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118 results on '"Fahmi, Daniar"'

3. Influence of metal particles shape on direct current voltage electric properties of nanofluids.

Author

Fahmi, Daniar, Akbar, Muhammad Fadlan, Negara, I. Made Yulistya, Hernanda, I. Gusti Ngurah Satriyadi, Asfani, Dimas Anton, Zaidan, Risyad Alauddin, and Fadhilah, Arkan

Subjects
ELECTRIC properties, INSULATING oils, ELECTRIC fields, DIELECTRIC properties, LEVITATION
Abstract

It is widely recognized that the application of nanoparticles has the potential to improve the dielectric properties of transformer oil. Nevertheless, there is a scarcity of studies that have utilized pure nanofluids, and in practical applications, it is inevitable for transformer oil to become contaminated. Therefore, this study conducted tests to investigate how the shape and size of metal contaminants impact the dielectric performance of Fe3O4 nanofluids. The findings from the levitation voltage test indicate that as the size and diameter of the particle increase, the levitation voltage value measured also increases, and conversely. Moreover, a higher concentration of nanoparticles leads to a higher measured levitation voltage value. On the other hand, the breakdown voltage test results demonstrate that larger and sharper particles result in lower measured breakdown voltage values, and vice versa. The simulation outcomes regarding electric field distribution reveal that larger and sharper particles correspond to higher measured electric field values, while the opposite is true for smaller and less sharp particles. [ABSTRACT FROM AUTHOR]

Published
2025
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5. Monitoring and implementation of charging protection valve regulated lead-acid battery bank for photovoltaic systems in electric vehicle charging stations using LabVIEW.

Author

Asfani, Dimas Anton, Maharani, Harfiana, Suryoatmojo, Heri, Fahmi, Daniar, Prabowo, Sidharta, Indra, Wibawa, Agus, Hapsara, Ide Bagus, Sudaryono, Sidqi, Firas Quthbi, and Putra, Dimas Fajar Uman

Subjects
ELECTRIC vehicle charging stations, ELECTRIC vehicles, PHOTOVOLTAIC power systems, LEAD-acid batteries, BATTERY management systems, ELECTRIC batteries
Abstract

The use of batteries to store electrical energy from photovoltaic (PV) output during stand-alone operation is important in electric vehicles. However, the charge and discharge technique is often not considered, thereby causing overvoltage and undervoltage capable of shortening the battery's life. Furthermore, the operating temperature during the charge and discharge processes needs to be observed to avoid overheating, which can reduce the battery performance. Therefore, this research monitored and implemented the charge-discharge process, and also controlled the protection of the voltage, current, and temperature parameters, to obtain a battery management system capable of preventing electrical energy from being damaged quickly. The monitoring and protection tool showed that the safety relay has been able to work to limit the charge/discharge current, temperature, and voltage of the battery SOC working limit set in accordance with the optimal work standard of 90% to 20%. However, in this research, it is still impossible to estimate the age and damage of the battery. [ABSTRACT FROM AUTHOR]

Published
2024
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6. The design and analysis of energy management for the optimal charging of electric vehicles based on estimated power flow and load conditions at electric vehicle stations using fuzzy logic controllers.

Author

Asfani, Dimas Anton, Nugroho, Onang Surya, Wikarta, Alief, Mukhlisin, Agus, Afkari, Muhammad Adib, Putra, Dhimas Khamim Eka, and Fahmi, Daniar

Subjects
ELECTRICAL load, ELECTRIC charge, HYBRID electric vehicles, ELECTRIC vehicles, FUZZY logic, ELECTRIC vehicle charging stations, ENERGY management
Abstract

Electric vehicles have become one of the alternatives for managing energy crises in the transportation sector. An increase in the number of these vehicles without being accompanied by a good charging station management system will have negative impacts on the network distribution system, such as voltage fluctuations, drops, stress, low power continuity, and even cause blackouts. Hence, designing an energy management system for electric vehicles at charging stations is necessary to obtain an optimal power flow model between the charging station and the grid. In this project, the optimal charging design and analysis were designed by considering the estimated power flow between the charging station and the grid, alongside the load conditions on the grid (off-peak/peak), using a fuzzy logic controller. This charging management uses the vehicle to vehicle (V2V), vehicle to grid (V2G), and grid to vehicle (G2V) concepts, which are regulated by the filling index and rating of the fuzzy rule scores. Through the two inputs above, the simulation results showed that the fuzzy-based system can flatten the peak load curve of electric vehicles, reduce the impact of peak loads on the grid, and provide cost-saving benefits. [ABSTRACT FROM AUTHOR]

Published
2024
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7. Optimal charging design and analysis for electric vehicles based on SOC and parking duration at charging stations using fuzzy logic based controllers.

Author

Asfani, Dimas Anton, Darmayanti, Nungki Dian S., Fahmi, Daniar, Prabowo, Sidartha, Indra, Wibawa, Agus, Hapsara, Ide Bagus, Sudaryono, Dewantara, Rayhan Alifa, and Putra, Dimas Fajar Uman

Subjects
AUTOMOBILE parking, ELECTRIC vehicles, FUZZY logic, ELECTRIC charge, PEAK load, HIGH voltages
Abstract

The increase in electric vehicles affects the distribution system by triggering several disturbances such as voltage stress, high voltage fluctuations, voltage drops during peak loads, damage to distribution transformers, and even blackouts. It allows proper management when charging the electric vehicle. Therefore, this study uses a fuzzy logic-based controller to design an optimal charging system for electric vehicles based on the SOC (State of Charge) and Parking Duration. This charging management uses the concept of the vehicle-to-vehicle power transfer directed by scoring. Furthermore, simulations are carried out with subscription restrictions to the grid. The results showed that using this optimal charging system can flatten the load curve with the two inputs. However, the simulation results showed that the presence of FLC in the system can reduce the peak load on the system from 12 kW to 5.1 kW, and SOC (state of charge) at departure time is higher than initial arrival, even in some conditions can reach 100%. [ABSTRACT FROM AUTHOR]

Published
2024
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8. Comparative analysis of AC and DC bus power efficiency for electric vehicle charging stations using equipment power input-output characteristics.

Author

Asfani, Dimas Anton, Riawan, Dedet Candra, Difrianti, Adlia, Fahmi, Daniar, Prabowo, Sidartha, Indra, Wibawa, Agus, Hapsara, Ide Bagus, Sudaryono, Fayumi, Fachry Azca Haidar, and Putra, Dimas Fajar Uman

Subjects
ELECTRIC vehicle charging stations, ELECTRIC vehicles, ELECTRICAL energy, ALTERNATING currents, COMPARATIVE studies
Abstract

Electric vehicle charging stations function similarly to conventional fueling stations, but the energy distributed is in the form of electricity. However, the distribution of electrical energy from PLN Grid and Photovoltaic sources to electric vehicles requires two types of bus architecture, namely Alternating Current (AC) and Direct Current (DC). The AC Bus Architecture uses AC whilst DC Bus Architecture uses DC to distribute electrical energy from the source to the vehicle, each comprising various advantages and disadvantages. Therefore, this research aims to compare the power efficiency of these two bus architectures from their equipment. Efficiency calculation is carried out by comparing the output and input values for each piece of equipment. The simulation test results show that the AC Bus system is more efficient at 97.28% when the battery is in standby mode. Meanwhile, the DC Bus is more efficient at 94.93% when the battery is in the charge-discharge mode. [ABSTRACT FROM AUTHOR]

Published
2024
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14. Investigation of Insulator Performance Under Artificial Contaminants

Author

Negara, I M. Yulistya, Asfani, Dimas, Hernanda, IGN Satriyadi, Fahmi, Daniar, Ksatria, Arief, S. H. Hutabarat, Ariel Kevin, Negara, I M. Yulistya, Asfani, Dimas, Hernanda, IGN Satriyadi, Fahmi, Daniar, Ksatria, Arief, and S. H. Hutabarat, Ariel Kevin

Abstract

There are three types of insulators, namely glass, ceramic, and polymer. Although polymers have hydrophobic properties that make them superior to other materials. However, in its application, ceramic and glass insulators are still used because they are cheaper. Environmental conditions around the work location of the insulator greatly affect its performance. Areas with high levels of pollution will result in the insulator being damaged quickly. The effect of seawater and fly-ash contaminants on the three types of insulators is discussed in this study. Experimental approaches and FEM-based simulations have been carried out. Pollution levels in seawater contaminants were standardized using ESDD. Meanwhile, the level of pollution in fly-ash contaminants is standardized using NSDD. Simulations and experiments were carried out at four levels of contamination, namely light, medium, heavy and very heavy. Then the simulation and test results are compared. The greater the ESDD and NSDD values, the greater the leakage current.

Published
2023

18. Partial discharge characteristics from polymer insulator under various contaminant.

Author

Fahmi, Daniar, Asfani, Dimas Anton, Hernanda, I Gusti Ngurah Satriyadi, Septianto, Bagus, Negara, I Made Yulistya, and Illias, Hazlee Azil

Subjects
*PARTIAL discharge measurement, *FLY ash, *BREAKDOWN voltage, *ENVIRONMENTAL degradation, *POLLUTANTS, *PARTIAL discharges
Abstract

• Polymer insulators are susceptible to damage and accelerated aging due to contaminants, impacting their performance and structural integrity. • This study conducts comprehensive investigations about discharge behaviors of polymer insulator when exposed to three distinct contaminants: fly ash, salt, and algae. • Measurements of inception and surface breakdown voltages, along with partial discharge patterns, reveal unique responses to each contaminant. Salt intensifies electrical stress under dry conditions, accelerating aging and increasing partial discharge compared to other contaminants. Fly ash alters Partial Discharge Inception Voltage and Surface Breakdown Voltage, enhancing surface discharge performance, while algae's biofouling process deteriorates insulator surfaces, decreasing PDIV and altering PD patterns. • The findings of this study contribute to the enrichment of references related to partial discharge (PD) phenomena caused by salt, fly ash, and algae contaminants. By identifying unique PD patterns associated with each contaminant, this research enhances the ability to diagnose and mitigate insulator degradation in diverse environmental conditions. The performance of polymer insulators can be significantly compromised by the presence of contaminants, resulting in damage, structural alterations, and accelerated aging. Hence, this research aimed to investigate the discharge behavior of polymer insulators when exposed to various types of contaminants. Three distinct contaminants, namely fly ash, salt, and algae, were prepared for the study. In order to assess the characteristics of these insulators, measurements of inception and surface breakdown voltages were conducted for each sample. Additionally, partial discharge measurements were performed at two different applied voltages to observe the patterns of partial discharge under different contaminants. To aid in distinguishing the characteristics of partial discharge, a statistical method based on graphical analysis was employed. Furthermore, visual inspection was carried out after the occurrence of partial discharge activity to provide an explanation for these phenomena. The findings of the study revealed that each contaminant produced a unique pattern, which was influenced by the specific elements present in the respective contaminant. It was observed that contaminants exhibit varying effects on partial discharge depending on their nature. Salt was found to induce faster stress propagation, fly ash inhibited stress propagation, and algae had a degrading effect on the surface of the polymer insulators. [ABSTRACT FROM AUTHOR]

Published
2024
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26. The Electrical Characteristics of Medium Voltage Insulators Against Contaminants at Coastal Area

Author

Yulistya Negara, I Made, Asfani, Dimas Anton, Fahmi, Daniar, Yulistya Negara, I Made, Asfani, Dimas Anton, and Fahmi, Daniar

Abstract

Insulators have an important role in an electrical distribution line. They has a role as a mechanical support and on electrical insulation that isolate the live line and dead part of the electrical poles. Environmental factors will affect the performance of the insulator. Every area where the isolator was installed has a unique characteristics, therefore the electrical characteristics of each insulator will be differ from an area to others area. This study investigated the electrical characteristics of the 20 kV insulator for some feeder that representing all regions in coastal area. Coastal area has four types of areas, namely industrial, household, city, and rural areas. The leakage current of sample of these four area were measured and the Non-Soluble Deposite Density (NSDD) of each sample were also measured. The results show that the industrial area had the highest leakage current value of 1.22 mA while the lowest leakage current was observed in the household area of 0.44 mA. These were also confirmed that the industrial area had the highest NSDD value of 0.2412 mg/cm2 and the lowest NSDD in household areas of 0.0228 mg/cm2 were observed. Moreover, It was also observed that the highest flashover voltages and insulation resistance were in rural areas of about 53.4 kV and 261.33 GΩ, respectively and the lowest flashovers were in household areas of about 39.34 kV and 118.83 GΩ, respectively.

Published
2021

27. Planar Sensor for Noise Cancellation During Partial Discharge Detection in Open Substation

Author

Azam, S. M. Kayser, Othman, Mohamadariff, Illias, Hazlee Azil, Latef, Tarik Abdul, Mahadi, Wan Nor Liza Wan, Fahmi, Daniar, Hossain, A. K. M. Zakir, and Ain, Mohd Fadzil

Abstract

In compliance with next-generation high-voltage substations, ultrahigh-frequency (UHF) planar sensors are becoming more popular than ever for their online features in partial discharge (PD) diagnostics. However, PD signals mixing with different noises still exist as a major challenge for UHF sensors. Especially in open substations, telecommunication interferences become predominant noise sources to an external UHF sensor placed outside of the equipment chamber. Even though band-stop filters are additionally connected to UHF sensors for denoising, the inherent noise cancellation mechanism is not yet found in any UHF sensor. With the best of our knowledge and survey, we are the first to introduce here a planar sensor that inherently eliminates telecommunication interferences during PD detection (PDD) for open substations even without using any postprocessing filters. To design our sensor, we have applied techniques of truncated partial ground plane for wideband characteristics and modified radiating patch for enhanced gain performance. A novel intermingled coupling resonator is designed to remove the GSM-900 band from within the sensor bandwidth. We have tested our prototype both for free-space propagation and PDD performances. The prototype has a compact physical size of $16\times $ 8 cm2 and an operational bandwidth of 792–1414 MHz. For a surface discharge source, the prototype successfully detects the PD signals at the earliest stage. Our prototype minimizes the ambient noise floor to 2.5 mV and improves the signal-to-noise ratio by more than 27.9 dB, which is relatively higher than conventional UHF sensors. The proposed sensor also has the potential of classifying PD sources.

Published
2023
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