Mochamad Ashari
Sepuluh Nopember Institute of Technology
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Publication
Featured researches published by Mochamad Ashari.
international conference on innovation management and technology research | 2012
Ramadoni Syahputra; Imam Robandi; Mochamad Ashari
This paper presents a reconfiguration methodology based on a fuzzy multi-objective approach for achieving the minimum active power loss and the maximum voltage magnitude of radial distribution networks with distributed generations. Multi-objective function are considered for load balancing among the feeders, minimization of the real power loss, deviation of nodes voltage, and branch current constraint violation, while subject to a radial network structure in which all loads must be energized. These objective functions are modeled with fuzzy sets to evaluate the imprecise nature of each objective. Originality of the research is that the fuzzy-based multi-objective optimization in reconfiguration of distribution network including the distributed generation. The implementation of the fuzzy multi-objective for distribution reconfiguration on a 70 nodes distribution network with distributed generation is described. The simulation results show that a 37.92% of active power loss reduction is achieved by the method.
international conference on innovative computing, information and control | 2007
Mochamad Ashari; Takashi Hiyama; M. Pujiantara; H. Suryoatmojo; M.H. Purnomo
This paper presents a novel dynamic voltage restorer (DVR) capable of handling deep sags including outage on a low voltage distribution system. The DVR recovers sags up to 10% of nominal voltage; otherwise, it will operate as an uninterruptible power supply (UPS). A transformer is connected in series with the load when restoring sags, and is reconfigured into parallel connection using switches when handling outages. The controller uses a Fuzzy Logic with 3 inputs to maintain the load voltage through d-q transformation. Preliminary results from laboratory tests are also presented in this paper.
international conference on information technology, computer, and electrical engineering | 2014
Ramadoni Syahputra; Imam Robandi; Mochamad Ashari
This paper presents an optimal distribution network reconfiguration with penetration of distributed energy resources (DER). The reconfiguration is done to achieve the minimum active power loss of radial distribution networks with DER penetration. As a further matter, the presence of DER to the distribution systems has become some problems such the increase of the voltage at which there are many DER. In this study, the technique of network reconfiguration is based on an extended fuzzy multi-objective. Multi-objective function are considered for the power loss minimization, deviation of bus voltage, and load balancing among the feeders, while subject to a radial network structure in which all loads must be energized. The extended fuzzy multi-objective for reconfiguration of distribution network has been tested on Yogyakarta 60-bus distribution network data. The test results show that a 3.83% of Yogyakarta 60-bus network power loss reduction is achieved by the method. Also, the improvement of the voltage profile at each bus is also achieved with this method.
international conference on information technology, computer, and electrical engineering | 2014
Soedibyo; Mochamad Ashari; Ramadoni Syahputra
This paper proposes a strategy of power loss reduction of radial distribution network with distributed generator (DG) integration based on a fuzzy multi-objective method in order to improve the distribution system efficiency. Multi-objective functions are considered for power loss reduction, minimization of bus voltage deviation, and maintaining the load balancing among the feeder of distribution network. These objective functions are modeled with fuzzy sets to evaluate the imprecise nature of each objective. Originality of this work is the fuzzy-based multi-objective optimization in reconfiguration of distribution network including the distributed generator. The application of the fuzzy based multi-objective for distribution network reconfiguration on a 33-bus distribution network with integration of distributed generator is described. The test results show that the power loss of 33-bus radial distribution network experienced a significant reduction and voltage profile of each bus has also improved. The results show that a 72.34% of power loss reduction is achieved for the IEEE 33-bus network with DG integration.
international conference on information technology computer and electrical engineering | 2015
Soedibyo; Budi Amri; Mochamad Ashari
Photovoltaic electricity generation is one alternative to use of renewable energy source. Efficiency of photovoltaic systems can be upgraded by operating photovoltaic panel at its optimum power point by using maximum power point tracking. Getting maximum power from the solar panels needed DC-DC converters by using the algorithm of MPPT. This paper presents a comparison study of the Buck-boost, Cuk, Sepic and Zeta converters as a device of MPPT. The algorithm for maximum power point tracking was a perturb and observe method. The simulation results of fourth converters were evaluated and compared, the parameters were observed of each DC-DC converters such forms of ripple current signal, the voltage on the input and the output sides, the input power and output power, as well as a steady state period and isolation signal between the input and output sides.
International Journal of Computer Applications | 2010
Bambang Sujanarko; Mochamad Ashari; Mauridhi Hery Purnomo
Cascaded Multilevel Inverter (ACMLI) was widely studied. Various control strategies have been investigated. However, most of the reported control strategies not discussed how to determinate voltage levels, firing angle, switching-state and other parameters control design. This work was developed a universal algorithm to overcome the problems in the various number of H-Bridges and various DC voltages of ACMLI. The proposed algorithm based on combination theorem and matrix operation. The MATLAB computer program and simulation using MATLAB SIMULINK in the binary, trinary, equal interval, sine quantization and random DC voltage are the methods for verify the proposed algorithm. The results program execution and simulation in the single phase of ACMLI show that the proposed algorithm produces ACMLI control more accurate and faster if compared with previous control strategies.
international seminar on intelligent technology and its applications | 2015
Soedibyo; Feby Agung Pamuji; Mochamad Ashari
This paper presents a system photovoltaic BPSX-60 in order to have continously electricity supply for low voltage grid. Output photovoltaic BPSX-60 is controlled by dc-dc boost converter to produce maximum power in order to obtain the MPP (Maximum Power Point). Output of the converter is controlled by fuzzy logic to obtain the MPP (Maximum Power Point) photovoltaic BPSX - 60, thus the efficiency photovoltaic BPSX - 60 can be increased. From the simulation using matlab 2010 can be concluded that the controller can shift power to 90 % maximum power of photovoltaic BPSX - 60.
international conference on innovative computing, information and control | 2007
B. Suprianto; Mochamad Ashari; M.H. Purnomo; M. Pujiantara; H.S. Atmojo
The master-slave control scheme for uniform current distribution among converter modules in a parallel connected converter system is presented in this paper. The objective of the paper is to introduce a fuzzy logic control application, develop the associated mathematical theory and prove the concept and its advantages through comparative simulation with existing, classical methods. A stable fuzzy logic controller for the master-slave current distribution loops of a paralleled DC-DC system is demonstrated. Simulation results show a good parameter insensitive transient response over a wide range load-step responses and no current fluctuation. Load resistance has step form 15 Omega, to 10 Omega.
International Journal of Computer Applications | 2010
Bambang Sujanarko; Mochamad Ashari; Mauridhi Hery Purnomo
Among the Artificial Intelligent (AI) technique, Neural Network (NN) is emerging technology that is advancing rapidly and having impact on many scientific and engineering applications. In this paper, NN apply on Asymmetric Cascaded Multilevel Inverter (ACMLI), in order to improve the controller easier to construct, simpler and better performance. To verify these goals, the system simulated based on Matlab Simulink after the NN controller build using m-file program. The simulation results show that the goals can realized.
international conference on innovative computing, information and control | 2007
P. Margo; P.M. Heri; Mochamad Ashari; Takashi Hiyama
Many controllers based fuzzy logic have been applied on electric power system. Frequently, time response of the fuzzy controllers is slowly, because the number of membership functions are too many. Many research are proposed to minimize the number of membership function, such as fuzzy polar controller method. By using this method, number of membership function can be minimized, so the time response of the controller become faster. This paper presents the dynamic voltage restorer (DVR) based fuzzy polar controller method to compensate balanced voltage sag. Simulation results show that this proposed method can compensate balanced voltage sag better than PI controller.