An investigation into the OLTC effects on voltage collapse

Zhu, Tianhua; Tso, S.K.; Lo, K.L.

doi:10.1109/59.867134

Cited by 60 publications

(23 citation statements)

References 6 publications

(6 reference statements)

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“…According to [3], approaches for finding the optimal configuration of a distribution system fall into the following four categories: heuristic methods [4] [5], rule-based approaches [6] [7], genetic algorithms [8], and mathematical programming. After finding the optimal configuration, power flow considerations should be made to ensure that the new state of the system does not overload any of the circuit elements, cause misoperations of protection equipment, or violate any voltage constraints.…”

Section: Introductionmentioning

confidence: 99%

Optimal Partitioning of Distribution Networks for Micro-Grid Operation

Kimble¹,

Vedullapalli²,

Makram³

2017

JPEE

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A great concern for the modern distribution grid is how well it can withstand and respond to adverse conditions. One way that utilities are addressing this issue is by adding redundancy to their systems. Likewise, distributed generation (DG) is becoming an increasingly popular asset at the distribution level and the idea of micro-grids operating as standalone systems apart from the bulk electric grid is quickly becoming a reality. This allows for greater flexibility as systems can now take on exponentially more configurations than the radial, one-way distribution systems of the past. These added capabilities, however, make the system reconfiguration with a much more complex problem causing utilities to question if they are operating their distribution systems optimally. In addition, tools like Supervisory Control and Data Acquisition (SCADA) and Distribution Automation (DA) allow for systems to be reconfigured faster than humans can make decisions on how to reconfigure them. As a result, this paper seeks to develop an automated partitioning scheme for distribution systems that can respond to varying system conditions while ensuring a variety of operational constraints on the final configuration. It uses linear programming and graph theory. Power flow is calculated externally to the LP and a feedback loop is used to recalculate the solution if a violation is found. Application to test systems shows that it can reconfigure systems containing any number of loops resulting in a radial configuration. It can connect multiple sources to a single micro-grid if more capacity is needed to supply the microgrid's load.

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Section: Introductionmentioning

confidence: 99%

Optimal Partitioning of Distribution Networks for Micro-Grid Operation

Kimble¹,

Vedullapalli²,

Makram³

2017

JPEE

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“…Based on previous work [9], we can obtain the maximum power transfer in a radial transmission system as shown in Eqs. (5) and (6). Whatever static load model is applied at bus 2, the power transfer capability is the same and is determined only by the parameters of the network and the voltage at the sending end bus.…”

Section: A Static Load Modelmentioning

confidence: 99%

“…Extending the power transfer capability helps to make the system re-enter a reasonable post-disturbance operating condition. In References [6] and [7], the authors use static analysis to show the ULTC's effect on the increase of maximum power transfer and its impact on system stability. However, voltage stability is a dynamic phenomenon and analysis based on static modeling is not sufficient and usually leads to erroneous results.…”

Section: Introductionmentioning

confidence: 99%

Impact of Load Tap Changing Transformers on Power Transfer Capability

Dong

Chowdhury

Crow

et al. 2004

Electric Power Components and Systems

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Power transfer margins are studied with under load tap changing (ULTC) transformers based on both static and dynamic analysis. Static analysis resultsshow that the ULTC can effectively increase the power transfer capability from a generation area to a load center by matching the generation side impedance with the load impedance. In dynamic analysis, both the ULTC and the load are considered as dynamic devices. The dynamic mechanism of mid-term voltage instability is analyzed using a load gain factor. Discrepancies in results from the two methods are explained. The effects of two types of ULTC-the network transformer and the distribution transformer are investigated. Both theoretical analysis and simulation results show that the network transformer is more beneficial for increasing the power transfer capability.

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“…The power transfer from generators to load centers affects load bus voltages. In addition to restoring the load, OLTC also extend the power transfer ability to the load center [1]. It is well known that the operation of OLTC has a significant influence on voltage stability.…”

Section: Introductionmentioning

confidence: 99%

Adaptive setting of OLTC to improve power transfer capability of power systems

Abu-Siada¹,

Islam²,

Mohamed³

2008

2008 International Conference on Condition Monitoring and Diagnosis

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Abstract--On load tap changing transformer (OLTC) has become a vital link in modern power systems. It acts to maintain the load bus voltage within its permissible limits despite any load changes. This paper discusses the effect of different static loads namely; constant power (CP), constant current (CI) and constant impedance (CZ) on the maximum power transfer limit from the generation to the load centre through the OLTC branch and in turn on the static stability margin of power systems. Then the paper introduces a novel approach for the on-line determination of the OLTC settings in order to improve the power transfer capability of transmission systems. The proposed approach is tested based on the simulation of a six-bus power system. Numerical results prove that the setting of transformer OLTC in terms of the load model has a major effect on the maximum power transfer in power systems. The adaptive settings of OLTC improve the power transfer capability according to the system operating condition.Index Term--OLTC, static load, power transfer limit, stability margin, ANN

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An investigation into the OLTC effects on voltage collapse

Cited by 60 publications

References 6 publications

Optimal Partitioning of Distribution Networks for Micro-Grid Operation

Optimal Partitioning of Distribution Networks for Micro-Grid Operation

Impact of Load Tap Changing Transformers on Power Transfer Capability

Adaptive setting of OLTC to improve power transfer capability of power systems

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