Partial discharge spectral response to variations in the supply voltage frequency

2012 ◽  
Vol 19 (2) ◽  
pp. 521-532 ◽  
Author(s):  
C. Nyamupangedengu ◽  
I. R. Jandrell
Keyword(s):  
Supply Voltage ◽  
Spectral Response ◽  
Partial Discharge ◽  
Voltage Frequency

scholarly journals Analysis of Cavity PD Characteristics’ Sensitivity to Changes in the Supply Voltage Frequency

Energies ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 478
Author(s):  
Tapiwa Venge ◽  
Cuthbert Nyamupangedengu
Keyword(s):  
Supply Voltage ◽  
Partial Discharge ◽  
Time Lag ◽  
Frequency Effect ◽  
Cavity Surface ◽  
Discharge Mechanism ◽  
Charge Decay ◽  
Research Findings ◽  
Voltage Frequency ◽  
Statistical Time

The supply voltage frequency effect on partial discharge (PD) phenomena has continued to draw research interest. Although most high voltage equipment operates at power frequency (50/60 Hz), testing is often done at different frequencies for various reasons. Despite some agreements and inconsistencies for the research findings of PD activity’s frequency dependence, there has been consensus on the recognition of the discharge mechanism parameters that influence how the supply voltage frequency affects PD activity. These parameters include statistical time lag, discharge area surface conductivity, and the residual charge decay. In this paper, a 3-capacitor model (ABC) is used to simulate how the changes in the discharge mechanism parameters influence PD characteristics as a function of the supply voltage frequency. The findings are that the phase-resolved partial discharge pattern (PRPDP) and PD repetition rate (PDRR) characteristics are more sensitive to variations in the probability of the seed electron availability at higher frequencies of the supply voltage. The opposite trend is observed for the cavity surface resistance. At lower resistance of cavity surface, the PRPDP and PDRR characteristics are more sensitive to changes in the supply voltage frequency than at higher resistances. The paper also confirms that incorporating equivalent resistances in the ABC model makes it more authentic than the model comprising of capacitors only.

scholarly journals EXCITATION OF PLASMA BY ELECTRIC PULSES IN NEON MEDIUM

2019 ◽  
pp. 203-206
Author(s):  
D.Yu. Zaleskyi ◽  
G.A. Krivonosov ◽  
G.V. Sotnikov
Keyword(s):  
Relaxation Time ◽  
Steady State ◽  
Pulse Duration ◽  
Supply Voltage ◽  
Unstable Mode ◽  
Plasma Source ◽  
Pulse Front ◽  
Electric Pulses ◽  
Front Duration ◽  
Voltage Frequency

We studied characteristics of the neon plasma source excited in the atmosphere under the following conditions: gas pressure is about 2 Torr, rectangular pulses have an amplitude from 200 to 800 V, pulse duration is from 0.2 to 10 μs, repetition rate is from 0.2 up to 1 kHz. There is a mode with a stable and unstable mode of existence of the plasma when the voltage on the electrodes of the plasma source varies from 800 to 350 V and from 350 to 250 V before the extinction of the plasma. The pulse from the PMT output in a steady state plasma has a decay of about 100 μs, the duration of which does not depend on the magnitude of the voltage, frequency and pulse duration. With a decrease in the supply voltage U, the pulse front duration with a photomultiplier is increased from 74 to 450 ns. It is shown that a large neon plasma relaxation time of 100 µs compared with a beam pulse duration of 1…2 µs allows only one time to change the phase of the accelerating field.

scholarly journals Partial Discharge Detection Using a Spherical Electromagnetic Sensor

Sensors ◽  
2019 ◽  
Vol 19 (5) ◽  
pp. 1014 ◽  
Author(s):  
Pietro Romano ◽  
Antonino Imburgia ◽  
Guido Ala
Keyword(s):  
Supply Voltage ◽  
Partial Discharge ◽  
Correct Diagnosis ◽  
Measurement Instrument ◽  
Warning Signal ◽  
Health State ◽  
Insulation System ◽  
Insulation Systems ◽  
Electromagnetic Sensor ◽  
Electrical Apparatus

The presence of a partial discharge phenomenon in an electrical apparatus is a warning signal that could determine the failure of the insulation system, terminating the service of the apparatus and/or the network. In this paper, an innovative partial discharge (PD) measurement instrument based on an antenna sensor is presented and analyzed. Being non-intrusive is one of the most relevant features of the sensor. The frequency response of the antenna sensor and the features to recognize different PD sources and automatically synchronize them with the supply voltage are described and discussed in details. The results show the performance of the instrument can make a fast and correct diagnosis of the health state of insulation systems.

scholarly journals Efficiency of Cascaded Neural Networks in Detecting Initial Damage to Induction Motor Electric Windings

Electronics ◽  
2020 ◽  
Vol 9 (8) ◽  
pp. 1314
Author(s):  
Maciej Skowron ◽  
Teresa Orłowska-Kowalska
Keyword(s):  
Neural Networks ◽  
Induction Motor ◽  
High Efficiency ◽  
Supply Voltage ◽  
Frequency Converter ◽  
Damage Classification ◽  
Voltage Frequency ◽  
Rotor Winding ◽  
Cage Induction Motor ◽  
Diagnostic Software

This article presents the efficiency of using cascaded neural structures in the process of detecting damage to electrical circuits in a squirrel cage induction motor (IM) supplied from a frequency converter. The authors present the idea of a sequential connection of classic neural structures to increase the efficiency of damage classification and detection presented by individual neural structures, especially in the initial phase of single or multiple electrical failures. The easily measurable axial flux signal is used as a source of diagnostic information. The developed cascaded neural networks are implemented in the measurement and diagnostic software made in the LabVIEW environment. The results of the experimental research on a 1.5 kW IM supplied by an industrial frequency converter confirm the high efficiency of the use of the developed cascaded neural structures in the detection of incipient stator and rotor winding faults, namely inter-turn stator winding short circuits and broken rotor bars, as well as mixed failures in the entire range of changes of the load torque and supply voltage frequency.

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