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Published in Philip A. Laplante, Comprehensive Dictionary of Electrical Engineering, 2018
increment at sample position n = 0 and zero elsewhere. A shifted impulse is also termed an impulse. See Dirac delta function. impulse generator (1) an electronic device delivering single pulses of various shapes, preferably square. (2) a high-voltage trigger generator. impulse noise a noise process with infrequent, but very large, noise spikes; it is also known as shot noise or salt and pepper noise. The phrase "impulsive noise" is frequently used to characterize a noise process as being fundamentally different from Gaussian white noise, in being derived from a probability density function with very heavy (long) tails. Applying impulsive noise to an image leaves most pixels unaffected, but with some pixels very bright or dark. impulse response the output of a linear timeinvariant system when the input is a pulse of short time duration. The system can be entirely characterized by the impulse response. In the case of a continuous time system with input f (t), the impulse signal (t) is defined as (i) (t) = 0, (ii)
Transformer Testing
Published in Leonard L. Grigsby, Electric Power Transformer Engineering, 2017
Shirish P. Mehta, William R. Henning
The generation, measurement, and control of impulse voltage waves is a very specialized subject. In this section, only a very brief general introduction to the subject is provided. Most impulse-generator designs are based on the Marx circuit. Figure 17.5 shows a schematic diagram of a typical Marx-circuit impulse generator with four stages. In principle, voltage multiplication is obtained by charging a set of parallel-connected capacitors in many stages of the impulse generator to a predetermined dc voltage, then momentarily reconnecting the capacitor stages in series to make the individual capacitor voltages add. The reconnection from parallel to series is accomplished through the controlled firing of a series of adjustable sphere gaps, adjusted to be near breakdown at the dc charging voltage. After the capacitors are charged to the proper dc voltage level, a sphere gap in the first stage is made to flash over by some means. This initiates a cascade flashover of all the sphere gaps in the impulse generator. The gaps function as switches, reconnecting the capacitor stages from parallel to series, producing a generator output voltage that is approximately equal to the voltage per stage times the number of stages.
Predicting the Class of Salt Contamination for Wind Turbine Blade under a Lightning Strike Using Fuzzy Inference System and Probabilistic Neural Network
Published in Electric Power Components and Systems, 2023
Shenglu Huang, Jiannfuh Chen, Mingshou Su, Chienyi Chen
In terms of the experimental research on wind turbine blades, Glushakow [2] proposed lightning and surge protection guidelines for wind turbine generators and electronic equipment. Radičević et al. [3] proposed an experimental method to determine the influence of wind turbine blade rotation on the likelihood of getting struck by lightning. Radičević et al. [4] used a reduced-size model to survey the impact of wind turbine blade rotation on the lightning strike incidence. Yokoyama [5] used a set of high-voltage impulse generator systems to experiment on three different of blade-samples for clarifying the causes of lightning damage to wind turbine blades. Abd-Elhady et al. [6] used an experimental method to evaluate air-termination systems for wind turbine blades. Guo et al. [7] used a 5 m blade specimen with tip receptors to survey the lightning attachment manner to the WT blade with lightning protection systems in different situations.