CN102116786A - Neutral point direct current online measurement device for transformer - Google Patents

Neutral point direct current online measurement device for transformer Download PDF

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Publication number
CN102116786A
CN102116786A CN2010106185696A CN201010618569A CN102116786A CN 102116786 A CN102116786 A CN 102116786A CN 2010106185696 A CN2010106185696 A CN 2010106185696A CN 201010618569 A CN201010618569 A CN 201010618569A CN 102116786 A CN102116786 A CN 102116786A
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CN
China
Prior art keywords
signal
neutral point
photoelectric
casing
copper bar
Prior art date
Application number
CN2010106185696A
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Chinese (zh)
Inventor
张英
梅桂华
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广东电网公司电力科学研究院
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Application filed by 广东电网公司电力科学研究院 filed Critical 广东电网公司电力科学研究院
Priority to CN2010106185696A priority Critical patent/CN102116786A/en
Publication of CN102116786A publication Critical patent/CN102116786A/en

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Abstract

The invention discloses a neutral point direct current online measurement device for a transformer, which comprises a Hall sensor, a copper bar, a transmission fiber, a signal processing module arranged in a box body, a photoelectric power conversion module, a measurement signal photoelectric conversion module and a power laser launching circuit module, wherein the copper bar penetrates through the two sides of the box body; the copper bar in the box body is sleeved with the Hall sensor; the signal processing module is used for receiving an output signal of the Hall sensor, converting the output signal into an optical signal and outputting the optical signal into the measurement signal photoelectric conversion module; the measurement signal photoelectric conversion module is used for converting the inputted optical signal into an electrical signal to output; the photoelectric power conversion module is used for providing power for the Hal sensor and the signal processing module; and the power laser launching circuit module is used for inputting medium power laser for the photoelectric power conversion module. The neutral point direct current online measurement device adopts the optical fiber to supply the energy and transmit the signals, blocks an over-voltage transmission path and improves the measurement stability and the accuracy.

Description

A kind of transformer neutral point DC current on-line measurement device

Technical field

The present invention relates to a kind of transformer neutral point dc current measurement device.

Background technology

In AC network,, generally there is not the DC current transformer of flowing through, so still there is not special transformer neutral point DC current in-situ measurement equipment at present because transformer is used to transmit AC energy.Continuous development along with HVDC (High Voltage Direct Current) transmission system, when bipolar two ends neutral ground mode of connection HVDC (High Voltage Direct Current) transmission system is in the bipolar current imbalance or the one pole the earth method of operation, direct current fails to be convened for lack of a quorum and invades AC system by the transformer neutral point earth lead in the ground, the AC system transformer is caused a series of influences such as DC magnetic biasing harm.For the degree and the braking measure of enforcement DC magnetic biasing of monitoring transformer DC magnetic bias, need carry out on-line measurement to the DC current of the transformer neutral point of flowing through.

At present, mainly adopt shunt or Hall element for the measurement of DC current.

Adopt shunt on-line measurement transformer neutral point DC current, shunt need be sealed in the transformer neutral point earth lead, flow through the voltage drop that shunt produces by detecting electric current, and voltage signal is amplified, after filtering etc. handles, obtains reflecting the signal of DC current values.Adopt the DC current in the shunt on-line measurement transformer neutral point earth lead to have following problem:

1, according to electric system related specifications regulation, in AC network,, save the insulation investment for reducing the transformer neutral point dielectric level, general 110kV and above electric pressure transformer neutral point do not allow serial connection equipment, need direct ground connection.2, the shunt series connection inserts the zero-sequence network of meeting change system in the transformer neutral point earth lead, and the relevant protective relaying device regular event that definite value is provided with has been finished in influence.3, when system is short-circuited fault, (size of zero-sequence current depends on power system capacity to flow through bigger zero-sequence current in the transformer neutral point earth lead, short trouble type and short dot position, maximum can reach tens thousand of amperes), the isolation measurement because shunt is unrealized, this zero-sequence current produces bigger voltage drop on shunt, follow-up voltage detecting and signal processing circuit are brought harm, and on shunt, produce a large amount of heats in the fault zero-sequence current short time, capacity to shunt has also proposed very high requirement, and normally used shunt is difficult to meet the demands.

Adopt Hall element on-line measurement transformer neutral point DC current, by detecting the magnetic field that electric current produces, the signal of output reflection current value uses Hall element can realize the isolation measurement of electric current.There is following problem in the simple Hall element on-line measurement transformer neutral point DC current of using:

1, Hall element generally is used for indoor, low pressure place, and on-line measurement transformer neutral point DC current needs Hall element to work long hours in transformer station outdoor high-voltage place, and work under bad environment has seriously reduced the reliability of Hall element.

2, owing to measuring principle, Hall element is very responsive to magnetic field, in stronger AC magnetic field, has reduced the Hall element measurement accuracy at transformer station's high pressure place internal memory.

3, Hall element inside is the electronic circuit that semiconductor element, amplifier etc. are formed, and is also relatively more responsive to electric field, at stronger electric field, the Hall element operate as normal also caused bigger influence at transformer station's high pressure place internal memory.

In case the superpotential in the 4 transformer station high pressure places acts on the Hall element, signal cable or feed cable (Hall element need of work external power source) by Hall element forms path easily, and the Hall element inside more weak devices such as Hall element of voltage endurance capability are caused damage.

Summary of the invention

The purpose of this invention is to provide a kind of working stability, measure transformer neutral point DC current on-line measurement device accurately.

Technical solution of the present invention is: a kind of transformer neutral point DC current on-line measurement device, comprise Hall element, it also is provided with copper bar, Transmission Fibers, be arranged on the signal processing module in the casing, photoelectric power modular converter and measuring-signal photoelectric switching circuit module and power laser radiating circuit module, wherein copper bar runs through the casing both sides, described Hall element is set on the interior copper bar of casing, signal processing module is used to receive described Hall element output signal and converts light signal to and export measuring-signal photoelectric switching circuit module to by Transmission Fibers, measuring-signal photoelectric switching circuit module is used for converting the light signal of input to electric signal output, the photoelectric power modular converter is used for providing power supply to described Hall element and signal processing module, and power laser radiating circuit module is used for to photoelectric power modular converter input mid power laser.

Copper bar seals in the transformer neutral point earth lead, make it to become the part of neutral ground lead, Hall element is as sensing head, realized isolation measurement to DC current, be arranged in the casing the influence of the effective outer highfield of decontamination chamber, magnetic field to sensor, the signal of Hall element output converts light signal to through signal processing module, transfers in the measuring-signal photoelectric switching circuit module by Transmission Fibers, converts the electric signal that satisfies other measuring and controlling equipment needs to.Produce laser by power laser radiating circuit module, the photoelectric power modular converter that offers in the casing converts electric energy to, as the power supply use of each circuit module in the casing.Above measure is isolated high-voltage field institute's equipment and low-voltage field institute equipment on electric fully, has cut off the superpotential transmission path, thereby has improved the functional reliability and the stability of measurement mechanism.

Be provided with the magnetic shielding cage in the described casing.Can further improve the magnetic working environment in the casing, improve the stability and the accuracy of measurement mechanism work.

Described casing is that stainless steel is made.Can play certain shielding action to the electric field of workplace.

Be provided with insulator between described copper bar and the casing.Open copper bar and casing are isolated, avoid occurring the electric current distributary phenomenon, can play the effect of fixing seal simultaneously.

Advantage of the present invention is: adopt optical fiber energy supply and transmission signals, realized the electrical isolation of high-voltage field institute's equipment and low-voltage field institute equipment, blocking-up superpotential transmission path has improved the electromagnetism working environment simultaneously, has improved the stability of measurement mechanism work and the accuracy of measurement.

Description of drawings

Accompanying drawing 1 is the structural representation of the embodiment of the invention;

Accompanying drawing 2 is the structural representation of casing in the embodiment of the invention;

1, Hall element, 2, casing, 3, copper bar, 4, signal processing module, 5, the photoelectric power modular converter, 6, Transmission Fibers, 7, measuring-signal photoelectric switching circuit module, 8, power laser radiating circuit module, 9, the magnetic shielding cage, 10, insulator.

Embodiment

Embodiment:

Consult Fig. 1-3, a kind of transformer neutral point DC current on-line measurement device, comprise Hall element 1, it also is provided with copper bar 3, Transmission Fibers 6, is arranged on signal processing module 4, photoelectric power modular converter 5 and measuring-signal photoelectric switching circuit module 7 and power laser radiating circuit module 8 in the casing 2, wherein copper bar 3 runs through the both sides of casing 2, and two places of intersecting with casing 2 are provided with insulator 10 respectively.Hall element 1 is set on the copper bar 3 in the casing 2, signal processing module 4 is used to receive the signal of Hall element 1 output and converts light signal to and exports measuring-signal photoelectric switching circuit module 7 to by Transmission Fibers 6, measuring-signal photoelectric switching circuit module 7 is used for converting the light signal of input to electric signal output, satisfies other measuring and controlling equipment needs.Photoelectric power modular converter 5 is used for providing power supply to Hall element 1 and signal processing module 4, and power laser radiating circuit module 8 is used for to photoelectric power modular converter 5 input mid power laser.

Casing 2 is made up of stainless steel, and its inside is provided with the magnetic shielding cage 9 of magnetic conductive material.

Hall element 1 adopts the inner straight survey type Hall element of not establishing the balance winding, after its output signal process in signal processing module 4 is amplified processing such as zeroing, low frequency filtering, Hall excitation and electric light conversion, convert light signal to, export by Transmission Fibers.The principle of work of photoelectric power modular converter 5 similar solar cells, the luminous energy of reception Optical Fiber Transmission converts the working power of electric energy as circuit in Hall element 1 casing such as grade to.Can select 1-12VDC output as required, according to the useful power of the different exportable 250mW-700mW of input optical power.

Measuring-signal photoelectric switching circuit 7 is to satisfy the electric signal of other measuring and controlling equipment requirements with the measuring light conversion of signals, and output is used for monitoring, controlling.Power laser radiating circuit 8 is mainly the fibre-optical coupled power laser diode, this module realizes the output of mid power laser, specified emissive power 2W, need external heating radiator, be extended fiber coupled power laser diode serviceable life, the emissive power of design operate as normal is 1W, be 50% of ratings, and fan is installed near heating radiator, when detecting radiator temperature, is started fan and carry out wind cooling temperature lowering above 50 ℃.

Transmission Fibers is an armored fiber optic.

Above-listed detailed description is at the specifying of one of the present invention possible embodiments, and this embodiment is not in order to limiting claim of the present invention, and the equivalence that all the present invention of disengaging do is implemented or change, all should be contained in the claim of this case.

Claims (4)

1. transformer neutral point DC current on-line measurement device, comprise Hall element, it is characterized in that: it also is provided with copper bar, Transmission Fibers, be arranged on the signal processing module in the casing, photoelectric power modular converter and measuring-signal photoelectric switching circuit module and power laser radiating circuit module, wherein copper bar runs through the casing both sides, described Hall element is set on the interior copper bar of casing, signal processing module is used to receive described Hall element output signal and converts light signal to and export measuring-signal photoelectric switching circuit module to by Transmission Fibers, measuring-signal photoelectric switching circuit module is used for converting the light signal of input to electric signal output, the photoelectric power modular converter is used for providing power supply to described Hall element and signal processing module, and power laser radiating circuit module is used for to photoelectric power modular converter input mid power laser.
2. a kind of transformer neutral point DC current on-line measurement device according to claim 1 is characterized in that: be provided with the magnetic shielding cage in the described casing.
3. a kind of transformer neutral point DC current on-line measurement device according to claim 1 and 2, it is characterized in that: described casing is that stainless steel is made.
4. a kind of transformer neutral point DC current on-line measurement device according to claim 3 is characterized in that: be provided with insulator between described copper bar and the casing.
CN2010106185696A 2010-12-31 2010-12-31 Neutral point direct current online measurement device for transformer CN102116786A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
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Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
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Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102270841A (en) * 2011-07-19 2011-12-07 中电普瑞科技有限公司 Positioning system for direct current magnetic bias suppression device
CN102981033A (en) * 2012-11-19 2013-03-20 广州东芝白云电器设备有限公司 Novel sensing system of DC tractive power supply system
CN104198796A (en) * 2014-08-22 2014-12-10 安阳师范学院 Direct current detection circuit and method based on transformer
CN105067862A (en) * 2015-07-16 2015-11-18 许继电气股份有限公司 Photoelectric current sensor
WO2015188593A1 (en) * 2014-06-12 2015-12-17 国网上海市电力公司 Alternating current and direct current wireless monitoring device
CN106771500A (en) * 2017-01-22 2017-05-31 中国南方电网有限责任公司超高压输电公司检修试验中心 A kind of HVDC transmission system difference channel current amount otherness detection method

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4682101A (en) * 1985-02-05 1987-07-21 Lem S.A. Current transformer for direct and alternating current
CN1696713A (en) * 2004-05-14 2005-11-16 欧阳南尼 Current measurement method, electronic type current transformer utilized, and new application of the current transformer
US20070257663A1 (en) * 2006-05-08 2007-11-08 Mende Michael J Current sensing circuit for use in a current measurement probe
CN201345536Y (en) * 2009-01-22 2009-11-11 广东省电力工业局试验研究所 Transformer neutral point capacitance-resistance mixed type inhibition direct current device
CN201909807U (en) * 2010-12-31 2011-07-27 广东电网公司电力科学研究院 On-line direct-current measuring device for transformer neutral point

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4682101A (en) * 1985-02-05 1987-07-21 Lem S.A. Current transformer for direct and alternating current
CN1696713A (en) * 2004-05-14 2005-11-16 欧阳南尼 Current measurement method, electronic type current transformer utilized, and new application of the current transformer
US20070257663A1 (en) * 2006-05-08 2007-11-08 Mende Michael J Current sensing circuit for use in a current measurement probe
CN201345536Y (en) * 2009-01-22 2009-11-11 广东省电力工业局试验研究所 Transformer neutral point capacitance-resistance mixed type inhibition direct current device
CN201909807U (en) * 2010-12-31 2011-07-27 广东电网公司电力科学研究院 On-line direct-current measuring device for transformer neutral point

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
张英, 饶章权: "基于GPRS 的变压器直流偏磁电流在线监测系统研究", 《广东电力》, vol. 23, no. 8, 30 August 2010 (2010-08-30) *

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102270841A (en) * 2011-07-19 2011-12-07 中电普瑞科技有限公司 Positioning system for direct current magnetic bias suppression device
CN102270841B (en) * 2011-07-19 2014-10-22 中电普瑞科技有限公司 Positioning system for direct current magnetic bias suppression device
CN102981033A (en) * 2012-11-19 2013-03-20 广州东芝白云电器设备有限公司 Novel sensing system of DC tractive power supply system
WO2015188593A1 (en) * 2014-06-12 2015-12-17 国网上海市电力公司 Alternating current and direct current wireless monitoring device
CN104198796A (en) * 2014-08-22 2014-12-10 安阳师范学院 Direct current detection circuit and method based on transformer
CN104198796B (en) * 2014-08-22 2019-03-12 安阳师范学院 D.C. current detecting circuit and method based on transformer
CN105067862A (en) * 2015-07-16 2015-11-18 许继电气股份有限公司 Photoelectric current sensor
CN106771500A (en) * 2017-01-22 2017-05-31 中国南方电网有限责任公司超高压输电公司检修试验中心 A kind of HVDC transmission system difference channel current amount otherness detection method
CN106771500B (en) * 2017-01-22 2019-06-21 中国南方电网有限责任公司超高压输电公司检修试验中心 A kind of HVDC transmission system difference channel current amount otherness detection method

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Application publication date: 20110706