• KIPS Transactions on Computer and Communication Systems
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• v.1 no.3
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• pp.181-186
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• 2012

PMU based power grid monitoring and control system, WAMAC (Wide Area Monitoring And Control) system is required system design for accurate power data without error and loss through a system-wide. In the paper, we propose system design that measured data from PMU transmitted without loss to PDC and DSM server. and we propose a method to verify the real-time "data has been transmitted accurately". Verification system has been designed to reflect the WAMAC system. Therefore the WAMAC can enhance the reliability of the analysis of the data, and it can monitor lossless real-time trend data.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.45 no.2
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• pp.140-147
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• 2017

This paper describes the design and implementation of previously developed PMU (Power Monitoring Unit) for LiPB (Lithium-ion Polymer Battery) that is electric propulsion used as unmanned aerial vehicle's power source. Improved PMU provides stable voltage and current to various sensors and elctric motors necessary during flight. Voltage and current monitoring function that is measured by improved PMU more precisely be enhanced and the monitoring channel and temperature sensor is added. To verify the improved performance of the equipment, it is integrated to electric propulsion system of unmanned aerial vehicle. PMU is calibrated through the ground test. And PMU's performance is checked through the flight test.

• Journal of Korea Society of Industrial Information Systems
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• v.21 no.1
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• pp.61-70
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• 2016

This paper describes a new PMU(parametric measurement unit) design technique for automatic test equipment(ATE). Only one DDA(differential difference amplifier) is used to force the test signals to DUT(device under test), while conventional design uses two or more amplifiers to force test signals. Since the proposed technique does not need extra amplifiers in feedback path, the proposed PMU inherently guarantees stable operation. Moreover, to measure the response signals from DUT, proposed technique also adopted only one DDA amplifier as an IA(instrument amplifier), while conventional IA uses 3 amplifiers and several resistors. The DDA adopted two rail-to-rail differential input stages to handle full-range differential signals. Gain enhancement technique is used in folded-cascode type DDA to get open loop gain of 100 dB. Proposed PMU design enables accurate and stable operation with smaller hardware and lower power consumption. This PMU is implemented with 0.18 um CMOS process and supply voltage is 1.8 V. Input ranges for each force mode are 0.25~1.55 V at voltage force and 0.9~0.935 V at current force mode.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2012.10a
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• pp.267-271
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• 2012

In this paper a power management unit for solar energy harvesting is proposed. If solar energy is sufficient, Power Management Unit(PMU) directly supplies load with solar energy. By contrast, if solar energy is insufficient to operate sensor nodes, voltage booster(VB) boosts the solar cell's output voltage, and then PMU supplies load with the harvested energy. The designed circuit had been fabricated using a 018um CMOS process. In the first case, the PMU supplies load with more energy than in the second case. In the second case where a VB is used, the PMU operates to supply load with solar energy even when illumination is low and minimum solar cells with very low output voltage are used.

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.346-347
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• 2011

In this paper, it is about virtual PMU and FEP are developed for developing the WAMAC(Wide Area Monitoring and Contorol) Test-Bed System. The Virtual PMU and FEP can be test in the WAMAC testbed for fully pretesting before developing WAMAC system. In the case studies, sever CPU tested the memory by the virtual PMUs and WAMAC Test-Bed syetem design is showed by using the virtual PMU and FEP.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.24_25
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• 2009

PMU 정보를 이용하여 실시간으로 전압안정도를 감시하는 기술은 계속적으로 연구가 진행되고 있다. 전압안정도를 해석하는 수많은 방법 중에서 국내계통에 가장 잘 맞는 알고리즘을 찾는 것이 무엇보다도 중요하다. 또한 PMU의 설치는 현재에는 한정적일 수 밖에 없으므로 최소의 PMU를 가장 적절한 위치에 설치하여 계통의 전압 안정도를 감시하는 것이 중요 하다. 본 논문에서는 소수의 PMU를 이용하여 실시간으로 전압안정도를 감시하는 기술을 제안하고자 한다. 계통데이터 중선로임피던스를 이용하여 최소한의 PMU로부터 전압안정도를 감시하도록 한다. 본 방법을 검증하기 위하여 한전 실계통을 사용하도록 한다.

• Proceedings of the KIEE Conference
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• 2000.07a
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• pp.75-79
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• 2000

This paper proposes the optimal placement with minimum set of Phasor Measurement Units (PMU's) using tabu search and makes an alternative plan to secure the robustness of the network with PMU's. The optimal PMU Placement (OPP) problem is generally expressed as a combinatorial optimization problem subjected to the observability constraints. Thus, it is necessary to make a use of an efficient method in solving the OPP problem. In this paper, a tabu search based approach to solve efficiently this OPP problem proposed. The observability of the network with PMU's is fragile at any single PMU contingency. To overcome the fragility, an alternative scheme that makes efficient use of the existing measurement system in power system state estimation proposed. The performance of the proposed approach and the alternative scheme is evaluated with IEEE sample systems.

• Proceedings of the KIEE Conference
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• 2005.07a
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• pp.344-346
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• 2005

GPS(Global Positioning System)를 기반으로 하는 PMU(Phasor Measurement Unit)에서 측정된 페이저 정보는 사용자에게 계통의 여러 가지 동특성 정보를 제공한다. 이러한 PMU 정보는 지역과 중앙에서 취득하여 계통의 안정도를 감시, 판단하는 방법으로 활용할 수 있다. 최근에는 여기에 발전된 컴퓨터 연산기능과 통신 기술을 접목하여 다양한 분야의 실시간 계통감시 기술이 연구되고 있다. 본 논문에서는 광역감시를 위하여 2곳 이상의 PMU 정보를 활용하는 VIP++ 알고리듬을 소개하고 시험계통을 이용한 모의를 통해 VIP++ 알고리듬의 유용성을 검증해 보인다.

• Proceedings of the KIEE Conference
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• 2002.07a
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• pp.342-344
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• 2002

This paper presents a new strategy to find starting points for placing optimally Phasor Measurement Units(PMUs). The performance of the starting point, initial placement set of PMUs, affect critically the computational burden and/or time, because the Optimal PMU Placement (OPP) problem is formulated the combinatorial optimization. By analyzing the properties of OPP solutions on IEEE sample systems in detail, a new strategy for initial PMU placement, in this paper, is proposed. To verify the performance of the suggested strategy, the comparison with the existing strategy and the new one, on IEEE sample systems. is performed. By using the new strategy, the numbers of search spaces to solve the OPP problem is drastically decreased.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.58 no.12
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• pp.2328-2334
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• 2009

Through the development of phasor measurement units (PMU), various aspects of power system dynamic behavior could be monitored and diagnosed. Monitoring dynamic voltage stability becomes one of achievements we can obtain from PMUs. It is very important to select the method appropriate to the KEPCO system since there are many voltage stability indices. In the paper, we propose an advanced WAVI (Wide Area Voltage Stability) for monitoring dynamic voltage stability. It reflects the PMU installation plan of KEPCO, thus it is suitable for KEPCO system specially. The salient features of the proposed index are; i) it uses only PMU measurements without coupling with EMS data. ii) it is computationally unburden so that it can be applied to real-time situation. The proposed index is applied to the KEPCO test system and the result shows that it successfully predicts voltage instability through the comparative studies.