CN87108187A - The method and the device of DC current transformer ratio direct-reading verification - Google Patents
The method and the device of DC current transformer ratio direct-reading verification Download PDFInfo
- Publication number
- CN87108187A CN87108187A CN87108187.3A CN87108187A CN87108187A CN 87108187 A CN87108187 A CN 87108187A CN 87108187 A CN87108187 A CN 87108187A CN 87108187 A CN87108187 A CN 87108187A
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- current
- current transformer
- resistance network
- measuring
- transformer ratio
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- Measurement Of Resistance Or Impedance (AREA)
Abstract
A kind of DC current transformer ratio direct measuring and realize the DC current transformer ratio direct-reading tester of this technology manufacturing.The ratio direct measuring that this tester is realized has broken out the example of passing through of measuring the DC current transformer ratio both at home and abroad with the indirect method of measurement.This tester is directly read-around ratio residual quantity value and symbol not only, and has accuracy height, cost is low, volume is little, in light weight, simple to operate characteristics.Therefore, it is the comparatively ideal tester of measurement unit.
Description
A kind of calibration equipment that relates to DC current transformer ratio direct measuring and realize this technology manufacturing.
At present, all adopt the indirect method of measurement to measure the ratio of DC current transformer both at home and abroad, both tested DC current transformer and standard the DC current transformer big current ratio devices of standard such as (or) current comparators were compared, measure the secondary current of the absolute error and the standard DC current transformer of tested DC current transformer secondary current, by calculating the corresponding ratio of tested DC current transformer.The shortcoming of this detection method is:
1, because the ratio of DC current transformer is to be calculated by two measurement data (by electric current absolute error value and working current value), so, all more loaded down with trivial details from the differentiation of the calculating that measures ratio of data and its symbol, therefore, inefficiency.
2, because the proving installation that this method adopted, it is digital voltmeter by two high resolving power, high input impedance, plural precision resister device, a composition such as high-precision DC current proportioning device is so measurement circuit is loaded down with trivial details, operative technique is complicated, proving installation cost height.
3, this method accuracy is low can not detect high precision DC current ratio instrument.
The object of the invention: realize the direct measurement of DC current transformer ratio.
The technology of the present invention solution is:
Adopt double-current comparator realization DC current transformer ratio directly to measure.At first, with the primary and secondary current conversion of tested DC current transformer the difference electric current and the normalization electric current of reflection DC current transformer ratio through the double-current comparator; Be difference electric current and normalization current conversion measuring voltage and bucking voltage respectively by measuring resistance network and compensating resistance network then; Realize the comparison of measuring voltage and bucking voltage at last by the computing zero indicator, regulate the compensation resistance values in the compensating resistance network, when measuring voltage equals bucking voltage, this section resistance value of compensating resistance network directly can be read the ratio difference of DC current transformer, thereby realization DC current transformer ratio is directly measured purpose.
Utilize the DC current transformer ratio direct-reading tester of above-mentioned DC current transformer ratio direct-reading method of calibration manufacturing,, detect current comparator mainly by the switching current comparer, the measuring resistance network, compensating resistance network and computing zero indicator are formed.
Advantage of the present invention is:
1, ratio direct-reading.Under the working current of determining, regulate ratio reading dial (both having regulated the compensating resistance in the compensating resistance network), when computing zero indicator nulling, just can directly read from the reading dial the ratio difference of tested DC current transformer.And, in measuring process, be subjected to the influence of working current fluctuation hardly, simple to operate, high efficiency.
2, accuracy height, it not only can directly examine and determine the ratio of DC current transformer, and can also examine and determine high-precision DC current ratio instrument, is suitable for the DC current ratio measurement standard as enterprise measurement department.
3, this tester when work, do not need other optional equipment, and cost is low, volume is little, in light weight, be easy to carry, not only can also be suitable for the industry spot calibrating in laboratory work.
Below in conjunction with description of drawings most preferred embodiment of the present invention.
Fig. 1 and Fig. 2 are fundamental diagram of the present invention.
In Fig. 1 and Fig. 2,1 detects current comparator, 2 switching current comparers, 3,4 demodulator amplifiers, 5 measuring resistance networks, 6 compensating resistance networks, 7 computing zero indicators, 8 tested DC current transformer, I
1The elementary working current of tested DC current transformer, I
2Tested DC current transformer secondary work electric current, I difference electric current, I
' 2Normalization electric current, W
1The elementary winding of switching current comparer, W
2The secondary winding of switching current comparer, W
cThe detection winding of switching current comparer, N
1Detect elementary winding, the N of current comparator
2Detect secondary winding, the N of current comparator
cDetect the detection winding of current comparator, the feedback winding that N detects current comparator.
The secondary winding W of conversion current comparator 2 in Fig. 1
2, detect the secondary winding N of current comparator 1
2, compensating resistance network 6 is connected successively with demodulator amplifier 4; The feedback winding N two ends of detecting current comparator 1 link to each other with measuring resistance network 5 with demodulator amplifier 3 respectively; Computing zero indicator 7 links to each other with compensating resistance network 6 with measuring resistance network 5 respectively.
In Fig. 2, the secondary winding W of switching current comparer 2
2Two ends, be connected with compensating resistance network 6 with demodulator amplifier 4 respectively; The feedback winding N two ends of detecting current comparator link to each other with measuring resistance network 5 with demodulator amplifier 3 respectively; Detect the secondary winding N of current comparator 1
2Elementary winding W with switching current comparer 2
1Series connection; Computing zero indicator 7 links to each other with compensating resistance network 6 with measuring resistance network 5 respectively.
When DC current transformer ratio direct-reading tester is worked, the elementary winding of tested DC current transformer 8 and the elementary winding N that detects current comparator 1
1Serial connection; The elementary winding W of the secondary winding of tested DC current transformer 8 and switching current comparer 2
1Serial connection (Fig. 1) is perhaps the elementary winding W of the secondary winding of tested DC current transformer 8 and switching current comparer 2
1With the secondary winding N that detects current comparator 1
2(Fig. 2) is in series.In Fig. 1, change the secondary current I of current comparator (comprising switching current comparer and demodulator amplifier 4) with tested DC current transformer 8
2Be converted to the normalization electric current I
' 2, the secondary winding W of this electric current by switching current comparer 2
2, and the magnetic potential that produces equate i.e. W with the elementary magnetic potential of switching current comparer 2
1I
2=W
2I
' 2, the normalization electric current I
' 2By detecting the secondary winding N of current comparator 1
2The magnetic potential difference that is produced is compared with the elementary magnetic potential that detects current comparator 1, its magnetic potential difference, is N
1I
1-N
2I
' 2The difference that detects the primary and secondary magnetic potential of current comparator 1 in Fig. 2 is N
1I
1-N
2I
2Above-mentioned two differences are by the detection winding N that detects current comparator 1 among Fig. 1, Fig. 2
cAfter detecting, through demodulator amplifier 3 output difference electric current I, this difference electric current produces the feedback magnetic potential by the feedback winding N that detects current comparator 1, makes the primary and secondary magnetic potential that detects current comparator 1 reach balance, both N
1I
1-N
2I
' 2=NI(Fig. 1) or N
1I
1-N
2I
2=NI(Fig. 2).Fig. 3 is measuring resistance network 5 and compensating resistance network 6 schematic circuits.Wherein: R is measuring resistance, the R of measuring resistance network 5
1Be the compensating resistance of compensating resistance network 6, and R, R
1For interlock is regulated.K
1, K
2Be switch, 7 are the computing zero indicator.In Fig. 3, the difference electric current I forms measuring voltage IR, normalization electric current I on the measuring resistance R of measuring resistance network 5
' 2Form bucking voltage I at compensating resistance network 6
' 2R
1Fig. 4 is the schematic circuit of computing zero indicator 7.Wherein: A
1～A
4Operational amplifier, γ
1～γ
5Computing resistance, 10 indicating instruments, E end are the input end (operational amplifier A of measuring voltage IR
1End of oppisite phase), F holds (operational amplifier A
2End of oppisite phase) or G end (operational amplifier A
3End of oppisite phase) be bucking voltage I
' 2R
1Input end, as ratio f during for just (or for negative), by switch K
2With bucking voltage I
' 2R
1Add to G end (or F end).Operational amplifier A
2, A
3Output terminal is respectively through computing resistance γ
2And γ
3Be connected with end of oppisite phase with the in-phase end of operational amplifier 4.In Fig. 4, when regulating compensating resistance R
1, when making indicating instrument 10 nullings, measuring voltage IR and bucking voltage I
' 2R balances each other, both IR=± I
' 2R
1, this moment tested DC current transformer ratio
(Fig. 1) or
(Fig. 2), as (N
2)/(N
1) R ± R
1=constant or (N
2)/(N
1) (W
2)/(W
1) R ± R
1During=constant, f=± RR then
1So compensating resistance R
1Can directly read the ratio value and the symbol of tested DC current transformer.Like this by regulating compensating resistance R
1Just realized the purpose of tested DC current transformer ratio direct-reading.
Claims (6)
1, a kind of method of DC current transformer ratio direct-reading verification is characterized in that:
A, adopt the double-current comparator, with the primary and secondary current conversion of tested DC current transformer be difference electric current I and normalization electric current I '
2,
R in b, the usefulness measuring resistance network 5 and the R in the compensating resistance network 6
1, with difference electric current I and normalization electric current I '
2Transfer measuring voltage IR and bucking voltage I ' to
2R
1,
C, by computing zero indicator 7 with measuring voltage IR and bucking voltage I '
2R
1Compare, regulate the resistance R in the compensating resistance network 6
1, make zero indicator 7 nullings, both made IR=
I
2' R
1, this moment, the ratio of tested DC current transformer was:
In d, the measuring process, the resistance R in regulating compensating resistance network 6
1The time, measuring resistance network 5 and compensating resistance network 6 keep ((N
2)/(N
1) R ± R
1) be constant, this moment tested DC current transformer ratio ((N
2)/(N
1) (W
2)/(W
1) R ± R
1) (R is a constant).
2, a kind of DC current transformer ratio direct-reading tester that uses the described DC current transformer ratio of claim 1 direct-reading method of calibration to make is characterized in that: form by detecting current comparator 1, switching current comparer 2, measuring resistance network 5, compensating resistance network 6 and computing zero indicator 7.
3, DC current transformer ratio direct-reading tester according to claim 2 is characterized in that: have in the secondary survey that detects current comparator 1:
A, with detect that current comparator 1 elementary magnetic potential is compared, pass to the normalization electric current I
' 2Or pass to the secondary winding N of the secondary current I of tested DC current transformer 8
2,
B, flow through the feedback winding N of difference electric current I.
4, DC current transformer ratio direct-reading tester according to claim 2 is characterized in that: have one the elementary magnetic potential of switching current comparer 2 the secondary of switching current comparer 2, normalization electric current I of upon mediation amplifier 4 outputs
' 2, and the secondary winding W that equates with the elementary magnetic potential of switching current comparer 2 of generation
2
5, DC current transformer ratio direct-reading tester according to claim 2 is characterized in that: the operational amplifier A in the computing zero indicator 7
2, A
3Output terminal is respectively through computing resistance γ
2And γ
3Be connected with end of oppisite phase with the in-phase end of operational amplifier 4.
6, according to claim 2 or 3 or 4 described DC current transformer ratio direct-reading testers, it is characterized in that:
The secondary winding W of a, switching current comparer 2
2, detect the secondary winding N of current comparator 1
2, compensating resistance network 6 with reconcile amplifier 4 and be connected successively, or the secondary winding W of switching current comparer 2
2Two ends, be connected with demodulator amplifier 4 with compensating resistance network 6 respectively.
The feedback winding N two ends of b, detection current comparator 1 connect mutually with demodulator amplifier 3 and measuring resistance network 5 respectively,
C, computing zero indicator link to each other with compensating resistance network 6 with measuring resistance network 5 respectively.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 87108187 CN1007091B (en) | 1987-12-16 | 1987-12-16 | Method and device for directly reading and ckecking dc mutual inductor comparison value difference |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 87108187 CN1007091B (en) | 1987-12-16 | 1987-12-16 | Method and device for directly reading and ckecking dc mutual inductor comparison value difference |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN87108187A true CN87108187A (en) | 1988-07-27 |
| CN1007091B CN1007091B (en) | 1990-03-07 |
Family
ID=4816397
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 87108187 Expired CN1007091B (en) | 1987-12-16 | 1987-12-16 | Method and device for directly reading and ckecking dc mutual inductor comparison value difference |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN1007091B (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1963556B (en) * | 2006-11-24 | 2010-04-14 | 中国计量科学研究院 | Apparatus for integrality checking proportion of cryo-current comparator and the method thereof |
| CN103885022A (en) * | 2014-03-31 | 2014-06-25 | 国家电网公司 | Rated current ratio measuring method based on transformer calibrator |
-
1987
- 1987-12-16 CN CN 87108187 patent/CN1007091B/en not_active Expired
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1963556B (en) * | 2006-11-24 | 2010-04-14 | 中国计量科学研究院 | Apparatus for integrality checking proportion of cryo-current comparator and the method thereof |
| CN103885022A (en) * | 2014-03-31 | 2014-06-25 | 国家电网公司 | Rated current ratio measuring method based on transformer calibrator |
| CN103885022B (en) * | 2014-03-31 | 2015-11-04 | 国家电网公司 | Based on the rated current ratio measuring method of mutual-inductor tester |
Also Published As
| Publication number | Publication date |
|---|---|
| CN1007091B (en) | 1990-03-07 |
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| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C13 | Decision | ||
| C14 | Grant of patent or utility model | ||
| C19 | Lapse of patent right due to non-payment of the annual fee | ||
| C19 | Lapse of patent right due to non-payment of the annual fee |