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Electromagnetic transients are considered in the implementation of three-phase automatic reclose on the transmission line of extra high voltage 750 kV. The influence of automatic shunting of phases and pre-insertion active resistance for limiting the characteristics of the aperiodic component of the current, which obstructs the transition of full c...
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Context 1
... component. All circuit breakers are equipped controlled switching device Switch Sync F236. The sinusoid with possible moments of commutation is depicted on Fig. 4. To assess the impact of the switching moment on the characteristics of the aperiodic component, a simulation model is developed. The description of which is given in the next ...
Context 2
... component. All circuit breakers are equipped controlled switching device Switch Sync F236. The sinusoid with possible moments of commutation is depicted on Fig. 4. To assess the impact of the switching moment on the characteristics of the aperiodic component, a simulation model is developed. The description of which is given in the next ...
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Citations
... The use of these switchers for power capacitor banks, evaluation of switching over voltages and inrush currents, study of the features of the operation circuit breakers with PIRs at switching-on capacitor banks are studied in the presented research. Note here that effectiveness of use the circuit breakers with PIRs have been actively studied in last years, thus some important results concerned to switching-on (energization) of power capacitor banks are presented in [5][6][7][8][9], to energization of aerial power transmission lines. In [10] were considered some peculiarities of switching-off (de-energization) highvoltage power capacitor banks by CapSwitchers. ...
The article presents results of numerical research of switching (energization and de-energization) power capacitor banks equipped by special switchers which include the sets of pre-insertion resistors with different resistances, in the terms of possible magnitudes of switching transitional voltages (over voltages) and inrush currents, and also the features of the circuit breakers operations with pre-insertion resistors at energization high-voltage (namely 110 kV in the presented article) power capacitor banks. Due to numerous simulations, there were estimated possible ratios of switching overvoltage at switching capacitor banks by SF 6 circuit breakers with pre-insertion resistors for all the range of resistances they are equipped, explained the nature of inrush currents spikes at presence of capacitive load (capacitances of connected cable and aerial power transmission lines) on busbar the capacitor banks are connected to. There were stated that, the use of circuit breakers with pre-insertion resistors for switching capacitor banks provide effective mitigation of switching overvoltage (at appropriated pre-insertion times) whereas the ratios of inrush currents at switching-on power capacitor banks by circuit breakers with pre-insertion resistors can reach high values (more than 4.5 amplitude of rated phase current). Right option of resistance and pre-insertion duration can help to reduce the inrush current. Magnitudes of currents at arc repeated restrikes in the capacitor banks switching-off mode can prevail their energization inrush current.
... The use of these switchers for power capacitor banks, evaluation of switching over voltages and inrush currents, study of the features of the operation circuit breakers with PIRs at switching-on capacitor banks are studied in the presented research. Note here that effectiveness of use the circuit breakers with PIRs have been actively studied in last years, thus some important results concerned to switching-on (energization) of power capacitor banks are presented in [5][6][7][8][9], to energization of aerial power transmission lines. In [10] were considered some peculiarities of switching-off (de-energization) highvoltage power capacitor banks by CapSwitchers. ...
The article presents results of numerical research of switching (energization and de-energization) power capacitor banks equipped by special switchers which include the sets of pre-insertion resistors with different resistances, in the terms of possible magnitudes of switching transitional voltages (over voltages) and inrush currents, and also the features of the circuit breakers operations with pre-insertion resistors at energization high-voltage (namely 110 kV in the presented article) power capacitor banks. Due to numerous simulations, there were estimated possible ratios of switching overvoltage at switching capacitor banks by SF6 circuit breakers with pre-insertion resistors for all the range of resistances they are equipped, explained the nature of inrush currents spikes at presence of capacitive load (capacitances of connected cable and aerial power transmission lines) on busbar the capacitor banks are connected to. There were stated that, the use of circuit breakers with pre-insertion resistors for switching capacitor banks provide effective mitigation of switching overvoltage (at appropriated pre-insertion times) whereas the ratios of inrush currents at switching-on power capacitor banks by circuit breakers with pre-insertion resistors can reach high values (more than 4.5 amplitude of rated phase current). Right option of resistance and pre-insertion duration can help to reduce the inrush current. Magnitudes of currents at arc repeated restrikes in the capacitor banks switching-off mode can prevail their energization inrush current.
... When assessing secondary arc current and resonance overvoltages, such lines are usually assumed to be ideally transposed, that is, having symmetry of phase and interface parameters. However, as studies have shown [5][6][7][8][9], such modeling of the line gives results that are far from the true results obtained when taking into account the real transposition, when at a separate step of the transposition the line is characterized by asymmetry of parameters [5][6][7][8][9][10][11][12][13]. Figure 2 shows a simplified diagram of the complete scheme of wire transposition. Figure 3 shows a diagram of the incomplete transposition cycle. ...
During the operation of EHV lines, the overwhelming proportions of single-phase short circuits can be eliminated in the cycle of a short-term no-current pause, followed by the restoration of the normal circuit. Thus, SPAR refers to the most important measure that increases the reliability of EHV power transmission. The success of elimination of arc short circuits in the SPAR cycle on the one hand, are determined by the characteristics of the secondary arc arising in long air gaps, and on the other hand-the effectiveness of used on lines of methods for reducing secondary arc currents and recovering stresses in the place of arc burning after its extinction. Implementation of SPAR is difficult the presence of recharge of the short circuit from the side of the non-disconnected phases. The paper shows how by proper adjustment of the operating parameters that determine the conditions for extinguishing the secondary arc we get an additional reduction in losses in the transmission line due to more accurate compensation of charging power. Streszczenie. Podczas eksploatacji linii najwyższych napięć, przeważająca część zwarć jednofazowych może być wyeliminowana w cyklu krótkotrwałej przerwy bezprądowej, po której następuje przywrócenie normalnej pracy. JSPZ jest więc najważniejszym środkiem zwiększającym niezawodność przesyłu energii elektrycznej w sieci najwyższych napięć. O powodzeniu likwidacji zwarć łukowych w cyklu JSPZ z jednej strony decydują charakterystyki łuku wtórnego powstającego w długich przerwach powietrznych, a z drugiej strony skuteczność stosowanych na liniach metod ograniczania prądów łuku wtórnego i odtwarzania napięć w miejscu wystąpienia łuku po jego zgaśnięciu. Realizację JSPZ utrudnia obecność wyładowań zwarciowych od strony faz nie rozłączonych. W artykule pokazano jak poprzez odpowiednie dobranie parametrów pracy określających warunki gaszenia łuku wtórnego uzyskujemy dodatkowe zmniejszenie strat w linii przesyłowej dzięki dokładniejszej kompensacji mocy obciążającej. (Ocena wpływu asymetrii międzyfazowej linii przesyłowej na zdolność przesyłu mocy przy braku jednej fazy).
... During the operation of electrical systems, there is always a As a result of the research carried out, the theory of the ac corona was created, the energy characteristics of the corona were obtained, formulas were proposed for calculating the average, average annual, maximum power losses per corona, methods and equipment were developed for measuring corona losses. The result of the generalization of the experimental material was the creation of methods: calculating corona losses for ultra-high voltage transmission lines [1-10], estimating annual energy losses for corona [11][12][13][14][15], and calculating the probability distribution functions of specific corona losses [11]. However, almost all existing methods for calculating ...
... The expressions for determining the active power loss in the transmission line contain the components of idling and short circuit losses. The latter are respectively directly and inversely proportional to the square of the voltage on the bus terminals, which makes it possible to choose the optimal value of the voltage level that provides a minimum sum of these components of losses [15]. ...
During the operation of electrical systems, there is always a As a result of the research carried out, the theory of the ac corona was created, the energy characteristics of the corona were obtained, formulas were proposed for calculating the average, average annual, maximum power losses per corona, methods and equipment were developed for measuring corona losses. The result of the generalization of the experimental material was the creation of methods: calculating corona losses for ultra-high voltage transmission lines, estimating annual energy losses for corona, and calculating the probability distribution functions of specific corona losses. However, almost all existing methods for calculating active power losses per corona are based on a number of assumptions, averaging and simplifications that introduce errors in planning the modes of electric power systems and are practically ineffective in operational calculations in real time. The main essence of all assumptions is reduced to a deterministic representation of factors affecting the corona (design, climatic, meteorological, regime), as well as the invariability of the passive parameters of ultra-high voltage power lines (longitudinal resistance and transverse conductivity).
In the process of substantiating the development of a bulk electrical network (BEN) of electric power systems (EPS), a set of the most economical options for its development is formed, their technical and economic comparison and the choice of the best solution for subsequent detailed design, construction and commissioning of network facilities. Taking into account the territorial and temporal aspect for managing the development of EPS, two main tasks are distinguished, which are solved sequentially. The methodological approach to solving the problem of optimizing the development of the main electrical network of EPS is proposed. The main idea of which is the joint use of linear streaming model of network development and structural model of EPS with the aim of forming set of the most rational options development of the main electrical network. Satisfying the restrictions on the limiting conditions static stability transmitted power in EPS sections, allows you to more fully take into account while optimizing the development of the electrical network, the conditions for its future functioning.
В монографії викладені теоретичні та практичні питання підвищення експлуатацій-ної надійності та ефективності роботи електричних мереж та електроустаковання енерге-тичної системи. Проаналізовано сучасний стан електроенергетичного устаткування ОЕС України. Наведено принципи побудови забезпечення ефективної, надійної та безпечної роботи електричних мереж та електроенергетичного устаткування, а також забезпечення ефективної, надійної та безпечної роботи електричних мереж та електроенергетичного устаткування. Розроблено засоби контролю та діагностування основного та допоміжного електрообладнання електроенергетичних мереж.
Призначена для наукових та інженерно-технічних співробітників, які займаються проектуванням, виготовленням та експлуатацією контрольно-діагностичного обладнання потужних турбогенераторів.
В монографії викладені теоретичні та практичні питання підвищення експлуатацій-ної надійності та ефективності роботи електричних мереж та електроустаковання енерге-тичної системи. Проаналізовано сучасний стан електроенергетичного устаткування ОЕС України. Наведено принципи побудови забезпечення ефективної, надійної та безпечної роботи електричних мереж та електроенергетичного устаткування, а також забезпечення ефективної, надійної та безпечної роботи електричних мереж та електроенергетичного устаткування. Розроблено засоби контролю та діагностування основного та допоміжного електрообладнання електроенергетичних мереж. Книга призначена для наукових та інженерно-технічних співробітників, які займаються проектуванням, виготовленням та експлуатацією контрольно-діагностичного обладнання потужних турбогенераторів.
One of the main elements of the power system is the extra high voltage transmission lines, which are system-forming for the bulk electric networks. The normal operation of the integrated power system depends on the reliability and efficiency of operation transmission line. To ensure efficient operation of the extra high voltage transmission line, it is necessary to optimize the voltage mode and reactive power. Optimization of the transmission line mode operation by minimizing the losses of active power in it, should be based on solving problems of optimization of voltage and reactive power. The control of the operating mode of the transmission line is the correct choice of the composition of the charging power compensation devices in order to regulate the voltage levels and power factors on the bus terminals. Optimization of the transmission line modes operation in this problem statement is performed, focusing on some of the most significant mode parameters. It should also be noted that previous studies have not addressed issues related to the corona discharge of wires and its impact on voltage distribution and the feasibility of depth regulation in lines of this voltage class. One of the measures to reduce electricity losses is to optimize the operating modes of transmission lines in terms of voltage and reactive power. In this formulation of the problem of transmission lines is considered in isolation for the three most common modes: minimum, maximum and operational operating mode of power transmission. The optimal voltage value at the beginning or end of the transmission line, as a rule, usually cannot be achieved due to the inability to increase the operating voltage to the maximum allowable value under the condition of equipment insulation and insufficient power and regulation of the installed compensating devices. By using modern devices for controlled charging compensation of the power line, you can achieve deeper regulation of reactive power and voltage, and, accordingly, minimize the loss of active power. A complex of interrelated mathematical models has been created to determine the economic effect of optimizing the mode of an electric network with extra high voltage transmission lines in terms of voltage and reactive power, taking into account the probabilistic nature of corona losses. Techniques, algorithms and methods have been developed for the operational optimization of the modes of individual power transmission lines, taking into account corona losses. Expressions for the optimal voltage of power lines and voltage control laws are obtained. A methodology and an algorithm for operational optimization of the mode of an electrical network with power lines in terms of voltage and reactive power have been developed. The verification of the adequacy and effectiveness of the proposed methods and algorithms was carried out by means of comparative calculations for real extra high voltage overhead lines and circuits of electrical systems with operating extra high voltage overhead lines.
One of the main elements of the power system is the extra high voltage transmission lines, which are system-forming for the bulk electric networks. The normal operation of the integrated power system depends on the reliability and efficiency of operation transmission line. To ensure efficient operation of the extra high voltage transmission line, it is necessary to optimize the voltage mode and reactive power. Optimization of the transmission line mode operation by minimizing the losses of active power in it, should be based on solving problems of optimization of voltage and reactive power. The control of the operating mode of the transmission line is the correct choice of the composition of the charging power compensation devices in order to regulate the voltage levels and power factors on the bus terminals. Optimization of the transmission line modes operation in this problem statement is performed, focusing on some of the most significant mode parameters. It should also be noted that previous studies have not addressed issues related to the corona discharge of wires and its impact on voltage distribution and the feasibility of depth regulation in lines of this voltage class. One of the measures to reduce electricity losses is to optimize the operating modes of transmission lines in terms of voltage and reactive power. Keywords-corona discharge power losses, deep voltage regulation, controlled reactive power compensation, minimizing criterion, parametrical and structural optimization methods.
