نتایج جستجو برای: harmonic load

تعداد نتایج: 194125  

Journal: :journal of advances in computer research 2016
s.mohammad bagher sadati jamal moshtagh abdollah rastgou

proper operations of transformer have several issues such as; preventing of unscheduled removal’s, increasing of reliability and continues supply of consumer demand. this result would be obtained that load and harmonic orders of sensitivity transformer at intervals appropriate for next hours and days is predicted to by selecting optimal utilization coefficient, reduction life of transformer is ...

Abstract:Today, one of the important issues of power quality (PQ) in power systems is the current harmonics. Increasing expansion of nonlinear loads at different parts of the electric network makes harmonic distortion flow through the network. This causes the network to have background voltage and current harmonic distortion and even affect on the PQ of linear load performance. Therefore, it is...

The progressive application of non-linear loads in distribution systems (DS) increases current harmonics flow in DS's apparatuses, especially distribution transformers (DTs). Since DTs' operating temperature rises due to the harmonics flow, their loading should be reduced such that the hot spot temperature (HST) is preserved under its permissible value. This means that DTs' available capacity i...

Journal: :the modares journal of electrical engineering 2010
ali yazdian varjani jo chicharo sarat - perera

this paper presents a new control methodology for active power filters that provide an adaptive online harmonic estimation with partial and selective harmonic reduction schemes, which has been implemented within an integrated controller. the proposed approach is to provide partial and selective reduction of those individual harmonics which exceed the recommended levels as set by regulatory bodi...

Journal: :the modares journal of electrical engineering 2010
abdol ali - abdipour mohammad hakkak zahra ghanian

the graphical technique for nonlinear circuits was described that enable us to optimize circuits to obtain maximum output power, maximum efficiency or minimum intermodulation. according to this method a high power amplifier in the ka band was designed. using a nonlinear model of the transistor, optimum slope for load-line was determined so that maximum power at the output was obtainable, then ...

The increase in the number of pulses in multipulse rectifiers leads to a reduction in harmonic current distortion. But this increase in the number of pulses leads to an increase in kVA, cost, and complexity of the multi-pulse rectifiers. As a result, in industrial applications, 12-pulse rectifiers are mainly used due to their lightweight, simple transformers, and low kVA rate, and low cost. The...

In this paper, modal analysis of the fluid-structure interaction has been investigated. Using classical laminated plate theory, a closed form solution for natural frequencies of FSI is extracted. For fluid, homogenous, inviscid and irrotational fluid flow is assumed. Then, a combined governing equation for the plate-fluid system is derived. In order to validate the equations and results, they a...

2018
A. S. Hussin M. H. Jopri

Received Jun 9, 2016 Revised Nov 20, 2016 Accepted Dec 11, 2016 This paper will review on the existing techniques and methodologies of harmonic load diagnostic system. The increasingly amount of harmonic producing load used in power system are the main contribution in quantifying each harmonic disturbance effects of the multiple harmonic producing loads and it became very important. Literature ...

Journal: :journal of operation and automation in power engineering 2007
h. r. imanijajarmi a. mohamed h. shareef

this paper presents an innovative active power filter design method to simultaneously compensate the current harmonics and reactive power of a nonlinear load. the power filter integrates a passive power filter which is a rl low-pass filter placed in series with the load, and an active power filter which comprises an rl in series with an igbt based voltage source converter. the filter is assumed...

A.R Nezamabadi K Rajabi, Sh Hosseini Hashemi

The forced vibration behaviors are examined for nonlocal strain gradient nanobeams with surface effects subjected to a moving harmonic load travelling with a constant velocity in terms of three beam models namely, the Euler-Bernoulli, Timoshenko and modified Timoshenko beam models. The modification for nonlocal strain gradient Timoshenko nanobeams is exerted to the constitutive equations by exc...

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