Методи та засоби оцінки впливу коронного розряду на якість електропостачання

Abstract

Дисертація на здобуття наукового ступеня доктора технічних наук за спеціальністю 05.09.03 – електротехнічні комплекси та системи. – Національний технічний університет «Харківський політехнічний інститут», Харків, 2021. У роботі міститься вирішення актуальної науково-технічної проблеми створення та вдосконалення методів і засобів контролю параметрів якості систем електропостачання, що дозволить підвищити достовірність контролю і діагностики стану систем електропостачання при обмеженнях на обсяг вимірювальної інформації. Ця проблема полягає в урахуванні впливу на якісні показники системи електропостачання такого погіршуючого фактора як коронний розряд. До цього часу коронний розряд враховувався як паразитний споживач потужності. В даній роботі звернуто увагу на зв'язок коронного розряду і погіршення якісних показників електропостачання: коронний розряд може спричиняти перешкоди для спрацювання релейного захисту; коронний розряд може стати джерелом умов для виникнення дугового розряду на ізоляторах; коронний розряд є індикатором проблеми ізоляційних частин електроенергетичної системи. В роботі запропоновано визначати наявність коронного розряду і його координати для можливості проведення заходів по його усуненню. Наявність коронного розряду і його координати запропоновано визначати по його акустичному випроміненню. Запропонований метод було перевірено в лабораторних умовах. За результатами лабораторних досліджень було з’ясовано акустичні спектри притаманні саме коронному розряду. Було розроблено математичну модель, що дозволяє визначити наявність акустичного спектру коронного розряду в шумах електричного обладнання. Запропонована технологія акустичного визначення коронного розряда та метод визначення коронного розряда за акустичним спектром дозволяють створювати прилади діагностики. Запропонований метод акустичної діагностики дозволяє використовувати розроблену апаратну акустично діагностуючу систему, яка дозволяє проводити експрес-діагностику при встановленні навіть на платформах, що пересуваються і мають значну швидкість руху. Результати експериментальних досліджень розробленої системи показали її відповідність технічним вимогам та можливість отримання діагностичної інформації при гальванічно незалежному діагностуванні.The dissertation on competition of a scientific degree of the doctor of technical sciences on a specialty 05.09.03 - electrotechnical complexes and systems. - National Technical University "Kharkiv Polytechnic Institute", Kharkiv, 2021. The dissertation is devoted to the decision of an actual scientific and technical problem of creation and improvement of methods and means of control of parameters of quality of power supply systems that will allow to increase reliability of control and diagnostics of a condition of power supply systems at restrictions on volume of measuring information. This problem is to take into account the impact on the quality of the power supply system of such a deteriorating factor as corona discharge. Qualitative parameters of power supply and quality of electric energy as an element of power supply, became a subject of researches of known scientists, among which, it is necessary to allocate Shidlovsky AK, Zharkin AF, Sokol EI, Zhezhelenko AD, Mushroom O. G., Zhelezko YS, Stogniy BS, Novsky VO, and others. From the point of view of qualitative indicators of power supply the corona discharge is an influential phenomenon as it exists at normal operating modes of system and influences operation of relay protection, can become a source of conditions for emergence of an arc discharge and is one of factors of change of uninterruptedness. impact on network equipment. Thus, according to the Electric Power Research Institute (EPRI) in the United States, the number of failures of polymer insulators on 115 and 138 kV transmission lines has increased. EPRI studies have shown that these failures are due to the constant impact on the insulation of corona discharges [39]. The study of the corona category was engaged in such scientists as: Alexandrov OP, Scanavi GI, Kaptsov NA, Popkov VI, Levitov VI, and others. Based on the characteristics of the corona discharge, it was mostly considered as a parasitic power consumer [66 – 88]. In this paper, attention is paid to the relationship between corona discharge and the deterioration of quality indicators of power supply. The paper proposes to determine the presence of the corona discharge and its coordinates for the possibility of measures to eliminate it. Remote means to determine the presence of corona discharge are relevant and such technologies are evolving. Already known and used in practice methods for determining the presence of corona discharge by ultraviolet radiation [94, 95], by infrared radiation [96, 97], by the existing electromagnetic background [43 – 47, 49, 60, 61, 62, 99], by the presence of chemical compounds [98, 100 – 106]. Remote control methods of insulators have shortcomings that did not allow to displace the visual inspection of electrical equipment, but only supplemented it. At the same time superficial inspections do not always allow to reveal defects as in most cases corona discharges are not visible. Thus, there is an urgent scientific problem associated with the lack of effectiveness of existing methods of determining the presence of corona discharge. The analysis revealed the need to develop and study new methods for determining the presence of a corona discharge and its coordinates. Such methods should be remote, galvanically discharged with minimal exposure to external factors, such as weather conditions, hours of day and others. In this paper, the presence of a corona discharge and its coordinates are proposed to be determined by its acoustic radiation. The solution of the specified problem on the basis of methods of the spectral analysis of the acoustic noises accompanying a corona discharge is offered. The following main scientific results were obtained: - for the first time a method of searching for corona discharge coordinates by acoustic radiation was proposed, which allowed to develop principles for means of automatic determination of corona discharge coordinates; - for the first time a method of determining the presence of a corona discharge by the spectrum of acoustic radiation by a corona discharge is proposed, which allows to determine the presence of a corona discharge by non-contact method; - further developed the theory of the origin of harmonic components in electric current, which, in contrast to the known, allowed to determine the corona discharge - as one of the sources of harmonic components in the normal state of the power system; - the corona discharge model was further developed, namely the dependences of the corona discharge spectrum of the acoustic radiation were revealed, which allows to obtain mathematically substantiated acoustic-energy dependences. Approaches and recommendations for construction of models and plans of measured complexes and carrying out on their basis of hardware monitoring and diagnostics of a condition of power supply system, in the form of a software package, and also in the form of the developed technical devices or their components that allow to create acoustic devices are of practical value. diagnostics of power supply system. The practical problem of automating the procedure of determining the presence and coordinates of the corona discharge at any time of day in any weather conditions, which allows to identify the corona discharge and significantly reduces the cost of finding one of the factors changing the quality of electricity. Based on the proposed approaches and methods, information technology for obtaining new diagnostic information using standard diagnostic methods and tools has been developed. The information-measuring technology for determining the presence and location of the corona discharge on high and ultra-high voltage electrical equipment has been developed, despite the modes of operation of the power supply system. A hardware information system has been developed, which allows to carry out rapid diagnostics of the presence of a corona discharge under different weather conditions and at different hours of the day. The results of experimental studies of the developed system showed its compliance with technical requirements and the possibility of obtaining diagnostic information for galvanically independent diagnosis. The design elements and the principle of operation of the developed system for rapid diagnostics are protected by Ukrainian patents for utility models (US Pat. No. 15299, US Pat. No. 24461). The results of the work are implemented in PJSC "Ukrhydroproekt" (Kharkov), in the survey of elements of the power supply system, in LLC "Kharkov specialized installation and maintenance company", in the analysis of the presence of corona discharge in the power supply system, in the educational process of automation and cybersecurity Technical University "Kharkiv Polytechnic Institute" in teaching the course "Technology, problems and prospects for the development of the industry."