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The paper deals with higher harmonics in a power system. The aim of the paper is to present a review of ideas of single-point measurement localization of prevailing harmonic sources in a power system. Knowledge about the location of the harmonic sources in a power system is useful to control harmonic levels at a power system. These knowledge is also useful to solve disputes between utilities and customers...
The paper considers specific features of problem statement for the medium-term generation scheduling in a wholesale electricity market environment. An approach is suggested to solve the problem on the basis of bilevel optimization models. Such models take into account possible distortion of data on economic parameters of generating units and further centralized scheduling of electricity generation...
Due to the technological development, the electronic power progress and economic stake, through the use of Wound Rotor Induction Motor (WRIM) has taken more and more places in different domains (transport, energy production, electric drive‥,) thanks to their robustness, efficiency and lower costs. Despite the performed work researches and the improvement that has been brought, these machines still...
This paper proposes a new adaptive auto reclosing scheme for extra high voltage transmission lines. The performance of an auto reclosing scheme depends not only on power system behavior and transmission lines characteristic but also secondary arc current. In this paper at first, an appropriate model of arc in extra high voltage transmission overhead line is investigated and after that, using symmetrical...
The aim of this paper is to present an impedance-based technique in order to fault detection in transmission overhead lines. When a fault happens in a power system, fast and reliable fault detection methods are not only desirable but also necessary. In this paper, an impedance-based fault detection technique is presented which applied in ANN. In this regard, using the zero sequence impedance values...
Smart grids are integrated communications and power system infrastructures to improve the efficiency, reliability and safety of power deliveries and its usages. In this paper, Time of Use (TOU) programs in smart grids is studied. In this regard, Real Time Pricing method (RTP) has been developed using multi objective load models. Also, the effects of smart grids on demand curve have been simulated...
Energy automation systems have been expanding and there are more Ethernet capable devices in the network. Protection relays, switches, GPS and also computers have many critic diagnosis information available via the network interface. The intention of this paper is to present how the already available information can be used in the human-machine interfaces and SCADA systems to have a more detailed...
Due to high penetration of distributed generation (DG) in distribution networks, transmission networks are no longer the only responsible for security issues in low voltage distribution networks. DG units should participate in security as well as power generation. In this paper, a DG placement problem is solved based on voltage stability analysis tools. Modal analysis and continuous power flow (CPF)...
Due to restriction of the coordination time interval (CTI) limit of the time-current characteristic (TCC) based protective devices, and the operating time constraints for protecting the line at the substation, the number of the protective devices in series in one distribution feeder is limited. However nowadays, for the purpose of ensuring the reliability of the power system, one popular way related...
Series capacitors (SCs) are installed on long transmission lines to reduce the inductive reactance of the lines. SCs and their associated over-voltage protection devices (typically metal oxide varistors, and/or air gaps) create several problems for distance protection relays and fault locators including voltage and/or current inversion, sub-harmonic oscillations, transients caused by the air-gap flashover...
In the procedure of connecting large wind parks (WP) to the external power grid, TSO's or DSO's request is that WPs in operation do not excessively affect the power quality in the connection point. In the process of determining WP operating procedures it is necessary to include switching operations in the WP main feeder. The transformers connected near the wind generator units are then energized and...
The rising of electricity and heating prices due to primary energy resources scarcity will drive households to generate their own energy on-site using renewable sources. Energy generation potential and energy demand are directly proportional to specific geographic location and urban density. This paper presents an analysis, based on software simulations, of different on-site electricity and heating...
In steel making industries, the electrical arc furnaces (EAFs) present the main non linear loads connected to the power supply. One of the problems associated with this and needed to be studied and solved is the harmonics produced by those furnaces. The solution of the problems requires study and analysis of the harmonics. This can be done by working a model for the furnace circuit. This model is...
Nowadays Wind turbines are used over a wide area as they are environmentally favorably means to product energy without emissions and moreover the fuel is wind which is free for use. Wind turbines are often installed in mountainous area where the soil resistivity and isokeraunic level is high. When the soil resistance is high, the potential rise caused by lightning strike to a wind turbine is more...
The growing demand for electricity makes the power grid ever expanding day by day and more and more complex. There is a potential requirement to continuously monitor the power grid and thus making it smarter and reliable. Traditional measurement systems are getting replaced by PMUs, which enables the online monitoring of the power system. With the aid of GPS, PMUs can measure the phasor values of...
In this paper an optimized five-level inverter topology is proposed for a four pole induction motor drive. This topology has developed by using the advantage of two identical voltage profile winding coils per phase in a four pole induction motor. The identical voltage profile winding coils are disconnected and each part of the winding is fed with two two-level inverters from both sides. Thereby four...
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