Slope-Permissive Under-Voltage Load Shed Relay for Delayed Voltage Recovery Mitigation

Halpin, S.M.; Harley, Keith; Jones, Robert A.; Taylor, L.

doi:10.1109/tpwrs.2008.926409

Cited by 54 publications

(51 citation statements)

References 9 publications

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“…If they do not stall but do not re-accelerate fast enough, a pronounced voltage dip may also result, which can be unacceptable for sensitive loads. This could also justify resorting to load shedding [12]. The voltage decay is obviously much faster than in case of long-term instability, as illustrated by the leftmost curves in Fig.…”

Section: B Protection Against Short-term Voltage Instabilitymentioning

confidence: 96%

A load shedding scheme against both short- and long-term voltage instabilities in the presence of induction motors

Otomega

Cutsem

2011

2011 IEEE Trondheim PowerTech

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This paper is the continuation of Ref. [9], where the impact of the induction motor loads on a load shedding protection scheme designed to deal with long-term voltage instability, initialy proposed in [10], was under study. For the load shedding scheme to cope with the fast response of motor loads, additional information exchange was required in order to enable the protection action with a reduced time delay. Therefore, the protection scheme changed from a purely distributed to wide-area, although simplicity was maintained. Moreover, the latter preserved important features such as closed-loop operation and redundancy between controllers.The proposed scheme was successfully tested under severe situation, as it was assumed that only non-motor loads can be shed.B. Otomega (bogdan.otomega@yahoo.com) is senior lecturer in the Power Systems Dept. of the "Politehnica" University of Bucharest, Romania. Induction motors due to their ability to reaccelerate after a fault, play an important role in short-term voltage instability. The objective of the paper is to report on the extension of the protection scheme dealing with short-term voltage instability.Furthermore, this paper will also compare the effect of shedding motor vs. non-motor loads. II. PRINCIPLE OF THE COMBINED PROTECTION SCHEME A. Protection against long-term voltage instabilityThe most important settings of an undervoltage load shedding scheme are the voltage threshold V th below which the controller starts curtailing load, and the delay τ before loads are effectively disconnected.In long-term voltage instability scenarios, where voltage degradation is precipitated by generator field current limitations, the voltage threshold value V th LT has to be set high enough, typically in the range [0.8 0.9] pu, as illustrated in Fig. 1 with the rightmost curve. The main consequence is that the corresponding delay τ LT should be large enough in order not to shed load inadvertently in case of a normally cleared fault. This is illustrated in Fig. 2, showing the minimum delay τ min LT that could be chosen when V th LT is set to 0.90 pu. Shorter delays could be considered if, at the same time, V th LT was set to a lower value.In the presence of induction motor loads, the final voltage collapse can be very fast, as illustrated by the five curves in the middle of Fig. 1, corresponding to various proportions

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Section: B Protection Against Short-term Voltage Instabilitymentioning

confidence: 96%

A load shedding scheme against both short- and long-term voltage instabilities in the presence of induction motors

Otomega

Cutsem

2011

2011 IEEE Trondheim PowerTech

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“…The objectives of a voltage recovery criterion are to ensure fault ride through by the majority of the loads and to minimize the risk of motor stalling. The authors of [3,45] proposed a TVRC for the transmission system; however, they did not consider the delayed voltage recovery problem (e.g., IM stalling) in the transmission system. Based on the TVRC transmission system developed by PJM [46], modified criteria were established in this paper and the criteria were applied to the transient voltage recovery characteristics of the Korean power system.…”

Section: Voltage Recovery Criteriamentioning

confidence: 99%

Multi-Phase Under Voltage Load Shedding Scheme for Preventing Delayed Voltage Recovery by Induction Motor Power Consumption Characteristics

Lee

Song

2018

Applied Sciences

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This paper aims to develop a multi-phase under voltage load shedding (MUVLS) strategy that effectively sheds the load to mitigate delayed voltage recovery (DVR). The major cause of the DVR phenomenon is related to the dynamic characteristics of induction motor (IM) loads. The deaccelerating and stalling of the IM load during disturbances is the main driving force of short-term voltage instability, resulting in an amount of reactive power consumption and excessive current draw. With the economic efficiency of energy use, the proportion of IM loads is gradually increasing, and this trend might deteriorate system stability. This paper focuses on the impact of IM loads in the Korean power system and analyzes the parameter sensitivity of IM loads and the proportion of appropriate IM loads. The proposed procedure for under voltage load shedding (UVLS) applies voltage stability criteria to decide the most efficient load shedding scheme. The determined MUVLS scheme can offer new and more effective remedial actions to maintain voltage stability, considering the characteristics of IM loads. Case studies on the Korean power system have validated the performance of the proposed MUVLS scheme under severe contingency scenarios, showing that the proposed strategy effectively mitigates DVR.

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“…1 relates to a shortterm voltage instability, where induction motors cannot reaccelerate after the fault has been cleared [1], [2]. To the authors' knowledge there are few publications devoted to the fast detection of short-term voltage instabilities, other than by monitoring low voltage and/or slow voltage recovery [13]. This interesting issue is outside the scope of this paper.…”

Section: B the Challenge: Doing Better Than Simple Voltage Monitoringmentioning

confidence: 99%

A short survey of methods for voltage instability detection

Glavić

Cutsem

2011

2011 IEEE Power and Energy Society General Meeting

117

100

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Abstract-This paper shortly surveys existing and proposed methods for voltage instability detection. The emphasis is on methods relying on real-time measurements as well as on longterm voltage instability. Methods are classified according to the required measurement configuration: local vs. wide-area, standard SCADA-type vs. synchronized phasor measurements, etc. In the various categories, some of the features are summarized, and what appears to the authors as advantages or limitations is shortly discussed. An important feature is the ability to anticipate instability. Some tracks for further work on the subject are also outlined.

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Slope-Permissive Under-Voltage Load Shed Relay for Delayed Voltage Recovery Mitigation

Cited by 54 publications

References 9 publications

A load shedding scheme against both short- and long-term voltage instabilities in the presence of induction motors

A load shedding scheme against both short- and long-term voltage instabilities in the presence of induction motors

Multi-Phase Under Voltage Load Shedding Scheme for Preventing Delayed Voltage Recovery by Induction Motor Power Consumption Characteristics

A short survey of methods for voltage instability detection

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