Agus Ulinuha - Academia.edu (original) (raw)
Papers by Agus Ulinuha
Journal of Solar Energy Research Updates
The demand of electricity that keeps increasing necessitates additional electricity generation. T... more The demand of electricity that keeps increasing necessitates additional electricity generation. The highly dependence of power generation on fossil fuels implies the intensive use of this resources that may cause them finish sooner than predicted. On the other hand, the use of fossil fuels for transportation is quite dominant. The development and use of electric transportation system is a solution for reducing fuel consumption. However, the electricity for supplying the electric transportation system is mainly from the generation system that uses fossil fuels. For further improvement, the energy supplied to the transportation system should come from the renewable energy generation. This may lead to minimum use of fossil fuels besides giving minimum effect on environment. This paper presents the development of renewable energy generation where the generated power is used to supply the storage that charges the electric bicycle. The power is generated by solar photovoltaic panels and it is saved in a battery. The charging for the bicycle is taken from the battery. The developed system is off-grid since the system may be placed in the non-electrified area. This prototype will be a role model regarding the combination of renewable energy generation and green transportation system.
The unbalanced conditions are taken into account in the Volt/VAr control of distribution system. ... more The unbalanced conditions are taken into account in the Volt/VAr control of distribution system. The aim of the control is to simultaneously minimize energy loss and improve voltage profile. The optimization may be achieved by optimal dispatch of Load Tap Changer (LTC) and shunt capacitors considering system unbalanced. A Genetic Algorithm (GA) is developed to determine the load curve division useful for effective LTC scheduling and switching constraint satisfaction. GA is also appointed for the dispatch due to the ability of simultaneously scheduling the devices and checking the fulfillment of switching constraints prior to performing calculations. The algorithm is further enhanced by including fuzzy approach into the existing GA procedure. For power flow analyses under unbalanced conditions, Forward/Backward Propagation Algorithm is developed. The optimization is implemented on the IEEE 34-bus unbalanced distribution system. The advantages of fuzzy inclusion are highlighted. The m...
Unbalanced power flow is essential calculation for analysis of unbalanced electrical distribution... more Unbalanced power flow is essential calculation for analysis of unbalanced electrical distribution system. A number of analyses on the system use unbalanced power flow calculation as the backbone of analyses. Therefore the accuracy of the calculation is crucial for the results of analyses. Unbalanced power flow is carried by considering three-phase system of distribution system. One of important aspect on unbalanced power flow calculation is modelling of system components. This paper proposes a model of the components as bus injection current for unbalanced power flow calculation using the method of forward-backward propagation algorithm. The algorithm works directly on the system without modification and requires modeling of shunt components as current injection. The method is appointed due to the robust and good convergence characteristics. The system model and the algorithm are implemented on the IEEE 34-bus system and the generated results are analyzed. Furthermore, the algorithm...
Warta LPM, 2020
The availability of water is a problem for the people of Sidomulyo, Krikilan, Sragen at dry seaso... more The availability of water is a problem for the people of Sidomulyo, Krikilan, Sragen at dry season. Having a higher altitude than other areas causes the water from the government water supply company difficult, reaching the area, particularly at the peak time. Some people using water from bore water also have the same problem of limited water. It is, therefore, necessary to bore the deep well for getting enough water to satisfy the people's needs. The deep level of the well should be enough to assure not to absorb the water source of people's well. In this program, the well with the deep of 81 m is bored, and PVC water pipes are placed inside the hole assuring only the deep bore water is taken out. This is aimed to avoid taking water from the low-level source, which may reduce the water going to the people's well. For pumping purposes, the submersible electric pump is used. It is 3 hp, 2500-Watt pump with a capacity of 18 m 3 per hour. From the 3-day pumping test, the capacity of well is very enough to provide water needs for the 34 families of Sidomulyo. High-water storage with the dimension of (2.4 x 2.4 x 2) m 3 has been constructed with a height of 7.4 m to the tank base. The power source is currently from the electrical utility but is planned will be from Solar Photovoltaic. From a financial perspective, the revenue from the water bill will support community activities.
2007 Australasian Universities Power Engineering Conference, 2007
Power flow calculation is normally carried out for fundamental frequency. Due to the extensive us... more Power flow calculation is normally carried out for fundamental frequency. Due to the extensive use of nonlinear loads, harmonic frequencies are present and need to be also considered. Unfortunately, unavoidable complexity and heavy computation burden are often encountered by involving nonlinear loads into the calculation. Multiple nonlinear loads typically employed in the real system will further weigh the computation down. This paper implements a decoupled approach to overcome the problem. The couplings between harmonics are rationally disregarded enabling separate calculations for every harmonic order. This will greatly reduce the complexity level and computation burden. However, the accuracy of this technique is somehow questioned due mainly to the neglected harmonic couplings. The accuracy of the implemented decoupled harmonic power flow (DHPF) algorithm is investigated by simulating the distorted IEEE 18-bus system and comparing the results with those generated by standard packages (e.g., HARMFLOW and ETAP). The implementation is then extended for the IEEE 123bus system including multiple nonlinear loads.
2008 Joint International Conference on Power System Technology and IEEE Power India Conference, 2008
The optimal voltage restoration and loss minimization in distribution system using Genetic Algori... more The optimal voltage restoration and loss minimization in distribution system using Genetic Algorithms (GAs) is presented. The optimization is carried out by scheduling Load Tap Changer (LTC) and shunt capacitors to simultaneously improve the voltage and minimize the energy loss. Two GAs are developed to determine the load interval division and the optimal schedule of the controllable devices, respectively. Encoding ability of the proposed method enables checking the fulfillment of switching constraints of any possible schedule prior to performing calculations. This will significantly reduce the computation burden due to unnecessary calculations for infeasible schedules. The optimization is performed for the IEEE 123-bus distribution system. The generated results indicate that the developed methods are effective for the optimal scheduling problem by providing voltage improvement and energy loss minimization.
Applied Mechanics and Materials, 2014
The enhancement of distribution system operation is proposed in this paper by optimally controlli... more The enhancement of distribution system operation is proposed in this paper by optimally controlling the installed switchable devices. The objective of the control is to simultaneously minimize system losses and improve system voltage profile. This objective may be achieved by optimally dispatching the controllable components (shunt capacitor and Load Tap Changer/LTC) taking into account system unbalanced. A Genetic Algorithm (GA) is developed to determine the load curve partition useful for effective LTC scheduling and switching constraint satisfaction. GA is also assigned to determine the hourly status of shunt capacitor switching and LTC tap position. For power flow analyses under unbalanced conditions, Forward/Backward Propagation Algorithm is developed and employed. The strategy is implemented on the IEEE 34-bus unbalanced distribution system and the resulted improvement is analyzed. The main contribution is inclusion of unbalanced system conditions into optimization problem.
IEEE Transactions on Power Delivery, 2008
The optimal scheduling of load tap changers (LTCs) and switched shunt capacitors for simultaneous... more The optimal scheduling of load tap changers (LTCs) and switched shunt capacitors for simultaneously minimizing energy loss and improving voltage profile while taking harmonics into account is performed using evolutionary-based algorithms (EAs). The proposed algorithm is capable of optimizing large distribution systems with different types of nonlinear loads. The decouple approach is employed for harmonic power-flow calculations, while two EAs are developed to determine the load interval division and near-optimal schedule. The inclusion of harmonics provides the optimization benefits while maintaining the acceptable distortion levels. The scheduling is carried out for the IEEE 123-bus with 14 shunt capacitors and 12 nonlinear loads. The main contributions are inclusion of harmonics in the optimal scheduling problem and its application to large distribution systems with multiple nonlinear loads.
Journal of Solar Energy Research Updates
The demand of electricity that keeps increasing necessitates additional electricity generation. T... more The demand of electricity that keeps increasing necessitates additional electricity generation. The highly dependence of power generation on fossil fuels implies the intensive use of this resources that may cause them finish sooner than predicted. On the other hand, the use of fossil fuels for transportation is quite dominant. The development and use of electric transportation system is a solution for reducing fuel consumption. However, the electricity for supplying the electric transportation system is mainly from the generation system that uses fossil fuels. For further improvement, the energy supplied to the transportation system should come from the renewable energy generation. This may lead to minimum use of fossil fuels besides giving minimum effect on environment. This paper presents the development of renewable energy generation where the generated power is used to supply the storage that charges the electric bicycle. The power is generated by solar photovoltaic panels and it is saved in a battery. The charging for the bicycle is taken from the battery. The developed system is off-grid since the system may be placed in the non-electrified area. This prototype will be a role model regarding the combination of renewable energy generation and green transportation system.
The unbalanced conditions are taken into account in the Volt/VAr control of distribution system. ... more The unbalanced conditions are taken into account in the Volt/VAr control of distribution system. The aim of the control is to simultaneously minimize energy loss and improve voltage profile. The optimization may be achieved by optimal dispatch of Load Tap Changer (LTC) and shunt capacitors considering system unbalanced. A Genetic Algorithm (GA) is developed to determine the load curve division useful for effective LTC scheduling and switching constraint satisfaction. GA is also appointed for the dispatch due to the ability of simultaneously scheduling the devices and checking the fulfillment of switching constraints prior to performing calculations. The algorithm is further enhanced by including fuzzy approach into the existing GA procedure. For power flow analyses under unbalanced conditions, Forward/Backward Propagation Algorithm is developed. The optimization is implemented on the IEEE 34-bus unbalanced distribution system. The advantages of fuzzy inclusion are highlighted. The m...
Unbalanced power flow is essential calculation for analysis of unbalanced electrical distribution... more Unbalanced power flow is essential calculation for analysis of unbalanced electrical distribution system. A number of analyses on the system use unbalanced power flow calculation as the backbone of analyses. Therefore the accuracy of the calculation is crucial for the results of analyses. Unbalanced power flow is carried by considering three-phase system of distribution system. One of important aspect on unbalanced power flow calculation is modelling of system components. This paper proposes a model of the components as bus injection current for unbalanced power flow calculation using the method of forward-backward propagation algorithm. The algorithm works directly on the system without modification and requires modeling of shunt components as current injection. The method is appointed due to the robust and good convergence characteristics. The system model and the algorithm are implemented on the IEEE 34-bus system and the generated results are analyzed. Furthermore, the algorithm...
Warta LPM, 2020
The availability of water is a problem for the people of Sidomulyo, Krikilan, Sragen at dry seaso... more The availability of water is a problem for the people of Sidomulyo, Krikilan, Sragen at dry season. Having a higher altitude than other areas causes the water from the government water supply company difficult, reaching the area, particularly at the peak time. Some people using water from bore water also have the same problem of limited water. It is, therefore, necessary to bore the deep well for getting enough water to satisfy the people's needs. The deep level of the well should be enough to assure not to absorb the water source of people's well. In this program, the well with the deep of 81 m is bored, and PVC water pipes are placed inside the hole assuring only the deep bore water is taken out. This is aimed to avoid taking water from the low-level source, which may reduce the water going to the people's well. For pumping purposes, the submersible electric pump is used. It is 3 hp, 2500-Watt pump with a capacity of 18 m 3 per hour. From the 3-day pumping test, the capacity of well is very enough to provide water needs for the 34 families of Sidomulyo. High-water storage with the dimension of (2.4 x 2.4 x 2) m 3 has been constructed with a height of 7.4 m to the tank base. The power source is currently from the electrical utility but is planned will be from Solar Photovoltaic. From a financial perspective, the revenue from the water bill will support community activities.
2007 Australasian Universities Power Engineering Conference, 2007
Power flow calculation is normally carried out for fundamental frequency. Due to the extensive us... more Power flow calculation is normally carried out for fundamental frequency. Due to the extensive use of nonlinear loads, harmonic frequencies are present and need to be also considered. Unfortunately, unavoidable complexity and heavy computation burden are often encountered by involving nonlinear loads into the calculation. Multiple nonlinear loads typically employed in the real system will further weigh the computation down. This paper implements a decoupled approach to overcome the problem. The couplings between harmonics are rationally disregarded enabling separate calculations for every harmonic order. This will greatly reduce the complexity level and computation burden. However, the accuracy of this technique is somehow questioned due mainly to the neglected harmonic couplings. The accuracy of the implemented decoupled harmonic power flow (DHPF) algorithm is investigated by simulating the distorted IEEE 18-bus system and comparing the results with those generated by standard packages (e.g., HARMFLOW and ETAP). The implementation is then extended for the IEEE 123bus system including multiple nonlinear loads.
2008 Joint International Conference on Power System Technology and IEEE Power India Conference, 2008
The optimal voltage restoration and loss minimization in distribution system using Genetic Algori... more The optimal voltage restoration and loss minimization in distribution system using Genetic Algorithms (GAs) is presented. The optimization is carried out by scheduling Load Tap Changer (LTC) and shunt capacitors to simultaneously improve the voltage and minimize the energy loss. Two GAs are developed to determine the load interval division and the optimal schedule of the controllable devices, respectively. Encoding ability of the proposed method enables checking the fulfillment of switching constraints of any possible schedule prior to performing calculations. This will significantly reduce the computation burden due to unnecessary calculations for infeasible schedules. The optimization is performed for the IEEE 123-bus distribution system. The generated results indicate that the developed methods are effective for the optimal scheduling problem by providing voltage improvement and energy loss minimization.
Applied Mechanics and Materials, 2014
The enhancement of distribution system operation is proposed in this paper by optimally controlli... more The enhancement of distribution system operation is proposed in this paper by optimally controlling the installed switchable devices. The objective of the control is to simultaneously minimize system losses and improve system voltage profile. This objective may be achieved by optimally dispatching the controllable components (shunt capacitor and Load Tap Changer/LTC) taking into account system unbalanced. A Genetic Algorithm (GA) is developed to determine the load curve partition useful for effective LTC scheduling and switching constraint satisfaction. GA is also assigned to determine the hourly status of shunt capacitor switching and LTC tap position. For power flow analyses under unbalanced conditions, Forward/Backward Propagation Algorithm is developed and employed. The strategy is implemented on the IEEE 34-bus unbalanced distribution system and the resulted improvement is analyzed. The main contribution is inclusion of unbalanced system conditions into optimization problem.
IEEE Transactions on Power Delivery, 2008
The optimal scheduling of load tap changers (LTCs) and switched shunt capacitors for simultaneous... more The optimal scheduling of load tap changers (LTCs) and switched shunt capacitors for simultaneously minimizing energy loss and improving voltage profile while taking harmonics into account is performed using evolutionary-based algorithms (EAs). The proposed algorithm is capable of optimizing large distribution systems with different types of nonlinear loads. The decouple approach is employed for harmonic power-flow calculations, while two EAs are developed to determine the load interval division and near-optimal schedule. The inclusion of harmonics provides the optimization benefits while maintaining the acceptable distortion levels. The scheduling is carried out for the IEEE 123-bus with 14 shunt capacitors and 12 nonlinear loads. The main contributions are inclusion of harmonics in the optimal scheduling problem and its application to large distribution systems with multiple nonlinear loads.