Muhd Hafizi Idris
Thumbnail Image
Preferred name
Muhd Hafizi Idris
Official Name
Muhd Hafizi, Idris
Alternative Name
Idris, Muhd Hafizi
Bin Idris, Muhd Hafizi
Idris, M. H.
Idris, Mohd Hafizi
Hafizi, Muhd
Hafizi Idris, Muhd
Main Affiliation
Scopus Author ID
55336452900
Researcher ID
E-5413-2011

Research Output

Filters

2
2
Reset filters

Settings
Now showing 1 - 2 of 2
No Thumbnail Available
Publication

Back flashover voltage on transmission tower of 275 KV extra high voltage line (case study: Galang-Binjai)

2025-06 , Muhd Hafizi Idris , Muzamir Isa , Ferry R. A. Bukit , Surya Hardi , Riza R. Wirasari

Overvoltage at the insulator terminal caused by a lightning strike can occur in two ways, i.e., a direct lightning strike on the phase line and ground wire. The insulator can be exposed to the phenomenon of back flashover (BFO) if the terminal voltage of the insulator is higher than its insulator critical voltage The lightning current characteristics are distinguished by the maximum current and the steepness. Differences in the characteristics in this study are identified as International Electrical Commission (IEC) and Conseil International des Grands Reseaux Electriques (CIGRE) impulse waveform standards. The footing-tower grounding system comes in different configurations, such as horizontal, vertical, and grid. Alternative transient program (ATP) software was used for simulating lightning strikes on ground wire and phase lines. The results exhibit that the highest critical voltage of the insulators on the footing tower through grid grounding when the surge current strikes ground wire (3308kV – 3395 kV), with the magnitude of the lightning current ranging from (48 kA – 3395 kA). For lightning direct stroke on the phase line, the critical voltage on vertical grounding is highest on (2938 kV-3021 kV). The surge current flow footing-tower is highest on the grid. The currents magnitude flow in footing tower were influenced by impedance of grounding.

View
No Thumbnail Available
Publication

Effect of load variation and fault resistance on the operation time of IDMT overcurrent relay

2025-05 , Muhd Hafizi Idris , Quah Swee Jhing , Muhd Hafizi Idris , Surya Hardi

Fault can occur in power system due to many factors such as lightning, tree or crane encroachment, animal intervention, human error etc. Each fault occurrence has its own fault resistance value, and this value is unknown to the protection relay used to the protect the circuit. Besides that, the connected load in power system is dynamic where the value is changing over time. It is very important for the protection relay to be as reliable as it can so that the fault can be isolated as soon as possible when a fault occur. This paper study the effect of fault resistance value and load variation on IDMT overcurrent relay operation time. This relay is used to protect the line from fault occurrence where the higher the fault current, the faster the operation time will be. MATLAB Simulink has been used to model the transmission line, source, connected load and IDMT overcurrent relay. Faults simulations were conducted for various fault resistance and load values and the effects on relay operation time have been analysed. From the results, it was found that, the higher the fault resistance, the higher the operation time while the higher the value of connected load at the end of the line, the faster the relay operation time

View