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Published in Philip A. Laplante, Comprehensive Dictionary of Electrical Engineering, 2018
for i {1, 2, . . . , N }, t [0, T ] and terminal condition K (i, T ) = 0 where A, B are, respectively, state and input matrices in the state equation, Q(i), R(i) are weighting state and input matrices for the i-th player, and its solution defines the gain in a Nash equilibrium in the game. coupled wave equations a special case of Maxwell's equations describing the propagation of two interacting electromagnetic fields in a nonlinear material. For example, in four wave mixing or optical phase conjugation, the probe and conjugate fields often obey coupled wave equations. coupler (1) a passive, wavelength-insensitive, fiber optic component that combines all inputs and distributes them to the outputs with a defined splitting ratio. The most common types are termed fused taper and dichroic. (2) a device inserted into an optical fiber communications link that is used to insert additional optical energy or signals onto the link and/or tap off some of the energy or signal on the link to another optical fiber. A coupler may also be used to combine power from two or more input fibers into one output fiber or to distribute the combined input power to a number of output fibers. Couplers are made in 1 × N , N × N , and N × M (input) ×(output) configurations where N and M are the number of fibers. The power combining and/or splitting ratios can vary from 50%/50% (a 3 dB coupler) in a symmetric 2 × 2 coupler to > 99%/ < 1% in an asymmetric coupler. coupling capacitor voltage transformer (CCVT) a potential transformer that uses the impedance of
Reactors
Published in Leonard L. Grigsby, Electric Power Transformer Engineering, 2017
Richard F. Dudley, Michael Sharp, Antonio Castanheira, Behdad B. Biglar
Line traps are a major component of power line carrier communication/data transmission/protective relaying systems utilized by utilities. The power transmission lines provide the telecommunications medium. The power line carrier system consists of line traps, coupling capacitors (CC) or coupling capacitor voltage transformer (CCVT), line tuners, line matching units (LMU), and radio transmitters and receivers. The main coil component of a line trap is essentially a dry-type air-core reactor. The other components of the line trap are the tuning device and the protective device, usually a distribution class metal oxide surge arrester. Figure 11.50 shows a fully encapsulated line trap mounted on a CCVT.
Instrument Transformers
Published in Shoaib Khan, Industrial Power Systems, 2018
The physical size and cost of a voltage transformer increases with the increase in voltage rating. In general, a capacitor voltage transformer (CVT) becomes more economical compared with an electromagnetic voltage transformer at voltages above 120 kV. A CVT is a combination of capacitive voltage divider and an inductive voltage transformer rated at a lower voltage. The principle diagram of a CVT in a single-line form is shown in fig. 6.6.
EPE-Based Pilot Relaying Scheme Immune to SIR Variations
Published in IETE Journal of Research, 2020
To test the capability of proposed pilot relaying scheme, digital simulations using EMTDC/PSCAD [18] have been carried out and results are obtained. The equivalent diagram of power system with series compensation in line-B is depicted in Figure 4. Three different power system test models are used to verify the proposed scheme. The model data and TL data are given in Tables 1 and 2, respectively. The model-3 is nothing but the uncompensated version of model-1. The performance of proposed pilot relaying scheme has been investigated for different conditions. A capacitor voltage transformer is used with a ratio of 400 kV/100 V. The ratio of current transformer (CT) is 2400A/1A. All the phasors of voltages and currents have been calculated using FFT block of power system computer aided design/electromagnetic transient and DC library.
A Survey on the Application of Phasor Measurement Units to the Protection of Transmission and Smart Distribution Systems
Published in Electric Power Components and Systems, 2023
T. S. Menezes, P. H. A. Barra, F. A. S. Dizioli, V. A. Lacerda, R. A. S. Fernandes, D. V. Coury
A backup protection method for shunt-compensated lines was proposed by [71]. The method used synchronized measurements from both ends of the lines to estimate the integrated impedance, which is the ratio of the voltage sum across the line over the sum of the currents through the same line. For non-fault conditions, this integrated impedance presented a high value, which was drastically reduced for a faulted phase. This technique was evaluated for different fault types, locations, and inception angles with some cases considering current transform saturation and a capacitor voltage transformer. This method showed prominent results even compared with the differential protection.
Fuzzy-Based Relaying Scheme for Transmission Line Based on Unsynchronized Voltage Measurement
Published in IETE Journal of Research, 2022
Biswapriya Chatterjee, Sudipta Debnath
Coupling capacitor voltage transformer (CCVT) is used in power system networks, which has voltage level above 138 kV for economic reason [17]. A study has been carried out to investigate the effect of CCVT transient during a fault in power system transmission line. Figure 8 reveals that the faulty phase voltage waveform in the presence CCVT transient during AG fault at t = 0.04s with Rf=10Ω and FIA = 0° experiences a small perturbation. The proposed technique gives a satisfactory result in the presence of CCVT transient.