ВДОСКОНАЛЕНИЙ МЕТОД РОЗРАХУНКУ ПІКОВИХ СТРУМІВ І ВТРАТ НАПРУГИ В МЕРЕЖІ ЕЛЕКТРОПОСТАЧАННЯ ГРУПИ МАШИН КОНТАКТНОЇ ЗВАРКИ
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| Title |
ВДОСКОНАЛЕНИЙ МЕТОД РОЗРАХУНКУ ПІКОВИХ СТРУМІВ І ВТРАТ НАПРУГИ В МЕРЕЖІ ЕЛЕКТРОПОСТАЧАННЯ ГРУПИ МАШИН КОНТАКТНОЇ ЗВАРКИ
Усовершенствованный метод расчета пиковых токов и потерь напряжения в сети электроснабжения группы машин контактной сварки Advanced Method of Calculation of Peak Currents and Voltage Losses in the Power Supply Network of Group of Resistance Welding Machines |
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| Creator |
ПОГРІБНЯК, Н.М.
УДОВІЧЕНКО, К.А. ЄГОРОВА, І.В. ПОГРЕБНЯК, Н.Н. УДОВИЧЕНКО, К.А. ЕГОРОВА, И.В. POGRIBNYAK, N. UDOVICHENKO, K. EGOROVA, I. |
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| Subject |
peak current
voltage loss electric network contact welding machine distribution function maximal calculated value пиковый ток потеря напряжения электрическая сеть машина контактной сварки функция распределения максимальное расчетное значение піковий струм втрата напруги електрична мережа машина контактної зварки функція розподілу максимальне розрахункове значення |
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| Description |
When the power supply network of resistance welding machines is designed, it is required to define the calculated values of peak currents and voltage losses, and one of the determining factors, when the network is chosen, is ensuring of the necessary level of voltage in it, because undervoltage leads to defects of connection, and at the same time excessive demands on the level of voltage increase the cost of the network. If the number of machines in the group does not exceed 16-17, the exact solution can be found using distribution functions of peak currents and voltage losses, which was calculated by selection of all possible variants of simultaneous operation of welding machines. Development of approximate method for reducing the amount of calculations is necessary for a large number of machines in the group. The exact calculation for small groups of machines shows that known approximate methods give higher values of peak currents and voltage losses. The idea of the new method of calculation is that peak currents of all three phases and drops of all linear voltages are calculated in complex form for every welder machine when only this machine is connected to the network. Next, the distribution functions of the peak currents of each phase and drops of three line voltages are determined separately by a single algorithm, which is considered, for example, for peak current of phase A. Machines are divided into 7 groups. The first group gets machines which are not connected to this phase, remaining machines are divided first in two groups by the phase of the current, and then each of these groups is divided into groups by the size of the current module. As a result, each of the groups has machines whose influence on the magnitude of the current of phase A is different as little as possible, which allows us to replace the current from each of the welding machines on the average of the current group. As a result of such separation in the calculation of the distribution function all possible combinations of the simultaneous operation of different numbers of machines from groups are considered. This way significantly reduces number of calculations comparing with an exact calculation. The probability and the total peak current are determined for each combination (the probability is calculated by average coefficient of inclusion). The results of calculation allow us to construct the distribution function of peak current of phase A with the boundary probability ex and to determine its maximum design value. In order to reduce the amount of calculation, the calculation of the distribution function is performed (with a margin Δex ) until it reaches a value of 1 - ex + Δex . The comparison of known and developed methods showed that the latter is the most accurate. Its use will provide a reasonable decrease in the capital cost of electric power supply network of welding machines, and at the same time the required level of voltage will be guaranteed. Запропонований наближений метод визначення пікових струмів і втрат напруги в електричній мережі живлення групи машин контактної зварки (МКЗ). На прикладах показана висока ефективність метода, якій може бути використаний при проектуванні мереж електропостачання МКЗ з метою обґрунтованого зменшення капітальних витрат на мережу при гарантованому забезпеченні необхідного рівня напруги в ній. |
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| Date |
2013-10-14T07:32:29Z
2013-10-14T07:32:29Z 2013 |
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| Type |
Article
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| Identifier |
Наукові праці Донецького національного технічного університету. Серія "Електротехніка і енергетика". № 1 (14), 2013 р., 358 с.
УДК 621.791.76 http://ea.donntu.edu.ua/handle/123456789/23200 |
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| Publisher |
ДонНТУ
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