RU2015107414A

RU2015107414A - Methods for measuring power losses from unbalanced, non-sinusoidal and reactive currents in three-phase transformers and four-wire power lines

Info

Publication number: RU2015107414A
Application number: RU2015107414A
Authority: RU
Inventors: Фёдор Дмитриевич Косоухов; Антон Олегович Филиппов; Николай Валерьевич Васильев; Наталья Юрьевна Криштопа; Зарина Равильевна Галиева; Алексей Сергеевич Паутов
Priority date: 2015-03-03
Filing date: 2015-03-03
Publication date: 2016-09-27
Also published as: RU2599280C2

Abstract

1. Способ измерения потерь мощности от несимметричных токов в трехфазных трансформаторах и четырехпроводных линиях, предусматривающий применение источника регулируемого трехфазного напряжения, отличающийся тем, что измеряют при несимметричной нагрузке коэффициенты обратной и нулевой последовательности токов в трехфазном трансформаторе (четырехпроводной линии) и по результатам измерения определяют коэффициент потерь мощности от несимметричных токов по формуле:откуда ΔР=КΔР,где R, R- активные сопротивления нулевой и прямой последовательности трансформатора (линии);ΔР- потери мощности от несимметричных токов;ΔP- потери мощности от тока прямой последовательности.2. Способ измерения потерь мощности от несинусоидальных токов в трехфазных трансформаторах и четырехпроводных линиях, предусматривающий применение источника регулируемого трехфазного напряжения, отличающийся тем, что измеряют при нелинейной нагрузке в трехфазном трансформаторе (четырехпроводной линии) действующее значение тока 1-й гармоники I, суммарный коэффициент нечетных и четных гармоник, кроме гармоник, кратных тремсуммарный коэффициент гармоник, кратных треми по результатам измерения определяют коэффициент потерь мощности от несинусоидальных токов по формуле:откуда ΔР=KΔP,где ΔР- потери мощности от несинусоидальных токов;ΔP- потери мощности от токов 1-й гармоники:к=2, 4, 5, 7, 8, 10…40 - порядковые номера нечетных и четных гармоник;j=3, 6, 9…39 - порядковые номера гармоник, кратных трем.3. Способ измерения потерь мощности от реактивных токов в трехфазных трансформаторах и четырехпроводных линиях, предусматривающей применение источника регулируемого трехфазного1. A method of measuring power losses from unbalanced currents in three-phase transformers and four-wire lines, which involves the use of a regulated three-phase voltage source, characterized in that the coefficients of the reverse and zero sequence of currents in a three-phase transformer (four-wire line) are measured at an unbalanced load and the coefficient is determined from the measurement results power losses from unbalanced currents according to the formula: whence ΔР = КΔР, where R, R- active resistances of zero and direct sequence elnosti transformer (lines); ΔR- power loss of asymmetric currents; ΔP- power loss by the direct current posledovatelnosti.2. A method for measuring power losses from non-sinusoidal currents in three-phase transformers and four-wire lines, which involves the use of an adjustable three-phase voltage source, characterized in that, under non-linear load in a three-phase transformer (four-wire line), the current value of the 1st harmonic current I, the total odd and even coefficient harmonics, in addition to harmonics that are multiples of the three-sum harmonic coefficient, multiples of three, from the measurement results determine the coefficient of power loss from n sinusoidal currents according to the formula: whence ΔР = KΔP, where ΔР is the power loss from non-sinusoidal currents; ΔP is the power loss from the 1st harmonic currents: k = 2, 4, 5, 7, 8, 10 ... 40 are the odd numbers and even harmonics; j = 3, 6, 9 ... 39 - serial numbers of harmonics that are multiples of three. 3. A method for measuring power losses from reactive currents in three-phase transformers and four-wire lines, involving the use of an adjustable three-phase source

Claims

1. A method of measuring power losses from unbalanced currents in three-phase transformers and four-wire lines, which involves the use of a regulated three-phase voltage source, characterized in that the coefficients of the reverse and zero sequence of currents in a three-phase transformer (four-wire line) are measured at an unbalanced load and the coefficient is determined from the measurement results power losses from unbalanced currents according to the formula:

whence ΔP _ε = K _ε ΔP ₁ ,

where R ₀ , R ₁ - the resistance of the zero and direct sequence of the transformer (line);

ΔР _ε - power loss from asymmetric currents;

ΔP ₁ - power loss from the current direct sequence.

2. A method for measuring power losses from non-sinusoidal currents in three-phase transformers and four-wire lines, which involves the use of a regulated three-phase voltage source, characterized in that, at non-linear load in a three-phase transformer (four-wire line), the current value of the 1st harmonic current I _1g , the total coefficient odd and even harmonics, except for harmonics that are multiples of three

total harmonic factor multiple of three

and the measurement results determine the coefficient of power loss from non-sinusoidal currents according to the formula:

whence ΔР _ω = K _ω ΔP _1g ,

where ΔР _ω - power loss from non-sinusoidal currents;

ΔP _1g - power loss from currents of the 1st harmonic:

k = 2, 4, 5, 7, 8, 10 ... 40 - serial numbers of odd and even harmonics;

j = 3, 6, 9 ... 39 - serial numbers of harmonics that are multiples of three.

3. A method for measuring power losses from reactive currents in three-phase transformers and four-wire lines, which involves the use of a regulated three-phase voltage source, characterized in that they measure the power factor (cosφ), phase current at the symmetric linear load in the three-phase transformer (four-wire line), and according to the results measurements determine the coefficient of power loss from reactive currents according to the formula:

whence ΔP _x = K _φ ΔP _R ,

where ΔP _x - power loss from reactive currents;

- loss of active power.