Switching performance improvement of IGBT modules using an active gate driver

High power insulated gate bipolar transistors (IGBTs) are integral to modern power conversion systems across railway traction, renewable energy, and HVDC transmission. Traditional gate drivers offer limited adaptability under dynamic conditions, leading to increased switching losses and reduced reliability. This paper proposes a novel current source based active gate driver (CS-AGD) tailored for high-power IGBT modules, enabling dynamic control of transient switching characteristics. We design and prototype a CS-AGD circuit, integrate it within a wide-range double-pulse test platform, and experimentally validate its performance under voltages up to 1000 V and currents up to 600 A. Results demonstrate significant reductions in switching losses and peak voltage/current overshoots compared to conventional gate driving strategies. The proposed solution offers enhanced controllability, opening new pathways for reliability- optimized and high-efficiency power electronic systems.

The device-circuit interactions of the power insulated gate bipolar transistor (IGBT) for a series resistor-inductor load, both with and without a snubber, are simulated. An analytical model for the transient operation of the IGBT, previously developed, is used in conjunction with the load circuit state equations for the simulations. The simulated results are compared with experimental results for all conditions. Devices with a variety of base lifetimes are studied. For the fastest devices studied (base lifetime=0.3 mu s), the voltage overshoot of the series resistor-inductor load circuit approaches the device voltage (500 V) for load inductances greater than 1 mu H. For slower devices, though, the voltage overshoot is much less, and a larger inductance can therefore be switched without a snubber circuit (e.g. 80 mu H for a 7.1 mu s device). The simulations are used to determine the conditions for which the different devices can be switched safely without a snubber protection circuit. Simulations are also used to determine the required values and ratings for protection circuit components when protection circuits are necessary.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Thermal behavior of power insulated gate bipolar transistor (IGBT) modules was studied in this paper experimentally. Due primarily to the thermal mismatch in IGBT sandwich structure, thermal stress induced solder fatigue failures, such as the forming and growing of voids and cracks in IGBT solder layers, were quasi-dynamically observed in thermal cycling test. Thermal stress simulation provided stress distribution and bending deformation in IGBT packaging numerically, which is in agreement with the test results. Emitter bonding wire lifting failure and local overheat induced chip burn-out failure, both observed in intermittent operating test, indicate that thermal nonuniform distribution is a main reason affecting IGBT reliability. The study results of this paper are profitable to high reliable IGBT module manufacture and application.

In high power applications, proper gate control strategy for insulated gate bipolar transistors (IGBTs) can increase their efficient and reliability. As to the feed-back control strategy, the key issues are the control speed and control stability. This paper proposed a new feed-back control method integrated in digital gate driver for high power IGBT. It aims for controlling the current and voltage slope suppressing the voltage overshoot and electromagnetic interference (EMI) in switching transient. The digital gate driver for large power IGBT detects the collector current and voltage in real time. Then the detected analog signal is digitally sampled and sent to the digital core on board. An algorithm similar to bang-bang control is deployed in forward control loop to adjust the gate drive resistance. The control stability and robustness can be guaranteed as a result. The whole detection and control process is accomplished in real time with only hundreds of nanoseconds. Thus, the proposed control method can optimized the IGBT switching transient with high reliability and time effectiveness. Experimental results validate the feasibility of the proposed feed-back digital control method.

The effect of the gate drive on the power-processing capacity of a hard-switched insulated-gate bipolar transistor (IGBT) in a bridge leg is investigated in this article. The performance of two active gate drive (AGD) techniques [variable ramp (VR) and push-pull (PP)] is compared against a conventional two-level [fast gate drive (FGD)] gate drive method. The two proposed techniques reduce the voltage overshoot, which allows the dc-bus voltage to be increased closer to the IGBT voltage rating, improving the utilization of the device's blocking voltage. Consequently, the safe operating area of the IGBT is extended without exceeding the thermal limit of the device (limited by the maximum junction temperature). An experimental method, the first of its kind in the literature, is developed to determine whether using these AGDs can lead to an increase in the power that the IGBT can process. This article reveals that the PP-AGD technique can increase the IGBT power throughput by approximately 5%-8% across a range of switching frequencies. This better IGBT utilization allows a given device to process more power or may allow the designer to choose lower power rated devices potentially leading to higher converter power density.

The power insulated gate bipolar transistor (IGBT) is used in many types of applications. Although the use of the power IGBT has been well characterized for many continuous operation power electronics applications, little published information is available regarding the performance of a given IGBT under pulsed power conditions. Additionally, component libraries in circuit simulation software packages have a finite number of IGBTs. This paper presents a process for characterizing the performance of a given power IGBT under pulsed power conditions. Specifically, signals up to 4.5 kV and 1 kA with approximately a 5 ¿s pulse width will be applied to a given IGBT. This process utilizes curve fitting techniques with collected data to determine values for a set of modeling parameters. These parameters are used in the Oziemkiewicz implementation of the Hefner model for the IGBT that is utilized in some circuit simulation software packages. After the nominal parameter values are determined, they can be inserted into the Oziemkiewicz implementation to simulate a given IGBT.

Moisture in a high power Insulated Gate Bipolar Transistor (IGBT) module raises serious concern on component and system level reliability. Employing diagnostic test methods on high power IGBT modules might provide an opportunity in detection and estimation of moisture, however has not received wide attention. This paper investigates on understanding the influence of moisture in high power IGBT modules through time and frequency dependent dielectric response measurements and partial discharge analysis. The moisture in the main insulation of an IGBT module under DC excitation produces a sharp rise in its response current introducing deviation in their respective time dependent dielectric properties. Alternatively, the frequency dependent dielectric response measurements under wide frequencies provide more information than their DC counterpart. This method enables discrimination of various defects such as moisture, physical defects, etc., thereby revealing a clear picture about the actual status. In particular, the lower frequencies reveal longer range ion movements, hence could be used for more accurate estimation of moisture. The higher frequencies though not accurate in moisture estimation reveal deviation in the material properties. These deviations alter the apparent dielectric characteristics such as loss factor, permittivity, etc., of the IGBT samples which becomes clear through simple comparative analysis. In conclusion, the findings in this paper might help in understanding the influence of moisture over the dielectric integrity of a high power IGBT module. Additionally, the permissible or acceptable level of moisture which might act as a threshold to initiate necessary precautionary measures could be subsequently developed.

The increase of the switching speed in power semiconductors leads to converters with better efficiency and high power density. On the other hand, fast switching generates some consequences like overshoots and higher switching transient, which provoke electromagnetic interference (EMI). This paper proposes a new closed-loop gate driver to improve switching trajectory in insulated gate bipolar transistors (IGBTs) at the hard switching condition. The proposed closed-loop gate driver is based on an active gate voltage control method, which deals with emitter voltage (VEe) for controlling diC/dt and gets feedback from the output voltage (vCE) in order to control dvCE/dt. The sampled voltage signals modify the profile of the applied gate voltage (vgg). As a result, the desired gate driver (GD) improves the switching transients with minimum switching loss. The operation principle and implementation of the controller in the GD are thoroughly described. It can be observed that the new GD controls both dvCE/dt and diC/dt accurately independent of the variable parameters. The new control method is verified by experimental results. As a current issue, the known trade-off between switching losses and EMI is improved by this simple and effective control method.

Insulated gate bipolar transistors (IGBTs) are usually connected in series to satisfy the requirements of high-power and high-voltage in power electronics applications. However, due to the parameter deviations of the series-connected IGBTs, it is difficult to ensure an equal voltage sharing between them during both transient and steady-state operations. This paper proposed a novel active gate drive (AGD) which operates basing on the active gate charge control strategy. The proposed active gate drive was able to achieve both minimized switching loss and proper voltage sharing between the series-connected IGBTs. The performance of the proposed active gate drive and active gate control method have been validated by experimental results, and promising results have been obtained.

The new smart high-voltage gate drivers, the IXBD4410 and the IXBD4411, were designed to drive and protect power MOS and insulated gate bipolar transistor (IGBT) devices and modules in a phase leg or a totem pole inverter output configuration. These gate drivers function reliably under extreme d nu /dt and di/dt noise environments, with the half bridge inverter output voltages limited only by the breakdown of the external discrete devices. The IXBD4410 provides a diagnostic fault output flag, reflecting the condition of not only the low side but the high side device in a half bridge application. The IXBD4410 family devices can be configured to detect operating overcurrents using a resistor in series with the power device source, or by using one of several desaturation sense circuits presented. If the drive current output of the IXBD4410 is not adequate, a simple circuit consisting of a pair of complementary bipolar transistors can be placed between the IXBD4410 family device and the power MOS, IGBT, or module.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Flyback converters with synchronous rectifiers are an important topic in power electronics, given their widespread use in various applications and the focus on efficiency improvement. However, flyback converters suffer from a high overvoltage across the synchronous rectifier on their secondary side. This overshoot voltage is a result of resonance between the flyback transformer stray inductance and the output capacitance of the rectifier. This paper presents an in-depth experimental study on the optimization of dead time and Active Gate Driving in flyback converters employing synchronous rectifiers, i.e. Silicon Carbide Power MOSFETs in place of the secondary rectifier driven synchronously with the primary switch. The focus is the influence of symmetrical dead time variation between the primary and secondary switches on switching losses and overshoot voltage. In addition, the influence of a three voltage level active gate driver on the overshoot voltage and switching losses is examined, finding no significant influence. The findings from this study contribute to the existing body of knowledge by providing a nuanced understanding of dead time optimization in flyback converters with synchronous rectifiers, as well as the utilization of Active Gate Drivers in such systems. The results have implications for the design and operation of these converters, potentially leading to more efficient and reliable systems.

As the insulated gate bipolar transistor (IGBT) modules have their own specific characteristic switching forms, their turn-on and turn-off times are changed according to practical applications. For the conventional gate drives, gate resistors are used to adjust the turn-on and turn-off times which change switching losses that have a significant amount in total losses. Collector current rate of change, $di_{C}/ dt$ and collector-emitter rate of change, $dv_{CE}/ dt$ are dependent on each other and they affect operating parameters in high power converters. Relations between current and voltages during the switching transitions are given and effects of the changes in electrical parameters for the operation of IGBT are described. Thereafter, closed-loop gate drive with analog control that performs independent control of $di_{C}/ dt$ and $dv_{CE}/ dt$ of a new generation IGBT module platform for high power applications is proposed. Unlike conventional gate drives, proposed closed-loop drive makes constant $di_{C}/ dt$ possible while $dv_{CE}/ dt$ is decreased to increase the efficiency of the power conversion system. This leads to decrease of the switching losses without changing the electromagnetic interference (EMI), IGBT voltage, and current stresses which are related with the rate of change of collector current. Simulations are performed in a double pulse test circuit in which new package next high power density dual (nHPD$^{2}$) family MBM450FS33F Hitachi dual IGBT with 3300V 450A ratings is modelled.

Ageing defect detection on IGBT power modules by artificial training methods based on pattern recognition

This paper reports a detailed analysis of the performance and stability of E-mode GaN HEMTs under soft and hard switching conditions. We developed a novel on-wafer setup that controls the overlapping between the gate and drain pulses and, simultaneously, senses the current at the source. This allowed us to plot the instantaneous power, the switching I-V locus and evaluate the switching losses on wafer level. The dynamic on-resistance RDS,ON is evaluated during hard and soft switching at room temperature and high temperature. The results demonstrate that (i) the properties of the buffer impact on dynamic-Ron, in soft- and hard-switching; devices with non-optimized buffer have stronger dynamic-Ron under hard switching; (ii) Ron-increase under hard switching is not strongly influenced by switching (power) losses; (iii) results indicate that a higher dynamic-Ron in hard switching is correlated to a wider switching locus. The proposed testing approach can be used as a screening tool to evaluate - in one single measurement - the switching losses, the dynamic-Ron and the impact of hard-switching on wafer level.

Insulated gate bipolar transistor (IGBT)-based pulsewidth modulation (PWM) inverters are commonly used in inductive load circuits such as motor control. During clamped inductive load turn off of the IGBT, high-power losses occur during two phases. Due to the large inductive motor load, the voltage across the IGBT rises to the bus voltage while carrying the full-rated current. In the second phase, the current decreases as the IGBT goes into its forward blocking mode. In this paper, the turn-off process during the first phase is analyzed in detail for the first time. A simple analytical model has been derived, based upon the initial steady-state minority carrier distribution, which allows predicting the rate of rise of the voltage during this time period where the collector current remains constant. The predictions of the analytical model are in excellent agreement with results obtained from two-dimensional (2-D) numerical simulations over a broad range of minority carrier lifetime values. This analytical model provides a good estimate (within 10%) of the power losses incurred during the first phase of turn off.