IGBT Failure Research Articles

An Enhanced Dynamic Collector Voltage and Current Clamping Method for Semiconductor in Electric Vehicles

The electric drive and the batteries are the two primary parts of an electric vehicle (EV). In order to increase the availability and dependability of the semiconductors used in traction converters, this research focuses on a new approach of semiconductor protection. The IGBT overshoot in voltage during a short circuit situation was successfully reduced by a newly created active voltage and current clamping circuit. This innovative method restricts IGBT’s collector-emitter voltage during the turn-off event. As soon as the collector-emitter voltage of the IGBT crosses a predetermined threshold, the IGBT is partially turned on. The IGBT is then kept operating linearly, minimizing the rate at which the collector current falls and, consequently, and the collector-emitter over voltage. Simultaneously, during the short circuit, the current is monitored by a high precision hall-effect sensor allegro make IC, which detects over current and provides a fault output within 1µs. As a result of the combination of current and voltage monitoring, the likelihood of the IGBT failure is reduced drastically.

Application and Verification of a Leg-Transfer Method for Three-Level Active Neutral-Point-Clamped Inverters for Railway Vehicles

In this paper, a two-leg-transfer switch structure method that can continuously supply three-phase power even when an accident occurs in a power semiconductor of a three-level active neutral-point-clamped (ANPC) inverter for railway vehicles is presented. The proposed method can minimize the ripple effect caused by power semiconductor faults by separating the faulty leg from the main circuit and connecting the load-side circuit to a neutral point. As a result of simulations, the average values of MAE and RMSE can be reduced by 1.53 [A] and 1.77 [A], respectively, when using the proposed leg-transfer switch structure compared to using the conventional structure. In the IGBT failure experiment, when the proposed method was applied to a three-level ANPC inverter, there was only a 0.21 [%] difference from the THD under normal conditions. As a result, the magnitude, phase, and total harmonic distortion of the three-phase current waveforms measured before and after the fault were identical. Thus, normal three-phase power could be effectively supplied to the load when the proposed leg-transfer switch method was applied after a power semiconductor fault occurred in the three-level ANPC inverter. If this leg-transfer switch method is applied in three-level ANPC inverterd for railway vehicles, track schedule errors can be minimized by continuously supplying three-phase power to the electric motor even when an accident occurs in a power semiconductor.

Real-time mode of operation data analysis to catch the thread-tip denotes the failure cause of the grid-tie PV central inverter

The inverter is considered the core of the PV power plant. The inverter’s failure leads to generation loss and decreases plant availability. So, it is required to investigate a clear Root Cause Analysis (RCA) to deduce the failure causes and implement the required corrective action in addition to the preventive action to avoid more inverter failure, hereby maintaining the plant available to a certain value. This paper discusses real-time mode operation data analysis of the PV grid-connected inverter due to real central inverter incidents in Benban solar park located in Egypt.The central inverter plays an important role in the Mega-Scale PV power plant. The main function of this inverter is to convert the DC power produced by the PV modules to AC power to be injected into the utility grid by considering specific characteristics based on the grid code. The availability of any PV power plant directly depends on the healthy inverter’s operation. The more increases for the installed inverters, the less availability loss in the case of inverter partial or catastrophic failures. So, it is required to focus on the failure causes of the central inverter by implementing a technical analysis using the available operational data. The monitored data of the central inverter in the PV power plant is classified into two types. The first type is the continuous time data stored in the memory. It represents the waveforms of inverter outputs like voltage, current, frequency, …. etc. Unfortunately, in case of a catastrophic failure, the central inverter is completely charred, and the continuous time data is lost due to storage memory damage. The second type is the operation data that is recorded by the SCADA system (per one-minute interval). Hereby, the operation data is the sole data in the case of the completely charred inverter. The representation of the operational data in curves indicates symptoms that can be used for the RCA processes. The investigation outcomes include three results. The first result is detecting the signature of the IGBT thermal stress on the voltage balance of the DC link capacitor. The second result is verifying a scenario for the cause of the IGBT failure by implementing a technical mathematical model based on the detected symptoms that denote the fault signature which is considered the thread-tip for detecting the failure cause. The third result is the simulating scenario for the interpretation of a DC link capacitors explosion due to the short circuit fault that occurred due to IGBT failure. The investigation in this paper is performed based on operation data analysis of the PV grid-connected inverter (central type) due to a real incident. The analysis methodology is based on mathematical calculation for the IGBT junction temperature using the measured heatsink temperature. The study concludes that after the IGBT failure occurred, it was a short circuit for a while and closed the terminals of the DC link capacitors. So, the DC link capacitors exploded and produced heavy sparks that led to enough fire to burn the inverter container completely.

An alternate hybrid PWM for uniform thermal sharing in single phase voltage-source inverter

The most prevalent reason for IGBT failure in voltage-source inverter (VSI) is thermal stress, which is influenced by the topology and modulation technique adopted. Hence, it is crucial to understand the impact of common sinusoidal pulse width modulation (PWM) strategies on the thermal behavior of VSI and develop improved PWM techniques. This paper presents an alternate hybrid PWM (AHPWM) switching sequence for a single-phase VSI to decrease its thermal stress and prolong its lifetime. To evaluate the number of cycles to failure of VSI, power loss and thermal analysis were conducted for VSI with AHPWM and compared with conventional PWMs. The thermal cycles experienced by IGBTs with different modulation techniques were experimentally validated using a laboratory prototype of VSI. These findings suggest that by employing AHPWM, the likelihood of VSI failure is reduced by at least one-and-a-half times, resulting in lower VSI maintenance costs.

An Open-Circuit Fault Diagnosis Algorithm Based on Signal Normalization Preprocessing for Motor Drive Inverter

In this paper, an open-circuit (OC) fault diagnosis algorithm for power switch in the motor drive inverter system is proposed, which uses signal normalization preprocessing to deal with the current fluctuation caused by the load change. For the proposed fault diagnosis algorithm, firstly, the three-phase currents are sampled by the sliding window, which can improve the timeliness of diagnosis. Then, the sampled data is preprocessed by the variable modulus length normalization to eliminate the influence of the load change. Especially in the transient state, the information of the data feature is retained and the impact of load change is removed. Moreover, the frequency domain feature of the data is extracted by the DFT. Finally, the dimension of the features is reduced by the PCA method and its contribution graph is used to locate the fault IGBT. Moreover, the method can overcome the misjudgment of IGBT failure caused by transient currents when the load changes in the drive system. The simulation and experiment results show its effectiveness and timeliness in the OC fault diagnosis of the inverter.

A Critical Fault-Tolerant Inverter Based on Internal Evolutionary Short-Circuit Failure Mechanism of IGBT Module

Long-term and stable operation after failure is a challenge for high-reliability power converters. An extreme characteristic of IGBT is deeply explored, and a new cold-redundant inverter topology is proposed in this article. A quantity of epoxy-encapsulated IGBT modules is analyzed in short-circuit (SC) failure for critical energy. The evolution of the IGBT failure mechanism is crucial to the stability of this structure. An ohmic mode is discovered in dynamic characteristics analysis. Based on the robustness experimental test, the results revealed the characteristics of the internal structure reorganization and the evolution law of the electrical parameters under the rated current pulse stress. The epoxy-encapsulated IGBT module has a stable SC failure impedance characteristic <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${R}_{{\text {sc}}}$ </tex-math></inline-formula> , with no more than 20% drift even after a 624-h continuous thermal cycle aging test. On this basis, the new cold-redundant inverter platform with this IGBT module is tested. There is only one paralleled safety leg connected in series with the faulty equipment without any additional complexity or extra cost. The full process like fault identification, isolation, structural reorganization, switching, and loading is verified and realized after the transient SC faults.

The Simulation Analysis of IGBT Module Based on COMSOL

IGBT, as the core device of high-capacity power electronic equipment, its stability is directly relevant to the normal operation of the equipment. It would cause system failure and major security incidents if aging failure phenomenon occurs. A complex multi-physical field coupling process is involved in the aging failure of IGBT. Based on Comsol software, this paper conducts a series of simulations on IGBT module model SKM50GB12T4, and also improves the simulation of the solder layer voids by combining with related literature on materials science to provide a basis for subsequent research on IGBT.

Open‐circuit submodule fault diagnosis in MMCs using support vector machines

Series connection of semiconductor submodules (SM) in a modular multilevel converter (MMC) makes the MMC prone to open-circuit (OC) IGBT failures inside SMs. If left undetected, these faults degrade the operation of the MMC and lead to its instability. This article proposes a method to detect, localise, and classify single OC SM faults in an MMC using support vector machines (SVM) trained with data obtained from the capacitor voltage balancing block of the MMC control system. The proposed method relies on data extracted from the sorted capacitor voltage arrays of the upper and lower phase arms. Therefore, it does not require extra measurements and hardware. Additionally, it offers a fixed time for detecting and localising OC SM faults. This method is easy to implement as SVM has a simple decision function. Time-domain simulation case studies are performed on a three-phase nine-level MMC to evaluate the performance of the proposed method.

Transient Heat Transfer Characteristics in a Flat Plate Heat Sink with Mini-Channels for Cooling High Heat Flux IGBT.

Effective cooling of a high heat flux IGBT electronic system is highly related to system efficiency and safety. A flat plate heat sink was designed to experimentally investigate the transient heat transfer characteristics of IGBT cooling. It is made of aluminum with 20 mini-channels of 249 mm × 3 mm × 4 mm dimensions, which were manufactured by milling machines and melt inert gas (MIG) welding technology to ensure no deformation. Experiments were conducted using deionized water at atmospheric pressure with flow rates of 3.2–9.5 L/min and heat fluxes of 104–347 W/cm2. It was found that instantaneous start-stop and transient heating power variation might cause IGBT failure, especially under low Reynolds and Nusselt number conditions. The temperature rise rate and cooling rate vary with different system parameters. Heating rate can be reduced by high flow rate due to local subcooled boiling. The concept of respond time (RT) based on the piecewise function is suggested to evaluate the influence of transient condition on heating rate. Analysis of flow fluctuation indicated that it would not be a threat to the system except for in extreme cases. These findings provide a reference for the considerations of the design and manufacture of IGBT cooling flat plate heat sinks with mini-channels.

IGBT lifetime model considering composite failure modes

As a new generation of power devices, IGBT devices are widely used in fields such as aerospace, power transmission and transformation. Failures happen to the modules under different mechanisms and temperature conditions, but the current practice rarely considers the interaction of multiple failure mechanisms in the lifetime model, leading to an over optimistic lifetime prediction. With the analysis of the IGBT failure mechanism, this paper studies the IGBT's overall failure probability distribution assuming the failure of bonding wire and solder layer follows Weibull distribution. By exploring the impacts of the Weibull parameters, the relationship between the lifetime of each failed component and the IGBT's overall lifetime is quantified with the fitted coupling coefficients. The analyzing results show that when the bonding wire and the solder layer have similar lifetime, the IGBT's whole lifetime will be reduced, and the reduction degree is affected by the shape parameters of Weibull distribution, up to 30%. The IGBT lifetime model considering coupling effect is then established, which is verified by the experiments. The experimental results prove the existence of coupling effect, as well as the superiority of the model in lifetime prediction, whose error is reduced by 4.1% compared with that without coupling effect.

IGBT Failure mechanism and boundary analysis under large current and high temperature turn-off

Considering overload working conditions in electromagnetic emission, the paper presents a simulation of IGBT turn-off under large current and high temperature. Numerous simulation result is received under a specific test circuit. Boundary conditions for temperature, current and starry inductance are obtained under a set of temperature criterion. Further analysis proves that after temperature reaches the criterion, high current density path swiftly extends from local area to a vertical current path throughout the cells. This method for IGBT theoretical boundary is useful for similar projects or working conditions.

Accelerated Aging Experiment of IGBT under Pulsed Power and Reliability Studies

Pulsed power technology gives full play to the characteristics of high pulses in the form of short pulses, and gradually occupies a certain position in industrial applications. It needs to ensure stability and durability while ensuring that the working parameters are met, the switching performance is particularly important., therefore, the reliability study of IGBT power module becomes an inevitable requirement for reliability evaluation in engineering. This article mainly introduces the experimental method of the accelerated aging experiment of IGBT under pulsed power conditions. The electro-thermal simulation is carried out through PLECS and the low-power experimental platform is built to obtain experimental data. Finally, the experimental data is analyzed, and the change rule of the failure characteristic parameters with the aging process under the pulse power condition and the IGBT failure standard different from the typical operating condition are obtained.

New Approach in the Fault Tolerant Control of Three-Phase Inverter Fed Induction Motor

This article provides an improved fault-tolerant control scheme for inverter-powered induction motors. The proposed strategy addresses the cancellation of power switch failures (IGBTs) regardless of their location in a reconfigurable induction motor control. The proposed fault-tolerant topology requires only minimal hardware modifications of the conventional six-switch three-phase drive, mitigating IGBT failures through reconfiguration based on the substitution of an entire inverter arm. The detection mechanism is based on the tridimensional method from which a database will be used for the learning of the neural network. In this method, the current from the stator is used as input to the system, so access to the induction motor is not necessary.

Accelerated Degradation of IGBTs Due to High Gate Voltage at Various Temperature Environments

In this study, degradation phenomena due to gate bias stress at elevated temperature for the reliability test of punch-through IGBTs, which are widely used in DC circuit systems for automotive applications, were investigated. For the reliability tests of various temperatures, 4000 times temperature cycle stress was applied in IGBTs between &#x2212;40&#x00B0;C and 200&#x00B0;C to accelerate the degradation process using the wide range temperature. And the delamination of the passivation layer and the metal layer in IGBTs was observed using the scan acoustic microscopy. In addition, the positive bias stress with 48 V at elevated temperature of 150&#x00B0;C for 60 min was applied to the gate, the threshold voltage increased up to 6.07 V due to charge trapping at gate oxide. We also compared the recovery of the devices, but the IGBTs that stressed with high DC field and elevated temperature slowed down the recovery process after 24 hours without reverse voltage. This work was focused to find the device recovery considering real conditions. Therefore, the various temperature stress and high electric field stress are important in the reliability test for IGBTs, it was reported the IGBT degradation process and failure symptoms using the accelerated and various reliability tests.

Review of IGBT Junction Temperature Extraction and Estimation Methods

IGBT is widely used in photovoltaic power generation, aerospace, electric vehicles, ships and other power electronic equipment due to its advantages such as simple driving, high power level, low power consumption, and good thermal stability. As the core component of power electronic equipment, IGBT has always been a major concern for manufacturers and users. Excessive temperature is considered to be the main cause of IGBT failure. In order to meet the needs of high reliability in these applications, it is important to manage and control the temperature of the IGBT. Therefore, how to estimate or measure the junction temperature of IGBT is the focus of research on IGBT reliability. This article introduces several published methods for measuring junction temperature, focuses on the Temperature sensitive electrical parameters (TSEP) method and thermal resistance network method, and conducts experimental verification through the IGBT double-pulse test platform. Trying to provide help for future junction temperature detection work.

Reliability modelling and analysis on MMC for VSC‐HVDC by considering the press‐pack IGBT and capacitors failure

Modular multi-level converter (MMC) with press-packing IGBT devices is the popular and key equipment of VSC-HVDC system, its reliability is directly related to the equipment safe operation. However, it is difficult to analyse the reliability using the failure statistical approach due to less fault data. In order to improve the reliability analyses accuracy, it is necessary to use the physical failure method by considering the main components fatigue failure mode. The reliability analysis models are presented for the MMC sub-module with the press-packing IGBT device and metallised film capacitors. First, based on the MMC-HVDC simulation model, the losses and the junction temperatures of the IGBT devices were derived by the temperature field model, which the failure rates can be calculated. Furthermore, based the corrosion failure mode, the failure rate calculation of the metallised film capacitor was investigated using the voltage stress and thermal stress, the reliability calculation of the MMC sub-module was presented by combining the main components failure rates. Finally, the reliability of the VSC-HVDC based MMC was also presented with the different operation mode. The achievement is helpful to assess and improve the reliability of the VSC-HVDC.

Investigation on single pulse avalanche failure of SiC MOSFET and Si IGBT

In this work, avalanche ruggedness and failure mechanism of SiC MOSFET in single-pulse Unclamped Inductive Switching (UIS) test are investigated and compared with Si IGBT. The experimental results show that SiC MOSFET can handle ∼20% higher avalanche energy at the same current density, and ∼50% higher current density at the same amount of energy. As SiC device has 5× smaller chip size, the advantage will disappear when comparison is performed with avalanche current. To improve the avalanche current capability of SiC MOSFET, failure mechanisms are analyzed. At first, the junction temperature is calculated with V-T model and thermal model, from which a linear dependence of temperature on avalanche current is revealed. Then, the probability of parasitic BJT turn-on is modeled analytically with the base-to-emitter resistance/voltage, which is found to be highly dependent on the p+ ohmic contact resistance (ρc) and base doping concentration (NB) designs of the device. Based on the modeling results, at the peak junction temperature 650 K in UIS test, the BJT turn-on can already be triggered for SiC MOSFET. The failure trigger temperature can be raised with a higher NB and lower ρc design, thus the avalanche current capability can be increased accordingly. On the other hand, with a much deeper p+ body structure design, the Si IGBT can prevent the BJT latch-up failure. Based on the failure analysis, a trench source structure of SiC MOSFET is proposed to further improve the avalanche capability for smaller chip size design.

Analysis on IGBT and Diode Failures in Distribution Electronic Power Transformers

Fault characteristics of power electronic components are of great importance for a power electronic device, and are of extraordinary importance for those applied in power system. The topology structures and control method of Distribution Electronic Power Transformer (D-EPT) are introduced, and an exploration on fault types and fault characteristics for the IGBT and diode failures is presented. The analysis and simulation of different fault types for the fault characteristics lead to the D-EPT fault location scheme.

Multiple Fault Diagnosis for Three-level Inverter Via Wavelet Analysis and Support Vector Machine

Inverter is an important part in the locomotive traction system. In this paper a fault diagnosis method of three-level NPC inverter with two IGBT failures concurrently in different bridges was introduced. With the Simulink toolbox in Matlab, We obtained the output voltages’ difference between faulty and fault-free cases, get Ua、Ub、Uc , d-q transformation on Ua、Ub、Uc , put three-phase into two-phase, Ud and Uq. Making use of wavelet analysis to process Ud and Uq, extracted the fault feature and construct the feature vector. The samples which contain the fault information were accessed finally. With the LIBSVM toolbox, the multi-fault classifiers were established. Finally, the simulation samples were trained and tested. Experimental results showed that the classification result was fine and achieved the desired objective.

Analysis of the Results of Accelerated Aging Tests in Insulated Gate Bipolar Transistors

The introduction of fully electric vehicles (FEVs) into the mainstream has raised concerns about the reliability of their electronic components such as IGBT. The great variability in IGBT failure times caused by the very different operating conditions experienced and the stochasticity of their degradation processes suggests the adoption of condition-based maintenance approaches. Thus, the development of methods for assessing their healthy state and predicting their remaining useful life (RUL) is of key importance. In this paper, we investigate the results of performing accelerated aging tests. Our objective is to discuss the design and the results of accelerated aging tests performed on three different IGBT types within the electrical powertrain health monitoring for increased safety (HEMIS) of FEVs European Community project. During the tests, several electric signals were measured in different operating conditions. The results show that the case temperature $(T_{C})$ , the collector current $(I_{C})$ , and the collector–emitter voltage $(V_{{\rm CE}})$ are the failure precursor parameters that can be used for the development of a prognostic and health monitoring (PHM) system for FEV IGBTs and other medium-power switching supplies.