scholarly journals Accurate Estimation of Frequency-Dependent Losses in High Voltage Test Transformers for the Assessment of Electric Discharge Powers

2019 ◽  
Vol 63 (3) ◽  
pp. 191-201
Author(s):  
Kada Laroussi ◽  
Samir Flazi
Keyword(s):  
Electric Discharge ◽  
High Voltage ◽  
Electrical Discharge ◽  
Voltage Source ◽  
Total Power ◽  
Accurate Estimation ◽  
Iron Core ◽  
Voltage Measurement ◽  
Voltage Transformer ◽  
Décharge Électrique

The work presented in this paper is related to the project GEMUDE (Genérateur Multifonction de Décharge Electrique) which aims to design a universal high-voltage generator for electrical discharge studies. To design this variable high voltage source that operates in the frequency range of 0 to 1 kHz, the assessment of transformer losses represents a crucial phase during the design process. These losses in the coils and iron core of the transformer are closely related to the frequency and nature of the materials used. This paper presents a comparative study of transformer losses using analytical methods and experimental calorimetry measurements. Steinmetz empirical formula is used to estimate magnetic core losses whereas coil losses are evaluated by solving Maxwell equations. The main goal is to control these losses to limit the internal temperature rise in the transformer through the implementation of an efficient cooling solution. The results obtained by the analytical method were satisfactory which confirm the feasibility of measuring the power absorbed by the various electrical discharge devices upstream of the high-voltage transformer. This is because it turns out that the power of the generator in charge is the total power of the electric discharge and the transformer losses. This method, termed Power Disparity Method (PDM). In this paper, it is an easy and reliable way as compared with high voltage measurement methods.

scholarly journals Resonant Power Frequency Converter and Application in High-Voltage and Partial Discharge Test of a Voltage Transformer

Energies ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 2014
Author(s):  
Banyat Leelachariyakul ◽  
Peerawut Yutthagowith
Keyword(s):  
High Voltage ◽  
Noise Level ◽  
Background Noise ◽  
Low Voltage ◽  
Frequency Converter ◽  
Partial Discharge ◽  
Voltage Source ◽  
Voltage Transformer ◽  
Background Noise Level ◽  
Power Frequency

This paper presents application of a resonant power frequency converter for high-voltage (HV) and partial discharge (PD) test of a voltage transformer. The rating voltage, power, and frequency of the system are 70 kVrms, 40 kVA, and 200 Hz, respectively. The testing system utilized the converter feeding to an HV testing transformer connected to a conventional partial discharge detection system. The converter system comprising a rectifier and insulated-gate bipolar (IGBT) switches with the H-bridge configuration was applied as a low-voltage source instead of a conventional motor-generator test set which requires large space and high cost. The requirements of the test according to the standards are quality of the test voltage and the background noise level. The required voltage must have the different voltage (DV) and total harmonic distortion (THDv) in the acceptable values of less than 5%. The DV is defined as the difference of the root mean square and peak voltages in percent. The required background noise level must be lower than 2.5 pC. Simulations and experiments were performed for verification of the developed system performance in comparison with those of the previously developed system based on the pulse width modulation converter. It is found that the developed system can provide the testing voltage with the DV and the THDv of lower than 1% and the background noise level of lower than 1 pC. Considering this achievement of promising performance, the developed system is an attractive choice for the HV and PD testing of voltage transformers in real practice.

Power Quality Improvement of High Voltage DC Link using Modified Shunt Active Power Filter

2018 ◽  
Vol 1 (1) ◽  
pp. 54-66
Author(s):  
Rakan Khalil Antar ◽  
Basil Mohammed Saied ◽  
Rafid Ahmed Khalil
Keyword(s):  
Power Quality ◽  
High Voltage ◽  
Pulse Width Modulation ◽  
Active Power Filter ◽  
Active Power ◽  
Voltage Source ◽  
Active Power Filters ◽  
Power Filter ◽  
Power Filters ◽  
Power Quality Improvement

A new control strategy for active power filters is proposed, modeled and implemented in order to improve the power quality of a line commutated converter High voltage DC link. The ability of reactive power and harmonics reductions are generally met by using passive and active power filters. In this paper, modified active power filter with a modified harmonics pulse width modulation algorithm is used to minimize the source harmonics and force the AC supply current to be in the same phase with AC voltage source at both sending and receiving sides of a line commutated converter high voltage DC link. Therefore, it is considered as power factor corrector and harmonics eliminator with random variations in the load current. The modified harmonics pulse width modulation algorithm is applicable for active power filter based on a three-phase five-level and seven-level cascaded H-bridge voltage source inverter. Simulation results show that the suggested modified multilevel active power filters improve total harmonics distortion of both voltage and current with almost unity effective power factor at both AC sides of high voltage DC link. Therefore, modified active power filter is an effective tool for power quality improvement and preferable for line commutated converter high voltage DC link at different load conditions.

scholarly journals High Voltage Electric Discharge for Recovery of Chlorogenic Acid from Tobacco Waste

2021 ◽  
Vol 13 (8) ◽  
pp. 4481
Author(s):  
Marija Banožić ◽  
Antun Jozinović ◽  
Jovana Grgić ◽  
Borislav Miličević ◽  
Stela Jokić
Keyword(s):  
Chlorogenic Acid ◽  
Process Parameters ◽  
Electric Discharge ◽  
High Voltage ◽  
Treatment Time ◽  
Strong Dependence ◽  
Extraction Procedure ◽  
Polynomial Equation ◽  
Experimental Conditions ◽  
Tobacco Waste

Three fractions of tobacco waste (scrap, dust and midrib) were subjected to a high voltage electric discharge (HVED) assisted extraction procedure under different experimental conditions: solvent:solid ratio (300, 500, 700 mL/g), frequency (40, 70, 100 Hz) and treatment time (15, 30, 45 min), in order to study the influence of these conditions on the content of chlorogenic acid. The content of chlorogenic acid ranged from 1.54 to 3.66 mg/100 g for scrap, from 1.90 to 2.97 mg/100 g for dust, and from 2.30 to 3.38 mg/100 g for midrib extract, showing a strong dependence on the applied process parameters. The temperature change and the change in pH and electrical conductivity of the extracts after high voltage discharge treatment were also observed. The studied process parameters showed a statistically significant effect on the chemical and physical properties of the extracts from tobacco waste as well as on the content of chlorogenic acid, indicating the potential of HVED assisted processes in the separation of chlorogenic acid from tobacco industry waste. Multiple regression analysis was used to fit the results for the chlorogenic acid to a second order polynomial equation and the optimum conditions were determined.

The Development of Precision 500/√3 kV Two-Stage Voltage Transformer with High-Voltage Excitation

2021 ◽  
pp. 1-1
Author(s):  
Hao Liu ◽  
Feng Zhou ◽  
Lixue Chen ◽  
Min Lei ◽  
Xiaodong Yin ◽  
...  
Keyword(s):  
High Voltage ◽  
Voltage Transformer ◽  
Two Stage

Variation in the particle size of FE–TI–B4C powders induced by high-voltage electrical discharge

2012 ◽  
Vol 51 (3-4) ◽  
pp. 129-136 ◽  
Author(s):  
O. N. Sizonenko ◽  
G. A. Baglyuk ◽  
A. I. Raichenko ◽  
É. I. Taftai ◽  
E. V. Lipyan ◽  
...  
Keyword(s):  
Particle Size ◽  
High Voltage ◽  
Electrical Discharge
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