has found that the large thermal gradients in this application create an additional constraint when using longer head lengths. A distortion in the reflected spectrum of the 5-mm FBG sensor is used to illustrate the underlying physical effect, which causes this limitation for IGBT junction temperature measurement. This additionally affects the length of head sizes providing accurate temperature readings of the IGBT surface hotspots, and significantly, this limit is location-dependent in a given IGBT geometry.