• 전기의세계
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• v.45 no.7
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• pp.45-50
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• 1996

이번에 대학에서 연구한 논문은 전체의 25%에 불과하며, 그나마 미국, 캐나다의 3-4개 대학에서 대부분의 논문을 발표하고 있는 형편이다. 이들 조차 기업체보다 열악한 실험 장비로 인하여, 상당히 어려움을 겪고 있고, 실리콘을 기반으로 한 소자는 거의 손을 떼고, SiC와 같이 신물질을 이용한 전력 소자에 대한 연구로 겨우 버티고 있는 실정이다. 우리나라 대학의 논문 수준은 이보다 더 낙후되어 있지만, 앞으로 더욱 열심히 노력하여 항복전압이 일어나지 않는 새로운 구조나, on-state voltage drop이 0 V인 정류기와 같은 기술적인 breakthrough를 가져올 수 있는 아이디어를 실현시킨다면, 다음 ISPSD에서는 멋지게 큰 홈런을 날릴 수 있으리라는 희망을 안고 귀국했다.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.14 no.1
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• pp.183-190
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• 2010

We propose an eFuse one-time programmable (OTP) memory cell based on a logic process, which is programmable by an external program voltage. For the conventional eFuse OTP memory cell, a program datum is provided with the SL (Source Line) connected to the anode of the eFuse going through a voltage drop of the SL driving circuit. In contrast, the gate of the NMOS program transistor is provided with a program datum and the anode of the eFuse with an external program voltage (FSOURCE) of 3.8V without any voltage drop for the newly proposed eFuse cell. The FSOURCE voltage of the proposed cell keeps either 0V or the floating state at read mode. We propose a clamp circuit for being biased to 0V when the voltage of FSOURCE is in the floating state. In addition, we propose a VPP switching circuit switching between the logic VDD (=1.8V) and the FSOURCE voltage. The layout size of the designed eFuse OTP memory IP with Dongbu HiTek's $0.15{\mu}m$ generic process is $359.92{\times}90.98{\mu}m^2$.

• Proceedings of the KIEE Conference
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• 1996.07c
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• pp.1579-1581
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• 1996

The high temperature characteristics of SOI BMFET are analyzed by the numerical simulation and compared with MOS-gated SOI power devices at high temperatures. The proposed SOI BMFET combines bipolar operation in the on-state with unipolar FET operation in the off-state, so that it may be suitable for high temperature operation without any significant degradation of performance such as the leakage current and blocking capability. The simulation results show that SOI BMFET with a higher doped n-resurf layer is the most promising device far high temperature application as compared with MOS-gated SOI power devices, exhibiting the low on-state voltage drop as well as the excellent forward blocking capability at high temperature.

• International Journal of Safety
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• v.7 no.2
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• pp.7-11
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• 2008

In this paper, a Magnetic Core Reactor (MCR) which forms a part of the DC reactor type three-phase high-Tc superconducting fault current limiter (SFCL) has been developed. This SFCL is more economical than other types with three coils since it uses only one high-Tc superconducting (HTS) coil. When DC reactor type three-phase high-Tc SFCL is developed using just one coil, fewer power electronic devices and shorter HTS wire are needed. The SFCL proposed in this paper needs a power-linking device to connect the SFCL to the power system. The design concept for this device was sprang from the fact that the magnetic energy could be changed into the electrical energy and vice versa. Ferromagnetic material is used as a path of magnetic flux. When high-Tc superconducting DC reactor is separated from the power system by using SCRs, this device also limits fault current until the circuit breaker is opened. The device mentioned above was named Magnetic Core Reactor (MCR). MCR was designed to minimize the voltage drop and total losses. Majority of the design parameters was tuned through experiments with the design prototype. In the experiment, the current density of winding conductor was found to be $1.3\;A/mm^2$, voltage drop across MCR was 20 V and total losses on normal state was 1.3 kW.

• Journal of the Korean Solar Energy Society
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• v.34 no.2
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• pp.16-23
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• 2014

This paper presents a renewable energy configuration plan of Micro grid in Gapa Island. To analyze the characteristics of Micro grid, BESS (Battery Energy Storage System), PMSG (Permanent Magnet Synchronous Generator) and SCIG (Squirrel Cage Induction Generator) are first modelled. The PMSG and SCIG will operate with basis on the real power curve. when the total power demand is larger than the total power generation, the BESS will be operated and the SOC (State Of Charge) is reduced. If the value of SOC could drop down to limited value, the system may be broken because of the voltage drop of BESS. To solve this problem, a DG (Diesel Generator) is used to charge the BESS and keep the voltage value of BESS with in a allowance limit. This paper represents simulation result when PMSG, SCIG connected to the Micro grid installed in Gapa Island. The simulation is carry out by using PSCAD/EMTDC program with actual line constant and transformer parameter in Gapa Island.

• 전기의세계
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• v.18 no.6
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• pp.9-22
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• 1969

This thesis has suggested a method of applying the Maximum Principle of Pontryagin to the optimal control of distributive electrical networks. In general, electrical networks consist of branches, nodes, sources and loads. The effective values of steady state currents and voltages are independent of time but only expressed as the functions of position. Moreover, most of the node voltages and branch currents are not predetermined, that is, initially unknown, and their inherent loop characteristics satisfy only Kirchhoff's current and voltage laws. The Maximum Principle, however, needs the initial fixed values of all state variables for its standand way of application. In spite of this inconsistency this thesis has undertaken to suggest a new approach to the successful solution of the above mentioned networks by introducing scaling factors and a state variable change technique which transform the boundary-value unknown problem into the boundary-value partially fixed and partially free problem. For the examples of applying the method suggested, the control problems for minimizing copper quantity in a distribution line have been solved with voltage drop constraint imposed on. In the case of uniform load distribution it has been shown that the optimal wire diameter of the distribution line is reciprocally proportional to the root of distance. For the same load pattern as above the wire diameter giving the minimum copper loss in the distribution line has been shown to be reciprocally proportional to distance.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.25 no.4
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• pp.266-269
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• 2012

The most recently IGBT (insulated gate bipolar mode transistor) devices are in the most current conduction capable devices and designed to the big switching power device. Use this number of the devices are need to high voltage and low on-state voltage drop. And then in this paper design of field stop IGBT is insert N buffer layer structure in NPT planar IGBT and optimization design of field stop IGBT and trench field stop IGBT, both devices have a comparative analysis and reflection of the electrical characteristics. As a simulation result, trench field stop IGBT is electrical characteristics better than field stop IGBT.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.33 no.3
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• pp.173-176
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• 2020

This study focuses on a pillar in which is implanted a P-type maneuver under a P base. This structure is called a super junction structure. By inserting the pillar, the electric field concentrated on the P base is shared by the pillar, so the columns can be dispersed while maintaining a high breakdown voltage. Ten pillars were generated during the multi epitaxial process. The interval between pillars is varied to optimize the electric field to be concentrated on the pillar at a threshold voltage of 6 V, a yield voltage of 4,500 V, and an on-state voltage drop of 3.8 V. The density of the filler gradually decreased when the interval was extended by implanting a filler with the same density. The results confirmed that the size of the depletion layer between the filler and the N-epitaxy layer was reduced, and the current flowing along the N-epitaxy layer was increased. As the interval between the fillers decreased, the cost of the epitaxial process also decreased. However, it is possible to confirm the trade-off relationship that deteriorated the electrical characteristics and efficiency.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.25 no.4
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• pp.247-252
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• 2012

IGBT (insulated gate bipolar transistor) has been widely used around the power industry as it has good switching performance and its excellent conductance. In order to reduce power loss during switch turn-on state, it is essential to reduce its resistance. However, trade off relationship between breakdown voltage and device conductance is the greatest obstacle on the way of improvement. Floating island structure is one of the solutions. Still, under optimized device condition for the best performance, improvement rate is negligible. Therefore, this paper suggests adding trench gate on floating island structure to eliminate JFET (junction field effect transistor) area to reduce resistance and activate floating island effect. Experimental result by 2D simulation using TCAD, shows 20% improvement of turn-on state voltage drop.

• Journal of Electrical Engineering and Technology
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• v.9 no.1
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• pp.127-135
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• 2014

In this paper a novel converter structure based on cascade converter family is presented. The suggested multilevel advanced cascade converter has benefits such as reduction in number of switches and power losses. Comparison depict that proposed topology has the least number of IGBTs among all multilevel cascade type converters which have been introduced recently. This characteristic causes low cost and small installation area for suggested converter. The number of on state switches in current path is less than conventional topologies and so the output voltage drop and power losses are decreased. Symmetric and asymmetric modes are analyzed and compared with conventional multilevel cascade converter. Simulation and experimental results are presented to illustrate validity, good performance and effectiveness of the proposed configuration. The suggested converter can be applied in medium/high voltage and PV applications.