Jurnal Info Sains : Informatika dan Sains

Web-Based New Student Admission System using the Rapid Application Development (RAD) Method at Penraujan Private Junior High School

2026-04-09T06:30:56+00:00

The advancement of information technology has significantly influenced the education sector, particularly in the management of new student admissions. Many schools still rely on manual registration processes that are time-consuming, prone to data entry errors, and inefficient in managing applicant data. Penraujan Private Junior High School is one of the institutions that continues to use a conventional registration system, resulting in administrative difficulties, especially during periods of increased enrollment. This study aims to develop a web-based new student admission system to improve the efficiency, accuracy, and accessibility of the registration process. The system enables prospective students to register online at any time and assists the school in managing, storing, and generating registration data and reports more effectively. The Rapid Application Development (RAD) method is applied in this research due to its emphasis on fast and iterative system development while accommodating user needs. The results of this study indicate that the proposed web-based admission system is able to streamline the registration process, reduce data input errors, and enhance the quality of administrative services at Penraujan Private Junior High School. This system also provides convenience for prospective students by allowing online registration without the need to visit the school directly.

Transformer Life Prediction Analysis Based on Thermal Aging at PT Ultra Sumatera Dairy Farm

2026-04-09T07:11:49+00:00

A transformer is a vital component in the electrical power distribution system that functions to transfer energy from medium voltage to low voltage. The reliability of a transformer is highly influenced by the thermal condition of its insulation, which determines its service life. This study aims to predict the effective lifespan of a 1250 kVA distribution transformer at PT. Ultra Sumatra Dairy Farm uses the thermal aging method based on the IEEE C57.91-2011 standard. The data used includes nameplate information, daily load profiles, and average ambient temperature. Based on the measurements, the transformer operates at an average load of 422.7 kVA (33.8% of its rated capacity) and an ambient temperature of 23°C. The calculated results show a hottest-spot temperature of 49.55°C with an aging acceleration factor (FAA) of 0.000649. The daily Loss of Life (LOL) value of 0.00000865% indicates that thermal aging occurs very slowly. Based on the Equivalent Aging Factor (FEQA), the theoretical effective lifespan of the transformer reaches approximately 31,660 years. However, in practice, the actual lifespan of the transformer is estimated to range between 25–35 years due to non-thermal factors such as moisture, oil oxidation, and load fluctuations. These results indicate that the thermal condition of the transformer remains very safe and efficient for long-term operation.

Analysis of the Relationship Between the Percentage of Load Imbalance and Power Losses in Distribution Transformers at PT. PLN (Persero) ULP Binjai Timur

2026-04-09T07:31:31+00:00

Distribution transformer is one of the most important components in the electric power distribution system. Distribution transformers often experience load imbalance problems. One previous study showed that load imbalance can reach 25.6% which contributes to increased power losses. This study aims to analyze the relationship between the percentage of load imbalance and the power losses incurred at PT. PLN (Persero) ULP East Binjai. This study was conducted with a quantitative approach by calculating the percentage of load imbalance and the resulting power losses. Data were collected through direct observation, voltage and current measurements, then calculations and analysis were carried out. The results showed that a greater percentage of load imbalance occurred at night at 12.96% while during the day at 10.03%. And the resulting power losses occurred at night at 853.3 Watts while during the day at 4,386.3 Watts. Thus, it can be concluded that the greater the percentage of load imbalance, the greater the power losses incurred.

Analysis of the Effect of Load Equalization On Neutral Current at the TP0067 Distribution Substation of PT PLN (Persero) ULP Tanjung Pandan

2026-04-09T07:56:23+00:00

Transformer load balancing is a mandatory maintenance activity that is regularly conducted to ensure the optimal performance of distribution systems. This activity serves as an essential effort to minimize neutral current, which contributes to power losses resulting from unbalanced loading conditions in distribution transformers. The load balancing process was carried out at Distribution Substation TP0067, with a capacity of 100 kVA, located within the operational area of PT PLN (Persero) ULP Tanjung Pandan. The procedure commenced with load measurements on each feeder and phase, followed by detailed calculations of the phase load distribution. Based on the analysis results, the phases requiring load transfer to achieve balance were identified. Following the implementation of the load redistribution plan, it is expected that the neutral current will be significantly reduced, thereby reducing power losses and enhancing the overall efficiency and reliability of the distribution system.

Performance Study of OCR (Over Current Relay) and GFR (Ground Fault Relay) Relays as Protection In 20 Kv Cubicles in Selayang GH PT. PLN UP2D North Sumatra

2026-04-09T08:10:53+00:00

Power system protection is crucial for maintaining energy distribution reliability. This study aims to evaluate the performance of Over Current Relay (OCR) and Ground Fault Relay (GFR) as protection systems in 20 kV cubicles at Selayang Switching Station (GH) PT PLN UP2D North Sumatra. The research method used is descriptive quantitative with an engineering case study approach. Data were collected through field observations, short-circuit fault current calculations, and physical testing using the Omicron CMC 353 secondary current injection tool. The results show that the maximum short-circuit fault current of 14.4 kA is still below the circuit breaker's breaking capacity of 16 kA. The pick-up current settings on feeders SLY 05, SLY 06, and SLY 07 met the sensitivity criterion (1.2 x Imax), and the time coordination (grading margin) between protection devices was within the ideal range of 0.25 to 0.5 seconds. Validation through injection testing showed high accuracy with an average operating time deviation of less than 10% according to PLN standards. The conclusion of this study confirms that the protection system at GH Selayang operates efficiently, precisely, and reliably in securing network assets and ensuring the continuity of electricity supply.

Impact of Stator Resistance Unbalance on the Efficiency and Torque of Three-Phase Induction Motor

2026-04-09T08:26:42+00:00

Three-phase induction motors are the main components in industrial power systems; However, their performance is vulnerable to internal disturbances such as stator resistance imbalance caused by aging, overheating, or manufacturing defects. This study aims to regularly analyze the impact of stator resistance imbalance on the efficiency and torque characteristics of a squirrel-cage induction motor using mathematical modeling based on an equivalent circuit. Unlike previous studies that employed external resistors, this research directly modifies the stator resistance parameters in the model to represent more realistic internal degradation. Simulations were conducted on a 3.73 kW, 400 V, 50 Hz motor with stator resistance imbalance variations ranging from 0% to 20%. The results show that the imbalance causes uneven current distribution and an increase in stator copper losses of up to 5.94% at the 20% imbalance condition, although the current imbalance percentage remains below 1%. As a result, the efficiency decreases linearly from 92.97% to 92.62%, while the mechanical torque experiences a slight reduction from 95.88 Nm to 95.28 Nm. This phenomenon also has the potential to increase torque ripple and uneven heating. The study demonstrates that even small stator resistance imbalances have a significant impact on motor performance and lifespan, and therefore should be considered in predictive maintenance strategies and energy efficiency optimization.

Efficiency Analysis of A 3-Phase Induction Motor using a Variable Speed Drive as a Speed Controller at PT. Indonesia Asahan Aluminum

2026-04-09T08:43:04+00:00

This paper analyzes the efficiency performance of a 7.5 kW three-phase induction motor controlled by a Variable Speed Drive (VSD) for industrial speed regulation applications. The motor is rated at 380 V, 50 Hz, four poles, with a nominal speed of 1440 rpm. A constant voltage-to-frequency (V/f) control strategy is implemented with operating frequencies varying from 30 Hz to 50 Hz. Simulation-based analysis is conducted to evaluate electrical input power, mechanical output power, rotational speed, torque, and efficiency under different operating conditions. The results show that the motor input power decreases from approximately 8.0 kW at 50 Hz to 4.0 kW at 30 Hz, indicating significant energy-saving potential during partial-speed operation. Motor efficiency increases with frequency, ranging from 80.0% at 30 Hz to a maximum of 88.8% at the rated frequency. The reduced efficiency at lower frequencies is mainly attributed to the dominance of constant losses such as core and mechanical losses. The study confirms that VSD-based speed control improves operational flexibility and enhances energy efficiency of three-phase induction motors, making it suitable for industrial applications with variable load and speed requirements.

Power Supply System Reliability Analysis at the TVRI Transmitter Station Sibolangit Uses UPS 40 kVa and 250 Kva

2026-04-09T08:59:26+00:00

This study aims to analyze the reliability of the power supply system at the Sibolangit TVRI Transmitter Station which uses Uninterruptible Power Supply (UPS) with a capacity of 40 kVA and 250 kVA as an important component in maintaining the operational continuity of the transmitter. A reliable power supply system is crucial to ensure broadcast quality and prevent service disruptions due to power supply failures. The methods used in this study include collecting UPS operation data through field monitoring, analyzing technical parameters such as Mean Time Between Failure (MTBF), Mean Time To Repair (MTTR), Availability, and comparing the performance of the two UPS units. Data were analyzed using statistical approaches and reliability engineering tools to evaluate the performance and failure patterns that occurred during the observation period. The results show that the 250 kVA UPS has a higher level of availability than the 40 kVA UPS, with an average MTBF value of XX hours and YY hours, respectively, and MTTR of AA hours and BB hours. The analysis also reveals the main factors that affect reliability, including the quality of the electricity supply from PLN, load conditions, and the implemented maintenance schedule. These findings provide technical recommendations regarding load management, improved preventive maintenance schedules, and risk mitigation strategies to improve power supply continuity, particularly for low-capacity UPS units. Thus, this study contributes to the understanding of power supply system reliability in broadcasting installations and provides a basis for planning for improving operational performance at the TVRI Sibolangit transmitter station.

Analysis of the Effect of Capacitor Bank Integration and Harmonic Filters on Improving Energy Efficiency and the Reliability of the Electrical System at Hotel Danau Toba Medan

2026-04-10T08:10:57+00:00

Hotel Danau Toba Internasional Medan consumes a large amount of electricity due to the use of inductive and non-linear loads, which can reduce power quality. This study aims to evaluate the existing power quality and assess the effect of installing capacitor banks and harmonic filters in improving the efficiency and reliability of the electrical system. The methods used in this study include direct measurements, analysis referring to the IEEE Std. 519-2014 standard, and simulations with ETAP software version 16.0.0. The measurement results show a low power factor of 0.759, with a voltage drop reaching 15.65 kV from a nominal voltage of 20 kV, and the highest voltage unbalance recorded at 2.64% on panel 1 during the weekend. Based on the simulation results, the installation of a capacitor bank with a capacity of 525.22 kVAR can improve the power factor to 0.972 and reduce the current from 2015.2 A to 1782.6 A. To prevent resonance caused by harmonics, a reactor detuned by 8% is used. This implementation has been proven to increase energy efficiency, maintain system stability, and generate operational cost savings of IDR 221,400,000 annually.

Analysis of KBL 02 Feeder Protection Coordination to Improve Reliability at PT PLN (Persero) Djty ULP Purwokerto City

2026-04-11T03:26:46+00:00

In 2017, the KBL02 feeder was recorded as having a low reliability level due to the high frequency of PMT and recloser tripping faults. Based on the fault data evaluation, most fault locations were downstream of the recloser, but the protection system actually caused the outgoing PMT to operate first. This condition resulted in a wider outage area and reduced electricity supply to customers, resulting in an increase in the SAIDI and SAIFI reliability index values at PT PLN (Persero) Purwokerto City ULP. The main problem was caused by inconsistencies in protection coordination between the outgoing PMT and the KBL02.067 recloser, which was influenced by recloser placement that was not aligned with the OCR and GFR settings. This study aims to evaluate protection coordination and determine recloser relocation based on fault current calculations and protection settings. The results are expected to improve protection system selectivity and enhance power distribution reliability at the KBL02 feeder.

Effectiveness of Goat Manure and Liquid Organic Fertilizer from Coffee Skin Waste on Growth of Cat's Whisher Cuttings (Orthosiphon Aristatus)

2026-04-11T03:43:53+00:00

This study aims to determine the effectiveness of goatmanure and liquid organic fertilizer made from coffee husk waste on the growth of Java tea (Orthosiphon aristatus) cuttings. The study used a factorial Randomized Block Design (RBD) consisting of two factors with 48 plots. The first factor was the application of goat manure, symbolized as “S,” with four treatment levels: S0 (without goat manure), S1 (250 g/polybag), S2 (350 g/polybag), and S3 (450 g/polybag). The second factor was the application of liquid organic fertilizer made from coffee husk waste, symbolized as “K,” with four treatment levels: K0 (0 ml/L water/polybag), K1 (30 ml/L water/polybag), K2 (60 ml/L water/polybag), and K3 (90 ml/L water/polybag). Thus, there were 16 treatment combinations with three replications. The parameters observed in this study were the time of shoot emergence, number of shoots, shoot length, number of leaves, plant height, and survival percentage. The results showed that the application of goat manure and liquid organic fertilizer from coffee husk waste on the growth of Java tea (Orthosiphon aristatus) cuttings had no significant effect on all observed parameters.

Analysis of Energy Consumption and Electrical Power Efficiency on Conventional and CNC Lathes at CV Wakinara Teknik

2026-05-07T03:54:38+00:00

This research is motivated by the high consumption of electrical energy in the machining process that has not been balanced with an analysis of power usage efficiency, especially on conventional lathes and CNC machines at CV Wakinara Teknik. The lack of monitoring and evaluation of energy consumption leads to potential electricity waste and suboptimal machine utilization in production activities. Therefore, this study aims to analyze the energy consumption and level of electrical power efficiency on both types of machines to determine the comparison of energy performance and potential savings opportunities. The research method used includes direct measurement of electrical parameters such as voltage, current, power, and power factor during the machine operation process. The data obtained are then analyzed to calculate energy consumption and power usage efficiency on each machine. In addition, a comparison of energy consumption characteristics between conventional and CNC lathes is conducted under similar workload conditions. The results show that CNC machines tend to have more stable energy consumption and higher power efficiency than conventional lathes, although under certain conditions their power consumption is greater due to the use of an automatic control system. Meanwhile, conventional lathes have higher fluctuations in energy consumption and relatively lower efficiency. These findings indicate that the application of CNC machines can improve energy efficiency in production processes, as well as provide a basis for developing more optimal energy management strategies in industrial environments.

Efforts to Reduce Non-Technical Losses by Maintaining Kwh Meters at PT. PLN (PERSERO) ULP Panarukan

2026-05-07T04:06:10+00:00

This study aims to analyze the effectiveness of kWh meter maintenance as an effort to reduce non-technical losses in the electricity distribution system at PT. PLN (Persero) ULP Panarukan. Non-technical losses, which are often caused by meter inaccuracy, recording errors, and illegal usage, have a direct impact on the company's revenue. Using a quantitative descriptive approach, this study compares the level of non-technical losses before and after the implementation of a structured kWh meter maintenance and replacement program. Data were collected through field observations, interviews, and documentation from PLN's internal systems (ACMT, AP2T, EIS). The results show that maintenance activities successfully improved measurement accuracy, which led to a decrease in unrecorded energy. Thus, non-technical losses were reduced and resulted in significant financial savings. In addition, the study proposes an age-based meter replacement Operational Target (TO) as a strategic framework for determining maintenance action priorities. It is concluded that optimizing the maintenance program for aging kWh meters is a crucial operational step in controlling non-technical losses and securing PT. PLN's revenue.

Design, Simulation, and Performance of Afsrg 8/8 in an Electric Power Generation System with Low Speed Drive

2026-05-07T04:20:09+00:00

Low-speed micro-hydro power plants require generators with high starting torque, good efficiency, and the ability to operate at low rotational speeds. This study designs and builds an Axial Flux Switched Reluctance Generator (AFSRG) with an 8/8 configuration to address those needs. AFSRG was chosen for its simple structure, robustness, and magnet-free operation. The methodology included geometric design using CAD software, electromagnetic simulation using FEMM, and experimental testing in a micro-hydro setup. The results show that the 8/8 AFSRG can generate 48V at 300 rpm with a system efficiency of 78%. AFSRG is feasible for use in remote micro-hydro power generation applications with low-speed water flow.

Automatic Power Transfer Control System Using Esp 32 Based on Wokwi Simulation

2026-05-07T04:46:13+00:00

The reliability of electrical power systems is crucial for supporting the continuity of critical sector operations. This study aims to design, implement, and evaluate an Automatic Transfer Switch (ATS) system using ESP32 microcontroller through Wokwi simulation platform. The research employs Research and Development (R&D) methodology with ADDIE approach, encompassing analysis, design, development, implementation, and evaluation phases. The system is equipped with intelligent control algorithms including moving average filter with 10-sample window size and multi-criteria fault detection requiring 5 consecutive samples for verification. Testing was conducted through four main scenarios: fault detection, transfer time measurement, return transfer, and system stability evaluation. Results demonstrate that the system achieves excellent performance with average transfer time of 2,391 seconds, significantly faster than IEEE 446-2017 standard (10 seconds). Voltage detection accuracy reaches 98.9% with MAPE of 1.08%, while system stability shows false switching rate of only 1.25%. The switching mechanism is dominated by relay mechanical delay (91.5% of total transfer time), with detection time contributing only 6.5% and processing time 2.0%. Compared to previous studies, ESP32-based ATS offers competitive performance with optimal balance between speed, accuracy, and cost-effectiveness. This research validates the effectiveness of simulation-driven development methodology using Wokwi platform, reducing development time by 65% and prototyping costs by 70%. The findings provide a significant contribution to developing accessible and efficient ATS solutions for small and medium-scale applications, while demonstrating Wokwi's capability as a reliable embedded systems development tool.