Handbook of Power Systems Engineering with Power Electronics Applications

Abstract

Double circuit line with LR constants 38 2.4.3 Single circuit line with stray capacitance C 41 2.4.4 Double circuit line with C constants 2.5 Typical Transmission Line Constants 2.5.1 Typical line constants 2.5.2 L, C constant values derived from typical travelling-wave velocity and surge impedance 2.6 Generator by Symmetrical Components (Easy Description) 2.6.1 Simplified symmetrical equations 2.6.2 Reactance of generator 2.7 Description of Three-phase Load Circuit by Symmetrical Components 52 3 FAULT ANALYSIS BY SYMMETRICAL COMPONENTS 53 3.1 Fundamental Concept of Symmetrical Coordinate Method 53 3.2 Line-to-ground Fault (Phase a to Ground Fault: 10G) 54 3.2.1 Condition before the fault 55 3.2.2 Condition of phase a to ground fault 56 3.2.3 Voltages and currents at virtual terminal point f in the 0-1 -2 domain 56 3.2.4 Voltages and currents at an arbitrary point under fault conditions 57 3.2.5 Fault under no-load conditions 58 3.3

Experimental Study of Transformer Residual Flux and the Method of Restraining Inrush Current

“…Thus whenever breaker Br1 is tripped, the tripping of all phase poles will be completed simultaneously at instant t op0 by chopping‐mode tripping of the breaker at the instant when the three‐phase moving contacts move apart from the fixed contacts almost simultaneously. This is in contrast to current‐zero mode tripping, which is the ordinary tripping mode in case of fault current tripping and/or load current tripping, where the tripping of the second and third poles is completed about 10 ms after the first pole trips, because each phase breaker pole can cut off a large current only at the time of current zero .…”

A Data-driven Approach for Estimating Relative Voltage Sensitivity

“…2and 3, the relationship between V r and P r or Q r is nonlinear. To calculate the voltage sensitivity to a small disturbance of ∆P r and ∆Q r around the operating point, we need to eliminate δ, replace P r by P r +∆P r , replace P 2 r by P 2 r + 2P r ∆P r and neglect ∆P r 2 , as suggested in [14]. By doing a similar procedure with respect to Q r and V r , the voltage sensitivity can be calculated as…”

Extraction algorithm of symmetrical components for controlling static converters of electric energy

“…The purpose of this article is to review the extraction algorithm of positive, negative and zero sequence using the generalized method of symmetrical components on the example of the three-phase coordinate system [9] and its application to a three-phase two-level inverter voltage. This method allows to extract the symmetrical components in a wide spectrum of currents and voltages.…”

“…Fig.1 shows described above formulas (1). On an example of asymmetric system the currents are taken [9]. Of great interest is the work [10], which is represented by the generalized method of decomposing to zero, positive and negative sequence of non-sinusoidal periodic electrical quantities, and representation of these values in different coordinate systems is discussed.…”