SU486287A1 - Method of measuring the capacity of electrical networks with insulated neutral - Google Patents
Method of measuring the capacity of electrical networks with insulated neutralInfo
- Publication number
- SU486287A1 SU486287A1 SU1875101A SU1875101A SU486287A1 SU 486287 A1 SU486287 A1 SU 486287A1 SU 1875101 A SU1875101 A SU 1875101A SU 1875101 A SU1875101 A SU 1875101A SU 486287 A1 SU486287 A1 SU 486287A1
- Authority
- SU
- USSR - Soviet Union
- Prior art keywords
- measuring
- capacity
- electrical networks
- network
- insulated neutral
- Prior art date
Links
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- Measurement Of Resistance Or Impedance (AREA)
Description
1one
Изобретение относитс к способам контрол изол ции электрических сетей.This invention relates to methods for monitoring the isolation of electrical networks.
Известен способ аналогичного назначени , по .которому емкость сети определ етс по величине оперативного тока, протекающего по искусственно созданному каналу нулевой последовательности.There is a method of similar purpose, for which the network capacity is determined by the magnitude of the operational current flowing through an artificially created zero-sequence channel.
Недостатками известного способа из.мерени емкости сети по величине оперативного тока вл ютс вли ние на Результаты измерени активной составл ющей сопротивлени сети, котора не вл етс посто нной при эксплуатации сети, а также вли ние асимметрИИ , П1ри которой на нейтрали по вл етс напр жение, выше измерительного, что отрицательно сказываетс на работе генератора оперативного тока и небезопасно дл оператора .The disadvantages of the known method of measuring the network capacity by the magnitude of the operational current are the effect on the measurement results of the active component of the network resistance, which is not constant during the operation of the network, as well as the effect of asymmetry, when the voltage appears on the neutral , higher than the measuring one, which adversely affects the operation of the operating current generator and is unsafe for the operator.
Цель изобретени - обеспечение безопасности производства измерений и расширение области применени способа. Это достигаетс тем, что по .каналу нулевой последовательнюсти оперативный ток подают короткими импульсами , а емкость сети определ ют по частоте собственных резонансных колебаний.The purpose of the invention is to ensure the safety of production measurements and expand the scope of application of the method. This is achieved by the fact that over the channel of the zero sequence the operating current is supplied with short pulses, and the network capacity is determined from the frequency of its own resonant oscillations.
Канал нулевой последовательности может быть создан, например, с помощью двух трансформаторов напр жени , первичные обмотки которых, соединенные в звезду, подключают к исследуемой сети, а нулевые точки обмоток заземл ют. В образованном канале нулевой последовательности короткие импульсы тока вызывают в системе затухающие колебани , частота которых обратно пропорциональна корню квадратному из величины емкости сети. Так как индуктивность элементов канала нулевой последовательности во врем измерений не измен етс и заранее известна, то, измерив резонансную частоту системы (частоту затухающих колебаний ), определ ют емкость исследуемой сети. Индуктивность силовых трансформаторов и токоприемников в канал нулевой последовательности не входит и на собственную резонансную частоту системы вли ни не оказывает , так как система имеет изолированную нейтраль, а сопротивление всех силовых токоприемников дл токов нулевой последовательности равно бесконечности.The zero sequence channel can be created, for example, by means of two voltage transformers, the primary windings of which, connected in a star, are connected to the network under study, and the zero points of the windings are grounded. In a zero-sequence channel formed, short current pulses cause damped oscillations in the system, the frequency of which is inversely proportional to the square root of the network capacitance value. Since the inductance of the zero sequence channel elements during measurements does not change and is known in advance, by measuring the resonant frequency of the system (frequency of damped oscillations), the capacity of the network under study is determined. The inductance of power transformers and current collectors does not enter the zero sequence channel and has no effect on the own resonant frequency of the system, since the system has an isolated neutral, and the resistance of all power current collectors for zero sequence currents is infinity.
На чертеже представлена схема, по сн юща предложенный способ.The drawing shows a diagram explaining the proposed method.
Измерение емкости сети производ т следующим образом.The network capacity is measured as follows.
К исследуемой сети подключают иервичные обмотки 1 и 2 двух трансформаторов напр жени 3 и 4, соединенные в звезду. Нулевые точки первичных обмоток заземл ют, создава тем самым искусственный канал нулевой последовательности. Ко вторым обмоткам трансформаторов напр жени 5 и 6,Connect the primary windings 1 and 2 of two voltage transformers 3 and 4 connected to a star to the network under study. The zero points of the primary windings are grounded, thus creating an artificial zero sequence channel. To the second windings of voltage transformers 5 and 6,
соединенным в открытый треугольник, подключают источник посто нного тока 7 на пеРедающем конце и нагрузочное сопротивление 8 с частотомером 9 иа приемном конце. Затем производ т включение и отключение выключател 10.connected to an open triangle, connect a source of direct current 7 at the forward end and a load resistance 8 with a frequency meter 9 and the receiving end. Then turn on and off switch 10.
При отключении выключател 10 в системе возникают затухающие колебани с частотой , величина которой обратно пропорциональна квадратному корню из величины емкости сети 11. За мерив частоту этих колебаний частотомером 9, определ ют величину емкости исследуемой сети.When the switch 10 is turned off, damped oscillations with a frequency occur in the system, the value of which is inversely proportional to the square root of the network capacitance value 11. For measuring the frequency of these oscillations by frequency meter 9, determine the capacitance value of the network under study.
Предмет изобретени Subject invention
Способ измерени емкости электрических сетей с изолированной нейтралью путем пропускани оперативного тока по искусственно созданному каналу нулевой последовательности , отличающийс тем, что, с целью расширени области применени способа и обеспечени безоласности производства измерений, оперативный ток подают короткими импульсами, а емкость сети определ ют по частоте собственных резонансных колебаний .A method for measuring the capacity of electrical networks with an insulated neutral by passing an operational current through an artificially created zero-sequence channel, characterized in that, in order to expand the field of application of the method and ensure measurement-free performance measurements, the operational current is supplied with short pulses resonance oscillations.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
SU1875101A SU486287A1 (en) | 1973-01-26 | 1973-01-26 | Method of measuring the capacity of electrical networks with insulated neutral |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
SU1875101A SU486287A1 (en) | 1973-01-26 | 1973-01-26 | Method of measuring the capacity of electrical networks with insulated neutral |
Publications (1)
Publication Number | Publication Date |
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SU486287A1 true SU486287A1 (en) | 1975-09-30 |
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Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
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SU1875101A SU486287A1 (en) | 1973-01-26 | 1973-01-26 | Method of measuring the capacity of electrical networks with insulated neutral |
Country Status (1)
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SU (1) | SU486287A1 (en) |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
RU2475915C2 (en) * | 2006-12-18 | 2013-02-20 | Ооо "Нпп Бреслер" | Adjustment method of compensation of capacitance fault-to-ground currents in electric networks |
RU2667313C2 (en) * | 2016-07-19 | 2018-09-18 | Николай Владиславович Данилов | Method of measuring equivalent capacity of network and device for implementation thereof |
-
1973
- 1973-01-26 SU SU1875101A patent/SU486287A1/en active
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
RU2475915C2 (en) * | 2006-12-18 | 2013-02-20 | Ооо "Нпп Бреслер" | Adjustment method of compensation of capacitance fault-to-ground currents in electric networks |
RU2667313C2 (en) * | 2016-07-19 | 2018-09-18 | Николай Владиславович Данилов | Method of measuring equivalent capacity of network and device for implementation thereof |
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