SU832498A1

SU832498A1 - Device for continuous testing of insulation of three-phase shaft electric networks with insulated neutral wire

Info

Publication number: SU832498A1
Application number: SU782650403A
Authority: SU
Inventors: Виталий Иванович Шуцкий; Станислав Иванович Гурин; Нинель Ароновна Гончар; Виктор Николаевич Пишков
Original assignee: Ижевский механический институт; Московский Ордена Трудового Красного Зна-Мени Горный Институт
Priority date: 1978-07-31
Filing date: 1978-07-31
Publication date: 1981-05-23

Description

1one

Изобретение относитс к электроизмерительной технике и может быть использовано дл непрерывного контрол состо ни изол ции трехфазных шахтных электрических сетей с изолированной нейтралью.The invention relates to electrical measuring equipment and can be used to continuously monitor the state of isolation of three-phase electrical power grids with insulated neutral.

Известно устройство, содержащее фильтры токов и напр жений нулевой последовательности, тиристоры, логический элемент И, синхронизатор и формирователь импульсов 1.A device is known that contains zero-sequence current and voltage filters, thyristors, an AND gate, a synchronizer, and a pulse shaper 1.

Недостаток известного устройства заключаетс в чувствительности.A disadvantage of the prior art device is its sensitivity.

Наиболее близким по. технической сущности к предлагаемому вл етс устройство дл непрерывного контрол изол ции трехфазных шахтных электрических сетей с изолированной нейтралью , содержащее кольцевые демодул торы , включенные своими измерительными цеп ми между нулем трехфазной сети и зег/шей и управл емые фазным напр жением одной из фаз и.линейным напр жейием двух других фаз, и регистратор, состо щий из трех пар логометрических лриборов, причем каждые два прибора, относ щиес к одной контролируемой фазе, расположены перпендикул рно и имеют общую номографическую шкалу 23.The closest to. The technical essence of the invention is a device for continuous monitoring of the isolation of three-phase mine electrical networks with insulated neutral, containing ring demodulators connected by their measuring circuits between the zero of the three-phase network and segres and controlled by the phase voltage of one of the phases and the linear the voltage of the other two phases, and the recorder, consisting of three pairs of ratiometric instruments, each two devices belonging to one controlled phase, are perpendicular and have a common but 23 scale.

Недостатками этого устройства вл ютс низка точность измерений и мала оперативность контрол .The disadvantages of this device are low measurement accuracy and low monitoring efficiency.

Цель изобретени заключаетс в повышении точности измерений и оперативности контрол .The purpose of the invention is to improve the measurement accuracy and speed of control.

Указанна цель достигаетс тем, что в известное устройство, содержащее кольцевой демодул тор, первый вход This goal is achieved by the fact that in a known device containing a ring demodulator, the first input

0 которого подсоединен к нулю трехфазной сети, а второй - к земле, и первый регистратор, введены второй, третий и четвертый регистраторы, блок измерени угла сдвига фазы, блок вы5 делени фазы с возросшей проводимостью изол ции и арифметический блок, причем первый вход блока выделени фазы с возросшей проводимостью изол ции подсоединен к фазам контро0 лируемой сети, а второй - к земле, выход которого соединен с третьим входом кольцевого демодул тора, первым входом второго регистратора, первым входом блока измерени угла сдвига 0 of which is connected to the zero of the three-phase network, and the second to the ground, and the first recorder, the second, third and fourth recorders, the phase angle measuring unit, the phase divider with the increased insulation conductance, and the arithmetic unit, and the first input of the allocation unit phases with increased insulation conductance are connected to the phases of the monitored network, and the second to ground, the output of which is connected to the third input of the ring demodulator, the first input of the second recorder, the first input of the shift angle measuring unit

5 фаз и первым входом арифметического блока, второй вход которого соединен с третьим регистратором и выходом кольцевого демодул тора, третий вход арифметического блока соединен с четвертым регистратором и выходом5 phases and the first input of the arithmetic unit, the second input of which is connected to the third recorder and the output of the ring demodulator, the third input of the arithmetic unit is connected to the fourth recorder and output

Claims

0 of the phase angle measurement unit, the second input of which is connected to the zero of the three-phase network, the output of the arithmetic unit is connected to the first recorder, and the second input of the second recorder and the third input of the phase angle measurement unit are connected to ground. The drawing shows a block diagram of the device. The device contains a ring demodulator 1, recorders 2-5, a block 6 for measuring the phase angle, a block 7 for phase separation with increased insulation conductance, an arithmetic block 8 and terminals 9-13. The device works as follows. at once. The phases and zero of the monitored three-phase network (not shown in the drawing) are connected respectively to terminals 9-12 of the device. The terminal 13 of the device is connected to ground. When there is an asymmetry in the conductance of isolating the phases of the monitored three-phase network, a voltage of the neutrons between terminals 12 and 13 appears, which triggers the phase separation unit 7 with increased insulation conductance and detects the phase voltage of the detected phase on the recorder 2. The ring demodulator 1 determines the projection of the neutral bias voltage to the phase voltage of the selected phase, which is recorded by the recorder 3. The phase angle measurement shock 6 determines the phase shift between the bias voltage neutral and voltage of the detected phase, which is detected by the recorder 5. The arithmetic unit 8 receives the voltage of the selected phase, the projection of the neutral bias voltage onto the direction of the selected phase and the phase shift angle between the neutral bias voltage and the detected phase voltage with increased insulation conductance where the calculation of the total conductance of the insulation occurs, its active and reactive components), and the results of the calculations are recorded by the register 4. To perform calculations of the conductivities In case of a symmetric leakage, it is switched on into any of the phases of the controlled three-phase network, the reference conductivity (not shown in the drawing). In case of asymmetrical leakage, the reference conductivity is included in the phase with the increased conductivity of the insulation, as a result of which the device measures and determines the new values of the insulation parameters. The use of the device for continuous monitoring of the isolation of three-phase mine electrical networks with isolated neutrons allows for improved measurement accuracy and control efficiency by automatically isolating the phase with increased insulation conductance and automating the calculation using an arithmetic unit. Apparatus of the Invention A device for continuous monitoring of isolation of three-phase mine electrical networks with insulated neutral, containing a ring demodulator, the first input of which is connected to zero of the three-phase network, and the second to ground, and the first recorder, characterized in that in order to improve measurement accuracy and control efficiency, the second, third and fourth recorders, a phase angle measurement unit, a phase separation unit with an increased insulation conductivity, and an arithmetic unit are introduced into the device, the first the phase separation unit path with increased insulation conductance is connected to the monitored network phases, and the second to ground, the output of which is connected to the third input of the ring demodulator, the first input of the second recorder, the first input of the phase angle measurement unit and the first input of the arithmetic unit, the second the input of which is connected to the third recorder and the output of the ring demodulator, the third input of the arithmetic unit is connected to the fourth recorder and the output of the measurement unit of the phase angle, the second input of which is connected A zero-phase three-phase network, the output of the arithmetic unit is connected to the first recorder, and the second input of the second recorder and the third input of the phase angle measurement unit are connected to ground. Sources of information taken into account in the examination 1. The author's certificate of the USSR 353308, cl. H 02 H 3/16.

2. Author's certificate CCtP 401937, .cl. G 01 R 31/02, 23.11.71 (prototype).