• Journal of the Korean Solar Energy Society
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• v.30 no.1
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• pp.7-12
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• 2010

As many grid-connected photovoltaic power conditioning systems (PVPCS)are installed in many residential areas simultaneously, these have raised potential problems of network protection on electrical power system. One of the numerous problems is an Islanding phenomenon. In this paper, active frequency drift (AFD) method, one of the anti-islanding methods which is analyzed by current magnitude compensation and calculation of the fundamental component. Both harmonic component and RMS value of the output current for THD analysis are provided and verified by simulation.

• Journal of the Korean Solar Energy Society
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• v.29 no.6
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• pp.75-80
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• 2009

Recently, as the grid-connected photovoltaic power conditioning systems (PVPCS) are installed in many residential areas, these have raised potential problems of network protection on electrical power system. One of the numerous problems is an Islanding phenomenon. In this paper, active frequency drift (AFD) method, one of the anti-islanding methods which is analyzed by current magnitude compensation and calculation of RMS value of the output power is proposed and verified by simulation.

• Proceedings of the KIPE Conference
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• 2005.07a
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• pp.520-522
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• 2005

Islanding phenomenon is undesirable because it lead to a safety hazard to utility service personnel and may cause damage to power generation and power supply facilities as a result of unsynchronized reclosure. In order to prevent this phenomenon, various anti-islanding methods have been studied. Even though the slip mode frequency shift (SMS) method has been regarded as a highly effective anti-islanding method, the analytical design method of that was not cleared. This paper proposes a modeling of the SMS method using non-detection zone (NDZ) and evaluation of the method according to the test conditions of IEEE Std. 929-2000. The SMS method is derived analytically through the modeling and verified visually by simulation and experiment.

• 한국태양에너지학회:학술대회논문집
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• 2009.11a
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• pp.297-302
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• 2009

As the grid-connected photovoltaic power conditioning systems (PVPCS) are installed in many residential areas, these have raised potential problems of network protection on electrical power system. One of the numerous problems is an Islanding phenomenon. In this paper, active frequency drift (AFD) method, one of the anti-islanding analyzed by current magnitude compensation and calculation of RMS value of the output power.

• Journal of Electrical Engineering and Technology
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• v.2 no.1
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• pp.19-28
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• 2007

The paper discussed various techniques for islanding detection and described in detail the working principles of ROCOF and vector shift relays. A simulator was used to investigate why the stability of both types of relays maybe affected by network and load switching, short-circuit faults and in the case of a ROCOF relay the loss of bulk generation or the tripping of a transmission feeder. Finally, to enhance the reliability of Loss of Mains protection, a new islanding detection technique based on a GPS synchronized phasor measurement system was proposed.

• Proceedings of the KIPE Conference
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• 2008.10a
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• pp.64-67
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• 2008

To detect islanding mode when the grid is being tripped is a major safety issue in the Utility Interactive Distributed Generation (UIDG) system. In this paper, analytical design method is suggested for AFD & RPV method under IEEE929-2000 recommended islanding test condition. We have discussed that there is a same point. we injected reactive component of the current by AFD & RPV methods, but the current reference generated is other waveform. Possible if amount of reactive components in this methods are same each method, there is happened same rates frequency variation. To verify the validity of the analytical comparison, this paper presents simulation and experimental results from single phase, 3[kW] inverter for the transformerless UIDG system.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.57 no.4
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• pp.582-588
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• 2008

Microgrids are new distribution level power networks that consist of various electronically-interlaced generators and sensitive loads. The important control object of Microgrids is to supply reliable and high-quality power even during the faults or loss of mains(islanding) cases. This paper presents power control methods to coordinate multiple distributed generators(DGs) against abnormal cases such as islanding and load power variations. Using speed-droop and voltage-droop characteristics, multiple distributed generators can share the load power based on locally measured signals without any communications between them. This paper adopts the droop controllers for multiple DG control and improved them by considering the generation speed of distribution level generators. Dynamic response of the proposed control scheme has been investigated under severe operation cases such as islanding and abrupt load changes through PSCAD/EMTDC simulations.

• Proceedings of the KIEE Conference
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• 2005.07b
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• pp.1699-1701
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• 2005

Islanding phenomenon is undesirable because it lead to a safety hazard to utility service personnel and may cause damage to power generation and rower supply facilities as a result of unsynchronized reclosure. In order to prevent this phenomenon, various anti-islanding methods have been studied. Even though the slip mode frequency shift(SMS) method has been regarded as a highly effective anti-islanding method, the analytical design method of that was not cleared. This paper proposes a modeling of the SMS method using non-detection tone(NDZ) and evaluation of the method according to the test conditions of IEEE Std. 929-2000. The SMS method is derived analytically through modeling and verified visually by simulation and experiment.

• Proceedings of the KIEE Conference
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• summer
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• pp.217-219
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• 2004

The installation of small sized dispersed generation(DG) units operating in parallel with the utility supply presents several technical problems for the protection and control of the system. One of the critical concerns is the occurrence of islanding. Hence, this paper propose the Digital Universal Relay(DUR) including anti-islanding function as DG interconnection interface. The existent islanding detection algorithms are examined. And the most effective and reliable method of those is modified for DUR application. The modified algorithm is evaluated through the modeling of the test system by PSCAD/EMTDC.

• The Transactions of the Korean Institute of Power Electronics
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• v.23 no.6
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• pp.373-380
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• 2018

This study proposes a new islanding detection method that uses the phase shift of feed-forward voltage and evaluates the performance of an existing method and the proposed method when the grid frequency changes within the allowable range under steady-state conditions. The investigated existing method, which is slip mode frequency shift (SMS), uses current phase shift to detect islanding. The SMS method supplies reactive current to the grid under this condition, but the proposed method does not generate additional reactive power because it does not depend on the current control loop. The performance in steady-state grid condition is evaluated through simulations and experiments.