The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
This paper presents a combined method for discrimination between inrush current and internal fault current of power transformers. The mentioned method is based on wavelet analysis of power system frequency which is estimated by Prony method. The Prony method is utilized to estimate power system frequency with three consecutive samples rapidly and also Daubechies wavelet family uses the estimated frequency...
This paper presents a new technique for inrush current detection of power transformers. The method is based on wavelet analysis of power system frequency which is estimated by Prony method. The Prony method is utilized to estimate power system frequency with three consecutive samples rapidly. After that, Daubechies wavelet family uses the estimated frequency to investigate the unbalanced conditions...
In this paper, a new technique is presented to discriminate between magnetizing inrush currents and internal fault currents in power transformers. The proposed technique uses two moving windows which both of them estimate magnitude of differential current of power transformer by different methods. The first moving window method is based on full-cycle Fourier algorithm (long window) and the second...
Smart Grid promises the highest efficiency in the history of electrical energy and one of its key components is Demand Response (DR). Incentive based programs however would have a different path in smart grid and their usage would be different in this new environment. In this paper, incentive based DR programs are briefly introduced, smart grid is presented and the influence of smart grid on incentive...
This paper presents a new parameter optimization technique in order to parameter optimization of Linear Optimal Control (LOC) and Power System Stabilizer (PSS) in multi-machine power system. The optimized LOC consists of the advantages of conventional stabilizers. Also, the proposed LOC demonstrates excellent performance with fast response in multi-machine power systems. These features are developed...
Fault occurrence and abnormal system condition are inevitable in power systems. To reduce the results of the mentioned conditions such damaged equipment or in the worst case, power system instability, it is required to do necessary tasks. One of the most important protection methods for this goal is distance protection. Due to mal-operation of distance relay, power system might be damaged. This paper...
This paper presents a new adaptive methodology for 2nd harmonic estimation of transformer differential protection in order to reduce the blocking time of transformer in inrush condition. The proposed algorithm provides a useful tool for signal estimation in non-sinusoidal power system such as faulty conditions or switching time. This method employs a variable window length algorithm for signal estimation,...
This paper presents a novel technique for three phase transformer protection, which the method effectively identify magnetizing inrush currents from internal fault currents. This technique employs symmetrical components. When transformer is switched, inrush current happens. This current have some features, which it is enough for identify itself. In this paper, by extract these features, a new criterion...
In this paper, the effects of Power System Stabilizer (PSS) along with an uncompensated or series compensated transmission line on turbine-generator shaft torsional oscillations are investigated. Time domain simulations and eigenvalue analysis are carried out in MATLAB and SIMULINK to study the interaction between PSS and torsional modes. A six-mass shaft is employed to accurately study the torsional...
This paper presents a new methodology for discrimination between inrush currents and internal faults for a three-phase power transformer. This algorithm is based on instantaneous inductance. First, this method calculates differential inductance of transformer phases from primary side view of transformer by using voltage and current signals. Then, the algorithm compares differential inductance with...
Metal-oxide surge arresters have dynamic characteristics which are significant for overvoltage coordination studies involving the fast front surges. This paper describes an operating analysis of the metal oxide surge arrester same IEEE model, Pinceti model, Popov model and a proposed model which is adequate for very fast rate of the rise of surge currents. The paper presents the application of surge...
The Medium-voltage (MV) circuit breakers can fail to interrupt three-phase fault currents when power systems have transient recovery voltage (TRV) characteristics which exceed the rating of the circuit breaker. Surge arresters protect equipment of transmission and distribution systems. Arresters installed today are all metal-oxide (MO) arresters without gaps. This paper presents the application of...
Permanent magnet synchronous motors are being manufactured and used increasingly in low to medium power range applications due to their inherent advantages. In transient state of the IPM motor reach maximum torque per ampere is necessary and in steady state optimal efficiency for IPM is desire. In this paper an optimal controller for IPM has been designed to achieve maximum torque per ampere in transient...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.