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.
Although active islanding detection techniques have smaller non-detection zones than passive techniques, active methods could degrade the system power quality and are not as simple and easy to implement as passive methods. The islanding detection strategy, proposed in this paper, combines the advantages of both active and passive islanding detection methods. The Distributed Generation (DG) interface...
Spinning reserve (SR) allows system operators to compensate for unpredictable imbalances between load and generation caused by sudden outages of generating units, errors in load forecasting or unexpected deviations by generating units from their production schedules. As the proportion of power produced by wind farms increases, it becomes more difficult to predict accurately the total amount of power...
In this paper, we propose a novel nonlinear approach to solve the short-term hydro scheduling problem under deregulation, considering head-dependency. The actual size of hydro systems, the continuous reservoir dynamics and constraints, the hydraulic coupling of cascaded hydro systems, and the complexity associated with head-sensitive hydroelectric power generation still pose a real challenge to the...
This paper presents an analysis of multi-in-feed HVDC interactions using small signal analysis techniques. The modeling details necessary to adequately represent the dynamics of the HVDC converters and the AC network are investigated and the models are validated against an Electromagnetic Transient Simulation program. The paper shows that AC network dynamics must be modeled in order to obtain meaningful...
The summary form only given. Phasor measurement units (PMUs) are considered as a promising tool for future monitoring, protection and control of power systems. In this paper, a unified approach is proposed in order to determine the optimal number and locations of PMUs to make the system measurement model observable and thereby can be used for power system state estimation. The PMU placement problem...
The summary form only given. Power-line-signaling-based schemes are regarded as promising solutions to the problem of anti-islanding protection of distributed generators (DGs). These schemes broadcast dedicated signals from the distribution substation to the downstream DGs and, therefore, transform the detection of islanded DGs into the determination of the signal presence at the DG sites. This paper...
This paper describes a new type of electric field sensor fabricated using micromachining technology. This micromachined sensor is dramatically smaller than conventional field mills, possessing a field chopping shutter measuring only 1 mm2. The shutter is moved using thermal actuators, thereby eliminating the wear and tear associated with rotating and moving elements of field mills. The sensor requires...
Recently, there has been renewed interest in modeling of electrical machines for the EMTP-type programs, with the goal of improving the machine-network interface. In this paper, we present a new voltage-behind-reactance induction machine model for the EMTP-type solution and power system transients. In the proposed model, the stator circuit is represented in phase coordinates and the rotor subsystem...
This panel paper provides a brief overview of the National Science Foundation's research and education activities in the program area of Electric Power and Energy. Examples of successful transfer of research into educational activities are numerous and while this paper cannot claim to provide an exhaustive survey, an attempt will be made to review some of the best practices described by Research and...
Summary form only given. Admittance-based rational modeling of multi-port systems is prone to error magnification in applications with high-impedance terminations. This problem is overcome by the modal vector fitting method (MVF) which is formulated in terms of modal components with inverse least-squares weighting by the eigenvalue magnitude. A direct realization of MVF is very demanding in computation...
A comprehensive model of a salient-pole synchronous machine is developed for a real-time environment. By obtaining the effective specific permeance of the machine from simple experimental measurements and the exact geometry of the rotor pole-arc, a model is developed that includes the exact distribution of windings and operating-point dependent saturation. This model offers a superior simulated response...
Operating in a Regional Transmission Organization market can be challenging for generators, because it is possible to misunderstand the effect of participant-submitted data. Such misunderstandings can have negative financial and operational impacts on the generator.
Summary form only given. The aim of this paper is to present an analytical, state-space model of an indirect, voltage-controlled cascaded-type multilevel static synchronous compensator (STATCOM) with dasiasquare wave controlpsila. The multilevel converter model is segmented into a dynamic and static part in order to accurately represent all internal feedback connections. Each voltage component is...
Summary form only given. This paper proposes a Fourier transform-based modified phasor estimation method to eliminate the adverse influence of the exponentially decaying DC offsets when discrete Fourier transform (DFT) is used to calculate the phasor of the fundamental frequency component in a relaying signal. By subtracting the result of odd-sample-set DFT from the result of even-sample-set DFT,...
Summary form only given. Electricity markets have been moving on from infancy toward maturity. Experiences have shown that competitive market operation needs to integrate with secure and reliable system operation; otherwise, market failure and/or blackout may happen. This panel will review PJM's practice on how to achieve equilibrium between economic efficiency and system operation risk. In PJM's...
This paper presents a model for evaluating small hydro power plants (SHPP) generation availability that can be applied to generation systems reliability and to generation planning studies. The model considers the uncertainties of rivers inflows and generation units operation. The river inflow is modeled as a stationary stochastic process by a multiple states Markov chain and the generator unit by...
This article investigates network policies and mechanisms to enhance security in SCADA networks using a mix of TCP and UDP transport protocols over IP. It recommends creating a trust system that can be added in strategic locations to protect existing legacy architectures and to accommodate a transition to IP through the introduction of equipment based on modern standards such as IEC 61850. The trust...
The effects of subsynchronous interharmonic voltages (SIVs) on three phase power transformers are presented and discussed. In a companion paper, the results of an experiment study a single phase transformer highlighted the need for accurate modeling of the magnetization curve. This study focuses on the magnetizing currents, rms values, and spectral components in the presence of SIVs. A suitable time...
The volume of data produced by existing partial discharge monitoring systems is often too large for engineers to examine in detail, leading to data being ignored and useful indicators of health being missed. The case study reported in this paper recorded 21,839 events around an HVDC reactor over a six day period. We estimate it takes one minute to check if an event requires detailed study, leading...
Summary form only given. The profitable operation of a wind project depends on two critical indices: wind energy deliverability and locational marginal prices (LMP). The traditional optimal power flow (OPF) study has been widely used to obtain those indices. However, the traditional OPF study generally provides only the peak load hour results, which ignore temporal constraints of power system components...
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.