IEEE 1434:2014 pdf free download – IEEE Guide for the Measurement of Partial Discharges in AC Electric Machinery
partial discharge (PD) quantity: The magnitude of an individual discharge in an insulation systemexpressed in terms of the apparent charge transfer(Q) measured at the terminals of the test object expressedin coulombs. In the case of complete windings, such measurements are limited to the low frequency rangeand the results obtained are a function of the bandwidth of the particular detection system.
power factor (cosf): The ratio of the power in watts (W) dissipated in a material to the product of theeffective sinusoidal voltage (V), and current (I), expressed in volt-amperes. Power factor is the cosine ofthe phase angle 0 between the voltage and the current.
power-factor tip-up: The difference in the power factor of the insulation measured at two designatedvoltages. In North America,these two voltages are often 25% and 100% of the rated phase-to-groundvoltage of the machine as is described in IEEE Std 286.
pseudoglow discharge: A type of partial discharge(PD) characterized by current pulses of relatively smallamplitude and, generally, a long rise time.As a result of the upper frequency limitation in their Fourierfrequency spectrum，pseudoglow discharges are not readily detected by conventional PD detectors.Pseudoglow discharges are also characterized by a diffused glow that cannot be visually distinguished fromthat resulting from a true-glow (or pulseless-glow ) discharge.
pulse discharge: A type of partial discharge(PD) phenomenon characterized by a spark-type breakdown.The resultant detected pulse discharge has a short rise time, and its frequency spectrum may extend as faras ≥ 100 MHz. Such a pulse discharge may be readily detected at the terminals of the winding orcomponent under by means of LF, HF,VHF , and UHF pulse detectors, that are generally designed for PDmeasurements within the frequency band from 10 kHz to GHz.
pulse height analysis: The measurement of the number of pulses occurring within a series of magnitudewindows over a defined phase period, not exceeding one half-cycle, of the alternating voltage applied to theobject under test. Sampling periods of one or more seconds may be involved.
pulse phase analysis(phase resolved PD analysis): A type of pulse height analysis in which there is morethan one phase window for each half-cycle of the alternating voltage applied to the object under test.
pulseless-glow discharge: A type of partial discharge (PD) phenomenon characterized by a diffused glow.The overall voltage waveform across a gap space undergoing pulseless-glow discharge does not indicatethe presence of any abrupt collapse in voltage, except for the two at the beginning of each half-cycle.Although discharge energy is expended over the pulseless region, a conventional PD detector will give noindication of this, as it will only respond to the two initiating breakdowns in each half-cycle.
resistance temperature detector (RTD): A temperature detector that is usually a three-terminal resistor,either 10 2 copper at 25 C or 100 2 platinum at 0 C, whose sensing element is about 25 cm in length,which is encapsulated within an insulating substrate of suitable thermal rating.RTDs are usually installedbetween top and bottom bars (coil legs) in a given slot. The measuring leads should be positioned such thatthey do not interfere with the stress control coating.
semiconducting slot coating: A coating, applied on the insulation surface of the slot parts of winding.Thesemiconducting coating,compound,or tape in which the powder filler or portion of powder filler is asemiconductive material and the electrical surface resistivity of this coating in such that when convertedinto a semiconducting solid layer，is in the range of 1 x 10’to 5 x 105 ohms per square. Thissemiconducting slot coating must have uniform tight contacts with the grounded walls of the stator slot.This coating provides minimum voltage between the surface of the coil or bar and the grounded stator core.