The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
Single Line to Ground (SLG) faults in non-effectively grounded networks are difficult to detect. Immune to neutral point grounding type, load conditions and system operation conditions, traveling-wave based method is an effective fault line identification method. However, due to the strong coupling between the double-circuit lines, the wavefront magnitude of them are the same, and the polarity of...
This paper investigates the optimal charging strategy for a plug-in electric taxi (PET) to maximize its operating profit by choosing proper charging slots, subject to uncertain electricity prices and time-varying incomes. As PET consumes more electricity and possesses different charging behaviors from the widely studied private electric vehicles, this problem deserves special treatment. First, in...
Economic dispatch problem (EDP) is an optimization problem with the objective to minimize the total generation cost subject to the power balance constraint and generator capacity limits. Typically, EDP is solved in a centralized manner, however, recently, several consensus-based algorithms have been proposed to solve EDP in a distributed manner. In these algorithms, it is assumed that information...
Inductors are a significant contributor to mass in many power applications including the dc link in high-power drives and in dc-dc power conversion equipment. Permanent magnet inductors may be used in place of traditional inductors in dc biased applications with significant (40%) mass savings. This paper sets forth a rigorous, systematic, and multi-faceted design paradigm for a permanent magnet inductor...
A new high impedance fault (HIF) detection method using time-frequency analysis for feature extraction is proposed. A pattern classifier is trained whose feature set consists of current waveform energy and normalized joint time-frequency moments. The proposed method shows high efficacy in all the detection criteria defined in this paper. The method is verified using the real-world data, acquired from...
In power systems forced oscillations occur, and identification of these oscillations is important for the proper operation of the system. Two of the parameters of interest in analyzing and addressing forced oscillations are the starting and ending points. To obtain estimates of these parameters, this paper proposes a time-localization algorithm based on the geometric analysis of the sample cross-correlation...
Phasor Measurement Units (PMUs) are being rapidly deployed in power grids due to their high sampling rates and synchronised measurements. The devices high data reporting rates present major computational challenges, in the requirement to process potentially massive volumes of data, in addition to new issues surrounding data storage. Fast algorithms capable of processing massive volumes of data are...
System splitting is an efficient way to prevent widespread blackout. Finding proper splitting schemes for on-line application is becoming increasingly difficult due to the combinatorial explosion nature of the problem. This paper considers a new problem formulation of system splitting with priority service areas and proposes an efficient three-stage method for designing on-line system splitting. These...
A modified forward backward sweep load flow algorithm for unbalanced radial distribution systems is proposed in this paper. The proposed algorithm modifies branch current calculation approach in backward sweep by using three matrices. They are matrices A, B and C. These matrices are used in identifying downstream buses and also in calculating branch current or power flow in an easy manner. For accurate...
The L-shaped method is a decomposition algorithm that is commonly used to solve large-scale two-stage stochastic programming problems. The classic single-cut L-shaped method usually suffer the performance issue because only a single optimality cut is applied at each major iteration. This paper presents an aggregated multi-cut version of the L-shaped method for solving two-stage transmission expansion...
Large-scale wind farm integration poses challenges to the modeling and simulation of power system electromagnetic transients. In this paper, state space modeling of typical induction generator wind farms is demonstrated using a subsystem assembly process, and a novel matrix exponential based simulation algorithm is applied, which is efficient, stable, and especially suitable for high dimensional nonlinear...
A large number of distributed generations (DGs) in a distribution grid always belong to different operators. Therefore, the exact changes in operation state caused by each single DG, such as the allocation of power loss, should be determined. This study proposes a method combining power flow algorithm, sensitivity analysis, and multi-step integration. The total changes caused by all the DGs can then...
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...
This paper proposes an online tracking algorithm to allocate and track the optimal charging frequency for lithium-ion (Li-ion) batteries in real time under any condition. The optimal frequency refers to the frequency of the sinusoidal component of the charging current at which the internal AC impedance of the battery cell is minimal. The AC impedance depends on the physical properties of the battery's...
The present article presents a novel and applied approach based on clustering to determine optimal locations, sizing of sub-transmission substations with their associated service area without determining location of candidate substations. The goal of this optimization is to minimize all of fixed costs and operation costs while all of constraints are met. Cost of equipment, construction, MV feeder...
Developing the control algorithms of electric machine drives for less noise and harmonics is proposed here for design improvements. Modern control algorithms for electric machine drives are implemented and their radiated magnetic fields are measured and imported into a digital signal processing unit. The measurement was implemented using magnetic field antennas which cover low frequencies. A digital...
In islanded microgrids (MG), distributed generators (DG) can be employed as distributed compensators for improving the power quality in consumer side. A multi-level hierarchical control is usually applied with each level dealing with different issues. In case of voltage unbalance compensation, droop control and virtual impedance can be applied in primary control to help the basic active and reactive...
Transmission switching planning under an AC power flow model is a challenging mathematical problem, incorporating nonlinearities, nonconvexities, and discrete variables. An effective solution methodology would develop an appropriate relaxation and then rely on methods from discrete optimization to simultaneously refine the relaxation, and perform enumeration, so as to obtain a sequence of narrowing...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.