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This paper compares how a dc fault affects a multi-terminal dc (MTdc) network depending on the HVDC transmission system topology. To this end, a six-step methodology is proposed for the selection of the necessary dc fault protection measures. The network consists of four voltage-source converters converters radially connected. The converters natural fault response to a dc fault for the different topologies...
The paper investigates the applicability of averaged-value models (AVM) for modular multilevel converters (MMC) operating in a voltage sourced converter based high voltage dc (VSC-HVDC) grid. The AVM models are benchmarked by comparison with a detailed electromagnetic transient (EMT) model of the grid including a full-detail MMC model. Analysis results show that the AVM is only effective as long as...
In this paper, a novel solution method is proposed for the optimal topology control problem in AC framework with N-1 reliability. The resultant new topology of the proposed method is guaranteed to yield a better objective function value than the global solution of the problem with the original topology. In order to prove our statement, semi-definite programming relaxation is formulated to find a lower...
This paper introduces an enhanced equivalent model of the half-bridge symmetrical monopole Modular Multilevel Converter (MMC) topology for the analyses of the electromagnetic transients. As compared with the existing MMC models, the proposed model reduces the simulation computational time without compromising accuracy, and contrary to the existing models, it provides accurate representation of the...
This article presents a topology for DC grids which enables very robust DC fault protection with moderate costs, good operating flexibility and simple controls. It is postulated that radial DC systems are best suited for limitedsize local DC grids. Radial topology enables robust and fast protection selectivity using only local signals and exploiting the advantages of hybrid DC circuit breakers. To...
A coordinated cyber-attack on grid meter readings and breaker statuses can lead to incorrect state estimation that can subsequently destabilize the grid. This paper studies cyber-attacks by an adversary that changes breaker statuses on transmission lines to affect the estimation of the grid topology. The adversary, however, is incapable of changing the value of any meter data and can only block recorded...
Planning the expansion of distribution systems (DS) is a nonlinear and combinatorial problem that combines technical and regulatory constraints. Commonly, the planning of DS is intended to achieve a radial topology to reduce its complexity. However, in a smart-grid context, distribution feeders are subject to reconfigurations to transfer load between feeders in failure events, or to compensate for...
Data centers are becoming a significant energy consumer. Server workload, cooling, and supporting infrastructure represents large loads for the grid. This paper intends to present a comprehensive literature review that account for generation, loads, storage, and topology of data centers. It is shown that green data centers are emerging which incorporate renewable energy sources to cap their carbon...
A reasonable unit restoration plan is pivotal for the restoration of a power system after blackout. In this paper, the units to be restored are divided into two types: network-layer units and plant-layer units. By analyzing their interactions between each other and the respective contributions to the system restoration, an optimization method of unit restoration based on NNIA for power system restoration...
Well planned and adjusted protection devices increase the reliability of the system against fault events. The directional overcurrent relays, for example, play an important role in the protection of meshed transmission systems. They are usually employed as backup protection of distance relays. However, even as backup protection, the correct coordination can be set to speed up the fault mitigation...
This paper describes a methodology and an automated process to implement node-breaker capabilities for representing major stations within Con Edison's footprint. This process creates a “hybrid” power flow model of Con Edison's system such that the user-defined stations are represented using the node-breaker model and the rest of the system is modeled using bus-branch representation. The process is...
New winding configurations for mutually coupled salient pole switched reluctance machines (MCSRMs) have been proposed that enables the application of three-phase standard inverters for variable speed drives. The proposed topologies comprise phase windings carrying balanced three phase currents from standard inverters along with DC excitation coils in the stator slots. Both concentrated and distributed...
In this paper, an I–V tracer which operates autonomously, with no need to be disconnected from its load, will be discussed. The current state of I–V tracers commercially available will be discussed and motivation will be provided for the online autonomous I–V tracer. Design of such an I–V tracer using the single-ended primary inductance converter (SEPIC) will be discussed, and simulation results of...
One big challenge raised by frequent topology change in today's power system is assessing the system protection security and dependability afterwards. This paper reviews the setting algorithm for the distance relays and proposes an automated setting calculation module. The calculation procedure is broken down into blocks which could be processed in parallel in order to improve the computation speed...
One of the most challenging proposals about the smart grid concept is the deployment of features that enable a power grid to reconfigure itself, isolating defects and recovering through alternative available routes after disturbances. This ability is known as Self-Healing, a concept most widespread in distribution power systems. In transmission power systems, however, there is a substantially lower...
Cyber security provided by robust power systems state estimation methods is evaluated. Tools and estimators developed in robust statistics theory are exploited. The idea consists in considering redundant robust estimation techniques with different robustness properties to improve the overall detection of attacks and synthesizing a decision making process to determine whether an attack is present or...
Exhaustive enumeration of a S-select-k problem for hypothesized substations outages can be practically infeasible due to exponential growth of combinations as both S and k numbers increase. This enumeration of worst-case substations scenarios from the large set, however, can be improved based on the initial selection sets with the root nodes and segments. In this paper, the previous work of the reverse...
Corrective transmission switching can improve the flexibility of power system. To avoid the computational complexity, a data mining approach for real-time corrective switching is proposed in this paper. A factorized expression that measures the approximate switching effects is first derived. The expression can be utilized to generate candidate transmission switching lists. Based on the factorized...
Network topology in distribution networks is often unknown, because most switches are not equipped with measurement devices and communication links. However, knowledge about the actual topology is critical for safe and reliable grid operation. This paper proposes a voting-based topology detection method based on micro-synchrophasor measurements. The minimal difference between measured and calculated...
This paper proposes a data-driven approach to detect the switching actions and topology transitions in distribution networks. It is based on the real time analysis of time-series voltages measurements. The analysis approach draws on data from high-precision phasor measurement units (μPMUs or synchrophasors) for distribution networks. The key fact is that time-series measurement data taken from the...
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