Surya Hardi | Universitas Sumatera Utara (original) (raw)

Papers by Surya Hardi

Journal of Physics: Conference Series, 2022

The grounding resistance value is directly proportional to soil resistivity. The resistance value... more The grounding resistance value is directly proportional to soil resistivity. The resistance value is better as low as possible for the equipment body grounding. The purpose is to provide a path of the short circuit current flows to the ground as protection and safety personal and also the equipment. The soil resistivity great is influenced by moisture and substance content in the soil. The highland soil and rocky soil commonly are poor the soil resistivity. Transmission line towers can be not avoided through the highland region. To reduce the soil resistivity value can widely be carried out by addition low material resistance (LMR) or LMR composite other materials. This research, to mitigate the value of the soil resistivity can be carried out by addition low material resistance (LMR) Zeolite composite with NaCl, Charcoal, and Soil. Various compositions of the LMR, NaCl, and Charcoal were used to find the lowest grounding resistance at certain depth. The three-point method was used ...

Journal of Physics: Conference Series, 2022

The primary source of voltage sags is a short circuit fault in the power system. Three-phase faul... more The primary source of voltage sags is a short circuit fault in the power system. Three-phase fault can result in a more severe effect on the equipment. The voltage sags have affected significantly on performance degradation of the induction motor. The motor behaviors can be investigated in terms of rotation speed, torque, peak current, and recovery time during and after voltage sags. This study is to investigate induction motor behavior under voltage sags using the alternative transient program (ATP) draw software in simulation models. Distinct rated capacity, mechanical inertia, and loads torque (constant, linear, and variable) of the motor were used to investigate the motor’s behavior during and after sag end. Voltage sags resulted from three-phase fault at the certain locations in industrial power systems. The motor rotation speed decreases in slightly distinct during voltage sag but recovery times required to motors are longer for the large capacity motors. The large motors crea...

Procedia Engineering, 2013

Applied Mechanics and Materials, 2013

This paper presents a study to investigate response of adjustable speed drives due to voltage sag... more This paper presents a study to investigate response of adjustable speed drives due to voltage sags. A small ASD of 0.39 kW, 50/60 Hz, and 400-480 V was used for testing how drives will respond to voltage sag types; A, B, C and D. The drive response is influenced by sag magnitude, sag duration and phase angle shift. Behavior of the diodes rectifier for conducting is influenced by sag magnitude and phase angle shift represented by sag of types C and D. The diodes rectifiers are reverse biased when it was supplied by voltage sags. Even though there are no charging currents to dc bus capacitor during voltage sags, the drives did not directly trip to certain sag magnitude and sag duration. Sensitivity of the ASD to voltage sag types is presented in voltage tolerance curve. Sag of type A produces highest sensitivity on the ASD and it trips for sag magnitude of 62.5% and 250 milliseconds in duration.

2010 4th International Power Engineering and Optimization Conference (PEOCO), 2010

... 456 Page 5. VI. REFERENCES [1] MS Racine, JD Parham and MH Rashid, “An overview of uninterrup... more ... 456 Page 5. VI. REFERENCES [1] MS Racine, JD Parham and MH Rashid, “An overview of uninterruptible power supplies”, IEEE Explorer, 2005. [2] S. Jayasimha and TP Kumar, “ Photovoltaic UPS “, TENCON 2003. [3] W. bower ...

2020 4rd International Conference on Electrical, Telecommunication and Computer Engineering (ELTICOM)

This study aims to get the best performance of cellular communication based on variations in empi... more This study aims to get the best performance of cellular communication based on variations in empirical radio propagation models and the number of base stations (BTS) in urban areas. The model is designed and simulated by using programming software. The observed performance parameters are the quality of the radio link and drop call. Simulation results found that the increase in base stations and mobile stations (MS) antennas height resulted quality increment of the radio link and decrement of drop call rate for all empirical models. Likewise, an increase in the number of BTSs to four in system, exerted quality improvement of radio links and decrement on drop call rate. It was also found that each increase in antenna height for the Hata radio link model produces zero dropped call as the quality of the Hata radio link is above the threshold, even when the antenna height is at the lowest.

ABDIMAS TALENTA: Jurnal Pengabdian Kepada Masyarakat

Water serves to transport minerals, vitamins, proteins and other nutrients throughout the body. B... more Water serves to transport minerals, vitamins, proteins and other nutrients throughout the body. Body temperature balance will greatly depend on water, because water is a lubricant of the body's tissues as well as pads of joints, bones, and muscles. Once the importance of water for human survival so that the availability and sustainability of water for living things must be maintained. In the life of modern society in Indonesia today, the supply of clean water to a community is usually supplied by local government-owned water companies. But due to network limitations or production capacity, often not all communities can enjoy the clean water facilities. Islamic boarding schools are religious-based educational facilities whose management is still constrained by funding problems. So the facilities are always in a limited state. As is the case with the Quran Al-Fitrah tahfidz Islamic boarding school, which is located in Namo Rambe, which has difficulty in providing clean water to be...

The need for clean water for human life is a primary need. Humans will not be able to live health... more The need for clean water for human life is a primary need. Humans will not be able to live healthy without clean water, because the human body really needs water, the water content in the human body is not less than 70% of body weight (adults). Water serves to transport minerals, vitamins, proteins and other nutrients throughout the body. Body temperature balance will greatly depend on water, because water is a lubricant of the body's tissues as well as pads of joints, bones, and muscles. Once the importance of water for human survival so that the availability and sustainability of water for living things must be maintained. Islamic boarding schools are religious-based educational facilities whose management is still constrained by funding problems. So the facilities are always in a limited state. As is the case with the Quran Al-Fitrah tahfidz Islamic boarding school, which is located in Namo Rambe, which has difficulty in providing clean water to be drunk at the boarding schoo...

Journal of Physics: Conference Series, 2021

The increase in load which increases every year causes a decrease in voltage on the line which is... more The increase in load which increases every year causes a decrease in voltage on the line which is getting bigger. The voltage drop on the transmission line greatly affects the quality of the voltage. The voltage that arrives at the electrical equipment will decrease which in turn reduces the performance of the equipment. The power flow study uses the Fast Decoupled method, the voltage on each bus can be determined. The performance parameters observed are the value of the power factor, voltage, active power, and reactive power to determine the parameters for the location and size of the capacitor bank capacities and the static var compensator (SVC). By increasing the power factor in the range of 0.85pu to 0.95pu, the bus voltage can fulfill the SPLN standard. Parameters are designed and simulated using the ETAP programming software version 12.6.0 by testing each bus that experiences a voltage drop in turn based on the voltage limit and the power factor value ≤ 0.85pu. Furthermore, se...

Journal of Physics: Conference Series, 2021

Substation grounding purpose is to secure the safety of personal that are in the vicinity and pro... more Substation grounding purpose is to secure the safety of personal that are in the vicinity and provide protection of the equipment when short circuit faults. The grounding grid design is an important factor in a substation for fulfilling standard requirements formulated by IEEE Std. 80. Commonly, substation grounding is grid configuration or combination of grid and rod. This study is designing a substation economically by considering the length of rod conductor used. Some grid configuration models were used for analyzing viz. rectangular shape, T-shape and L-shape. The models were compared with the existing design in the Galang substation for finding the minimum conductor length. The grid grounding of the Galang substation is the rectangular shape. By using ETAP package software, the important parameters in design substations such as step voltage, touch voltage for 50 kg body weight can be obtained. The parameters must fulfill the IEEE std. 80-2013 as a safety requirement for designi...

2020 4rd International Conference on Electrical, Telecommunication and Computer Engineering (ELTICOM), 2020

This paper discusses the arrangement of differential relays at the Langsa substation. The ratio o... more This paper discusses the arrangement of differential relays at the Langsa substation. The ratio of CT mounted on the transformer to the primary side is 150/1 A and on the secondary side is 1000/1 A. This result is taken with consideration of the current value calculated from 127.02 A on the primary and 952.62 A on the secondary side. For the sensitivity of the mismatch error is still good because it is still under 5% on the primary side which is 0.89% and the secondary side is 1.13%. The differential current also shows the normal condition of 0.1 A and the restraint current 1.205 A. Using the ETAP 12.6.0 simulation, relay can work well when interference occurs at the current setting indication 1.29 A is greater than the operating current 1.65 A and the relay does not work during an external fault with a setting current of 1.29 A equals to an operating current of 1.29 A.

2020 4rd International Conference on Electrical, Telecommunication and Computer Engineering (ELTICOM), 2020

The design of the substation grounding system is very important to provide safety and protection ... more The design of the substation grounding system is very important to provide safety and protection for both the equipment and operators around it. To achieve this condition, the design must meet predetermined standards. Commonly the grounding is grid construction. On the other hand, an efficient system design is also needed. One of the determining factors is the total length conductor used. An attempt to minimize the number of lengths was carried out to improve efficiency, namely, modify grid conductor and ground rod parameters but still meet the safety criteria determined according to the IEEE-80 2000 standard. The grid grounding system generally uses copper conductors. This paper discusses the efficiency that can be expected by replacing copper conductors with other cheaper materials, namely aluminum 5005. The ground area used is rather small. The design and analysis are carried out with the SGD (Substation Grounding Grid Designer) application developed on Lab-VIEW software with a c...

Journal of Physics: Conference Series, 2021

Computation of the generator neutral grounding system through a distribution transformer can be d... more Computation of the generator neutral grounding system through a distribution transformer can be done through manual calculations. A lot of data is used in calculations so that the possibility of recurring calculations. This is very difficult and causes a large difference in the calculation results. Therefore, a computer-based computing system is needed to overcome problems like this. Several papers have been developed on the calculation of the voltage capacity through medium grounding, the length of the electrodes attached to the ground of the generator, one-phase faults to the ground, and zero sequence current disturbances. Therefore, this paper discusses modeling using the LabView Graphical User Interface (GUI) application to create it easier to design neutral grounding for equipment. As an implementation, modeling using Std. C62.92.2TM-2017 data and the results of the generator neutral grounding design can be easy, faster, and more accurate.

2019 3rd International Conference on Electrical, Telecommunication and Computer Engineering (ELTICOM)

Substation design that refers to IEEE Standard 80–2000 can be carried out through manual calculat... more Substation design that refers to IEEE Standard 80–2000 can be carried out through manual calculation. Considering that there are lot of data involved used and also repeated calculations, it will be very difficult and requires high accuracy. Therefore, a computer-based computing system is needed to solve this problem. This paper discusses an application modelling of LabViewgraphical user interface to provide convenience in designing the substation grounding grid. Some options have been developed such as grounding grid resistance calculation method, conductor diameters determination, grounding grid selection with ground rod and without ground rod and weight body. The effect of any changes in design can be known directly and compared with limit of the touch voltage and the step voltage allowed. For validation, the model used data from Std. 80–2000 and compared with some design model already existed. As a result of this application, grounding grid design process will be easy, more accurate, and faster.

Long transmission line has many problems, one of which is the voltage drop at the load center. Th... more Long transmission line has many problems, one of which is the voltage drop at the load center. The Banda Aceh subsystem is a sub-system with a load center connected via a 150 kV transmission line with a North Sumatra subsystem. This transmission line has a length of nearly 700 km. Very low voltage in the subsystem Banda Aceh occurred in the operating system when only one generating unit on the plant Nagan Raya. The increase in voltage drop is done by installing a capacitor bank in the Banda Aceh subsystem. The results of installing capacitor banks can increase system voltage in the range of 7–8 kV, enlarge the power transfer from the North Sumatra subsystem and reduce the risk of black out due to low voltage on the system.

Substation design that refers to IEEE Standard 80–2000 can be carried out through manual calculat... more Substation design that refers to IEEE Standard 80–2000 can be carried out through manual calculation. Considering that there are lot of data involved used and also repeated calculations, it will be very difficult and requires high accuracy. Therefore, a computer-based computing system is needed to solve this problem. This paper discusses an application modelling of LabViewgraphical user interface to provide convenience in designing the substation grounding grid. Some options have been developed such as grounding grid resistance calculation method, conductor diameters determination, grounding grid selection with ground rod and without ground rod and weight body. The effect of any changes in design can be known directly and compared with limit of the touch voltage and the step voltage allowed. For validation, the model used data from Std. 80–2000 and compared with some design model already existed. As a result of this application, grounding grid design process will be easy, more accur...

Adjustable speed drive (ASD) is an equipment designed to control the speed of an induction motor.... more Adjustable speed drive (ASD) is an equipment designed to control the speed of an induction motor. Because of easy process control and energy saving, it mainly found in commercial and industrial facilities. Unfortunately, ASD is sensitive to power disturbances such as voltage sags. This paper analyzes the behavior of diodes rectifier current under normal condition and voltage sags of type A and C. Based on the experiment results, the behavior of diode currents are reverse bias during voltage sag and high inrush current appears after the voltage sag ends. Impact of type A voltage sag with various conditions are presented by voltage tolerance curve

Journal of Physics: Conference Series

Lightning is one of the primary sources that cause failure on over head transmission system. It c... more Lightning is one of the primary sources that cause failure on over head transmission system. It can lead to the transmission line insulator to be over voltage. Commonly, transmissions lines are equipped with ground wire and consist of one or two ground wire which it is depending on tower construction. Over voltage on the transmission line can occur in two ways viz., direct lightning strike on phase line and ground wire produce propagating wave to both sides the phase line and result in damage on insulator. Direct lightning stroke on ground wire or the tower structure of transmission can cause phenomenon back flashover (BFO) on insulator. The lightning current characteristic is distinguished in lightning maximum current and steepness of lightning current. This paper discusses influence of in different lightning characteristics on BFO in extra high voltage transmission line in simulation using ATP draw. The lightning surge currents of IEC and VDE standards were injected to the ground ...

In web-based student information system development, usability requirements are the most importan... more In web-based student information system development, usability requirements are the most important of non-functional requirements since they determine the acceptability of systems. Nevertheless, usability requirements are usually unconsidered in early stage of system development. Mostly the developers consider the functional requirement with expected to develop system with high function and technology. But high function without usability is not the main of the aims of system development. This paper aims to propose a requirement to assist and support the development process of student information system. This study conducts in-depth interview method to capture usability requirement which involves administrator, programmer, lecturer, and students. By using several task to guide user operate the system, some issues is discovered. Based on study, the result discovers that interactive design, task completion efficiency and interactivity is impact to usable system. It means the study need...

Journal of Physics: Conference Series, 2022

The grounding resistance value is directly proportional to soil resistivity. The resistance value... more The grounding resistance value is directly proportional to soil resistivity. The resistance value is better as low as possible for the equipment body grounding. The purpose is to provide a path of the short circuit current flows to the ground as protection and safety personal and also the equipment. The soil resistivity great is influenced by moisture and substance content in the soil. The highland soil and rocky soil commonly are poor the soil resistivity. Transmission line towers can be not avoided through the highland region. To reduce the soil resistivity value can widely be carried out by addition low material resistance (LMR) or LMR composite other materials. This research, to mitigate the value of the soil resistivity can be carried out by addition low material resistance (LMR) Zeolite composite with NaCl, Charcoal, and Soil. Various compositions of the LMR, NaCl, and Charcoal were used to find the lowest grounding resistance at certain depth. The three-point method was used ...

Journal of Physics: Conference Series, 2022

The primary source of voltage sags is a short circuit fault in the power system. Three-phase faul... more The primary source of voltage sags is a short circuit fault in the power system. Three-phase fault can result in a more severe effect on the equipment. The voltage sags have affected significantly on performance degradation of the induction motor. The motor behaviors can be investigated in terms of rotation speed, torque, peak current, and recovery time during and after voltage sags. This study is to investigate induction motor behavior under voltage sags using the alternative transient program (ATP) draw software in simulation models. Distinct rated capacity, mechanical inertia, and loads torque (constant, linear, and variable) of the motor were used to investigate the motor’s behavior during and after sag end. Voltage sags resulted from three-phase fault at the certain locations in industrial power systems. The motor rotation speed decreases in slightly distinct during voltage sag but recovery times required to motors are longer for the large capacity motors. The large motors crea...

Procedia Engineering, 2013

Applied Mechanics and Materials, 2013

This paper presents a study to investigate response of adjustable speed drives due to voltage sag... more This paper presents a study to investigate response of adjustable speed drives due to voltage sags. A small ASD of 0.39 kW, 50/60 Hz, and 400-480 V was used for testing how drives will respond to voltage sag types; A, B, C and D. The drive response is influenced by sag magnitude, sag duration and phase angle shift. Behavior of the diodes rectifier for conducting is influenced by sag magnitude and phase angle shift represented by sag of types C and D. The diodes rectifiers are reverse biased when it was supplied by voltage sags. Even though there are no charging currents to dc bus capacitor during voltage sags, the drives did not directly trip to certain sag magnitude and sag duration. Sensitivity of the ASD to voltage sag types is presented in voltage tolerance curve. Sag of type A produces highest sensitivity on the ASD and it trips for sag magnitude of 62.5% and 250 milliseconds in duration.

2010 4th International Power Engineering and Optimization Conference (PEOCO), 2010

... 456 Page 5. VI. REFERENCES [1] MS Racine, JD Parham and MH Rashid, “An overview of uninterrup... more ... 456 Page 5. VI. REFERENCES [1] MS Racine, JD Parham and MH Rashid, “An overview of uninterruptible power supplies”, IEEE Explorer, 2005. [2] S. Jayasimha and TP Kumar, “ Photovoltaic UPS “, TENCON 2003. [3] W. bower ...

2020 4rd International Conference on Electrical, Telecommunication and Computer Engineering (ELTICOM)

This study aims to get the best performance of cellular communication based on variations in empi... more This study aims to get the best performance of cellular communication based on variations in empirical radio propagation models and the number of base stations (BTS) in urban areas. The model is designed and simulated by using programming software. The observed performance parameters are the quality of the radio link and drop call. Simulation results found that the increase in base stations and mobile stations (MS) antennas height resulted quality increment of the radio link and decrement of drop call rate for all empirical models. Likewise, an increase in the number of BTSs to four in system, exerted quality improvement of radio links and decrement on drop call rate. It was also found that each increase in antenna height for the Hata radio link model produces zero dropped call as the quality of the Hata radio link is above the threshold, even when the antenna height is at the lowest.

ABDIMAS TALENTA: Jurnal Pengabdian Kepada Masyarakat

Water serves to transport minerals, vitamins, proteins and other nutrients throughout the body. B... more Water serves to transport minerals, vitamins, proteins and other nutrients throughout the body. Body temperature balance will greatly depend on water, because water is a lubricant of the body's tissues as well as pads of joints, bones, and muscles. Once the importance of water for human survival so that the availability and sustainability of water for living things must be maintained. In the life of modern society in Indonesia today, the supply of clean water to a community is usually supplied by local government-owned water companies. But due to network limitations or production capacity, often not all communities can enjoy the clean water facilities. Islamic boarding schools are religious-based educational facilities whose management is still constrained by funding problems. So the facilities are always in a limited state. As is the case with the Quran Al-Fitrah tahfidz Islamic boarding school, which is located in Namo Rambe, which has difficulty in providing clean water to be...

The need for clean water for human life is a primary need. Humans will not be able to live health... more The need for clean water for human life is a primary need. Humans will not be able to live healthy without clean water, because the human body really needs water, the water content in the human body is not less than 70% of body weight (adults). Water serves to transport minerals, vitamins, proteins and other nutrients throughout the body. Body temperature balance will greatly depend on water, because water is a lubricant of the body's tissues as well as pads of joints, bones, and muscles. Once the importance of water for human survival so that the availability and sustainability of water for living things must be maintained. Islamic boarding schools are religious-based educational facilities whose management is still constrained by funding problems. So the facilities are always in a limited state. As is the case with the Quran Al-Fitrah tahfidz Islamic boarding school, which is located in Namo Rambe, which has difficulty in providing clean water to be drunk at the boarding schoo...

Journal of Physics: Conference Series, 2021

The increase in load which increases every year causes a decrease in voltage on the line which is... more The increase in load which increases every year causes a decrease in voltage on the line which is getting bigger. The voltage drop on the transmission line greatly affects the quality of the voltage. The voltage that arrives at the electrical equipment will decrease which in turn reduces the performance of the equipment. The power flow study uses the Fast Decoupled method, the voltage on each bus can be determined. The performance parameters observed are the value of the power factor, voltage, active power, and reactive power to determine the parameters for the location and size of the capacitor bank capacities and the static var compensator (SVC). By increasing the power factor in the range of 0.85pu to 0.95pu, the bus voltage can fulfill the SPLN standard. Parameters are designed and simulated using the ETAP programming software version 12.6.0 by testing each bus that experiences a voltage drop in turn based on the voltage limit and the power factor value ≤ 0.85pu. Furthermore, se...

Journal of Physics: Conference Series, 2021

Substation grounding purpose is to secure the safety of personal that are in the vicinity and pro... more Substation grounding purpose is to secure the safety of personal that are in the vicinity and provide protection of the equipment when short circuit faults. The grounding grid design is an important factor in a substation for fulfilling standard requirements formulated by IEEE Std. 80. Commonly, substation grounding is grid configuration or combination of grid and rod. This study is designing a substation economically by considering the length of rod conductor used. Some grid configuration models were used for analyzing viz. rectangular shape, T-shape and L-shape. The models were compared with the existing design in the Galang substation for finding the minimum conductor length. The grid grounding of the Galang substation is the rectangular shape. By using ETAP package software, the important parameters in design substations such as step voltage, touch voltage for 50 kg body weight can be obtained. The parameters must fulfill the IEEE std. 80-2013 as a safety requirement for designi...

2020 4rd International Conference on Electrical, Telecommunication and Computer Engineering (ELTICOM), 2020

This paper discusses the arrangement of differential relays at the Langsa substation. The ratio o... more This paper discusses the arrangement of differential relays at the Langsa substation. The ratio of CT mounted on the transformer to the primary side is 150/1 A and on the secondary side is 1000/1 A. This result is taken with consideration of the current value calculated from 127.02 A on the primary and 952.62 A on the secondary side. For the sensitivity of the mismatch error is still good because it is still under 5% on the primary side which is 0.89% and the secondary side is 1.13%. The differential current also shows the normal condition of 0.1 A and the restraint current 1.205 A. Using the ETAP 12.6.0 simulation, relay can work well when interference occurs at the current setting indication 1.29 A is greater than the operating current 1.65 A and the relay does not work during an external fault with a setting current of 1.29 A equals to an operating current of 1.29 A.

2020 4rd International Conference on Electrical, Telecommunication and Computer Engineering (ELTICOM), 2020

The design of the substation grounding system is very important to provide safety and protection ... more The design of the substation grounding system is very important to provide safety and protection for both the equipment and operators around it. To achieve this condition, the design must meet predetermined standards. Commonly the grounding is grid construction. On the other hand, an efficient system design is also needed. One of the determining factors is the total length conductor used. An attempt to minimize the number of lengths was carried out to improve efficiency, namely, modify grid conductor and ground rod parameters but still meet the safety criteria determined according to the IEEE-80 2000 standard. The grid grounding system generally uses copper conductors. This paper discusses the efficiency that can be expected by replacing copper conductors with other cheaper materials, namely aluminum 5005. The ground area used is rather small. The design and analysis are carried out with the SGD (Substation Grounding Grid Designer) application developed on Lab-VIEW software with a c...

Journal of Physics: Conference Series, 2021

Computation of the generator neutral grounding system through a distribution transformer can be d... more Computation of the generator neutral grounding system through a distribution transformer can be done through manual calculations. A lot of data is used in calculations so that the possibility of recurring calculations. This is very difficult and causes a large difference in the calculation results. Therefore, a computer-based computing system is needed to overcome problems like this. Several papers have been developed on the calculation of the voltage capacity through medium grounding, the length of the electrodes attached to the ground of the generator, one-phase faults to the ground, and zero sequence current disturbances. Therefore, this paper discusses modeling using the LabView Graphical User Interface (GUI) application to create it easier to design neutral grounding for equipment. As an implementation, modeling using Std. C62.92.2TM-2017 data and the results of the generator neutral grounding design can be easy, faster, and more accurate.

2019 3rd International Conference on Electrical, Telecommunication and Computer Engineering (ELTICOM)

Substation design that refers to IEEE Standard 80–2000 can be carried out through manual calculat... more Substation design that refers to IEEE Standard 80–2000 can be carried out through manual calculation. Considering that there are lot of data involved used and also repeated calculations, it will be very difficult and requires high accuracy. Therefore, a computer-based computing system is needed to solve this problem. This paper discusses an application modelling of LabViewgraphical user interface to provide convenience in designing the substation grounding grid. Some options have been developed such as grounding grid resistance calculation method, conductor diameters determination, grounding grid selection with ground rod and without ground rod and weight body. The effect of any changes in design can be known directly and compared with limit of the touch voltage and the step voltage allowed. For validation, the model used data from Std. 80–2000 and compared with some design model already existed. As a result of this application, grounding grid design process will be easy, more accurate, and faster.

Long transmission line has many problems, one of which is the voltage drop at the load center. Th... more Long transmission line has many problems, one of which is the voltage drop at the load center. The Banda Aceh subsystem is a sub-system with a load center connected via a 150 kV transmission line with a North Sumatra subsystem. This transmission line has a length of nearly 700 km. Very low voltage in the subsystem Banda Aceh occurred in the operating system when only one generating unit on the plant Nagan Raya. The increase in voltage drop is done by installing a capacitor bank in the Banda Aceh subsystem. The results of installing capacitor banks can increase system voltage in the range of 7–8 kV, enlarge the power transfer from the North Sumatra subsystem and reduce the risk of black out due to low voltage on the system.

Substation design that refers to IEEE Standard 80–2000 can be carried out through manual calculat... more Substation design that refers to IEEE Standard 80–2000 can be carried out through manual calculation. Considering that there are lot of data involved used and also repeated calculations, it will be very difficult and requires high accuracy. Therefore, a computer-based computing system is needed to solve this problem. This paper discusses an application modelling of LabViewgraphical user interface to provide convenience in designing the substation grounding grid. Some options have been developed such as grounding grid resistance calculation method, conductor diameters determination, grounding grid selection with ground rod and without ground rod and weight body. The effect of any changes in design can be known directly and compared with limit of the touch voltage and the step voltage allowed. For validation, the model used data from Std. 80–2000 and compared with some design model already existed. As a result of this application, grounding grid design process will be easy, more accur...

Adjustable speed drive (ASD) is an equipment designed to control the speed of an induction motor.... more Adjustable speed drive (ASD) is an equipment designed to control the speed of an induction motor. Because of easy process control and energy saving, it mainly found in commercial and industrial facilities. Unfortunately, ASD is sensitive to power disturbances such as voltage sags. This paper analyzes the behavior of diodes rectifier current under normal condition and voltage sags of type A and C. Based on the experiment results, the behavior of diode currents are reverse bias during voltage sag and high inrush current appears after the voltage sag ends. Impact of type A voltage sag with various conditions are presented by voltage tolerance curve

Journal of Physics: Conference Series

Lightning is one of the primary sources that cause failure on over head transmission system. It c... more Lightning is one of the primary sources that cause failure on over head transmission system. It can lead to the transmission line insulator to be over voltage. Commonly, transmissions lines are equipped with ground wire and consist of one or two ground wire which it is depending on tower construction. Over voltage on the transmission line can occur in two ways viz., direct lightning strike on phase line and ground wire produce propagating wave to both sides the phase line and result in damage on insulator. Direct lightning stroke on ground wire or the tower structure of transmission can cause phenomenon back flashover (BFO) on insulator. The lightning current characteristic is distinguished in lightning maximum current and steepness of lightning current. This paper discusses influence of in different lightning characteristics on BFO in extra high voltage transmission line in simulation using ATP draw. The lightning surge currents of IEC and VDE standards were injected to the ground ...

In web-based student information system development, usability requirements are the most importan... more In web-based student information system development, usability requirements are the most important of non-functional requirements since they determine the acceptability of systems. Nevertheless, usability requirements are usually unconsidered in early stage of system development. Mostly the developers consider the functional requirement with expected to develop system with high function and technology. But high function without usability is not the main of the aims of system development. This paper aims to propose a requirement to assist and support the development process of student information system. This study conducts in-depth interview method to capture usability requirement which involves administrator, programmer, lecturer, and students. By using several task to guide user operate the system, some issues is discovered. Based on study, the result discovers that interactive design, task completion efficiency and interactivity is impact to usable system. It means the study need...