CN205263293U - Zero device is examined to current transformer examination autozero based on current comparison appearance - Google Patents

Abstract

The utility model discloses an automatic zero-adjustment and zero-detection device for current transformer verification based on a current comparator. Its voltage regulator is connected with a current booster, and the secondary side of the current transformer is respectively connected with a tested current transformer and an auxiliary transformer. A current comparator is connected between the current transformer under test and the auxiliary transformer. The auxiliary transformer, current comparator and current transformer under test are all connected to the corresponding interface of the current transformer calibrator. Zero box, the current transformer under test is connected to the current load box, the verification data communication terminal of the current transformer calibrator is connected to the communication terminal of the computer, the first load adjustment serial port of the current transformer calibrator is connected to the electronic zero adjustment box The control terminal is connected, the second load adjustment serial port of the current transformer calibrator is connected to the control terminal of the current load box, and the voltage regulator control serial port of the current transformer calibrator is connected to the control terminal of the voltage regulator. The utility model realizes the automatic verification of the high-precision current transformer.

Description

Automatic zero-adjustment and zero-detection device for current transformer verification based on current comparator

technical field

The utility model relates to the technical field of electrical measurement, in particular to an automatic zero-adjustment and zero-detection device for current transformer verification based on a current comparator.

Background technique

In various provincial electric power experiment institutes, provincial metering bureaus and some regional power supply bureaus, in order to verify high-precision current standard transformers, double-stage current transformers and current comparators are widely used as standard transformers. Due to the large workload of current standard transformer verification, complicated data processing, and high requirements for verification personnel, in order to meet modern needs and facilitate computer information processing, intelligence has become the future development trend and research hotspot of current standard transformer calibrator.

At present, the most authoritative statutory verification organization in China - the National High Voltage Metering Station, uses the zero adjustment box, the zero indicator, the comparison ritual transformer calibrator and the zero magnetic flux transformer (or current comparator) to test the high precision current standard transformer Perform a calibration check. During the above calibration and verification process, manually adjust the voltage regulator to increase the current to the current point specified in the regulations (JJG313-2010 "Current Transformer for Measurement" Verification Regulations), and then manually adjust each gear plate of the zero adjustment box to adjust the load of the auxiliary winding At the same time, observe the state of the pointer of the zeroing instrument to make it point to the zero position, then improve the display accuracy of the zeroing instrument, and manually adjust each gear plate of the zeroing box again to make the zeroing instrument point to zero until the accuracy requirements are met. The above-mentioned whole verification process all has the problems of low degree of automation and heavy workload.

Utility model content

The purpose of this utility model is to provide an automatic zero-adjustment and zero-detection device for current transformer verification based on a current comparator, which can realize automatic verification of standard current transformers and improve verification work efficiency.

In order to achieve this purpose, a current transformer verification automatic zero-adjustment and zero-detection device based on a current comparator designed by the utility model includes a voltage regulator, a current booster, an auxiliary transformer, a current comparator, and a current transformer. A calibrator, a current load box, an electronic zero-adjustment box and a computer, wherein the primary of the voltage regulator is used to connect to an AC power supply, the secondary of the voltage regulator is connected to the primary of the current booster, and one end of the secondary of the current booster It is used to connect the non-polar end of the primary winding of the current transformer under test, the other end of the secondary side of the current booster is connected to the non-polar end of the primary winding of the auxiliary transformer, and the polar end of the primary winding of the auxiliary transformer is connected to the current comparator The non-polar end of the primary winding is connected, the polar end of the primary winding of the current comparator is connected to the polar end of the primary winding of the current transformer under test, the polar end of the compensation winding of the current transformer under test, the second polarity end of the current comparator The polarity end of the secondary winding, the polarity end of the compensation winding of the current comparator, and the differential current branch signal inflow terminal K of the current transformer calibrator are all connected to the polarity end of the secondary winding of the current transformer under test; the current comparator compensation Both the non-polar end of the winding and the non-polar end of the compensation winding of the current transformer under test are connected to the ground terminal D of the current transformer calibrator, the ground terminal D of the current transformer calibrator is grounded, and the secondary winding of the current comparator The non-polar end of the auxiliary transformer is connected to the polar end of the secondary winding of the auxiliary transformer, and the non-polar end of the secondary winding of the auxiliary transformer is connected to the secondary standard terminal T _O of the current transformer calibrator. The two ends of the zero winding are docked with the zero adjustment terminals at both ends of the electronic zero adjustment box, and the non-polar end of the secondary winding of the current transformer under test is connected in series with the secondary test terminal T _X of the current transformer calibrator The current load box, the zero winding of the current comparator is connected to the zero detection terminal J of the current transformer calibrator;

The calibrator verification data communication terminal of the current transformer calibrator is connected to the communication terminal of the computer, the first load adjustment control serial port of the current transformer calibrator is connected to the control terminal of the electronic zero adjustment box, and the current transformer calibrator The second load adjustment control serial port is connected to the control terminal of the current load box, and the voltage regulator control serial port of the current transformer calibrator is connected to the control terminal of the voltage regulator.

The beneficial effects of the utility model:

The above-mentioned standard current transformer automatic verification device based on the current comparator provided by the utility model solves the problems of low automation, heavy workload, extremely low work efficiency, complicated data processing, and serious problems in the current verification process of high-precision current transformers The high requirements of the verification personnel have realized the automatic verification of high-precision current transformers and improved work efficiency.

Description of drawings

Fig. 1 is the circuit diagram of the present utility model;

Among them, 1—voltage regulator, 2—current booster, 3—auxiliary transformer, 4—current comparator, 5—current transformer calibrator, 6—current load box, 7—electronic zero adjustment box, 8— Computer, 9—current transformer under test.

detailed description

Below in conjunction with accompanying drawing and specific embodiment the utility model is described in further detail:

The utility model provides an automatic zero-adjustment and zero-detection device for current transformer verification based on a current comparator, as shown in Figure 1, which includes a voltage regulator 1, a current booster 2, an auxiliary transformer 3, and a current comparator 4 , current transformer calibrator 5, current load box 6, electronic zero adjustment box 7 and computer 8, wherein, the primary (terminal A and terminal X) of described voltage regulator 1 is used for connecting AC power supply, voltage regulator 1 The secondary (terminal a and terminal x) of the current booster 2 is connected to the primary side of the current booster 2, and one end of the secondary side of the current booster 2 is used to connect the non-polar end of the primary winding of the current transformer 9 under test, and the secondary side of the current booster 2 The other end is connected to the non-polar end of the primary winding of the auxiliary transformer 3, the polar end of the primary winding of the auxiliary transformer 3 is connected to the non-polar end of the primary winding of the current comparator 4, and the polar end of the primary winding of the current comparator 4 Connect with the polarity end of the primary winding of the current transformer 9 under test, the polarity end of the compensation winding NB of the current transformer 9 under test, the polarity end of the secondary winding N21 of the current comparator 4, the compensation winding of the current comparator 4 The polarity terminal of NB1 and the differential current branch signal inflow terminal K of the current transformer calibrator 5 are connected to the polarity terminal of the secondary winding N2 of the current transformer 9 under test; the non-polar terminal of the current comparator 4 compensation winding NB1 The non-polar end of the compensation winding NB of the current transformer 9 under test is connected to the ground terminal D of the current transformer calibrator 5, the ground terminal D of the current transformer calibrator 5 is grounded, and the secondary winding N21 of the current comparator 4 The non-polar end of the auxiliary transformer 3 is connected to the polar end of the secondary winding N1 of the auxiliary transformer 3, and the non-polar end of the secondary winding N1 of the auxiliary transformer 3 is connected to the secondary standard terminal _T0 of the current transformer calibrator 5 , the two ends of the auxiliary transformer 3 zeroing winding N0 are docked with the zeroing terminals at both ends of the electronic zeroing box 7, the non-polar end of the secondary winding N2 of the tested current transformer 9 is connected with the current transformer calibrator 5 The current load box 6 is connected in series between the terminals T and _X of the secondary test, and the zero winding NU of the current comparator 4 is connected to the zero detection terminal J of the current transformer calibrator 5;

The calibrator verification data communication end of the current transformer calibrator 5 is connected to the communication end of the computer 8 (to obtain the calibrator verification data), and the first load adjustment control serial port of the current transformer calibrator 5 is connected to the electronic zero adjustment box 7 is connected to the control terminal (adjust the load carried by the secondary winding N0 of the auxiliary transformer 3), the second load adjustment control serial port of the current transformer calibrator 5 is connected to the control terminal of the current load box 6 (adjust the current transformer under test 9 load), the voltage regulator control serial port of the current transformer calibrator 5 is connected to the control terminal of the voltage regulator 1 (by controlling the boost of the voltage regulator 1 to achieve the purpose of controlling the loop current).

In the above technical solution, the zero winding NU of the current comparator 4 is connected to the zero detection terminal J of the current transformer calibrator 5 through the shielded wire 10 .

In the above technical solution, the calibrator verification data communication end of the current transformer calibrator 5 is connected to the communication end of the computer 8 through the communication serial port.

In the above technical solution, the primary side of the voltage regulator 1 is used to connect to a 220V AC power supply.

In the above technical solution, the secondary voltage of the voltage regulator 1 is 250V.

In the above technical solution, the electronic zero-adjustment box 7 is an electronic zero-adjustment device, which is directly controlled by the computer 8 to realize the setting of the load carried by the secondary winding N1 of the auxiliary transformer 3 without manual operation.

In the above technical solution, the current transformer calibrator 5 includes a conventional current transformer calibrator module, a zero detection module and a zero indication module, and the input terminal of the zero detection module is the zero detection terminal J of the calibrator ;The output terminal of the zero detection module is connected with the input terminal of the zero position indication module to display the zero position; the output terminal of the zero detection module is connected with the conventional current transformer calibrator module, and when the zero detection module detects the zero position signal, it notifies the conventional current The transformer calibrator module performs error measurement.

A method for performing automatic calibration of a standard current transformer by utilizing the above-mentioned current transformer calibration automatic zero adjustment and zero detection device based on a current comparator, which includes the following steps:

Step 1: The control computer 8 sends a measurement instruction to the current transformer calibrator 5, and the current transformer calibrator 5 controls the voltage regulator 1 to boost the voltage after receiving the measurement instruction;

Step 2: When the current transformer rated current dial gauge value of the current transformer calibrator 5 reaches a preset verification value, the electronic zero adjustment box 7 is controlled by the current transformer calibrator 5 to adjust the auxiliary transformer 3 Zero operation, at the same time, the zero detection module in the current transformer calibrator 5 detects the zero position corresponding to the zero winding of the current comparator 4 in real time, and displays it in real time;

Step 3: When the zero detection module in the current transformer calibrator 5 detects that the zero winding of the current comparator 4 is zero, the error measurement of the current transformer 9 under test is performed by the current transformer calibrator 5, and the The error measurement result is uploaded to the computer 8;

Step 4: Carry out the error measurement of the current transformer 9 under test when the rated current percentage indicator value of the current transformer calibrator 5 of the current transformer calibrator 5 reaches the rest of the preset verification values according to the above steps 2 and 3;

Step 5: After the error measurement of the tested current transformer 9 corresponding to all preset verification values is completed, the computer 8 controls the voltage regulator 1 to return to zero, and the experiment is completed.

In the above technical solution, the preset verification value includes 1%, 5%, 20%, 100% and 120% of the prescribed verification value. The above procedure is the verification procedure of JJG313-2010 "Current Transformer for Measurement".

In step 3 of the above technical solution, the current transformer calibrator 5 uploads the error measurement results to the computer 8 for display and storage.

The content not described in detail in this specification belongs to the prior art known to those skilled in the art.

Claims (5)

1. the detecting current transformer automatic zero set zero-detection device based on current comparator,It is characterized in that: it comprises pressure regulator (1), current lifting device (2), auxiliary mutual inductor (3), electricityStream comparator (4), current transformer calibrator (5), current capacity case (6), electronics zeroingCase (7) and computer (8), wherein, described pressure regulator (1) elementary for connecting interchangePower supply, the secondary connection current lifting device (2) of pressure regulator (1) elementary, current lifting device (2) is secondaryOne end be used for connecting the non-polar end of (9) windings of tested current transformer, current lifting device(2) non-polar end of (3) windings of the secondary other end and auxiliary mutual inductor is connected, auxiliaryHelp the polar end of (3) windings of transformer and the non-utmost point of (4) windings of current comparatorProperty end connect, the polar end of (4) windings of current comparator and tested current transformer (9)The polar end of a winding connects, the polarity of described tested current transformer (9) compensation windingThe polar end of end, current comparator (4) Secondary Winding, current comparator (4) compensation windingThe poor stream of polar end summation current transformer tester (5) tributary signal flow into terminal K and all connectThe polar end of tested current transformer (9) Secondary Winding; Current comparator (4) compensation windingThe non-polar end of non-polar end and tested current transformer (9) compensation winding be all connected electric currentThe ground terminal D of mutual-inductor tester (5), the earth terminal of current transformer calibrator (5)Sub-D ground connection, the non-polar end of current comparator (4) Secondary Winding and auxiliary mutual inductor (3)The polar end of Secondary Winding connects, the non-polar end of auxiliary mutual inductor (3) Secondary Winding and electricityThe secondary standard binding post T of current transformer tester (5)_OConnect auxiliary mutual inductor (3)Dock with the zeroing binding post at electronics zeroing case (7) two ends at the two ends of zeroing winding, testedTwo of the non-polar end of current transformer (9) Secondary Winding and current transformer calibrator (5)Inferior tested binding post T_XBetween series current Burden box (6), zero of current comparator (4)Winding is connected with current transformer calibrator (5) zero-detection terminals J;

Tester calibrating data communication end and the computer (8) of current transformer calibrator (5)Communication ends connect, the first load adjustment control serial ports of current transformer calibrator (5) with electricityThe control end of son zeroing case (7) connects, and the second load of current transformer calibrator (5) is adjustedWhole control serial ports is connected with the control end of current capacity case (6), current transformer calibrator (5)Pressure regulator control serial ports be connected with the control end of pressure regulator (1).

2. the detecting current transformer based on current comparator according to claim 1 certainlyMoving zeroing zero-detection device, is characterized in that: zero winding of described current comparator (4) passes throughShielding line (10) is connected with current transformer calibrator (5) zero-detection terminals J.

3. the detecting current transformer based on current comparator according to claim 1 certainlyMoving zeroing zero-detection device, is characterized in that: the verification of described current transformer calibrator (5)Instrument calibrating data communication end is connected with the communication ends of computer (8) by communication serial port.

4. the detecting current transformer based on current comparator according to claim 1 certainlyMoving zeroing zero-detection device, is characterized in that: described pressure regulator (1) elementary for connecting 220VAC power.

5. the detecting current transformer based on current comparator according to claim 1 certainlyMoving zeroing zero-detection device, is characterized in that: the secondary voltage of described pressure regulator (1) is 250V.