• Proceedings of the KAIS Fall Conference
• /
• 2010.05a
• /
• pp.67-70
• /
• 2010

국가차원의 신 재생에너지 활성화 방안에 따라 태양광, 풍력발전 등의 대규모 분산전원 단지의 도입이 이루어지고 있으며, 현재 배전계통의 전압조정 방법은 배전용 변전소의 부하시 탭 절환기(Under Load Tap Changer, 이하 ULTC)와 배전선로의 선로전압조정장치(Step Voltage Regulator, 이하 SVR)로 수용가에 규정전압(220${\pm}$6%)을 만족시키는 전압을 공급한다. 하지만 대규모의 태양광, 풍력 등의 분산 전원이 배전계통에 도입되는 경우, 전력품질[과전압/저전압]의 문제가 발생된다. 본 논문에서는 부하율에 따라 변화된 LDC 정정치를 적용 및 시뮬레이션을 통한 수용가 직하 및 말단의 규정전압(220${\pm}$6%) 즉 207V이하의 저전압, 233V이상의 과전압 여부를 검증함으로써 전력품질을 유지 할 수 있는 태양광전원이 연계된 배전계통의 최적전압운용 알고리즘을 개발하였다.

• Journal of the Institute of Electronics and Information Engineers
• /
• v.53 no.11
• /
• pp.107-113
• /
• 2016

All circuits in power input can only use the power provided by an external power supply. General electronic circuits use a secondary supply generated by a converter using a primary power in the power input. But protection and detection circuit for over-voltage circuit or under-voltage in power input have to use that input power because there is no other supply in power input. Therefore, previous electronics for satellite can protect only over-voltage using a zener diode, and can't detect over-voltage and under-voltage events, and provide a detection capability for over-voltage and under-voltage only for secondary supply. The proposed circuit can detect over-voltage and under-voltage using a single supply for the primary power input, +28V, with the threshold characteristics for MOS-FET, and the accuracy for a detection circuit is increased by 2.5%.

• Proceedings of the KIPE Conference
• /
• 2019.11a
• /
• pp.142-143
• /
• 2019

본 논문은 계통과 연계하여 운전하거나 계통사고시나 의도적인 단독 운전이 필요한 경우 계통과 분리하여 운전하기 위한 UPQC(Unified Power Quality Conditioner)를 기반으로 하는 인버터를 제안한다. UPQC 기반의 인버터는 계통 연계시에 과전압, 저전압 등의 계통 전압의 변동이 발생 했을 시 이를 보상하여 부하에 전달되는 전력의 품질을 유지 할수 있다. UPQC의 개념에 대하여 설명하고, 계통 연계시의 전압 보상, 단독 운전시의 시퀀스에 대하여 설명하고, 이를 시뮬레이션을 통해 검증한다.

• Proceedings of the KIEE Conference
• /
• 2008.07a
• /
• pp.699-700
• /
• 2008

전기에너지는 가정 및 일반 사업장에서 필수적인 원동력이 되고 있다는 것은 누구나 인식하고 있다, 또한 사소한 전기사고로 인해 발생될 안전사고로 인명이나 전기화재 등을 예방하기 위해 누전이나 과전류 보호에 많은 연구결과로 인해 사고방지에 큰 도움을 주고 있다, 이번 연구는 전기사용안전을 위하여 저압의 누전이나 과전류에 대해서 요함을 인식한 것과 같이 저전압선로에서의 과전압의 발생원인과 과전압의 사고 유형과 과전압 보호장치 구성과 중요함을 알리고 저압회로 차단기에 삽입하여 좀 더 안정된 안전대책과 제품의 개발이나 인증을 득할 기기들의 방안을 제시해본다.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.24 no.8
• /
• pp.109-118
• /
• 2010

It is expected that distribution system, interconnected with wind turbines, would experience the voltage problem due to WT's output. But most papers just consider this problem using the simulation or the theory only. In this paper, we verify this problem through the measurement at the distribution system and wind turbine. We explain the method for voltage management at distribution system. And we verify that the voltage of D/L interconnected with WTs could not be maintained properly using pole transformer's tap only. We consider some method to solve this problem and we propose the installation of SVR(step voltage regulator). Finally we show this method's validity through the simulation.

• Journal of the Korean Institute of Navigation
• /
• v.21 no.3
• /
• pp.75-81
• /
• 1997

The switching components to control the speed of dc motor, which perform vital fuction in a modern motor vehicle or a ship, are susceptibile to suffer damage or upset by switching transient. An equivalent circuit was derived, in this paper, to select an ideal component having immunity against the switching transient among varisotor, zenner diode, etc. Furthermore, we have carried out the optimal improved transient protection circuit design in the view of cost effectiveness, proper wave form of transient defined by the international regulations. The process and cause of the damages in the switching components were examined. Then, the immunity improvement of semiconductor switching components to control a dc motor has been achieved considering impedance condition accoring to the variation of the diverting transient current.

• Journal of KIISE:Computer Systems and Theory
• /
• v.29 no.11
• /
• pp.601-610
• /
• 2002

Intra-task voltage scheduling (IntraVS), which adjusts the supply voltage within an individual task boundary, is an effective technique for developing low-power applications. In this paper, we propose a novel intra-task voltage scheduling algorithm for hard real-time applications based on average-case execution time. Unlike the conventional IntraVS algorithm where voltage scaling decisions are based on the worst-case execution cycles, tile proposed algorithm improves the energy efficiency by controlling the execution speed based on average-case execution cycles while meeting the real-time constraints. The experimental results using an MPEG-4 decoder program show that the proposed algorithm reduces the energy consumption by up to 34% over conventional IntraVS algorithm.

• Proceedings of the KAIS Fall Conference
• /
• 2010.05a
• /
• pp.56-59
• /
• 2010

태양광과 풍력과 같은 분산전원이 배전계통에 연계되어 운용되는 경우, 수용가의 규정전압인 220${\pm}$6%(207[V]~233[V])를 벗어나는 현상이 발생할 수 있다. 본 논문에서는 태양광이 연계되는 위치에 따라 변동하는 선로임피던스(R${\pm}$jX)에 의하여 발생하는 순시 전압상승 및 전압강하에 의한 전력품질[과전압/저전압] 저하 현상을 LabVIEW S/W를 이용하여 확인하였으며, 이에 따른 문제점을 분석하고 그 해결책을 제시하였다.

• Aerospace Engineering and Technology
• /
• v.6 no.1
• /
• pp.109-113
• /
• 2007

In this paper, the design process of the High Voltage Power Supply for RLG(Ring Laser Gyroscope) is described. The specification for High Voltage Power Supply(HVPS) is proposed. Also, The analysis of Flyback converter topology is explained. The Design for the HVPS is composed of the inverter circuit, feedback control circuit, high frequency switching transformer design, and voltage doubler circuit.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.12 no.6
• /
• pp.2698-2706
• /
• 2011

This paper deals with the optimal operation algorithm of SVR(Step Voltage Regulator) which is located with primary feeders and proposes the optimal operation system to evaluate customer voltage. The existing algorithm of SVR adapts the constant sending voltage method, which may cause the power quality problems such as overvoltage and under voltage variations in case where the distributed generations are interconnected with the primary feeders. Therefore, this paper proposes the optimal algorithm of LDC method for SVR using least square method to obtain the optimal setting values. Also, this paper presents the optimal evaluation system based on the former algorithm. The simulation results according to the types and capacities of distributed generations shows the effectiveness.