Internal and external faults in a power transformer are discriminated in this paper using an algorithm based on a combination of a discrete wavelet transform (DWT) and a probabilistic neural network (PNN). DWT decomposes high-frequency fault components using the maximum coefficients of a ¼ cycle DWT as input patterns for the training process in a decision algorithm. A division algorithm between a zero sequence of post-fault differential current waveforms and the differential current coefficient in the ¼ cycle DWT is used to detect the maximum ratio and faults. The simulation system uses various study cases based on Thailand’s electricity transmission and distribution systems. The simulation results demonstrated that the PNN and BPNN are effectively implemented and perform fault detection with satisfactory accuracy. However, the PNN method is most suitable for detecting internal and external faults, and the maximum coefficient algorithm is the most effective in detecting the fault. This study will be useful in differential protection for power transformers.

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Energy consumption in buildings has increased significantly as population and economic activities are concentrated in urban areas. Air conditioning accounts for a significant percentage of energy consumption in buildings, especially in tropical climates. The main area where heat can be transferred into the building is through glass windows. Thus, this study aims to evaluate feasibility in terms of overall thermal transfer value (OTTV), energy, and economics for retrofitting different glass materials in an office building in Thailand by using building energy code (BEC) software. The software uses Thailand’s building energy code as the standard to evaluate the energy performance of the case study building in comparison with different glass types used in retrofitted cases. From an economic perspective, the internal rate of return (IRR) and discounted payback periods (DPP) were used as determining indexes. The results demonstrated that retrofitted windows with the best energy-efficient glass might achieve energy performance, but installation cost can reduce economic feasibility, while the glass with the second lowest heat transfer coefficient can reduce the OTTV by 68.89% and building energy consumption by 16.87%. However, it can achieve the highest economic performance with 10.70% IRR and DPP at 11.83 years. Therefore, the balance between energy and economic factors must be considered to provide energy-efficient and investment-friendly glass materials for retrofit projects. In addition, the study focuses specifically on tropical climates. Thus, the finding may not be reflected similarly for buildings located in different regions.

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The high-voltage direct current (HVDC) transmission system, which links the Gurun Substation of the National Electric Authority of Malaysia (Tenaga Nasional Berhad, TNB) with the Khlong Ngae Station of the Electricity Generating Authority of Thailand (EGAT), has been extensively researched to achieve the highest quality because it is the largest of its kind in Thailand, and there is a plant to expand its transmission power. However, the impact on the whole system is under-researched. To study and develop this system, the HVDC transmission line is modelled with the MATLAB/Simulink program and a laboratory setup to investigate the effect of transmission line distance, load power, and voltage on power loss, voltage drop, and waveform. The HVDC transmission line parameters are calculated from the actual transmission line parameters and converted to the simulation model parameters using the per-unit method. The model is verified and tested by the simulation program before creating the experimental setup. The simulation and experimental results demonstrate the effects of changing system conditions via the three aspects. All the three conditions directly affect the HVDC transmission line; nevertheless, they affect each aspect differently.

Bottled-beverage production systems require considerable machinery and sophisticated control systems. A malfunction in the production system can result in machine stoppages, thereby decreasing productivity and resulting in the production output not meeting the required target. Therefore, the problem of frequent stoppages of the production system must be resolved. The ‘Fast Restart Function’ is a proposed feature that can help reduce machine downtime by decreasing the time required for the product to drain from the conveyor. In this study, using this strategy, the investigated manufacturing system’s efficiency increased from 86.81% to 90.29%, enabling an increase in the average production capacity by 27,187 bottles per day, i.e., a 3.48 percent increment of the daily capacity. When employed in inefficient production systems or systems facing frequent shutdowns, this system is of considerable value for mitigating production stoppages.

This paper aims to measure and analyze the behavior of the fault current when the interturn fault occurs between turns in three-phase induction motors. A 3-HP induction motor is used in the experiment setup to study the effects of a short circuit during the interturn fault occurrence. For induction motor, the winding of induction motor is divided into 5 positions so that the interturn fault signals can be obtained. The results from interturn fault characteristics study shown that current waveform during interturn fault has a sudden change and increases in short period of time. In addition, when interturn fault occurs, the size of load and length of gap are influential factors that affect fault current, not the position of fault. Finally, the results obtained from the analysis will be beneficial in the development of a fault detection scheme.

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