• Journal of Electrical Engineering and Technology
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• v.8 no.3
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• pp.472-477
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• 2013

An internet-based, real-time GPS synchronized wide-area power system frequency monitoring network(FNET) has been monitoring wide-area power system frequency in continuous time in the United States. This paper analyzes the FNET measurement to the verified disturbances in the US eastern interconnected power system and simulates it using the dynamic system model. By comparing the frequency measurements with its simulation results to the same disturbances in detail, this paper finds that the sequence of monitoring points to detect the frequency fluctuation caused by the disturbances is matched well in the measured data and the simulation results. The similarity comparison index is also proposed to quantify the similarity of the compared cases. The dynamic model based simulation result is expected to compensate for the lack of FNET measurement in its applications.

• Journal of Ocean Engineering and Technology
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• v.36 no.1
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• pp.50-60
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• 2022

The deep ocean engineering basin (DOEB) of the Korea Research Institute of Ship and Ocean Engineering (KRISO) is equipped with an extreme-environment reproduction facility that can analyze the motion characteristics of offshore structures and ships. In recent years, there have been requirements for a wide range of six-degree-of-freedom (6-DOF) motion measurements for performing maneuvering tests and free-running tests of target objects (offshore structures or ships). This study introduces the process of developing a wide-area motion measurement technology by incorporating the auto-tracking technology of the towing carriage system to overcome the existing 6-DOF motion measurement limitation. To realize a wide range of motion measurements, the automatic tracking control system of the towing carriage in the DOEB was designed as a speed control method. To verify the control performance, the characteristics of the towing carriage according to the variation in control gain were analyzed. Finally, a wide range of motions was tested using a model test object (a remotely operated vehicle (ROV)), and the wide-area motion measurement technology was implemented using an automatic tracking control system for a towing carriage.

• Journal of Electrical Engineering and Technology
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• v.4 no.4
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• pp.451-456
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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 has become one of the achievements we can obtain from PMUs. It is very important to select the most appropriate method for the Korea Electric Power Corporation (KEPCO) system since there are many voltage stability indices. In this paper, we propose an advanced WAVI (Wide Area Voltage Stability) that is well suited for the purposes of monitoring the dynamic voltage stability of KEPCO's PMU installation plan. The salient features of the proposed index are: i) it uses only PMU measurements without coupling with EMS data; ii) it is computationally unburdened and can be applied to real-time situations. The proposed index is applied to the KEPCO test system and the results show that it successfully predicts voltage instability through comparative studies.

• International Journal of Computer Science & Network Security
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• v.23 no.3
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• pp.130-138
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• 2023

The Smart grids are considered as multi-disciplinary power systems where the communication networks are highly employed. This paper presents optimal wide area measurement system (WAMS) configuration in Nordic power system. The transition from SCADA to WAMS becomes now trend in all power systems to ensure higher reliability and data visibility. The optimization applied in this research considered the geographical regions of the Nordic power system. The research considered all the devices of WAMS namely phasor measurement units (PMUs), phasor data concentrators (PDCs) and communication links. The study also presents two scenarios for optimal WAMS namely base case and N-1 contingency as different operating conditions. The result of this research presents technical and financial results for WAMS configuration in a real power system. The optimization results are performed using MATLAB 2017a software application.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.61 no.4
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• pp.174-179
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• 2012

The social and economic level of damages might be highly increased in the case of wide-area black-outages, because of heavy dependence of electricity. Therefore, the development of a wide-area protection relay intelligence techniques is required to prevent massive power outages and minimize the impact strength at failure. The frequency monitoring and prediction for wide-area protection relaying intelligence has been considered as an important technology. In this paper, a network-based frequency monitoring system developed for wide-area protection relay intelligence is presented. In addition, conventional techniques for frequency estimation are compared, and a method for advanced frequency estimation and measurement to improve the precision is proposed. Finally, an integrated monitoring system called K-FNET(Korea-Frequency Monitoring Network) is implemented based on the GPS and various energy monitoring cases are studied.

• Journal of Electrical Engineering and Technology
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• v.6 no.6
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• pp.776-785
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• 2011

Since the Internet-based real-time Global Positioning System(GPS) synchronized widearea power system frequency monitoring network (FNET) was proposed in 2001, it has been monitoring the power system frequency in interconnected United States power systems and numerous interesting behaviors have been observed, including frequency excursion propagation. We address the consistency of a frequency excursion detection order of frequency disturbance recorders in FNET in relation to the same generation trip, as well as the ability to recreate by power systems dynamic simulation. We also propose a new method, as an application of FNET measurement, to locate a tripped generator using power systems dynamic simulation and wide-area frequency measurement. The simulation database of all the possible trips of generators in the interconnected power systems is created using the off-line power systems dynamic simulation. When FNET detects a sudden drop in the monitoring frequency, which is most likely due to a generation trip in power systems, the proposed algorithm locates a tripped generator by finding the best matching case of the measured frequency excursion in the simulation database in terms of the frequency drop detection order and the time of monitoring points.

• Transactions on Electrical and Electronic Materials
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• v.18 no.5
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• pp.279-286
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• 2017

In this paper, an optimal approach for the wide-area regulation of control devices in a transmission network is proposed. In order to realize an improved voltage profile and reduced power loss, existing devices such as tap-changing transformers, synchronous machines, and capacitor banks should be controlled in a coordinated and on-line manner. It is well-understood that phasor measurement units in transmission substations allow the system operators to access the on-line loading and operation status of the network. Accordingly, this study proposes efficient software applications that can be employed in area operation centers. Thus, the implanted control devices can be regulated in an on-line and wide-area coordinated approach. In this process, efficient objective functions are devised for both voltage profile improvement and power loss reduction. Subsequently, sensitivity analysis is carried out to determine the best weighting factors for these objectives. Extensive numerical studies are conducted on an IEEE 14-bus test system and a real-world system named the Azarbayjan Regional Transmission Network. The obtained results are discussed in detail to highlight the promising improvements.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.43 no.1 s.307
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• pp.7-12
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• 2006

In this paper we proposed a real-time remote monitoring system for interoperability between local area and wide area for wireless data communication. In local area, we used a miniaturized low-power wireless module and in wide area used CDMA Cellular System's Packet Data Service. The measurement results can be spread via Internet access in real-time

• Journal of Electrical Engineering and Technology
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• v.8 no.1
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• pp.70-79
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• 2013

In this paper, a comparative study on the frequency estimation methods using IRDWT (Improved Recursive Discrete Wavelet Transform), FRDWT(Fast Recursive Discrete Wavelet Transform), and GCDFT(Gain Compensator Discrete Fourier Transform) is presented. The 345[kV] power system modeling data of the Republic of Korea by EMTP-RV is used to evaluate the performance of the proposed two kinds of RDWT(IRDWT and FRDWT) and GCDFT. The simulation results show that the frequency estimation technique based on FRDWT could be the optimal frequency measurement method, and thus can be applied to FDR(Fault Disturbance Recorder) for wide-area blackout protection or frequency measurement apparatus.

• 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.