مجله کیفیت و بهره وری صنعت برق ایران
سال چهارم شماره 1 (پیاپی 7، بهار و تابستان 1394)

The main goal of this paper is to present a novel model for a distribution company (Disco) energy acquisition in a competitive electricity market environment with interruptible load (IL) and distributed generation (DG). The work formulates the Disco energy acquisition model as a bilevel optimization problem with some real considerations، and then studies and designs an algorithm of this optimization problem too. In order to achieve this goal، a novel two-step procedure is proposed. At the first step، a real model for an industrial IL is introduced to examine how problem modeling and solving are affected by IL model. The introduced method shows a good performance of problem modeling and solving algorithm both in terms of solution quality and computational results. A Real case study is carried out considering a test system with some assumptions. Results show the general applicability of the proposed model، with potential cost saving for the Disco.

Information about network components is of great importance for asset management decision making. This information is needed as input for the asset management decision process to come to a decision. To be able to extract the requested information، analysis and evaluation are needed. On the other hand، for efficient and economical asset management from reliability view point، analysis of failure rate for determination of origin of fault in component is an important task for asset manager. The failure rate of components is obtained by gathering data in outage management process that is available usually in detail in outage databases in electrical distribution. In this paper، failure analysis of process is obtained by assessment of process of component entry in distribution system. In this analysis، failure factors and sub-factors of each process is assigned by focus group and then relation between factors and causes of component failure is obtained by Delphi method. Finally، reasons of process-based failure are invested by modeling of failure rate for each process.

In this paper، an energy management in a building with zero energy with renewable sources، solar، fuel cell and grid- connected electric vehicle will be provided. For this purpose، mathematical models for each of these sources and power electronic converters for hybrid power generation system with regard to the time of the simulation. A prominent feature of this work can be coordinated planning electric vehicle to cover the building''s load. To validate the performance of the proposed power management strategy، simulation was performed in MATLAB software. The results show that the proposed power management enables the implementation of zero energy in the building.

Increasing energy prices has caused a special interest in unconventional energy sources. Associated gas is mostly flared as an useless byproduct of oil extraction while regarding it’s high heating value and considerable available volume in the country، it has a huge potential for use. Electricity generation is one of the most economical options to recover associated gas. This article investigates technical feasibility and economical justifiability of this method. Gas turbine، reciprocating engine and steam turbine are modelled using Thermoflow software، allowable conditions of these power generators’ fuel are gathered and needed preparation technologies are studied. After cost estimation a comprehensive parametric analysis is conducted which studies the effects of associated gas composition’s variation، gas flow، ambient temperature، design point، electricity price and discount rate on project economy. Results show using this energy source is completely feasible and by choosing appropriate power generator mostly economical.

The main purpose of this study is to identify an optimal and economic point to implementing the DSM policies by customers and evaluating its potential. To achieve this goal at the first step we present a bottom up probabilistic method based on equipment which is used for Detecting the DSM effectiveness and load modeling. The second step is about cost-benefit analyzing of DSM policies considering the lifetime of DSM policies and Electricity prices for Daily consumption curve. Then the economic point to implementing the DSM policies is determined and the customers can recognize the best choice to how to reduce their load. At the Third step، factors like seeking welfare and household income are considered at the presented method. This method is challenged by RBTS test system. The results show a 38. 6 percent reduction of the average load which is considered as an economic and optimal point for implementing the DSM policies. Also the customers due to seeking welfare and household income can be away or close to this optimal point.

In this paper، a novel method is proposed to estimate the online value of Thévenin Equivalent (TE) from a generator bus using Phasor Measurement. Three consecutive phasor values of voltage and current (V،I) recorded at generator bus are used to estimate the TE. To synchronize the consecutive phasors to the same reference and correcting the phase drift، a virtual vector in triangulation method is proposed. It is shown that the triangle construction in case of inconsistency is possible when the virtual vector is used. In addition، a new method to eliminate the noisy or irrelevant measurements is introduced. The algorithm is tested on standard IEEE 30-Bus network that is simulated in time domain by DigSILENT software both in steady state and transient conditions. The algorithm performance also is investigated and approved in the university protection laboratory with a typical test case system. The interesting results approve the novelty and efficiency of the proposed method