SU792474A1

SU792474A1 - Device for compensating for earthing active current

Info

Publication number: SU792474A1
Application number: SU782653615A
Authority: SU
Inventors: Дмитрий Николаевич Степанчук; Алексей Андреевич Чупайленко
Original assignee: Донецкий Ордена Трудового Красного Знамени Политехнический Институт
Priority date: 1978-08-04
Filing date: 1978-08-04
Publication date: 1980-12-30

Description

Изобретение относится к устройствам для компенсации активной составляющей тока замыкания на землю и предназначено для использования,- в первую очередь, в шахтных кабельных сетях, специфика эксплуатации которых требует повышенной надежности и безопасности эксплуатации.The invention relates to devices for compensating the active component of the earth fault current and is intended for use, first of all, in mine cable networks, the operation of which requires increased reliability and safety of operation.

Изобретение может найти широкое применение как в промышленных, так и в городских или сельских сетях с номинальным напряжением 6-10 кВ.The invention can find wide application in both industrial and urban or rural networks with a rated voltage of 6-10 kV.

Известно устройство для компенсации активной составляющей тока замыкания на землю, состоящее из дугогасящего , реактора, установленного в нейтрали, блока выбора напряжения, однофазного трансформатора, первичная · .обмотка которого подключена к выходу блока выбора напряжения, а. вторичная обмотка служит _;для подключения к нейтрали сети, а также трехфазного трансформатора, две группы вторичных обмоток которого соединены по схеме зигзаг и подключены к выходу блока выбора напряжения, а первичная обмотка служит для подключения на напряжение сети IllA device is known for compensating the active component of the earth fault current, consisting of an arcing suppressor, a reactor installed in the neutral, a voltage selection unit, a single-phase transformer, the primary ·. Winding of which is connected to the output of the voltage selection unit, a. secondary winding serves _; for connecting to the neutral of the network, as well as a three-phase transformer, two groups of secondary windings of which are connected in a zigzag circuit and connected to the output of the voltage selection unit, and the primary winding is used to connect to the mains voltage Ill

Устройство обладает рядом недостатков: сложная схема, требующая дополнительно два специальных трансформатора; устройство трудно поддается автоматизации; недостаточная точность настройки, так как требуется специальный блок регулирования напряжения; низкая надежность работы устройства.The device has several disadvantages: a complex circuit requiring an additional two special transformers; the device is difficult to automate; insufficient adjustment accuracy, since a special voltage regulation unit is required; low reliability of the device.

Из известных устройств наиболее близким к предлагаемому по назначению и технической сущности является устройство, содержащее дроссель насыщения и дугогасящую катушку, которая снабжена компенсирующей подмагничивающей и дополнительной обмотками, причем дополнительная обмотка соединена последовательно с дросселем насыщения и подсое-, диняется к фазе, отстающей по отношению к поврежденной фазеOf the known devices, the closest to the intended purpose and technical essence is a device containing a saturation inductor and an arc suppression coil, which is equipped with a compensating magnetizing and additional windings, the additional winding connected in series with the saturation inductor and connected, connects to a phase lagging with respect to damaged phase

Недостатками этого устройства являются сложность осуществления автома тического регулирования компенсации, недостаточная точность настройки устройства, так как требуется специальное устройство для регулирования напряжения, подаваемого с отстающей фазы и, как следствие, снижается надежность работы сети.The disadvantages of this device are the difficulty of automatic compensation control, insufficient accuracy of the device settings, since a special device is required to regulate the voltage supplied from the lagging phase and, as a result, the reliability of the network decreases.

Целью изобретения является повышение точности компенсации.The aim of the invention is to increase the accuracy of compensation.

Эта цель достигается тем, что устройство для компенсации активного тока замыкания на землю, содержащее основной компенсирующий дроссель с подмагничиванием, снабженный дополнительной рабочей обмоткой, а также дополнительный дроссель с подмагничиванием, рабочая . . обмотка которого последовательно соединена с дополнительной рабочей обмоткой основного компенсирующего дросселя, дополнительно снабжено присоединительным тансформатором, в нейтраль которого включен основной компенсирующий дроссель, и блоком выбора фаз, причем последовательно соединенные рабочая обмотка дополнительного дросселя и . дополнительная рабочая обмотка основного компенсирующего дросселя включены через блок выбора фаз к вторичной обмотке присоединительного трансформатора, соединенной в треугольник.This goal is achieved in that the device for compensating the active earth fault current, comprising a main compensating inductor with magnetization, equipped with an additional working winding, and also an additional inductor with magnetization, working. . the winding of which is connected in series with the additional working winding of the main compensating inductor, is additionally equipped with a connecting tansformer, in the neutral of which the main compensating inductor is included, and a phase selection unit, the working winding of the additional inductor being connected in series and. The additional working winding of the main compensating inductor is connected through the phase selection unit to the secondary winding of the connecting transformer connected in a triangle.

На фиг. 1 изображена принципиальная схема устройства для компенсации активного тока на землю,·' на фиг. 2 - вектора диаграммы напряжений в режиме замыкания на землю.In FIG. 1 shows a schematic diagram of a device for compensating active current to earth, · 'in FIG. 2 - vector voltage diagram in the mode of earth fault.

Устройство компенсации активного тока замыкания на землю (фиг. 1) содержит основной компенсирующий дроссель с подмагничиванием 1, снабженный компенсирующей 2, подмагничивающей 3 и дополнительной рабочей 4 обмотками. Компенсирующая обмотка 2 включена между нулевой точкой сети 5 и землей, а подмагничивающая обмотка 3 подключена к источнику постоянного токаThe device for compensating the active earth fault current (Fig. 1) contains the main compensating inductor with magnetization 1, equipped with compensating 2, magnetizing 3 and additional working 4 windings. Compensating winding 2 is connected between the zero point of the network 5 and the ground, and the magnetizing winding 3 is connected to a DC source

Устройство содержит также дополнительный маломощный дроссель с подмагничиванием 6, снабженный рабочей 7 и подмагничивающей 8 обмотками. Подмагничивающая обмотка 8 питается от источника постоянного тока После довательно соединенные рабочая 7 и дополнительная рабочая 4 обмотки подключены через блок выбора фаз 9 и присоединительный трансформатор 10 на линейное напряжением сети Uq_c, взятое между фазой, в которой произошло замыкфше на землю, и фазой опережающей по отношению к поврежденной фазе. Первич- .The device also contains an additional low-power inductor with magnetization 6, equipped with a working 7 and magnetizing 8 windings. The magnetizing winding 8 is powered by a direct current source. The subsequently connected working 7 and additional working 4 windings are connected through a phase selection unit 9 and an connecting transformer 10 to a line voltage Uq _c , taken between the phase in which the earth fault occurred and the leading phase in relation to the damaged phase. Primary.

792474 4 ная обмотка 11 присоединительного трансформатора 10, соединенная в треугольник , подключена к фазам 5, а вторичная обмотка 12, соединенная в треу- ₅ ' гольник, включена на блок выбора фаз 9. При однофазном замыкании на землю, например фаза А (фиг. 2), на устройство подается линейное напряжение Пас взятое между фазой, в которой произошло замыкание на землю, и фазой, опережающей поврежденную фазу. Напряжение U_OGраспределяется на рабочей обмотке 7 дополнительного дросселя с подмагничиванием 6 (Uqp ) и дополнительной рабочей обмотке 4 основного компенсирующего дросселя с подмагничиванием 111^.4 792 474 Naya 11 connecting the transformer winding 10 connected in a triangle, connected to the phases 5 and the secondary winding 12 connected in treu- ₅ 'Golnik is included on the phase selection unit 9. In the single-phase ground fault, for example phase A (FIG. 2), the line voltage Paz taken between the phase in which the earth fault occurred and the phase ahead of the damaged phase is applied to the device. The voltage U _{OG is} distributed on the working winding 7 of the additional inductor with magnetization 6 (Uqp) and the additional working winding 4 of the main compensating inductor with magnetization 111 ^.

Напряжение U на дополнительной обмотке 4 обеспечивает встречное напряжение вводимой электродвижущей силы Eq по отношению к активной составляющей тока замыкания на землю.The voltage U on the additional winding 4 provides a counter voltage of the introduced electromotive force Eq with respect to the active component of the earth fault current.

При точной компенсации тока замыкания на землю напряжение на дополнительной обмотке 7 совпадает по величине и противоположтЛ по фазе напряжению, падающему на переходном сопротивлении в месте замыкания на землю.With accurate compensation of the earth fault current, the voltage at the additional winding 7 coincides in magnitude and is opposite in phase to the voltage incident on the transition resistance at the point of earth fault.

При возрастании активной составляющей тока замыкания на землю величина и _к становится недостаточной для полной компенсации. В этом случае увеличивается подмагничивание в дополнительном дросселе с подмагничиванием 6, это уменьшает индуктивное сопротивление рабочей обмотке 7 , а следовательно, уменьшает и возрастает U^.With an increase in the active component of the earth fault current, and _k becomes insufficient for full compensation. In this case, the magnetization increases in an additional inductor with a magnetization 6, this reduces the inductive resistance of the working winding 7, and therefore, decreases and increases U ^.

При уменьшении активной составляющей тока замыкания на землю для достижения полной компенсации необходимо уменьшить подмагничивание в дополнительном дросселе 6 до тех, пор, пока не будет выполнено условие ·With a decrease in the active component of the earth fault current, in order to achieve full compensation, it is necessary to reduce the magnetization in the additional choke 6 until the condition

Использование· новых элементов блока выбора фаз и присоединительного трансформатора, вторичная обмотка которого соединена в треугольник, позволило в случае возникновения замыкания на землю подать на устройство линейное напряжение, а не фазное, что повышает точность рабо- ты устройства при больших уровнях активного тока замыкания на землю. При этом диапазон допустимых значений активного тока, который может быть скомпенсирован данным устройством, возрастает, в раз по сравнению с прототипом, где для компенсации подавалось фазное напряжение.The use of · new elements of the phase selection unit and the connecting transformer, the secondary winding of which is connected in a triangle, made it possible to apply a linear voltage rather than a phase voltage to the device in case of an earth fault, which increases the accuracy of the device at high levels of active earth fault current . In this case, the range of acceptable values of the active current, which can be compensated by this device, increases by a factor compared to the prototype, where a phase voltage was applied for compensation.

В свою осередь повышение точности компенсации активного тока замыкания на землю и расширение диапазона компенсируемых токов позволяет повысить надежность работы компенсированной сети, а также повысить безопасность работы людей в случае замыкания на землю, что особенно важно й условиях ^шахтных электрических сетей.In turn, increasing the accuracy of compensation of the active earth fault current and expanding the range of compensated currents can improve the reliability of the compensated network, as well as improve the safety of people in case of earth fault, which is especially important under the conditions of mine electrical networks.

Claims

The invention relates to devices for compensating the active component of the earth fault current and is intended for use, first of all in the mine cable networks, the specificity of operation of which requires increased reliability and safety of operation. The invention can find wide application in both industrial and urban rural networks with a nominal voltage of 6-10 kV. A device is known for compensating the active component of the earth fault current consisting of an arcing reactor installed in neutral ka voltage selection, single-phase transformer, the primary winding of which is connected to the output of the voltage selection block, and. the secondary winding is used to connect to the neutral of the network, as well as a three-phase transformer, two groups of secondary windings of which are connected in a zigzag scheme and connected to the output of the voltage selection unit, and the primary winding is used to connect to the network voltage 111The device has several disadvantages: complex circuit , additionally requiring two special transformers; the device is difficult to automate; adjustment accuracy is insufficient, since a special voltage regulating unit is required; low reliability of the device. Of the known devices, the one closest to the one proposed by purpose and technical entity is a device containing a saturation throttle and an arcing coil, which is equipped with a compensating bias and additional windings, the additional winding being connected in series with the saturation fussel and the connecting winding. It is driven to the phase lagging behind the damaged phase J2. The disadvantages of this device are the complexity of the automatic adjustment of compensation, the lack of accuracy in setting up the device, since a special device is required to control the voltage supplied from the lagging phase and, as a result, the reliability of the network is reduced. The aim of the invention is to improve the accuracy of compensation. This goal is achieved by the fact that a device for compensating the active ground fault current, containing a main compensating choke with bias, equipped with an additional working winding, as well as an additional choke with bias, is working. the winding of which is sequentially connected to the additional working winding of the main compensating throttle is additionally equipped with a connecting tansformer, in the neutral of which the main compensating choke is included, and a phase selector unit, with the series-connected working winding of the additional throttle and. The additional working winding of the main coaxing throttle is connected through a phase selector to the secondary winding of a connecting transformer connected in delta. FIG. 1 is a schematic diagram of a device for compensating active current to earth; FIG. 2 - vector of voltage diagram in the closure mode or to ground. The active ground fault current compensation device (Fig. 1) contains a main compensating choke with bias 1, equipped with a compensating 2, magnetizing 3 and an additional 4 company windings} the winding 2 is connected between the zero point of the network 5 and the ground, and the biasing winding 3 is connected The device also contains an additional low-power choke with bias 6, equipped with a working 7 and biasing 8 windings. The magnetizing tool 8 is powered by a direct current source C / nj. A series-connected working 7 and additional working 4 windings are connected via a phase selector 9 and a connecting transformer 10 to a linear voltage of the UQC network. taken between the phase in which the earth fault occurred and the phase ahead in relation to the damaged phase. Primary The winding 11 of the connecting transformer 1O, connected in delta, is connected to phases 5, and the secondary winding 12, connected to a triangle, is connected to the phase selector 9. With a single-phase short circuit to earth, for example, phase A (Fig. 2), the device is supplied with a linear voltage O to, taken between the phase in which the fault occurred to the earth and the phase ahead of the damaged phase. The voltage Ude is distributed on the working winding 7 of additional chokes with bias 6 (Uqp) and an additional working winding 4 of the main compensating droplets with biasing lU. The voltage O JL on the additional winding 4 provides the counter voltage of the input electromotive force E ei with respect to the active component of the ground fault. With an accurate compensation of the ground fault current, the voltage on the additional winding 7 coincides in magnitude and is opposite in phase to the voltage falling on the transient resistance at the ground fault point. As the earth-fault current increases, U j becomes insufficient to fully compensate. In this case, the magnetization increases in the additional choke with a magnetization 6, this reduces the inductive resistance of the working winding 7, and consequently, decreases O l p and Uy increases. When the active component of the earth-fault current is reduced, in order to achieve full compensation, it is necessary to reduce the bias in the additional choke 6 until the condition-Ugji, -0) is satisfied. The use of new elements of the phase selection unit and the connecting transformer, the secondary winding of which is connected in delta, made it possible in the event of a ground fault to apply a linear voltage rather than a phase voltage to the device, which improves the accuracy of the device at high levels of the active current circuit the earth. At the same time, the range of allowable values of the active current, which can be compensated by this device, increases by 5 P compared to the prototype, where the phase voltage was applied to compensate. In turn, increasing the accuracy of compensation of the active ground-fault current and extending the range of the compensated currents improves the reliability of the compensated network, as well as increases the safety of people's work in the event of a ground fault, which is especially important in the conditions of the mine electrical networks. The invention The device for compensating the active ground fault current, containing the main compensating choke with bias, equipped with an additional working winding, as well as an additional choke with magnetic biasing, the working winding of which is successively connected to the additional working winding of the compensating throttles, 46 characterized by . that, in order to improve the accuracy of compensation, it is equipped with a connecting transformer, in the neutral of which the main compensating choke is included, and ohm phase selection, with the series-connected working winding of additional throttles and the additional working winding of the compensating throttle are cleared (Through the phase selection block to the secondary winding of the connecting transformer, triangle. Sources of information taken into account during the examination 1. USSR Certificate No. 559325 , class H 02 H 1 / O2, 1977.

2. USSR author's certificate N9 494817, cl. H 02 H 1/02, 1975.

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