A model for calculating losses in transformer related to orders and harmonic amplitude under analysis of joule effect, eddy current and hysteresis

Author(s):  
Gabriel Santos ◽  
Bruno M. Laurindo ◽  
Marcio Z. Fortes ◽  
Bruno W. França ◽  
Flavio G.R. Martins

AbstractThe electrical transformer is one of the most used equipment in electrical power systems. The non-linear electrical loads are increasing, mainly in the electrical distribution system, and the electrical power transformer is inserted in this scenario, supplying these loads. Consequently, the increasing non-linear loads affect the electrical transformers and their factors directly, like in the dependency between temperature and harmonic increase. Therefore, to study the influence of harmonics in the transformer’s temperature, one should understand how it will behave with these changes in the electrical power system. For this reason, in this article, numeric simulations and tests were performed to predict the transformer temperature behavior. The proposal is a numeric technique for coupling two equations, thermal and electromagnetic, of an electrical transformer, considering heat sources regarding joule, eddy current, and hysteresis effect. To evaluate the numeric simulation and understanding the electrical transformer behavior in real-life, tests with specific harmonic orders (3rd, 5th, and 7th) and their combinations and a test with less than 10% total harmonic distortion, according to IEEE 519 standard were performed. It is verified that the electrical transformer temperature rises with the increase in harmonic amplitude and its orders. Results show that the industry must be aware of the effects of the increasing non-linear loads when designing the next generation of transformers concerning their durability and lifetime.

Author(s):  
Ashutosh Srivastava ◽  
Amarjeet Singh

Harmonics in the power system is not new issue. This phenomenon has been introduced by technocrat throughout in the history of electrical power system. Maintaining the power quality in a power system is an essential assignment due to increase in wide variety of non-linear loads. The current drawn by such non linear loads are non-sinusoidal and therefore contains harmonics. Therefore, it becomes necessary to compensate these unwanted harmonics for better performance of the system. In this paper, a review of compensations of harmonics in distribution system has been explained.


2011 ◽  
Vol 403-408 ◽  
pp. 5007-5014
Author(s):  
Pratul Arvind ◽  
Rudra Prakash Maheshwari

Electric Power Distribution System is a complex network of electrical power system. Also, large number of lines on a distribution system experiences regular faults which lead to high value of current. Speedy and precise fault location plays a pivotal role in accelerating system restoration which is a need of modern day. Unlike transmission system which involves a simple connection, distribution system has a very complicated structure thereby making it a herculean task to design the network for computational analysis. In this paper, the authors have simulated IEEE 13- node distribution system using PSCAD which is an unbalanced system and current samples are generated at the substation end. Considering the application of signal processing tools to power systems a talk of modern day research, Gabor decomposition of the current samples are also presented which is utilised for locating all ten types of faults. It is kept in mind that Gabor transform has not been applied to current samples of distribution system as per the literature available till date.


2020 ◽  
Vol 124 (1281) ◽  
pp. 1789-1797
Author(s):  
M. Bekhti ◽  
M. Bensaada ◽  
M. Beldjehem

ABSTRACTOne of the most critical aspects of a small satellite is the electrical power system (EPS) since the electrical power is necessary for the satellite to operate correctly during its predefined lifetime. The electrical power system consists mainly of solar cells, batteries, voltage converters and protection circuits. The electrical power system is responsible of providing stable power to the rest of the satellite subsystems.In satellite electrical power systems, overcurrent protection is now becoming an important function handled by the power distribution module (PDM). This paper proposes a method to evaluate the suggested protection. With the proposed procedure we should be able to verify that every possible failure does not travel through the EPS and cause a fatal degradation of the electrical power system. This will allow a complete evaluation of functionality of the protection hardware.This paper discusses the design and implementation of the power distribution module (PDM) for the coming generation of small satellites for the Algerian Space Agency (ASAL). The design must provide a reliable protection for the subsystems from the overcurrent associated with a device failure.


Sensors ◽  
2021 ◽  
Vol 21 (8) ◽  
pp. 2699
Author(s):  
Marceli N. Gonçalves ◽  
Marcelo M. Werneck

Optical Current Transformers (OCTs) and Optical Voltage Transformers (OVTs) are an alternative to the conventional transformers for protection and metering purposes with a much smaller footprint and weight. Their advantages were widely discussed in scientific and technical literature and commercial applications based on the well-known Faraday and Pockels effect. However, the literature is still scarce in studies evaluating the use of optical transformers for power quality purposes, an important issue of power system designed to analyze the various phenomena that cause power quality disturbances. In this paper, we constructed a temperature-independent prototype of an optical voltage transformer based on fiber Bragg grating (FBG) and piezoelectric ceramics (PZT), adequate to be used in field surveys at 13.8 kV distribution lines. The OVT was tested under several disturbances defined in IEEE standards that can occur in the electrical power system, especially short-duration voltage variations such as SAG, SWELL, and INTERRUPTION. The results demonstrated that the proposed OVT presents a dynamic response capable of satisfactorily measuring such disturbances and that it can be used as a power quality monitor for a 13.8 kV distribution system. Test on the proposed system concluded that it was capable to reproduce up to the 41st harmonic without significative distortion and impulsive surges up to 2.5 kHz. As an advantage, when compared with conventional systems to monitor power quality, the prototype can be remote-monitored, and therefore, be installed at strategic locations on distribution lines to be monitored kilometers away, without the need to be electrically powered.


Author(s):  
Diego A. Monroy-Ortiz ◽  
Sergio A. Dorado-Rojas ◽  
Eduardo Mojica-Nava ◽  
Sergio Rivera

Abstract This article presents a comparison between two different methods to perform model reduction of an Electrical Power System (EPS). The first is the well-known Kron Reduction Method (KRM) that is used to remove the interior nodes (also known as internal, passive, or load nodes) of an EPS. This method computes the Schur complement of the primitive admittance matrix of an EPS to obtain a reduced model that preserves the information of the system as seen from to the generation nodes. Since the primitive admittance matrix is equivalent to the Laplacian of a graph that represents the interconnections between the nodes of an EPS, this procedure is also significant from the perspective of graph theory. On the other hand, the second procedure based on Power Transfer Distribution Factors (PTDF) uses approximations of DC power flows to define regions to be reduced within the system. In this study, both techniques were applied to obtain reduced-order models of two test beds: a 14-node IEEE system and the Colombian power system (1116 buses), in order to test scalability. In analyzing the reduction of the test beds, the characteristics of each method were classified and compiled in order to know its advantages depending on the type of application. Finally, it was found that the PTDF technique is more robust in terms of the definition of power transfer in congestion zones, while the KRM method may be more accurate.


Energies ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3956
Author(s):  
Khaled Guerraiche ◽  
Latifa Dekhici ◽  
Eric Chatelet ◽  
Abdelkader Zeblah

The design of energy systems is very important in order to reduce operating costs and guarantee the reliability of a system. This paper proposes a new algorithm to solve the design problem of optimal multi-objective redundancy of series-parallel power systems. The chosen algorithm is based on the hybridization of two metaheuristics, which are the bat algorithm (BA) and the generalized evolutionary walk algorithm (GEWA), also called BAG (bat algorithm with generalized flight). The approach is combined with the Ushakov method, the universal moment generating function (UMGF), to evaluate the reliability of the multi-state series-parallel system. The multi-objective design aims to minimize the design cost, and to maximize the reliability and the performance of the electric power generation system from solar and gas generators by taking into account the reliability indices. Power subsystem devices are labeled according to their reliabilities, costs and performances. Reliability hangs on an operational system, and implies likewise satisfying customer demand, so it depends on the amassed batch curve. Two different design allocation problems, commonly found in power systems planning, are solved to show the performance of the algorithm. The first is a bi-objective formulation that corresponds to the minimization of system investment cost and maximization of system availability. In the second, the multi-objective formulation seeks to maximize system availability, minimize system investment cost, and maximize the capacity of the system.


2002 ◽  
Vol 12 (06) ◽  
pp. 1333-1356 ◽  
Author(s):  
YOSHISUKE UEDA ◽  
HIROYUKI AMANO ◽  
RALPH H. ABRAHAM ◽  
H. BRUCE STEWART

As part of an ongoing project on the stability of massively complex electrical power systems, we discuss the global geometric structure of contacts among the basins of attraction of a six-dimensional dynamical system. This system represents a simple model of an electrical power system involving three machines and an infinite bus. Apart from the possible occurrence of attractors representing pathological states, the contacts between the basins have a practical importance, from the point of view of the operation of a real electrical power system. With the aid of a global map of basins, one could hope to design an intervention strategy to boot the power system back into its normal state. Our method involves taking two-dimensional sections of the six-dimensional state space, and then determining the basins directly by numerical simulation from a dense grid of initial conditions. The relations among all the basins are given for a specific numerical example, that is, choosing particular values for the parameters in our model.


Author(s):  
Luis Ivan Ruiz Flores ◽  
J. Hugo Rodri´guez Marti´nez ◽  
Guillermo D. Taboada ◽  
Javier Pano Jimenez

Nowadays the refining sector in Mexico needs to increase the quantity and quality of produced fuels by installing new process plants for gasoline and ultra low sulphur diesel. These plants require the provision of electricity and steam, among other services to function properly, which can be supplied by the power plants currently installed in each refinery through an expansion of their generation capacity. These power plants need to increase its production of electricity and steam at levels above their installed capacity, which involves the addition of new power generating equipment (gas or steam turbo-generators) as well as the raise of the electrical loads. Currently, the Mexican Petroleum Company (PEMEX) is planning to restructure their electrical and steam systems in order to optimally supply the required services for the production of high quality fuels. In this paper the present status of the original electrical power systems of the refineries is assessed and the electrical integration of new process plants in the typical schemes is analyzed. Also this paper shows the conceptual schemes proposed to restructure the electrical power system for two refineries and the strategic planning focused on implement the modifications required for the integration of new process plants that will demand about 20 MW for each refinery by 2014. The results of the analysis allowed to identify the current conditions of the electrical power systems in the oil refining industry or National Refining Industry (NRI), and thereby to offer technical solutions that could be useful to engineers facing similar projects.


Author(s):  
Pratul Arvind ◽  
Rudra prakash Maheswari

Electric Power Distribution System is a complex network of electrical power system. Also, large number of lines on a distribution system experiences regular faults which lead to high value of current. Speedy and precise fault location plays a pivotal role in accelerating system restoration which is a need of modern day. Unlike transmission system which involves a simple connection, distribution system has a very complicated structure thereby making it a herculean task to design the network for computational analysis. In this paper, the authors have simulated IEEE 13- node distribution system using PSCAD which is an unbalanced system and current samples are generated at the substation end. A Fuzzy c-mean (FCM) and statistical based approach has been used. Samples are transformed as clusters by use of FCM and fed to Expectation- Maximization (EM) algorithm for classifying and locating faults in an unbalanced distribution system. Further, it is to be kept in mind that the combination has not been used for the above purpose as per the literature available till date.


2022 ◽  
pp. 1361-1385
Author(s):  
Amam Hossain Bagdadee ◽  
Li Zhang

The review this article conducts is an extensive analysis of the concept of a smart grid framework with the most sophisticated smart grid innovation and some basic information about smart grid soundness. Smart grids as a new scheme for energy and a future generation framework encourages the expansion of information and progress. The smart grid framework concord will potentially take years. In this article, the focus is on developing smart networks within the framework of electric power systems.


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