CN103235279A - Electronic transformer output checking device - Google Patents

Abstract

The invention relates to an electronic transformer output verification device, comprising a reference transformer, a converter, a merging unit, a data acquisition card and a calibrator, the reference transformer is connected to the data acquisition card, and the converter The input end is connected to the transformer to be calibrated, and the output end is respectively connected to the data acquisition card and the merging unit, and the merging unit and the data acquisition card are respectively connected to the calibrator. Compared with the prior art, the invention has the advantages of high calibration accuracy, convenient operation and the like.

Description

An electronic transformer output calibration device

technical field

The invention relates to a transformer calibration technology, in particular to an electronic transformer output calibration device.

Background technique

According to the description of the IEC standard, electronic transformers have analog voltage or digital output. Current and voltage transformers for electrical measuring instruments and relay protection devices with a frequency of 15-100 Hz. It can be seen that its function and application range are exactly the same as those of conventional transformers. The difference is that the output of electronic transformers is weak analog voltage signals or digital quantities that can be directly used by secondary equipment, such as the standard value of analog output of electronic current transformers. 22.5, 150, 200, 225mV (for measurement) and 4V (for protection), and the digital output standard values are 2D41H (for measurement) and 01CFH (for protection). The conventional current transformer output is a current signal, generally 5A or 1A, which can directly drive the relay protection device. It can be seen that the output mode of the electronic transformer is very different from the output mode of the traditional electromagnetic transformer, and the traditional calibration method cannot meet the requirements of the calibration of the electronic transformer.

Contents of the invention

The object of the present invention is to provide an electronic transformer output verification device with high verification accuracy and convenient operation in order to overcome the above-mentioned defects in the prior art.

The purpose of the present invention can be achieved through the following technical solutions:

An electronic transformer output verification device, characterized in that it includes a reference transformer, a converter, a merging unit, a data acquisition card and a calibrator, the reference transformer is connected to the data acquisition card, and the converter The input end of the input terminal is connected to the transformer to be verified, and the output end is connected to the data acquisition card and the merging unit respectively, and the merging unit and the data acquisition card are respectively connected to the calibrator.

The converter includes an analog-to-digital conversion unit, an analog signal output port and a digital signal output port, and the transformer to be verified is connected to the analog-to-digital conversion unit and the analog signal output port respectively, and the analog-to-digital conversion unit is connected to the analog-to-digital conversion unit The digital signal output port is connected, and the analog signal output port is connected with the data acquisition card.

It also includes a synchronous clock, which is set between the data acquisition card and the merging unit.

The data acquisition card is provided with two input channels and an output channel, and the two input channels are respectively connected with the output end of the reference transformer and the analog signal output port, and the output channel is connected with the PCI of the calibrator. Or PXI interface connection.

The merging unit is connected with the Ethernet transmission interface of the calibrator.

Compared with the prior art, the present invention has the following advantages:

1. Dual-channel synchronous sampling, which can ensure the accuracy of phase error measurement, and the absolute accuracy can reach more than 0.05%.

2. It can meet the requirements of on-site calibration of 0.2-level electronic transformers.

3. Since both analog and digital calibration are direct methods, there is no difference, so the output of the standard channel and the electronic transformer to be verified does not need to match, which is convenient for the manufacture of standard transformers and supporting equipment.

Description of drawings

Fig. 1 is a structural schematic diagram of the present invention.

Detailed ways

The present invention will be described in detail below in conjunction with the accompanying drawings and specific embodiments.

Example

As shown in Figure 1, a kind of electronic transformer output checking device comprises reference transformer 1, converter, merging unit 5, data acquisition card 6, synchronous clock 7 and calibrator 8, and described reference transformer 1 Connect with data acquisition card 6, the input end of described converter is connected with transformer 2 to be verified, and output end is connected with data acquisition card 6 and merging unit 5 respectively, and described merging unit 5, data acquisition card 6 are respectively Connect with calibrator 8. The synchronous clock 7 is set between the data acquisition card 6 and the merging unit 8 .

The converter includes an analog-to-digital conversion unit 3, an analog signal output port 4 and a digital signal output port, and the transformer to be verified 2 is connected to the analog-to-digital conversion unit 3 and the analog signal output port 4 respectively, and the described The analog-to-digital conversion unit 3 is connected to the digital signal output port, and the analog signal output port 4 is connected to the data acquisition card 6 .

The data acquisition card 6 is provided with two input channels and an output channel, and the two input channels are respectively connected with the output terminal of the reference transformer 1 and the analog signal output port 4, and the output channel is connected with the verification Instrument 8 PCI or PXI interface connection. The merging unit 5 is connected to the Ethernet transmission interface of the calibrator 8 .

The present invention integrates analog verification (adopting direct digital verification method) and digital verification (adopting A/D mode), and the requirements of each component are as follows:

1. For the design of the reference transformer, since the analog and digital calibration are direct methods, there is no difference, so the standard channel and the output of the electronic transformer under test do not need to match, which is convenient for the manufacture of standard transformers and supporting equipment.

2. Selection of high-precision synchronous data acquisition card. A/D conversion is a key part of the whole verification system. Moreover, synchronous sampling has a great influence on the angular difference of the transformer. So choosing the right data acquisition card is critical.

3. Synchronous clock design. Synchronous clock and data acquisition card interface, etc.

4. Development of calibrator data processing software. It uses virtual instrument technology, and many functions are completed by software, so the development of output processing software is also very important, which can enhance the intelligence and interactivity of the whole system.

Claims (5)

1. a kind of electronic transformer output verification device, it is characterized in that, comprise reference transformer, converter, merging unit, data acquisition card and calibrator, described reference transformer is connected with data acquisition card, described The input end of the converter is connected to the transformer to be calibrated, and the output end is respectively connected to the data acquisition card and the merging unit, and the merging unit and the data acquisition card are respectively connected to the calibrator. 2. A kind of electronic transformer output calibration device according to claim 1, is characterized in that, described converter comprises analog-to-digital conversion unit, analog signal output port and digital signal output port, and described to-be-verified The transformers are respectively connected to the analog-to-digital conversion unit and the analog signal output port, the analog-to-digital conversion unit is connected to the digital signal output port, and the analog signal output port is connected to the data acquisition card. 3. A kind of electronic transformer output verification device according to claim 1, is characterized in that, also comprises synchronous clock, and this synchronous clock is arranged between data acquisition card and merging unit. 4. a kind of electronic transformer output verification device according to claim 2, is characterized in that, described data acquisition card is provided with two input channels and an output channel, and described two input channels are respectively connected with reference The output end of the transformer is connected to the analog signal output port, and the output channel is connected to the PCI or PXI interface of the calibrator. 5 . The electronic transformer output verification device according to claim 1 , wherein the merging unit is connected to the Ethernet transmission interface of the calibrator. 6 .

Images