scholarly journals Synchronous Study of Ferroresonance and Inrush Current Phenomena and their Related Reasons in Ground Power Networks

2010 ◽  
Vol 27 (1) ◽  
pp. 82-87 ◽  
Author(s):  
Amin Akrami ◽  
Mohammad Ghaderi ◽  
Saeed Ghadi
Keyword(s):  
Power Transformers ◽  
Inrush Current ◽  
Power Networks ◽  
Transient Phenomena ◽  
Controlled Switching ◽  
Inrush Currents ◽  
Very High ◽  
Inductive Reactance

Synchronous Study of Ferroresonance and Inrush Current Phenomena and their Related Reasons in Ground Power NetworksEnergizing the power transformers usually results in flowing very high inrush currents. This harmful current can be minimized using controlled switching and considering the value of residual flux. But nowadays, developing the ground power networks results in high increment of ferroresonance phenomenon occurrence due to the line' capacitance reactance and nonlinear inductive reactance of power transformer's core. In this study, these transient phenomena and their cause have studied synchronously.

scholarly journals Pre-energize Analysis on 3 Phase Transformer by Considering Each Phase Flux

2019 ◽  
Vol 3 (2) ◽  
Author(s):  
Hadwim Septiawan
Keyword(s):  
Electric Power System ◽  
Voltage Source ◽  
Inrush Current ◽  
Test Results ◽  
Transient Phenomenon ◽  
Inrush Currents ◽  
Current Value ◽  
Type 3 ◽  
Very High ◽  
Load Conditions

Inrush current is a transient phenomenon that occurs when a transformer is first energized to a voltage source at no-load conditions. It causes a very high inrush current. Inrush currents can adversely affect the electric power system and can cause improper work of a relay protection errors. The purpose of this study is to determine the amount of inrush current and minimize the amount of inrush current by using the pre-fluxing method.In this study, a test was carried out using a 3-kVA core type 3 phase transformer. This test is done by giving DC flux before the transformer is connected to the voltage source, then the three transformer phases are energized simultaneously at a certain voltage angle so that the inrush current may could be minimized. The test results show that the transformer that is given a DC flux always has a relatively small inrush current. In this test the inrush current is reduced to a minimum value at an ignition angle of 90 degrees with an inrush current value of 0.74 A in phase R, 3.41 A in phase S, and 3.80 A in phase T.

scholarly journals Designing A Protective Relay for Differential Protection of Power Transformers Using Clarks Transform and S Transform

2019 ◽  
Author(s):  
Javad Padam
Keyword(s):  
Power Transformer ◽  
Computational Cost ◽  
Power Transformers ◽  
Inrush Current ◽  
Differential Protection ◽  
Two Phase ◽  
Transient Phenomena ◽  
S Transform ◽  
Three Phase ◽  
Clarke Transformation

Given that power transformers are one of the most important components of each network, their protection is an important part that the power transformer errors must be accurately identified and distinguished from each other. Therefore, identification and differentiation of transient phenomena of power transformers, including internal and external errors and magnetic inrush current are essential. In this research, Clarke transform and S transform were used to distinguish between these phenomena that the proposed algorithm is very suitable in terms of three characteristics of accuracy, speed and computational cost. Initially, the simulation of internal, external errors and magnetic inrush current of the transformer was performed for different transformer scenarios. For this purpose, 1060 signal tests were performed under different conditions. Subsequently, the signals of differential current obtained by Clarke transformation and S transformation were analyzed and appropriate criteria were extracted for detecting the current of internal errors from external errors and inrush current. The simulated internal and external errors include three- phase, three-phase to ground, two- phase, two- phase to ground and phase to ground error. Simulations were performed using PSCAD software and implementation of the proposed algorithm in MATLAB environment. The results of this study prevent the unwanted performance of differential protection to prevent undesirable electrifying. It is clear that the description of transient phenomena is the first step towards improving new ideas and criteria for protection with the greater reliability of power transformer which can be controlled better such unusual conditions that are currently used in equipment and relay.

scholarly journals ANALISIS ARUS INRUSH SAAT SWITCHING KAPASITOR BANK PADA BUSBAR 2 (Suatu Studi DI PT.PLN (persero) GARDU INDUK GANDUL)

2020 ◽  
Vol 4 (1) ◽  
pp. 16-22
Author(s):  
Irfan Hidayat ◽  
Nur Hanifah Yuninda ◽  
Imam Arif Raharjo
Keyword(s):  
Electrical Equipment ◽  
Inrush Current ◽  
State University ◽  
Study Program ◽  
Transient Phenomena ◽  
Education Study ◽  
Before And After ◽  
Electrical Engineering Education ◽  
Inrush Currents ◽  
Peak Value

Irfan Hidayat, Analysis of Inrush Flow when Switching Bank Capacitors on Busbar 2. Thesis. Jakarta, Electrical Engineering Education Study Program, Faculty of Engineering, Jakarta State University 2018. Supervisor: Nur Hanifah Yuninda, ST., MT., And Imam Arif Raharjo, S.Pd., MT. This study aims to analyze the inrush current when switching bank capacitors. The inrush current can be defined as the magnitude of the current surge that first appears in the circuit, when the circuit is connected to the load. As with transient phenomena, inrush currents in electrical circuits are considered undesirable. In every electrical equipment there must be an inrush current. The inrush current is dangerous for the system when the peak value of the inrush current is very large. To reduce the value of inrush current using a series reactor. The research method used in this study is the experimental method using a research design with pre-experimental design used is one-group pretest-posttest design. In collecting data, the circuit inductance data is collected and on the bank capacitors. To analyze how much the inrush current and frequency before and after the addition of a series reactor. The results showed inrush current when switching capacitor banks before the addition of series reactors exceeded the IEEE Std C37.012-2005 standard where the inrush current is allowed 100 times the rms current. The value of the inrush current and frequency at each step before the addition of the series reactor is: step 1 = 16.29 kA, 4.16 kHz; Step 2 = 289.7 kA, 147.32 kHz; Step 3 = 349.22 kA, 133.2 kHz; Step 4 = 372.47 kA, 126.28 kHz; Step 5 = 386.03 kA, 122.7 kHz; Step 6 = 410.146 kA, 125.15 kHz. The value of the inrush current and frequency at each step after the addition of the series reactor is: step 1 = 1.1 kA, 0.2 kHz; Step 2 = 26.56 kA, 13.5 kHz; Step 3 = 30.68 kA, 11.7 kHz; Step 4 = 36.35 kA, 12.3 kHz; Step 5 = 41.08 kA, 13.05 kHz; Step 6 = 45.27 kA, 13.8 kHz. So that the inrush current is in accordance with the IEEE Std C37.012-2005 standard. ABSTRAK Irfan Hidayat, Analisis Arus Inrush saat Switching Kapasitor Bank pada Busbar 2. Skripsi. Jakarta, Program Studi Pendidikan Teknik Elektro Fakultas Teknik Universitas Negeri Jakarta 2018. Dosen Pembimbing: Nur Hanifah Yuninda, ST., MT., dan Imam Arif Raharjo, S.Pd., MT. Penelitian ini bertujuan untuk menganalisis arus inrush pada saat switching kapasitor bank. Arus inrush dapat didefinisikan sebagai besarnya lonjakan arus pertama kali muncul pada rangkaian, saat rangkaian terhubung dengan beban. Sama halnya dengan fenomena transien, arus inrush dalam rangkaian listrik dianggap sebagai hal yang tidak diinginkan. Pada setiap peralatan listrik pasti terjadi arus inrush. Arus inrush berbahaya bagi sistem ketika nilai puncak arus inrush terjadi sangat besar. Untuk mereduksi besar nilai arus inrush menggunakan reaktor seri. Metode penelitian yang digunakan pada penelitian ini adalah metode eksperimen menggunakan rancangan penelitian dengan desain pre-experimental yang digunakan adalah one-group pretest-posttest design. Pada pengumpulan data, dilakukan pengambilan data  induktansi rangkaian dan pada kapasitor bank. Untuk menganalisis seberapa besar arus inrush  dan frekuensi sebelum dan sesudah penambahan reaktor seri. Hasil penelitian menunjukan arus inrush saat switching kapasitor bank sebelum penambahan reaktor seri melebihi standart IEEE Std C37.012-2005 dimana arus inrush yang di ijinkan 100 kali arus rms. Besar nilai arus inrush dan frekuensi pada setiap step sebelum penambahan reaktor seri sebesar: step 1 = 16,29 kA, 4,16 kHz; Step 2 = 289,7 kA, 147,32 kHz; Step 3 = 349,22 kA, 133,2 kHz; Step 4 = 372,47 kA, 126,28 kHz; Step 5 = 386,03 kA, 122,7 kHz; Step 6 = 410,146 kA, 125,15 kHz. Besar nilai arus inrush dan frekuensi pada setiap step setelah penambahan reaktor seri sebesar: step 1 = 1,1 kA, 0,2 kHz; Step 2 = 26,56 kA, 13,5 kHz; Step 3 = 30,68 kA, 11,7 kHz; Step 4 = 36,35 kA, 12,3 kHz; Step 5 = 41,08 kA, 13,05 kHz; Step 6 = 45,27 kA, 13,8 kHz. Sehingga arus inrush sesuai dengan standart IEEE Std C37.012-2005.

Evaluation of the Power Transformer Magnetizing Inrush Currents

2020 ◽  
Vol 10 (10) ◽  
pp. 20-32
Author(s):  
Aleksey A. KUVSHINOV ◽  
◽  
Vera V. VAKHNINA ◽  
Aleksey N. CHERNENKO ◽  
◽  
...  
Keyword(s):  
Power Transformer ◽  
Geomagnetic Disturbance ◽  
Inrush Current ◽  
Geomagnetic Disturbances ◽  
Disturbance Intensity ◽  
Magnetizing Inrush Current ◽  
Inrush Currents ◽  
Instantaneous Values ◽  
The Mathematical Model ◽  
Analytical Expressions

The mathematical model of a shell-core power transformer’s magnetization branch is substantiated. By using the model, analytical expressions for the magnetizing current instantaneous values under the conditions of geomagnetic disturbances can be obtained. Quantitative assessments of the magnetizing inrush current amplitudes and durations versus the geomagnetic disturbance intensity are obtained. The dynamics of the power transformer magnetic system saturation transient and changes in the magnetization inrush current amplitudes and durations after a sudden occurrence of geomagnetic disturbances are shown. The error of estimating the magnetizing inrush current amplitudes under geomagnetic disturbances is determined based on comparison with experimental data.

scholarly journals New Approaches for the Observation of Transient Phenomena in Critical Marine Environment

2021 ◽  
Vol 9 (6) ◽  
pp. 578
Author(s):  
Roberta Ferretti ◽  
Massimo Caccia ◽  
Massimo Coltorti ◽  
Roberta Ivaldi
Keyword(s):  
Mediterranean Sea ◽  
Marine Environment ◽  
Environmental Conditions ◽  
Marine Environments ◽  
Transient Phenomena ◽  
New Approaches ◽  
Marine Vehicles ◽  
New Methodologies ◽  
Biogeochemical Parameters ◽  
Very High

This paper focuses on the development of new approaches to observe transient phenomena in critical marine environments using autonomous marine vehicles (AMVs) for the acquisition of physical and biogeochemical parameters of water and seabed characterization. The connection with metrological principles, together with the adoption of observing methodologies adjustable according to the specific marine environment being studied, allows researchers to obtain results that are reliable, reproducible, and comparable with those obtained through the classic monitoring methodologies. Tests were executed in dramatically dynamic, sensitive, and fragile areas, where the study and application of new methodologies is required to observe phenomena strongly localized in space and requiring very high resolutions, in time. Moreover, the harsh environmental conditions may present risks not only for the quality and quantity of the acquired data but also for the instrumentation and the operators. This is the case, for instance, in polar marine environments in proximity of tidal glaciers and in the Mediterranean Sea in areas characterized by seabed degassing activities, where AMV-supported monitoring procedures can allow for the safe observation of not repeatable and not completely predictable events.

Sign in / Sign up

Export Citation Format

Share Document