List of Articles Losses

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  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
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  2 - Determination of Private DG Energy Sourced Electricity Purchasing Price by DISCOs with Considering the Capacitor Placement and ENS Costs
  B. Rezaei M. S. Ghazizadeh V. Vahidinasab
  After the restructuring and privatization of the electricity industry, the main purpose of the DISCOs is to increase their income, according to the existing laws. The existence of private distributed generation (DG) units in the distribution network and the possibility More

  After the restructuring and privatization of the electricity industry, the main purpose of the DISCOs is to increase their income, according to the existing laws. The existence of private distributed generation (DG) units in the distribution network and the possibility to buy additional electricity of DG with a less price than the wholesale market, capacitor installation, payment of energy not supplied to customers, the cost of energy losses and voltage drop problem in the distribution network, has created opportunities and challenges for DISCOs that are looking for adopting a suitable strategy for higher profits. In this paper, as the first scenario, it is depicted that when there is no DG unit in the network the increasing in the DISCO’s income is achievable by optimal allocation of both fixed and switched capacitors. In the second scenario, this is done by determination of the maximum acceptable DG energy sourced electricity purchasing price with a known location, and in the third one, by determination of the purchase price from the DG while the locating has been done by the DISCO. Simulation studies are done on a 20kV 18-bus distribution network in Rasht city, and the results are presented at the end. Manuscript profile
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  3 - Double-band Hysteresis Current Controller to Reduce Switching Losses of BLDC Drive and Its Comparison with Single-Band Hysteresis
  H.  Torkaman M. R.  Hassanzadeh Aghdam
  In this paper, a double-band hysteresis current controller (DBHCC) as a new switching method in feeder inverter of a BLDC motor is proposed and implemented. Then, it is compared with the single-band hysteresis current controller (SBHCC). It has been shown that in the pr More

  In this paper, a double-band hysteresis current controller (DBHCC) as a new switching method in feeder inverter of a BLDC motor is proposed and implemented. Then, it is compared with the single-band hysteresis current controller (SBHCC). It has been shown that in the proposed method, the average switching frequency of switches is reduced compared to SBHCC by preserving other advantages. Thus, switching losses are reduced and the lifetime of switches is increased. In addition, it has desirable effects on reducing electromagnetic interferences and noise. In addition, speed control, torque, current ripple and transient states are investigated in both states. Three-phase reference currents for hysteresis switching are obtained using a PI regulator and integrating with output signals from Hall-effect sensors. BLDC motors are used widely in the industry due to more advantages in comparison with others. In order to drive this motor, a three-level cascade half-bridge voltage source inverter with constant DC link for each phase is used. Simulation results are obtained and analyzed using MATLAB/Simulink environment. Manuscript profile
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  4 - Winding Losses Calculation in Multi-Winding Traction Transformer Using a Semi-Numerical Method
  D. Azizian G. Gharehpetian
  Nowadays, multi-winding transformers are widely used in power systems, especially in traction networks and steel producing companies. The multi-winding transformers have special geometry. They encounter with serious problems and difficulties in design procedure in compa More

  Nowadays, multi-winding transformers are widely used in power systems, especially in traction networks and steel producing companies. The multi-winding transformers have special geometry. They encounter with serious problems and difficulties in design procedure in comparison with conventional two-winding transformers. Considering the importance of windings losses (and the generated heat), the current research firstly focuses on thermal calculations in this type of transformers, also introduces a semi-numerical technique for electromagnetic analysis of split-winding traction system transformer. Combining finite element and analytical methods, the windings losses distribution due to eddy currents is calculated and the modeling results are validated using the experimental results. As shown, the introduced semi-numerical method is a powerful technique for electromagnetic modeling and winding losses calculations in split-winding transformers. Also, the winding losses of the split-winding transformer are discussed and compared to the conventional two-winding transformer results. Finally, the relation between the winding losses and frequency is studied in this paper. Manuscript profile
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  5 - Lifetime Estimation of Distribution Transformers in Present of Harmonic Loads: Case Study of Ilam Distribution Transformers
    A. Moradkhani M. H. Parhizgari D. Bagheri
  One of the main components of distribution systems is transformer, and their failure will cause irreparable damage in power systems and distribution companies. These failures are to increase the losses of the transformers due to the increase of harmonics, especially the More

  One of the main components of distribution systems is transformer, and their failure will cause irreparable damage in power systems and distribution companies. These failures are to increase the losses of the transformers due to the increase of harmonics, especially the current harmonics. These losses increase the temperature of transformers and reduced the lifetime of distribution transformers. In this paper evaluated losses and lifetime in the presence of harmonic loads in Ilam distribution transformers. Technical and practical assessments of the presence of harmonic loads and their effect on the lifetime of transformers have been investigated. According to the obtained results the useful lifetime of some transformers from 30 years to 17 years are decreased. Manuscript profile
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  6 - Hoof trimming as a part of lameness control in dairy farms
  Reyhane Sangtarash Marzieh Faezi
  Production diseases and conditions is common on intensive dairy farming which lead to pain and uncomforting or death in affected animals. Lameness has negative effects on comfort and economic issues. In many cases, lameness is associated with pain, which may change the More

  Production diseases and conditions is common on intensive dairy farming which lead to pain and uncomforting or death in affected animals. Lameness has negative effects on comfort and economic issues. In many cases, lameness is associated with pain, which may change the cow's motivation to perform certain behaviors (such as walking, lying, etc.) for pain reduction and discomfort. Reduced milk yield, poor reproductive performance, shortened productive time, increased culling risk and treatment costs are the major related economic losses. Despite all the negative effects of lameness on animals and the dairy industry, limited research has been done to evaluate preventive measures. Low awareness of lameness maybe the biggest problem in its detection and control. Lameness control strategies usually include hoof trimming and treatment of motility disorders. The aim of this study is to investigate the importance of hoof trimming and its effect on claw health (effect of hoof trimming on infectious diseases, non-infectious diseases or other claw-related injuries), behavioral variables (lying time and locomotion score), physiological variables (heart rate, respiration rate, plasma cortisol level, etc.), production variables (milk production and reproduction) and other factors related to hoof trimming. Manuscript profile