• Journal of the Korean Physical Society
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• 제73권9호
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• pp.1356-1361
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• 2018

Replacing conventional Si diodes with SiC diodes in Si insulated gate bipolar transistor (IGBT) modules is advantageous as it can reduce power losses significantly. Also, the fast switching nature of the SiC diode will allow Si IGBTs to operate at their full high-switching-speed potential, which at present conventional Si diodes cannot do. In this work, the electrical test results for Si-IGBT/4HSiC-Schottky hybrid substrates (hybrid SiC substrates) are presented. These substrates are built for two voltage ratings, 1.7 kV and 3.3 kV. Comparisons of the 1.7 kV and the 3.3 kV Si-IGBT/Si-diode substrates (Si substrates) at room temperature ($20^{\circ}C$, RT) and high temperature ($H125^{\circ}C$, HT) have shown that the switching losses in hybrid SiC substrates are miniscule as compared to those in Si substrates but necessary steps are required to mitigate the ringing observed in the current waveforms. Also, the effect of design variations on the electrical performance of 1.7 kV, 50 A diodes is reported here. These variations are made in the active and termination regions of the device.

• Journal of Power Electronics
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• 제9권5호
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• pp.708-717
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• 2009

In this paper a new zero voltage transition PWM bridgeless PFC is introduced. The auxiliary circuit provides soft switching condition for all semiconductor devices. Also, in the resonant path of the auxiliary circuit, only two semiconductor devices exist. Therefore the resonant conduction losses are low. Furthermore, the auxiliary circuit semiconductor elements consist of only one diode and one switch. The proposed auxiliary circuit is applied to a bridgeless PFC converter to further reduce conduction and switching losses. In this paper, the operating modes of this converter are explained and the resulting ideal and simulation waveforms are shown. The presented experimental results justify the theoretical analysis.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2014년도 전력전자학술대회 논문집
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• pp.367-368
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• 2014

This paper investigates characteristics of high power semiconductor device losses in 5MW-class Permanent Magnet Synchronous Generator (PMSG) Medium Voltage (MV) wind turbines. High power semiconductor device of press-pack type IGCT of 6.5kV is considered in this paper. Analysis is performed based on neutral point clamped (NPC) 3-level back-to-back type voltage source converter (VSC) supplied from grid voltage of 4160V. This paper describes total loss distribution at worst case under inverter and rectifier operating mode for the power semiconductor switches. The loss analysis is confirmed through PLECS simulations. In addition, the loss factors due to di/dt snubber and ac input filter are presented. The investigation result shows that IGCT type semiconductor devices generate the total efficiency of 97.74% under the rated condition.

• 전력전자학회논문지
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• 제19권2호
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• pp.173-183
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• 2014

In this paper, an analysis of power losses for the three-level T-type and neutral-point clamped (NPC) PWM inverters is presented, in which the conduction and switching losses of semiconductor devices of the inverters are taken into account. In the inverter operation, the conduction loss depends on the modulation index (MI) and power factor (PF), whereas the switching loss depends on the switching frequency. Power losses for the T-type and NPC inverters are analyzed and calculated at the different operating points of MI, PF and the switching frequency, in which the four different models of semiconductor devices are adopted. In the case of lower MI, the NPC-type is more efficient than the T-type, and vice versa. The validity of the power loss analysis has been verified by the simulation results.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2001년도 Proceedings ICPE 01 2001 International Conference on Power Electronics
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• pp.31-35
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• 2001

IGCTs have established themselves as the power semiconductor of choice at medium voltage levels within the last few years because of their low conduction and switching losses. The trade-off between these losses can be adjusted by various lifetime control techniques and the growing demand for these devices is driving the need for standard types to cover such applications as Static Circuit Breakers (low on-state) and Medium Voltage Drives (low switching losses). The additional demands of Traction (low operating temperatures) and Current Source Inverters (symmetric blocking) would normally result in conflicting demands on the semiconductor. This paper will outline how a range of power devices can meet these needs with a limited number of wafers and gate units. Some of the key differences between IGCTs and IGBTs will be explained and the outlook for device improvements will be discussed.

• Journal of Power Electronics
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• 제18권5호
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• pp.1325-1335
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• 2018

This paper presents a discontinuous pulse width modulation (DPWM) method to reduce switching losses in an indirect matrix converter (IMC) drive. The IMC has a number of power semiconductor switches. In other words, it consists of a rectifier stage and an inverter stage for AC/AC power conversion, which are composed of 12 and 6 switching devices, respectively. Therefore, the switching devices of the IMC suffer from high switching losses in the IMC drives. Various topologies to reduce switching losses have been studied by eliminating a number of switches from the rectifier stage. In this study, in contrast to prior research, a DPWM method is presented to reduce the switching losses of the inverter stage. The effectiveness of the proposed method to reduce switching losses in IMC drives is verified by simulations and experimental results.

• 대한안전경영과학회지
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• 제8권2호
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• pp.13-23
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• 2006

The present study has investigated the patterns and the causes of safety -accidents on the accident-data in semiconductor Industries through near miss report the cases in the advanced companies. The ratio of incomplete actions to incomplete state was 4 to 6 as the cases of accidents in semiconductor industries in the respect of Human-ware, Hard- ware, Environment-ware and System-ware. The ratio of Human to machine in the attributes of semiconductor accident was 4 to 1. The study also investigated correlation among the system related to production, accident, losses and time. In semiconductor industry, we found that pattern of safety-accident analysis is organized potential, interaction, complexity, medium. Therefore, this study find out that semiconductor model consists of organization, individual, task, machine, environment and system.

• Journal of Power Electronics
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• 제19권1호
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• pp.68-78
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• 2019

The emergence of high voltage conversion applications has resulted in a trend of using semiconductor device series associations. Series associations allow for operation at blocking voltages, which are higher than the nominal voltage for each of the semiconductor devices. The main challenge with these topologies is finding a way to guarantee the voltage balance between devices in both blocking and switching transients. Most of the methods that have been proposed to mitigate static and dynamic voltage unbalances result in increased losses within the device. This paper introduces a new series stack topology, where the voltage unbalances are reduced. This in turn, mitigates the switching losses. The proposed topology consists of a circuit that ensures the soft switching of each device, and one auxiliary circuit that allows for switching energy recovery. The principle for the topology operation is presented and experimental tests are performed for two modules. The topology performs excellently for switching transients on each of the devices. The voltage static unbalances were limited to 10%, while the activation/deactivation delay introduced by the lower module IGBT driver takes place in the dynamic unbalances. Thus, the switching losses are reduced by 40%, when compared to hard switching configurations.

• Journal of Power Electronics
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• 제14권5호
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• pp.899-907
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• 2014

This paper proposes a single-phase bidirectional AC/DC converter topology applied in V2G systems, which consists of an inverter and a bidirectional non-inverting buck-boost converter. This topology can operate in four modes: buck charging, boost charging, buck discharging and boost discharging with high input current quality and unity input power factor. The inverter switches at line frequency, which is different from conventional voltage source inverters. A bidirectional buck-boost converter is utilized to adapt to a wider charging voltage range. The modulation and control strategy is introduced in detail, and the switching patterns are optimized to reduce the current ripple. In addition, the semiconductor losses are analyzed. Simulation and experimental results demonstrate the validity and effectiveness of the proposed topology.

• 전력전자학회논문지
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• 제25권6호
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• pp.451-458
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• 2020

In this study, a trade-off analysis of a power conversion system (PCS) is performed in accordance with a power semiconductor device to establish the suitable operating frequency range for the anyplace induction heating system. A resonant network is designed under each operating frequency condition to compare and analyze the PCS losses depending on the power semiconductor device. On the basis of the simulation results, the PCS losses and frequency condition are calculated. The calculated results are then used for a trade-off analysis between Si-MOSFET and GaN-HEMT based on PCS. The suitable operating frequency range is determined, and the validity of the analysis results is verified by the experiment results.