scholarly journals Review of Partial Discharge Activity Considering Very-Low Frequency and Damped Applied Voltage

Energies ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 440
Author(s):  
Mohamad Ghaffarian Niasar ◽  
Xiaolei Wang ◽  
Respicius Clemence Kiiza
Keyword(s):  
Partial Discharge ◽  
Time Lag ◽  
Low Frequency ◽  
Research Field ◽  
Very Low Frequency ◽  
Main Development ◽  
Charge Decay ◽  
Power Frequency ◽  
Statistical Time ◽  
Inception Voltage

When detecting the presence of partial discharge (PD) activity in the insulation system in high-voltage equipment, the excitation voltages at variable frequency have been widely used instead of power-frequency (50/60 Hz) sinusoidal voltage in order to reduce the charging power. This work reviews the relevant research on PD activity at very low frequency (VLF) method, including sinusoidal or cosine-rectangular voltage shape, and damped AC (DAC) method. Based on the research history and development status, some major PD characteristics, such as PD inception voltage (PDIV), PD amplitude, PD charge, PD phase-resolved pattern, and several hot issues, such as surface charge decay and statistical time lag, have been discussed. Moreover, the advantages, disadvantages, and applied conditions of two reviewed methods has been summarized. Finally, the prospects have been made on the main development trends of this research field in the future.

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.

Characterization and comprehension of corona partial discharge in air under power frequency to very low frequency voltage

2018 ◽  
Vol 20 (5) ◽  
pp. 054016 ◽  
Author(s):  
Yuanxiang ZHOU ◽  
Zhongliu ZHOU ◽  
Ling ZHANG ◽  
Yunxiao ZHANG ◽  
Yajun MO ◽  
...  
Keyword(s):  
Partial Discharge ◽  
Low Frequency ◽  
Very Low Frequency ◽  
Power Frequency

scholarly journals Study on Partial Discharge Characteristics of C6F12O Mixed Gas

2021 ◽  
Author(s):  
Xiajin Rao ◽  
Dajian Li ◽  
Xiaofei Xia ◽  
Yi Su ◽  
Yufeng Lu ◽  
...  
Keyword(s):  
Breakdown Voltage ◽  
Low Voltage ◽  
Partial Discharge ◽  
Buffer Gas ◽  
Mixing Ratio ◽  
Mixed Gas ◽  
Discharge Characteristics ◽  
Power Frequency ◽  
The Difference ◽  
Inception Voltage

Abstract The greenhouse effect of SF6 increasingly limits its application in various gas insulated equipment. C6F12O combines the advantages of insulation resistance, safety and environmental protection. When mixed with buffer gas, C6F12O is considered to have potential application prospects in medium and low voltage equipment. In this paper, about the partial discharge characteristics of the mixed gas, an experimental study was carried out. The partial discharge initiation voltage and discharge extinction voltage of mixed gas under power frequency voltage are measured and compared with the breakdown voltage. The results show that with the increase of mixing ratio, the partial discharge initiation voltage and extinction voltage of mixed gas gradually increase, and the effect of gas pressure on high mixing ratio is obvious. The difference between the partial discharge inception voltage and the breakdown voltage is larger than that of pure N2. The research in this paper can provide an important reference for the application, operation and protection of C6F12O mixed gas in medium and low voltage equipment.

Sign in / Sign up

Export Citation Format

Share Document