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Investigation on ferroresonance due to power transformer energization in high voltage 400 kV transmission grid

Polewaczyk Mateusz, Robak Sylwester, Szewczyk Marcin

Archives of Electrical Engineering

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2019

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Vol. 68, nr 4

771--786

EN

This paper presents a study on ferroresonance occurring in a high voltage 400 kV transmission grid due to energization of power transformer under no-load conditions. The system scenarios analyzed in the present paper are considered as critical for development and modernization plans as currently announced by the national grid operator in Poland. The PSCAD simulation model was developed and applied for several study cases of a system with double-circuit arrangement of a transmission line. It is shown that the ferroresonant oscillations can be initiated by two-phase switching operation of a line circuit breaker. The impact of the double-circuit length on the ferroresonance mode and severity is demonstrated with the use of the Poincaré map analysis and Short Time Fourier Transform. It is demonstrated that the length of the transmission line that is mutually coupled in the double-circuit arrangement has a significant impact on the ferroresonance occurrence and on its mode. As the ferroresonance can pose severe threat to the power system components due to the severe overvoltage and overcurrent oscillations, the analysis presented in this paper demonstrates the necessity of the ferroresonance analyses for any re-designed transmission system.

2

Comparison of transformer modeling on riser pole arresters behavior during switching transients

Abbaszadeh A., Abedi M., Doustmohammadi A.

Archives of Electrical Engineering

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2017

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Vol. 66, nr 4

717--730

EN

Arresters are widely used in power systems to protect other equipment against overvoltages. However, in some conditions, they can’t operate successfully. One of the disturbances leading to the failure of the riser pole arresters is the ferroresonance overvoltages. In this paper, at first the influence of different transformer simulation models of ATP software on the occurrence of ferroresonance is studied and then the effect of ferroresonance on the riser pole arrester has been scrutinized through the thermal and electrical performance of the arrester in an underground distribution system. The results show that the arrester temperature rises due to energy dissipation in a ferroresonance circumstance, which indeed may result into the explosion of the arrester. Also, applying different models of the transformer in the ATP software and comparing the results, it is shown that the available models do not show the same effect on the arrester.

3

Novel power quality data analysis and reporting framework for wide-area system of registration and processing of power quality data

Rezmer J., Leonowicz Z.

Transactions on Environment and Electrical Engineering

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2015

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Vol. 1, No. 1

1--3

EN

This paper presents a novel method for data analysis and visualization, including real-time visual monitoring and proposal for combined area PQ indices on the example of the developed and operational comprehensive system of registration, archiving and data processing for the wide-area monitoring of power quality in a separated part of real power grid with distributed renewable generation. Real case studies related to power quality disturbances are presented.

4

Transformer Modelling for the Frequency and Transient Analyses, with Non-Uniform Inductance Emulating the Inter-Turn Magnetic Coupling

Saied M. M.

Electrical Power Quality and Utilisation. Journal

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2014

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Vol. 17, iss. 1

1--11

EN

A new procedure for analyzing power transformer windings with location-dependent circuit parameters, such as the series inductance, is presented. This dependence is introduced in order to take the inter-turn mutual inductive coupling into consideration. It can be expressed either by analytical expressions or even in a tabulated form. The paper addresses both the frequency and time domain analyses. They are based on replacing the winding by an adequate number of equivalent cascade connected two-ports. In contrast to the usual practice of applying the simple medium line representation, each of these two-ports is treated as a long transmission line. Their A, B, C, D generalized circuit constants will be therefore generally location-and frequency-dependent. The analyses will be conducted in the complex s-domain. The corresponding time-domain results can then be obtained by applying a numerical inverse Laplace transform. Expressions for the winding’s input impedance with different treatments of the transformer’s neutral point will be derived for any assumed number of the equivalent two-ports. Results pertinent to the frequency characteristics including the resonance frequencies are presented. The paper also describes the winding’s transient response to the application of two standard voltage stimuli. The suggested approach is validated by its application to a case study for which an analytical closed-form solution is available. The analysis of windings exhibiting nonuniformities in more than one equivalent.

5

Sterowanie łączem HVDC poprawiające stabilność systemu elektroenergetycznego

Nogal Ł.

Przegląd Elektrotechniczny

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2012

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R. 88, nr 3a

121-124

PL

Artykuł przedstawia metodę sterowania łączem HVDC, łączącym podsystemy, opartą na zmiennych stanu. Sterowanie stabilizuje system elektroenergetyczny, uaktywnia się w stanach nieustalonych i stanowi dodatkowe sterowanie w stosunku do regulacji przepływów mocy. Proponowany algorytm stabilizujący uzyskany został z wykorzystaniem bezpośredniej (drugiej) metody Lapunowa. Celem sterowania jest maksymalizacja tłumienia kołysań mocy czynnej w liniach wymiany.

EN

This paper addresses the state-variable stabilizing control of the power system using HVDC connecting control areas in an interconnected power system. This stabilizing control is activated in the transient state and is supplementary with respect to the main steady-state control designed for power flow regulation. Proposed stabilizing control laws, have been derived using direct Lyapunov method with the aim to maximize damping of power swings.