• 전기학회논문지
• /
• 제64권2호
• /
• pp.342-348
• /
• 2015

In this paper, fuel cell power generation system that is being studied in recent railway field was applied to compensate for the voltage drop due to the load as driving electric vehicle. PSIM simulation program is to be used to implement the modeling of the electric railway for AC AT feeder system. For it, It was applied to the product-type single-phase PLL algorithm, step-down converter is controlled as power so as to have the fuelcell generation system. Based on it's result, a reactive power due to the catenary impedance in accordance with the current flowing is compensated as linked with fuelcell generation system which supplied the current to the power supply grid. and then its performance was confirmed that voltage compensation effect obtained at SubStation (SS), SubSectioning Post (SSP), Sectioning Post (SP).

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2001년도 하계학술대회 논문집 A
• /
• pp.289-291
• /
• 2001

This paper represents the application of the Static Var Compensator (SVC) on the electric railway power supply system to compensate for the voltage drop. The high reactance of line and a heavy train load consume a significant amount of the reactive power which results the voltage drop. This paper shows that the SVC is necessary for voltage compensation in the railway power supply system and verify effectiveness of the SVC through the simulation by using PSCAD/EMTDC. In this paper, the case studies were performed with the various line length and train loads.

• ETRI Journal
• /
• 제36권4호
• /
• pp.643-653
• /
• 2014

To reduce interconnect delay and power consumption while improving chip performance, a three-dimensional integrated circuit (3D IC) has been developed with die-stacking and through-silicon via (TSV) techniques. The power supply problem is one of the essential challenges in 3D IC design because IR-drop caused by insufficient supply voltage in a 3D chip reduces the chip performance. In particular, power bumps and TSVs are placed to minimize IR-drop in a 3D power delivery network. In this paper, we propose a design methodology for 3D power delivery networks to minimize the number of power bumps and TSVs with optimum mesh structure and distribute voltage variation more uniformly by shifting the locations of power bumps and TSVs while satisfying IR-drop constraint. Simulation results show that our method can reduce the voltage variation by 29.7% on average while reducing the number of power bumps and TSVs by 76.2% and 15.4%, respectively.

• Journal of Power Electronics
• /
• 제1권1호
• /
• pp.9-18
• /
• 2001

The performance analysis of a three-phase parallel active power filter that compensates PCC voltage and the unbalanced loads is presented in this paper. The proposed scheme in this paper employs a PWM voltage-source inverter and has two operation modes. Firstly, it operates as a conventional active filter with reactive power compensation when PCC voltage is within the 15% voltage drop range. Secondly, it operates as a voltage compensator when PCC voltage is not within the 15% voltage drop range. And both APF and voltage compensator compensate asymmetries caused by nonlinear loads. Finally, two methods of detecting the negative sequence are reviewed, and the validity of this scheme is investigated through analysis of simulation and experimental results for a prototype active power filter system rate at 10KVA.

• 전력전자학회:학술대회논문집
• /
• 전력전자학회 1999년도 전력전자학술대회 논문집
• /
• pp.26-30
• /
• 1999

The constraint condition is the stator voltage and the stator current to operate the motor in the flux weakening region. The maximum current is limited by the inverter current rating and the machine thermal rating. Given DC link voltage to control the motor in the flux weakening the maximum voltage is determined by considering PWM strategy, dead time, voltage drop of the inverter switching device, and the margin of the voltage for current forcing. In this paper, the new method to determine the available maximum voltage is derived by the analythic method and by considering the factors of the voltage drop. So Determining the maximum voltage is very useful to enlarge the speed operation region in the flux weakening operation, the utility of the maximum voltage is increased.

• 조명전기설비학회논문지
• /
• 제24권12호
• /
• pp.100-108
• /
• 2010

A low voltage wire should be used considering that a load used in the end is a low voltage. In regard to these wires, there are needs for research about the wire thickness calculation in accordance with IEC standard because the standardization process for IEC (KS standard) was completed on June 30, 2005, and they stopped producing NEC-standard products by the order from Korean Agency for Technology and Standards under Ministry of Knowledge Economy (former Ministry of Commerce, Industry and Energy) since July 1, 2006. This study compared, in terms of the thickness calculation of low voltage wire, a reduction factor application by IEC standard about allowed current and an application for calculation of voltage drop. It also proposed the formula for IEC standard to decrease errors and resolve the difficulty of standardized calculation by analyzing the difference between simplified formula and standardized formula that are the most frequently used calculation method of voltage drop.

• 조명전기설비학회논문지
• /
• 제20권5호
• /
• pp.18-24
• /
• 2006

본 논문은 순간전압강하 보상을 위해 축전지와 울트라커패시터가 병렬로 연결된 무정전 전원장치 시스템을 제안하였다. 축전지와 병렬로 연결된 울트라커패시터는 정전시 순간전압강하를 보상하고, 출력전압의 전압 변동률을 감소시키는 역할을 한다. 무정전 전원장치에서 울트라커패시터의 빠른 순간전압보상 구현을 위해 3[kVA]의 시스템을 제작하여 실험을 수행하였다. 실험결과를 통하여 울트라커패시터의 빠른 보상특성과 울트라커패시터를 사용함으로써 출력전압의 변동률이 5[%]이내를 만족함을 확인하였다.

• 전기학회논문지
• /
• 제64권4호
• /
• pp.640-645
• /
• 2015

Near surface transit system has should be constructed as installation cost of light rail transit with elevated track. So, distance between two substations is longer than conventional system. The long feeding distance results in severe voltage drop. This paper proposes a PWM rectifier instead of diode rectifier. The PWM rectifier has some advantages. This is able to control output voltage constantly to reduce voltage drop and to use regeneration power without additional inverter. This paper analyse on improved voltage profile and cost of substation with PWM rectifier. The analysis of voltage profile use PSIM, and the installation cost of substation with PWM rectifier is compared to substation with diode rectifier.

• 한국조명전기설비학회:학술대회논문집
• /
• 한국조명전기설비학회 2006년도 춘계학술대회 논문집
• /
• pp.37-42
• /
• 2006

전선에서 전압강하는 열 손실을 의미한다. 이 열은 절연체의 특성을 변화시켜 절연성능을 저하시키게 되고 나아가 누전, 감전, 정전 및 화재 등의 사고를 일으키는 원인이 되기도 한다. 그러므로 전압강하에 대한 최적화 설계는 전기설비의 안전성과 경제성을 보장하는 중요한 요소가 되고 있다. 이에 저압의 전기설비인 가로등, 빌딩, 지하철역사 등 공공의 안전확보가 요구되는 다중 분산부하계통에서의 전압강하가 전기배선에 미치는 영향을 분석하고, 안전성 및 경제성 확보를 위한 전압강하산정 프로그램 및 최적화 방안을 연구 제시하고자 한다.

• 한국조명전기설비학회:학술대회논문집
• /
• 한국조명전기설비학회 2007년도 추계학술대회 논문집
• /
• pp.225-229
• /
• 2007

The output voltage of a synchronous generator is regulated constantly by field current control of excitation system. Synchronous generator exciter has two type, first one is Drop control type by thyristor and second one is exciter current control type through power output by PWM control. Control method of the second one prevails, but when the power devices have a breakdown, output voltage of the generator rises rapidly. This exciter must have a protection circuit and system is complicated, so reliability is poor Excitation control type which is drop control type control only 10% of the power, so it can be improved precision. When a trouble come to the controller, output voltage of a generator don't rise excessively and the voltage rise about 10%, so it has a excellent reliability. This paper prove stability of the digital AVR.