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关键词： Switching loss   Switching transient process   Accurate calculation method   Approximate analytical calculation  

摘要： Accurately revealing the generation mechanism and the mathematical relationship with system parameters of the power loss in the switching transients of high-voltage large power IGBT devices is very important for the device selection and circuit design of converter equipment. To reveal the mechanism of generating switching losses, this paper analyzes the switching transient processes of the IGBT devices in the basic commutation circuit in detail. Then this paper proposes an accurate calculation method based on a finite state machine (FSM) for the switching losses of IGBT devices, and verifies the correctness of this method. To further reveal the mathematical relationships among switching losses, device parameters, and loop parameters, approximate analytical formulas for the switching loss of different switching transient processes are mathematically derived, which can provide a theoretical basis for reducing the switching losses in converters.

关键词： 10-kV class   4H-SiC   differential specific ON-resistance   IGBT   laser annealing   waffle substrate  

摘要： The silicon carbide (SiC) waffle-substrate n-channel insulated gate bipolar transistor (IGBT) is a vertical IGBT designed to operate at blocking voltages below about 15 kV. At these voltages, the drift and anode layers are too thin to allow complete removal of the n(+) substrate. Instead, a waffle pattern is etched through the substrate to expose the buried anode layer while preserving the structural integrity of the wafer. The feasibility of this approach is demonstrated by fabricating a 10-kV class n-channel IGBT with a differential specific on-resistance of 160 m ***(2).

关键词： Insulated gate bipolar transistors (IGBT)  

摘要： Owing to the advantages of short-circuit failure mode, double-sided heat dissipation, and low thermal resistance, press-pack insulated gate bipolar transistors (PP-IGBTs) are widely used in high-power-density applications, such as high-voltage direct-current converters. As the core device of large-capacity power equipment, the reliability of a PP-IGBT is directly related to the security of the power system. In recent years, a silver-sintered package has been proposed to improve the electro-thermal performance of PP-IGBTs. However, the long-term reliability of this package has not been proven. In response to this problem, 3300-V/50-A silver-sintered PP-IGBT (SPP-IGBT) modules are used in long-reliability research. First, electro-thermal-stress finite-element models of PP-IGBTs and SPP-IGBTs were proposed and the accuracy of models verified by experiments. Through a simulation comparison, the results show that under the rated operating conditions, the on-voltage and maximum temperature of SPP-IGBTs dropped by 9.3% and 3.7%, respectively. In addition, the temperature and stress of each component were reduced, among which the surface stress of the IGBT chip emitter dropped by as much as 24.7%. Subsequently, a power-cycle test platform was established, and three PP-IGBTs and three SPP-IGBTs were tested. Finally, the experimental results were compared and analyzed, and the reasons for the sharp increase of on-voltage and metal melt were explored. The results show that the silver-sintered package improves the electrical-thermal performance and long-term reliability of the module. © 2022

关键词： Insulated gate bipolar transistors   Voltage   Logic gates   Mathematical models   Capacitance   MOSFET   Charge carrier processes   Behavioral model   excess carrier distribution   finite differential method   high-power insulated gate bipolar transistor (IGBT)   quasi static (QS) and nonquasi static (NQS) assumptions  

摘要： The calculation for carrier distribution in the quasi-neutral base region is necessary for modeling the turn-off process of an insulated gate bipolar transistor (IGBT). The carrier distribution difference between quasi static (QS) and nonquasi static (NQS) conditions and its influences on turn-off characteristics of a high-power IGBT are worthy of further study. In this article, the carrier distribution differences between QS and NQS conditions in different turn-off stages are first analyzed. In addition, based on the derived conclusions, a novel method modeling the turn-off process of high-power IGBTs is further proposed. In the method, the turn-off process before the collector-emitter voltage increases to the direct current (dc) voltage is modeled under the QS condition. In contrast, after the collector-emitter voltage increases to the dc voltage, the turn-off process is modeled under the NQS condition. Subsequently, the method is verified by comparisons with popular models and experiments. By adopting both QS and NQS assumptions, the proposed method can simplify the calculation and avoid considering the two-dimensional carrier distribution effect in the base. The method is implemented into SABER circuit simulator with MAST language and shows a high accuracy and considerable calculation efficiency.

关键词： Performance coefficient   TiO2-H2O Nano fluid   Si-IGBT power module   Micro-nozzle model  

摘要： In this paper, in order to improve the cooling power, the thermal effects of using titanium oxide nanoparticles with different concentrations and perforated nozzles with paddle blades are investigated. In this simulation, by presenting a new design for a Si-IGBT power module, three types of paddle blades with a simple nozzle type to pump cooling fluid are evaluated and compared. The boundary condition is that a constant heat flux enters from the top of the module, i.e., IGBT and the Diode. In order to further investigate the thermal effects, an attempt has been made to investigate the temperature of the module under a heat flux of 150 W cm(-2), 180 W cm(-2), 255 W cm(-2), so that the IGBT heat flux is always higher than the Diode input flux. In this robust and three-dimensional simulation extracted from ANSYS-FLUENT commercial software, it was found that turbulent kinetic energy increases with increasing number of nozzle blades. At the same time, increasing the volume fraction of nanoparticles from 0.01 to 0.05 leads to improved heat transfer and ultimately reduces the thermal peak created in the study space. In addition, increasing the transverse mass flow rate improves cooling, which reduces the performance coefficient (COP) of the system.

关键词： hybrid high voltage direct current circuit breaker   circuit breakers   fast short-circuit current isolation   MOV branch   power grids   IGBT   short-circuit currents   HVDC power convertors   hybrid HVDC circuit breaker prototype   insulated gate bipolar transistor   insulated gate bipolar transistors   power transmission faults   voltage stress   Zhangbei four-terminal voltage source converter-HVDC project   voltage-source convertors   PSCAD-EMTDC computer simulation   varistors   HVDC power transmission   electrical stress   short-circuit current isolation   metal oxide varistors  

摘要： This paper proposes a +/- 535 kV hybrid high voltage direct current (HVDC) circuit breaker. In this paper, the interruption processes of the main branch, transferring branch, and MOV (metal oxide varistors) branch are studied by PSCAD/EMTDC computer simulation. Simulation results indicate that an insulated gate bipolar transistor (IGBT) in the main branch will withstand the highest electrical stress (3305 V/2200 A) and the IGBT in the transferring branch will withstand the highest voltage stress (3327 V). Finally, the +/- 535 kV hybrid HVDC circuit breaker prototype is manufactured;the test is carried out. Test results suggest that the +/- 535 kV hybrid HVDC circuit breaker prototype developed for the Zhangbei four-terminal voltage source converter (VSC)-HVDC project can interrupt a +/- 25 kA (high current) within 2.84 ms. The simulation results agreed very well with the actual test results of our novel +/- 535 kV hybrid HVDC circuit breaker. The novel +/- 535 kV hybrid HVDC circuit breaker functioned exceptionally well in achieving fast short-circuit current isolation.

关键词： Silicon carbide  

摘要： This paper informs the design guidelines, fabrication process, and evaluation of a 1.7-kV and 300-A multi-chip half bridge power module using the novel Si-IGBT and SiC-MOSFET hybrid switch in each switch position. The module achieves its maximum DC current rating with a 6:1 current ratio of Si to SiC. This high current ratio yields significant cost savings compared to an all-SiC power module. The module employs high-reliability silver clips, which replaces conventional wire bonds for top-side interconnection, to partly enable a low power loop inductance of 12.38 nH. A novel thermal pyrolytic graphite-encapsulated metal baseplate is key to reducing the thermal coupling among the adjacent Si and SiC die, enabling higher junction temperature for SiC die relative to the Si die. © 2022

关键词： Insulated gate bipolar transistors   Parameter extraction   Integrated circuit modeling   Switches   Optimization   Behavioral sciences   Charge carrier processes   Automatic optimization   insulated gate bipolar transistors (IGBT)   parameter extraction   physics-based models  

摘要： The physics-based IGBT models have been proved to be very effective in accurately simulating the voltage, current, and carrier dynamics. However, the biggest challenge for those promising models is lack of detailed IGBT device parameters, which chip manufacturers generally seldom reveal. To extract precise and robust device parameters, a novel parameter extraction scheme based on the particle swarm optimization (PSO) algorithm is proposed in this article. The state-of-the-art Fourier-series-based (FSB) IGBT model is used to ensure the accuracy of the parameter extraction scheme. In the proposed scheme, IGBT parameters are simultaneously extracted by IGBT static and dynamic characteristic curves to account for global interaction between all those IGBT parameters during parameter optimization. The experiment is carried out to verify the proposed parameter extraction scheme. It should be noteworthy that only an experimental switching waveform under an arbitrary operating condition is required to implement global searching for the optimal parameters by our proposed scheme. The output characteristic curves and the switching waveforms of the FSB model under different operating conditions using the proposed parameter extraction scheme are in good agreement with the experimental waveforms. Results confirm the effectiveness and usefulness of the obtained device parameters by the randomly selected operating condition. Finally, the global sensitivity analysis is introduced to further demonstrate the reliability of the proposed parameter extraction scheme.

摘要： 2022-RA-66

关键词： switch-faults   fault-tolerant   vehicular system   Z-source inverter   induction motor   IGBT  

摘要： This paper presents an efficient and fast fault-tolerant control scheme for a bidirectional Z-source inverter (BiZSI)-fed induction-motor drive system for vehicular applications. The proposed strategy aims for the fault detection, localization and diagnosis of the proposed system during switch failures in the inverter module. Generally, power-semiconductor switch failures in inverter modules occur due to open- and short-circuit faults. An efficient modulation scheme is proposed and design specifications are thoroughly derived to obtain high voltage gains across the BiZSI network. A suitably fast detection and diagnosis scheme to isolate the faulty leg and resume the normal operation is discussed in this paper. The control scheme is provided such that the faulty leg is isolated and the motor phase is fed from a redundant leg to resume the operation. A feasible localization algorithm based on experimentally derived values and switching vectors is implemented. In addition, a fast fault diagnosis method based on current estimation and motor speed variation is designed and implemented. Moreover, the most important advantages of the proposed strategy include lower hardware requirements and less harmonic distortion in the output currents. Finally, the simulation and experimental results are presented to validate the feasibility of the theoretical analysis. An extensive performance evaluation of the proposed system with fault ride-through capabilities is performed to prove its suitability for vehicular applications. To validate its merits, the proposed strategy is compared with similar fault-tolerant schemes currently used in the industry.