Claim Missing Document
Check
Articles

Found 3 Documents
Search
Journal : Indonesian Journal of Electrical Engineering and Computer Science

Modeling frequency response of transformer winding to investigate the influence of RLC S Al-Ameri; M. F. M. Yousof; Norhafiz Azis; S. Avinash; M. A. Talib; Ali. A. Salem
Indonesian Journal of Electrical Engineering and Computer Science Vol 14, No 1: April 2019
Publisher : Institute of Advanced Engineering and Science

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.11591/ijeecs.v14.i1.pp219-229

Abstract

Frequency response measurements are used for power transformer winding failures detection. The variation between frequency responses indicate mechanical changes in the transformer winding. One method to investigate winding failures in transformer is to develop a reliable circuit model which can simulate the frequency response of an actual winding. The main reason to use the model is because it is expensive to create damages on an actual winding. This paper proposes n-stages circuit ladder network to simulate the response of a winding which has unique design. It presents a new technique to calculate the resistance, inductance and capacitance of the winding. Then, the relationship between the RLC parameters and the frequency response is studied. The winding chosen in this investigation is a single phase 33kV transformer winding. The simulated frequency response was compared with the measured response to verify the proposed model. The model can give a comprehensive understanding about the effect of RLC parameters on the frequency response.
Examination on the physical properties of untreated kenaf insulation paper at different beating degrees Muhammad Umair; Norhafiz Azis; Rasmina Halis; Jasronita Jasni
Indonesian Journal of Electrical Engineering and Computer Science Vol 17, No 2: February 2020
Publisher : Institute of Advanced Engineering and Science

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.11591/ijeecs.v17.i2.pp759-766

Abstract

This paper examines the physico-mechanical properties of untreated kenaf based insulation paper with consideration on different beating degrees. Kenaf bast fibers were first processed through soda pulping process. Different beating degrees were subjected to the processed pulps. Physical parameters of the paper were measured for each of the beating degrees. It is found that as the beating revolution increases, the kenaf based insulation paper’s density, tensile index and burst index increase while thickness and tear index decrease. 
Electromagnetic force distribution computations due to switching surge in disc-type winding Nurul Farahwahida Md Yasid; Norhafiz Azis; Mohd Fairouz Mohd Yousof; Jasronita Jasni; Mohd Aizam Talib; Avinash Srikanta Murthy
Indonesian Journal of Electrical Engineering and Computer Science Vol 30, No 2: May 2023
Publisher : Institute of Advanced Engineering and Science

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.11591/ijeecs.v30.i2.pp659-669

Abstract

This manuscript discusses the computation of electromagnetic forces on a disc-type winding due to a standard switching impulse (SSI). First, the resistances, inductances and capacitances (RLC) of a 30 MVA, 33/11 kV disc-type distribution transformer were estimated to obtain the winding equivalent circuit. The transient voltage waveforms for each of the disc layers and corresponding resonances of the windings under the SSI were then obtained in time domains. Next, the axial and radial force distributions in the disc winding due to the SSI were computed. The forces on each disc layer and along the disc windings due to the SSI were computed based on the analytical and numerical methods via the finite element method (FEM) respectively. The non-uniform switching impulse voltage distribution results in non-uniform force distribution along the disc winding. The magnitude of the axially directed force on the disc winding is found to be higher as compared to the radially directed force.