• List of Articles تلفات

      • Open Access Article

        1 - Review of Water Conveyance and Distribution Efficiency in Irrigation Networks in Iran and its Estimation Methods
        zeynab sojoodi Seyyed Mehdi Hashemy Shahedany
        Irrigation networks are responsible for the distribution and delivery of agricultural water, so improving their performance reduces losses and increases the efficiency of water distribution, and thus leads to improved water efficiency. Investigating the operation of irr More
        Irrigation networks are responsible for the distribution and delivery of agricultural water, so improving their performance reduces losses and increases the efficiency of water distribution, and thus leads to improved water efficiency. Investigating the operation of irrigation networks is essential for planning and improving irrigation networks and systems. The first purpose of the assessment is to determine the amount of losses that occur in the process of distribution and delivery of agricultural water in the network of irrigation canals. Losses in agricultural water conveyance and distribution systems occur for two main reasons: leakage and improper performance of canal structures that cause operating losses. Various factors such as weed growth in canals, accumulation of sediment in canals, accumulation of garbage in canals, cracking of canal cover, crushing or moving of concrete parts in canals, destruction due to poor quality of materials and lack of sufficient knowledge of total operation and the wisdom of the country's water decision-makers is increasing losses in agricultural distribution and delivery systems. Factors influencing the operation of networks include regular annual maintenance process and the operation of network operators to timely and correctly adjust the catchment structures to prevent unstable hydraulic conditions in the main and secondary channels, which can be invested in training operators and teams. Management and operation in irrigation networks significantly reduced the volume of operation losses. In this study, the results of studies on the determination of conveyance and distribution efficiencies in irrigation networks have been reviewed and summarized. Manuscript profile
      • Open Access Article

        2 - Placement of AVRs and Reconfiguration of Distribution Networks Simultaneously and Robust Considering Load Uncertainty
        M. R.  Shakarami Y. Mohammadi Pour
        : In this paper, optimal locating for AVRs and reconfiguration of distribution networks were assessed simultaneously as an optimization problem. A new objective function was introducing which incorporated several electrical indices including real power losses, reactive More
        : In this paper, optimal locating for AVRs and reconfiguration of distribution networks were assessed simultaneously as an optimization problem. A new objective function was introducing which incorporated several electrical indices including real power losses, reactive power losses, reliability, voltage profile, voltage stability, and load capacity of lines (MVA). Various load levels were incorporated into the objective function to make sure that switch status in reconfiguration and AVR taps and locations would be robust against load variations. This paper also introduced a new method for calculating the load levels with respect to load uncertainty. It also considered all loads based on a voltage-dependent model. Several scenarios are defined to thoroughly assess the proposed approach. Integer particle swarm optimization algorithm (IPSO) was used to solve the mentioned optimization problem. The results obtained by the simulation of 33-bus and 69-bus standard IEEE .radial power distribution networks demonstrated the effectiveness of the proposed approach Manuscript profile
      • Open Access Article

        3 - Analysis and Implementation of a Step-Down DC-DC Converter with a New Control Method to Reduce Converter Losses
        Mohamad Reza Banaei sajad gabeli sani
        A step-down converter based on buck and buck-boost converters with a loss reduction technique is proposed in this paper. Utilizing non-electrolytic capacitors in the implementation of the proposed converter has resulted in an increase in circuit life and a reduction in More
        A step-down converter based on buck and buck-boost converters with a loss reduction technique is proposed in this paper. Utilizing non-electrolytic capacitors in the implementation of the proposed converter has resulted in an increase in circuit life and a reduction in weight and volume. This paper compares the proposed converter to other buck converters. To increase the output efficiency of the converter in comparison to other structures, a new method based on determining the working duty-cycles has been employed to reduce the losses of the converter, resulting in an increase in the converter's output efficiency. In order to demonstrate the differences in efficiency between the proposed method and the conventional method, the efficiency of the converter has been calculated using real-world conditions and the output loss results have been compared. In addition, the proposed converter has a common ground with the input source and has a suitable reduction gain. Finally, this converter has been implemented as a PCB and tested with 100 watts of output power. Manuscript profile