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"Vol 13, No 1 (2021): Jurnal Teknik Elektro"
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<![CDATA[Strategi Pengisian Baterai pada Sistem Panel Surya Standalone Berbasis Kontrol PI Multi-Loop ]]>
<![CDATA[Hidayat, Khusnul]]>;
<![CDATA[Hasani, Mohammad Chasrun]]>;
<![CDATA[Mardiyah, Nur Alif]]>;
<![CDATA[Effendy, Machmud]]>
<![CDATA[ Jurnal Teknik Elektro Vol 13, No 1 (2021): Jurnal Teknik Elektro ]]>
Publisher : <![CDATA[Jurusan Teknik Elektro, Fakultas Teknik, Universitas Negeri Semarang ]]>
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DOI: 10.15294/jte.v13i1.29765
<![CDATA[This study discusses the power control strategy in a standalone photovoltaic-battery hybrid system. The life-time of the battery will be shorter if the battery is often charged with high current and exceeds its State-of-Charge (SoC). Therefore, a control method is needed to control the power flow on the DC bus and the charging current as well as the SoC of the battery so that the battery has a long life-time. The proposed system uses two dc-dc converters to connect photovoltaic (PV) and lead-acid batteries to the load. The unidirectional DC-DC converter is used as the interface between the PV and the DC bus, the bidirectional DC-DC converter is used as the interface between the battery and the DC bus. The control strategy plays a role in controlling the power flow between the converter and the load to maintain the balance of power in the system and controlling the battery to support PV when the available PV power is not enough to meet the load. The multi-loop control strategy is proposed in this study, one of the loops is used to maintain the SoC of the battery in order to control the PV output power to avoid over-charging. Another loop is used to ensure the balance of the system's power when the battery is charging at its maximum charge current. The proposed control system is implemented without requiring any conditions for the control to operate. The simulation results show that the proposed multi-loop control can control the power flow in the system while maintaining the maximum charging current and battery SoC limits.]]>
<![CDATA[Penyelesaian Masalah Economic Dispatch Menggunakan Equilibrium Optimizer ]]>
<![CDATA[Zebua, Osea]]>;
<![CDATA[Ginarsa, I Made]]>;
<![CDATA[Ari Nrartha, I Made]]>
<![CDATA[ Jurnal Teknik Elektro Vol 13, No 1 (2021): Jurnal Teknik Elektro ]]>
Publisher : <![CDATA[Jurusan Teknik Elektro, Fakultas Teknik, Universitas Negeri Semarang ]]>
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DOI: 10.15294/jte.v13i1.28698
<![CDATA[This paper presents a metaheuristic method, namely Equilibrium Optimizer (EO) to solve the economic dispatch (ED) problem. The main objective function to be achieved is to minimize the total fuel costs of all generating units to meet the total load demand and to satisfy various operating constraints. Three case studies are used to test the effectiveness of the EO method in solving ED problems, they are three generators case, six generators case, and fifteen generators case. The simulation of solving ED problems using the EO method is implemented using MATLAB software and is carried out 30 times for each case study. The results of EO method are compared with Particle Swarm Optimization (PSO), Grey Wolf Optimizer (GWO), and Whale Optimization Algorithm (WOA) methods. The simulation results show that the EO method can solve the ED problem more optimal than all other comparison methods for all the case studies by producing the minimum total fuel costs.]]>
<![CDATA[Optimalisasi Pengereman Regeneratif dengan Perubahan Sudut Eksitasi pada Pulsa Tunggal ]]>
<![CDATA[Kusumaningrum, Nazila]]>;
<![CDATA[Riyadi, Slamet]]>;
<![CDATA[Pratomo, Leonardus Heru]]>;
<![CDATA[Setyawan, Florentinus Budi]]>
<![CDATA[ Jurnal Teknik Elektro Vol 13, No 1 (2021): Jurnal Teknik Elektro ]]>
Publisher : <![CDATA[Jurusan Teknik Elektro, Fakultas Teknik, Universitas Negeri Semarang ]]>
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DOI: 10.15294/jte.v13i1.28600
<![CDATA[Most of the energy is wasted into heat energy due to conventional braking, so an optimal braking strategy is needed. A Regenerative braking utilizes the kinetic energy of the engine into electrical energy by changing the function of an electric machine into a generator. The regenerative braking system uses a Switched Reluctance Machine (SRM) which has several advantages; simple construction, does not require maintenance, and return energy to the battery. The method that can be used in the regenerative braking system of the SRM is the change of excitation angle to produce the maximum peak phase current. This study aims to optimize regenerative braking by changing the angle (θeks) using simple controls to produce energy that is greater than the battery voltage so that current may flow to the battery when braking occurs. The results of the analysis for method implementation were proven by testing the devices in the laboratory.  Based on the results of the tests, the exact angle was obtained, namely the value of θeks = 20º and the value of θkom = 170º with an initial speed of 1822 RPM, reduced into 1522 RPM by braking process, which could produce a peak current of 12,5 A and a current flowing to the battery was 5A.]]>
<![CDATA[Segmentasi Citra Pembuluh Darah Retina Menggunakan Operasi Morfologi Iteratif ]]>
<![CDATA[Nurdinawati, Vita]]>;
<![CDATA[Hendryani, Atika]]>;
<![CDATA[Barasabha, Thareq]]>
<![CDATA[ Jurnal Teknik Elektro Vol 13, No 1 (2021): Jurnal Teknik Elektro ]]>
Publisher : <![CDATA[Jurusan Teknik Elektro, Fakultas Teknik, Universitas Negeri Semarang ]]>
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DOI: 10.15294/jte.v13i1.29747
<![CDATA[Retinal vessel segmentation is part of the morphological extraction of retinal blood vessels that plays an essential role in medical image processing. Manual segmentation is possible to do, but it is time-consuming and requires special operators. Moreover, the possibility of variability between operators is vast. This study aims to answer the shortcomings of the manual segmentation process by automatically segmenting retinal blood vessels. The main contribution of this study is the use of a simple method to iteratively segment retinal blood vessels. All processes in the segmentation are simulated using Matlab. The algorithm was evaluated by comparing the results of the automatic segmentation with 20 manually segmented images from the STARE dataset. The result show specificity 98.13%, accuracy 93.60%, sensitivity 56.42%, precision 80.48%, and the dice coefficient 64.06%. In conclusion, the automatic retinal blood vessel image segmentation process worked well.]]>
<![CDATA[Otomatisasi Sistem Fertigasi Tetes untuk Tanaman Berbasis Mikrokontroler ]]>
<![CDATA[Rosma, Iswadi Hasyim]]>;
<![CDATA[Sukma, Dian Yayan]]>;
<![CDATA[Solihin, Ikhram Minata]]>
<![CDATA[ Jurnal Teknik Elektro Vol 13, No 1 (2021): Jurnal Teknik Elektro ]]>
Publisher : <![CDATA[Jurusan Teknik Elektro, Fakultas Teknik, Universitas Negeri Semarang ]]>
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DOI: 10.15294/jte.v13i1.31123
<![CDATA[The process of manual fertilization and irrigation of plants has disadvantages such as it requires human labor and is inefficient in the use of fertilizers and water sources. Therefore, the purpose of this research is to design and develop an automatic fertigation system. The method used in this research is a drip fertigation technique where the fertigation liquid that has been stirred is placed in a tank with 100 cm height from ground. With the gravitational force, the fertigation liquid is distributed through pipes, hoses and emitters around the plant. While the control system and automation of fertigation distribution to plants is carried out based on a microcontroller that need the condition of soil moisture values around the plant. If the watering time and humidity values are met, the electronic valve will open so that the fertigation liquid flows from the tank to the plants. Furthermore, in this study the tests were carried out to determine the uniformity coefficient and debit of drip fertigation. From the results, it shows that the emitter’s debit influenced by the liquid level in the tank. The uniformity coefficient obtained in the two tests is greater than 90%. From the two tests carried out from the moisture sensor 1 and 2, it shows the mean percentage error for both sensor is less than 1.7%, while the percentage error of soil moisture sensor 1 is 1.6% and the percentage error of soil moisture sensor 2 is 1%, respectively. Meanwhile, from the ultrasonic sensor testing it was obtained 0% of error. It also shows from the testing conducted that the fertigation system works very well and successfully.]]>
<![CDATA[Segmentasi Citra Pembuluh Darah Retina Menggunakan Operasi Morfologi Iteratif ]]>
<![CDATA[ Jurnal Teknik Elektro Vol 13, No 1 (2021): Jurnal Teknik Elektro ]]>
Publisher : <![CDATA[Jurusan Teknik Elektro, Fakultas Teknik, Universitas Negeri Semarang ]]>
Show Abstract
|
Download Original
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Original Source
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Check in Google Scholar
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DOI: 10.15294/jte.v13i1.29747
<![CDATA[Retinal vessel segmentation is part of the morphological extraction of retinal blood vessels that plays an essential role in medical image processing. Manual segmentation is possible to do, but it is time-consuming and requires special operators. Moreover, the possibility of variability between operators is vast. This study aims to answer the shortcomings of the manual segmentation process by automatically segmenting retinal blood vessels. The main contribution of this study is the use of a simple method to iteratively segment retinal blood vessels. All processes in the segmentation are simulated using Matlab. The algorithm was evaluated by comparing the results of the automatic segmentation with 20 manually segmented images from the STARE dataset. The result show specificity 98.13%, accuracy 93.60%, sensitivity 56.42%, precision 80.48%, and the dice coefficient 64.06%. In conclusion, the automatic retinal blood vessel image segmentation process worked well.]]>
<![CDATA[Strategi Pengisian Baterai pada Sistem Panel Surya Standalone Berbasis Kontrol PI Multi-Loop ]]>
<![CDATA[ Jurnal Teknik Elektro Vol 13, No 1 (2021): Jurnal Teknik Elektro ]]>
Publisher : <![CDATA[Jurusan Teknik Elektro, Fakultas Teknik, Universitas Negeri Semarang ]]>
Show Abstract
|
Download Original
|
Original Source
|
Check in Google Scholar
|
DOI: 10.15294/jte.v13i1.29765
<![CDATA[This study discusses the power control strategy in a standalone photovoltaic-battery hybrid system. The life-time of the battery will be shorter if the battery is often charged with high current and exceeds its State-of-Charge (SoC). Therefore, a control method is needed to control the power flow on the DC bus and the charging current as well as the SoC of the battery so that the battery has a long life-time. The proposed system uses two dc-dc converters to connect photovoltaic (PV) and lead-acid batteries to the load. The unidirectional DC-DC converter is used as the interface between the PV and the DC bus, the bidirectional DC-DC converter is used as the interface between the battery and the DC bus. The control strategy plays a role in controlling the power flow between the converter and the load to maintain the balance of power in the system and controlling the battery to support PV when the available PV power is not enough to meet the load. The multi-loop control strategy is proposed in this study, one of the loops is used to maintain the SoC of the battery in order to control the PV output power to avoid over-charging. Another loop is used to ensure the balance of the system's power when the battery is charging at its maximum charge current. The proposed control system is implemented without requiring any conditions for the control to operate. The simulation results show that the proposed multi-loop control can control the power flow in the system while maintaining the maximum charging current and battery SoC limits.]]>
<![CDATA[Otomatisasi Sistem Fertigasi Tetes untuk Tanaman Berbasis Mikrokontroler ]]>
<![CDATA[ Jurnal Teknik Elektro Vol 13, No 1 (2021): Jurnal Teknik Elektro ]]>
Publisher : <![CDATA[Jurusan Teknik Elektro, Fakultas Teknik, Universitas Negeri Semarang ]]>
Show Abstract
|
Download Original
|
Original Source
|
Check in Google Scholar
|
DOI: 10.15294/jte.v13i1.31123
<![CDATA[The process of manual fertilization and irrigation of plants has disadvantages such as it requires human labor and is inefficient in the use of fertilizers and water sources. Therefore, the purpose of this research is to design and develop an automatic fertigation system. The method used in this research is a drip fertigation technique where the fertigation liquid that has been stirred is placed in a tank with 100 cm height from ground. With the gravitational force, the fertigation liquid is distributed through pipes, hoses and emitters around the plant. While the control system and automation of fertigation distribution to plants is carried out based on a microcontroller that need the condition of soil moisture values around the plant. If the watering time and humidity values are met, the electronic valve will open so that the fertigation liquid flows from the tank to the plants. Furthermore, in this study the tests were carried out to determine the uniformity coefficient and debit of drip fertigation. From the results, it shows that the emitter’s debit influenced by the liquid level in the tank. The uniformity coefficient obtained in the two tests is greater than 90%. From the two tests carried out from the moisture sensor 1 and 2, it shows the mean percentage error for both sensor is less than 1.7%, while the percentage error of soil moisture sensor 1 is 1.6% and the percentage error of soil moisture sensor 2 is 1%, respectively. Meanwhile, from the ultrasonic sensor testing it was obtained 0% of error. It also shows from the testing conducted that the fertigation system works very well and successfully.]]>
<![CDATA[Optimalisasi Pengereman Regeneratif dengan Perubahan Sudut Eksitasi pada Pulsa Tunggal ]]>
<![CDATA[ Jurnal Teknik Elektro Vol 13, No 1 (2021): Jurnal Teknik Elektro ]]>
Publisher : <![CDATA[Jurusan Teknik Elektro, Fakultas Teknik, Universitas Negeri Semarang ]]>
Show Abstract
|
Download Original
|
Original Source
|
Check in Google Scholar
|
DOI: 10.15294/jte.v13i1.28600
<![CDATA[Most of the energy is wasted into heat energy due to conventional braking, so an optimal braking strategy is needed. A Regenerative braking utilizes the kinetic energy of the engine into electrical energy by changing the function of an electric machine into a generator. The regenerative braking system uses a Switched Reluctance Machine (SRM) which has several advantages; simple construction, does not require maintenance, and return energy to the battery. The method that can be used in the regenerative braking system of the SRM is the change of excitation angle to produce the maximum peak phase current. This study aims to optimize regenerative braking by changing the angle (θeks) using simple controls to produce energy that is greater than the battery voltage so that current may flow to the battery when braking occurs. The results of the analysis for method implementation were proven by testing the devices in the laboratory.  Based on the results of the tests, the exact angle was obtained, namely the value of θeks = 20º and the value of θkom = 170º with an initial speed of 1822 RPM, reduced into 1522 RPM by braking process, which could produce a peak current of 12,5 A and a current flowing to the battery was 5A.]]>
<![CDATA[Penyelesaian Masalah Economic Dispatch Menggunakan Equilibrium Optimizer ]]>
<![CDATA[ Jurnal Teknik Elektro Vol 13, No 1 (2021): Jurnal Teknik Elektro ]]>
Publisher : <![CDATA[Jurusan Teknik Elektro, Fakultas Teknik, Universitas Negeri Semarang ]]>
Show Abstract
|
Download Original
|
Original Source
|
Check in Google Scholar
|
DOI: 10.15294/jte.v13i1.28698
<![CDATA[This paper presents a metaheuristic method, namely Equilibrium Optimizer (EO) to solve the economic dispatch (ED) problem. The main objective function to be achieved is to minimize the total fuel costs of all generating units to meet the total load demand and to satisfy various operating constraints. Three case studies are used to test the effectiveness of the EO method in solving ED problems, they are three generators case, six generators case, and fifteen generators case. The simulation of solving ED problems using the EO method is implemented using MATLAB software and is carried out 30 times for each case study. The results of EO method are compared with Particle Swarm Optimization (PSO), Grey Wolf Optimizer (GWO), and Whale Optimization Algorithm (WOA) methods. The simulation results show that the EO method can solve the ED problem more optimal than all other comparison methods for all the case studies by producing the minimum total fuel costs.]]>
