• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2022.10a
• /
• pp.121-122
• /
• 2022

In this paper, the device performance with the structure of Nanosheet FET (NSFET) and FinFET is simulated through a three-dimensional device simulator. Current-voltage characteristics of NSFET and FinFET were simulated with respect to channel doping concentrations, and the performance such as threshold voltage and subthreshold swing extracted from the current-voltage characteristics was compared. NSFET flows more drain current and has a higher threshold voltage in current-voltage characteristics depending on channel doping concentration than that of FinFET. The subthreshold voltage swing (SS) of NSFET is steeper than that of FinFET

• Journal of the Korean Institute of Telematics and Electronics C
• /
• v.34C no.9
• /
• pp.1-9
• /
• 1997

Novel class A CMOS second-generation current conveyors (CCII) using 0.6.mu.m n-well standard CMOS process for high-frequency current-mode signal processing were developed. The CCII consists of a regulated current-cell for the voltage input and a cascode current mirror for the current output. In this architecture, the two input stages are coupled by current mirrors to reduce the current input impedance. Measurements of the fabricated cCII show that the current input impedance is 308 .ohm. and the 3-dB cutoff frequency when used as a voltage amplifier extends beyond 10MHz. The linear dynamic ranges of voltage and current are from -0.5V to 1.5V and from -100.mu.A to +120.mu.A for supply voltage V$\_$DD/ = -V$\_$SS/=2.5V, respectively. The power dissipation is 2 mW and the active chip area is 0.2 * 0.2 [mm$\^$2/].

• The Transactions of the Korean Institute of Electrical Engineers
• /
• v.38 no.4
• /
• pp.261-268
• /
• 1989

A novel current controlled PWM voltage source type converter and control strategy is proposed that is able to draw nearly sinusoidal current at unity power factor from three phase power lines. Current error vector control scheme is used which has two operating states : low harmonic current content state and quick current response state. The state is changed according to the current error to optimize the steady state and transient state performances. To regulate the dc oupput voltage, the magnitude of the reference current is determined by a controller dc voltage error. The ac input power factor can be controlled with unity, and even leading or lagging by adjusting the relative position of the reference current with respect to the supply voltage.

• Journal of Electrical Engineering and Technology
• /
• v.8 no.4
• /
• pp.840-849
• /
• 2013

This paper presents a statistical approach to analyze electrical tree inception voltage, electrical tree breakdown voltage and tree breakdown time of unsaturated polyester resin subjected to AC voltage. The aim of this work was to show that Weibull and lognormal distribution may not be the most suitable distributions for analysis of electrical treeing data. In this paper, an investigation of statistical distributions of electrical tree inception voltage, electrical tree breakdown voltage and breakdown time data was performed on 108 leaf-like specimen samples. Revelations from the test results showed that Johnson SB distribution is the best fit for electrical tree inception voltage and tree breakdown time data while electrical tree breakdown voltage data is best suited with Wakeby distribution. The fitting step was performed by means of Anderson-Darling (AD) Goodness-of-fit test (GOF). Based on the fitting results of tree inception voltage, tree breakdown time and tree breakdown voltage data, Johnson SB and Wakeby exhibit the lowest error value respectively compared to Weibull and lognormal.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.26 no.6
• /
• pp.16-28
• /
• 2012

This paper proposes a quasi Z-source converter(QZSC) with a diode-capacitor output filter to improve the output DC voltage boost ability. The proposed converter has the same quasi Z-source network topology compared with the conventional converter. But the proposed method is adopted a diode-capacitor filter as its output filter, since the conventional method is used an inductor-capacitor as its output filter. Under the condition of the same input-output DC voltage, the proposed method has more lower shoot-through duty ratio than the conventional method. Also, because the proposed converter has same voltage boost factor under lower shoot-through duty ratio compared with the conventional converter, the proposed converter can be operated with the lower capacitor voltage of Z-source network and the lower input current. To confirm the validity of the proposed method, PSIM simulation and a DSP based experiment were performed to acquire the output DC voltage 120[V] under the input DC voltage 80[V]. And the capacitor voltage and inductor current in Z-source network, the output voltage of each converter were compared and discussed.

• Proceedings of the KIEE Conference
• /
• 2004.07c
• /
• pp.1885-1887
• /
• 2004

This paper presents the aspect and distribution of voltage and current harmonics being made at low voltage power systems. The voltage and current harmonics in power systems supplying various loads were monitored and analyzed. We have examined the results compared to advanced countries' harmonics control standards. As a result, the current harmonics were significantly greater than the voltage harmonics. In particular, the harmonics of currents flowing through loads with power switching electronics was pronounced. Also, the contents of current harmonics of street lamp circuits was about 30%, and it was decreased to 12.3% with the installation of scries reactor. On the whole, The measured results of voltage and current harmonics exceeds the regulation limits recommended by IEEE std 519-1992.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2003.05a
• /
• pp.693-695
• /
• 2003

In this paper, we have investigated temperature-dependent characteristics of current-voltage for double gate MOSFET with main gate and side gate. DG MOSFET has the main gate length of 50nm and the side gate length of 70nm. We have investigated the temperature-dependent characteristics of current-voltage and drain voltage is changed from 0V to 5.0V at $V_{mg}$ =1.5V and $V_{sg}$ =3.0V. We have obtained a very good characteristics of current-voltage for 77K. We have simulated using ISE-TCAD tool for characteristics analysis of device.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.65 no.1
• /
• pp.103-107
• /
• 2016

In general, the voltage stability of induction generator is lower than synchronous generator. Induction generator has a number of advantages over the synchronous generator on the side of price and maintenance. So Induction generator has been applied to the small hydroelectric power of low output. Induction generator usually generates a high current during grid connection. The high current that occurs during grid connection can cause a voltage drop in the system. In order to increase the supply of the induction generator, it is necessary to propose a method of reducing high current. This paper proposes some method of the soft start to reduce voltage drop caused by the large starting current. soft-start method has high voltage drop effect than direct start method, control of firing angle can be increased the voltage drop effect.

• Proceedings of the KIEE Conference
• /
• 2002.11d
• /
• pp.3-11
• /
• 2002

This paper presents the trend of low voltage and high current technology for DC-DC converters. It can be said that the output voltage of the on-board power supply has been rapidly moving forward a low voltage in proportion to the minuteness of the semiconductors. As for as its speed is concerned, the change of the market situation seems to be faster than that of R&D for the low voltage and high current products put out by power supply manufacturers. Here, the present situation and the trend of non-isolated type step-down DC-DC converter and isolated type DC-DC converter called "Brick" will be taken up mainly from the fellowing point of view. -low voltage and high current keeping up with the current demand for the latest telecommunication networks and broadband. -build-up of the total solution for dispersion system power supply. In this paper, an explanation is given to mainly concerning to the newest products in the supplier's position.

• Nuclear Engineering and Technology
• /
• v.35 no.3
• /
• pp.226-233
• /
• 2003

The discharge characteristics of a prototype ion source was investigated, which was developed and upgraded for the NBI (Neutral Beam Injection) heating system of KSTAR (Korea Superconducting Tokamak Advanced Research). The ion source was designed for the arc discharge of magnetic bucket chamber with multi-pole cusp fields. The ion source was discharged by the emission-limited mode with the control of filament heating voltage. The maximum ion density was 4 times larger than the previous discharge controlled by a space-charge-limited mode with fully heated filament. The plasma (ion) density and arc current were proportional to the filament voltage, but the discharge efficiency was inversely proportional to the operating pressure of hydrogen gas. The maximum ion density and arc current were obtained with constant arc voltage ($80{\sim}100V$), as $8{\times}10^{11}cm^{-3}$ and 1200 A, respectively. The estimated maximum beam current was about 35 A, extracted by the accelerating voltage of 80kV.