Pack Insulated Gate Bipolar Transistor Research Articles

A Thermal Twin Modeling Method of Press Pack IGBT Based on Power Loss

The thermal modeling of a press pack insulated gate bipolar transistor (PP-IGBT) is crucial for device reliability estimation and operation management. However, the traditional finite element model (FEM) cannot simulate the temperature of a PP-IGBT device in real time, resulting in lifetime evaluation delays and errors. Therefore, this article proposes a thermal twin (TT) modeling method of a PP-IGBT based on power loss. First, common PP-IGBT TT modeling based on the reduced-order model (ROM) technology is introduced, and an optimized PP-IGBT TT modeling method based on power loss is proposed and compared with the common TT modeling method. Second, the electro-thermal coupling PP-IGBT FEM is determined, and the optimized PP-IGBT TT and a digital interface based on FEM simulation results are established and analyzed. Finally, the digital twin (DT) interaction system of the PP-IGBT is established, and the accuracy of the proposed TT model is verified via infrared experiments. The results reveal that the proposed PP-IGBT TT realizes the real-time and comprehensive mapping of the device temperature, and has great applicability potential in temperature monitoring and reliability evaluation.

Optimization on Thermomechanical Behavior for Improving the Reliability of Press Pack IGBT Using Response Surface Method

A press pack insulated gate bipolar transistor (PP IGBT) device consists of multiple materials. Under the influence of alternating current and clamping force, the device suffers from complex thermomechanical stress. However, the experience-based packaging design does not consider the coupling effect of junction temperature fluctuation ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\Delta T_{\mathrm{ j}}$ </tex-math></inline-formula> ) and mechanical stress, which may not ensure the optimal thermomechanical behavior and cause the advance failure of the PP IGBT device. Thus, it is significant to provide a theoretical basis and select appropriate parameters for device packaging design. In this article, a finite-element model of a 3300-V/50-A PP IGBT device is first built and verified via experiments. The influence of principal parameters on the thermomechanical behavior is then illustrated. Next, the response surface method is proposed to reveal the significance level of each parameter. According to simulation results under different combinations of parameters, quadratic response surfaces are obtained. The combined effects of packaging parameters on <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\Delta T_{\mathrm{ j}}$ </tex-math></inline-formula> and stress are clarified. Finally, optimal results are derived and verified. An approximate 4 °C decrease in <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\Delta T_{\mathrm{ j}}$ </tex-math></inline-formula> and a 19.8% decrease in stress are achieved simultaneously in the long-time power cycling test. A 2.6 °C reduction in junction temperature is achieved under the practical high-voltage direct current (HVDC) condition.

Method of Turns Arrangement of Noncircular Rogowski Coil With Rectangular Section

The circular Rogowski coil with a rectangular section is the most common and basic measuring unit of current. However, in some situations, a noncircular Rogowski coil is more suitable because of the limited space to be embedded in and the demand for decreasing the size of the Rogowski coil. Circular Rogowski coil is usually wound uniformly to guarantee the positional accuracy and anti-interference ability considering the very good symmetry. However, for noncircular Rogowski coil, the turns arrangement is usually designed based on experience due to the lack of theoretic direction. This article first proposed a method of turns arrangement of the noncircular Rogowski coil with a rectangular section, which the positional accuracy and anti-interference ability can be achieved at the same time. By establishing the equivalent relation between mutual inductance and electric potential, the turns density of the noncircular Rogowski coil can be acquired by solving the charge density on its equivalent electrodes. The turns density is proven to be unique. For a given turn number, the turns arrangement of the noncircular Rogowski coil can be obtained by discretizing the turns density. As an example of the method, a square Rogowski coil, which can be used in chip current measurement in Press Pack insulated gate bipolar transistors (IGBTs), is particularly designed and contrasted with the traditional square Rogowski coil with turns equidistantly arranged to verify the great positional accuracy and anti-interference ability. The results of the calculation and experiment show that this method is very effective.

Research on the Multiphysics Field-Circuit Coupling Model of Press Pack IGBT Considering the Application of Hybrid HVDC Breakers

Press pack insulated gate bipolar transistor (PP IGBT) is suitable for the hybrid high voltage direct current (HVdc) breaker to clear the fault current of the flexible HVdc transmission system with its advantages of double-side cooling, short-circuit failure mode, and easy to connect in series. However, it should have the ability to transmit the fault current, which is up to five or six times of its rated current, within several milliseconds depending on the distances between two stations without external cooling system. The junction temperature of PP IGBT will increase sharply and it is not possible to be measured during that situation. Therefore, the accurate prediction of junction temperature is extremely important for the packaging design of PP IGBT according to its working condition. In this article, an electro-thermo-mechanical multiphysics field-circuit coupling model of PP IGBT, which is coupled with the electrical, thermal, and mechanical fields, is proposed to predict the collector current, clamping force, and junction temperature. The 3-D mechanical model is decoupled with the 1-D electro-thermal Cauer network model to simplify this multiphysics model without reducing its accuracy. Both the normal and worst working conditions are analyzed through this multiphysics field-circuit model.

Study on the Method to Measure Thermal Contact Resistance Within Press Pack IGBTs

The accurate measurement of the thermal contact resistance between multilayers within press pack insulated gate bipolar transistors (PP IGBTs) is significant for optimizing their thermal resistance to improve reliability, as thermal contact resistance accounts for about 50% of their total thermal resistance under the rated clamping force. The components within PP IGBTs are very small, and an external clamping force is needed to ensure they work normally. Thus, the methods of thermal contact resistance measurement of steady-state and transient methods are no longer suitable. In this paper, the method of thermal structure function is proposed to measure the thermal contact resistance between multilayers within PP IGBTs. The accurate measurement of the transient thermal impedance curve of PP IGBTs is the key to this method, and it can then be transformed to a cumulative and differential structure function to determine the thermal contact resistance accurately. A single fast recovery diode chip submodule is fabricated to predict the thermal contact resistance behavior within PP IGBTs in this experiment, and the experimental results agree well with theoretical values. Furthermore, the influence of both the high temperature and the clamping force on the thermal contact resistance can also be obtained from this method accurately.

Analysis and Experiments for IGBT, IEGT, and IGCT in Hybrid DC Circuit Breaker

As power semiconductor devices are the key components of hybrid DC circuit breakers (HCBs), how to select suitable devices is critical for the whole HCB design. First, this paper compared the general characteristics of press pack insulated gate bipolar transistor (IGBT), injection-enhanced gate transistor (IEGT), and integrated gate commutated thyristor (IGCT). Then working conditions of devices were analyzed from the perspective of HCBs. According to these, vital features of devices including maximum turn-off current, on-state voltage, conduction ability, and robustness of power semiconductor devices were carefully analyzed and compared. Related experiments were implemented to compare maximum turn-off capability, and the 4.5 kV/3 kA IGBT/IEGT was able to turn off 19 and 22 kA respectively after 5-ms current conduction. Analysis and experiments indicated that IGCT was suitable for natural commutation low-voltage and low-current hybrid circuit breakers, due to its low on-state voltage and huge surge current conduction ability. Comparatively, IGBT and IEGT were more suitable for very high current interruption, and IEGT was the superior selection among available commercial devices. However, the interference should be considered in applications.

High-Frequency Experimental Characterization and Modeling of Six Pack IGBTs Power Modules

In this paper, a method to characterize the high-frequency (HF) behavior of six pack insulated gate bipolar transistors (IGBTs) power module (PM) is presented. The method is based on experimental measurements at the external pins of the device and it allows one to extract internal inductive and capacitive parasitic coupling without the knowledge of structural and physical parameters of the PM. The HF model of a six pack IGBTs PM has been developed, in the frequency range of 150 kHz–30 MHz, and it has been implemented in MATLAB environment. The method has been experimentally validated by comparing the frequency behavior of the PM with the simulated response. Moreover, the HF conducted disturbances, generated by the PM and measured in the dc link, have been compared with the simulation results verifying the proposed model.

On the Operation of a Press Pack IGBT Module Under Short Circuit Conditions

Press pack insulated gate bipolar transistor (IGBT) modules connected in series for high-voltage direct current (HVDC) converter applications are designed such that when a failure occurs, it occurs in a safe manner by the formation of a stable short circuit, while redundant modules take up the voltage blocking function of the failed module. One such design using individual pressure contacts is described and the events occurring from the initiation of the short circuit to its final failure due to open circuit are reported from an electronics packaging materials design point of view. Experiments to hasten the failure under accelerated test conditions on modules were performed and interrupted at various stages of operation under a short circuit condition. The formation and subsequent aging of the metallurgical alloy under short circuit conditions was investigated by analyzing cross sections of the alloy forming the short circuit. Liquid metal corrosion along with the formation of intermetallics with poor conductivities lead to the final failure by open circuit