New Method for Measuring Mechanical Vibration Loss and Dielectric Loss of Piezoelectric Transducer under High-Power Excitation

In order to acquire enough energy, high power pulse must be used to drive a piezoelectric transducer. At the same time, it is a key technology to design an impedance matching circuit between a signal generator and a piezoelectric transducer so that signal source can transmit energy to the piezoelectric transducer effectively. In the paper, the impedance matching theory is analyzed. And, a method of using an oscilloscope to measure resonance frequency of the piezoelectric transducer is tested, through which, a perfect matching circuit is designed.

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Multilevel Converters Criticism and a New Method to Improve High Power Applications: Restructured Controlled Transformer

Advances in Electrical and Electronics Engineering - IAENG Special Edition of the World Congress on Engineering and Computer Science 2008 ◽

10.1109/wcecs.2008.22 ◽

2008 ◽

Author(s):

Mohammad Golkhah ◽

Mohammad Tavakoli Bina

Keyword(s):

High Power ◽

New Method ◽

Multilevel Converters

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New Method for Assessment Ageing Condition of Oil Impregnated Insulation Pressboard Based on Frequency Domain Spectroscopy

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.513-517.323 ◽

2014 ◽

Vol 513-517 ◽

pp. 323-327 ◽

Cited By ~ 1

Author(s):

Jian Hao ◽

Jin Fu ◽

Pei Guo ◽

Gao Lin Wu ◽

Qian Wang ◽

...

Keyword(s):

Dielectric Loss ◽

Moisture Content ◽

Frequency Domain ◽

Condition Assessment ◽

New Method ◽

Time Saving ◽

Interpolation Curve ◽

Ageing Condition ◽

Cellulose Insulation

It is important to assess the condition of the cellulose insulation in transformer. However, taking paper samples from a transformer is both impractical and destructive. In this paper, a new method for assessment ageing condition of oil impregnated insulation pressboard based on frequency domain spectroscopy (FDS) was proposed. The FDS measurements were taken on oil impregnated insulation pressboards with five ageing levels at moisture content of 1.22%, 2.06%, 3.02% and 3.87%. The dielectric loss of all the samples were calculated bytanδ (f)interpolationandthe ageing condition assessment database which contains data of five ageing levels and 1%-4% moisture content was built. It is found that thetanδ (f)interpolation is more sencentive to ageing and moisture. It could realize the ageing condition assessment by comparing thetanδ (f)interpolation curve with the curves in the database.The assessing result of the middle-low main insulation life of a 220kV transformer valided that it is effective and time saving to use the new method for ageing condition assessment.

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High Power UV-Light Irradiation as a New Method for Defect Passivation in Degraded Perovskite Solar Cells to Recover and Enhance the Performance

Scientific Reports ◽

10.1038/s41598-019-45756-1 ◽

2019 ◽

Vol 9 (1) ◽

Cited By ~ 6

Author(s):

Farzaneh Arabpour Roghabadi ◽

Nasibeh Mansour Rezaei Fumani ◽

Maryam Alidaei ◽

Vahid Ahmadi ◽

Seyed Mojtaba Sadrameli

Keyword(s):

Solar Cells ◽

High Power ◽

Uv Light ◽

Perovskite Solar Cells ◽

Light Irradiation ◽

New Method ◽

Uv Light Irradiation ◽

Defect Passivation

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Voltage regulation and phase quantity increase of two high-power 12-phase rectifiers

International Journal of Power Electronics and Drive Systems (IJPEDS) ◽

10.11591/ijpeds.v10.i3.pp1454-1460 ◽

2019 ◽

Vol 10 (3) ◽

pp. 1454

Author(s):

Valery Safonov ◽

Mikhail Dziuba

Keyword(s):

High Power ◽

Harmonic Distortion ◽

Voltage Regulation ◽

Total Harmonic Distortion ◽

New Method ◽

Matlab Simulink ◽

Electromagnetic Processes ◽

The Common

In this article, we present a new method of simultaneously increasing the phase quantity and regulating the rectified voltage for two 12-phase high-power rectifiers operating at a common load. Self-excited voltage inverters separately form the necessary voltages for voltage regulation and for increasing the phase quantity. The formed voltage is input with the help of a common booster transformer. Separating the inverters functions and using the common booster transformer makes it possible to reduce the installed power of the equipment significantly compared to similar circuits when the regulation range of the rectified voltage is up to 5%. Calculations show that the inverter power for increasing the phase quantity is about 3% of the rectifier power. The circuit was modeled in MatLab/Simulink and the electromagnetic processes in the rectifier were studied. The proposed method makes it possible to reduce the total harmonic distortion of the network current and the pulsation coefficient of the rectified voltage to the values typical for 24-phase rectifiers.

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