CN202141798U - Electric energy meter verification circuit for error test and DC and even harmonic test - Google Patents

Abstract

The utility model relates to an electric energy meter verification circuit for error test and direct current and even harmonic test. On the basis of the previous error test circuit and direct current and even harmonic test circuit, the circuit structure is improved, and the The controllable switch realizes the switching of the two circuits. Compared with the manual wiring used in the test on the electric energy meter verification device in the past, which is cumbersome and the test efficiency is not high, the utility model can realize the basic error test of the electric energy meter and the DC and even harmonic test on the electric energy meter verification device The automatic conversion wiring can effectively improve the automation of the test.

Description

A watt-hour meter verification circuit for error test and DC and even harmonic test

technical field

The utility model relates to a verification circuit of an electric energy meter, in particular to an electric energy meter verification circuit capable of automatically switching error tests and direct current and even harmonic tests. the

Background technique

The DC and even harmonic test is specified in "IEC62053 Special Requirements for Electric Energy Measuring Equipment" and the national standard "GB/T 17215.321-2008 Special Requirements for Alternating Current Measuring Equipment Part 21: Static Active Energy Meters (Class 1 and Class 2)" Influence quantity test of the required electric energy meter. the

The DC and even harmonic test method circuit recommended in GB/T 17215.321-2008 Appendix A is shown in Figure 1, and the waveform is shown in Figure 2. In Figure 1, in order to ensure the accuracy of the measurement, the balanced impedance should be equal to the impedance of the instrument under test (EUT); the balanced impedance should preferably be an instrument of the same type as the EUT; the rectifier diode should be of the same type ; In order to improve the balance condition, the resistance RB can be introduced in the two branches, and its resistance value should be approximately 10 times that of the tested meter (EUT). the

The verification device of the electric energy meter is generally multi-meter position. When detecting the basic error of the electric energy meter, the current loop of the electric energy meter is connected in series. Taking the four-meter position device as an example, the wiring method is shown in Figure 3 (due to the basic error test and DC The conversion of the even harmonic test is only the conversion of the current circuit, and does not involve the conversion of the voltage circuit, so the following description of the connection of the electric energy meter in this article does not involve the voltage connection). Taking the four-meter device as an example, the wiring method is shown in Figure 4 according to the test method recommended in Appendix A of GB/T 17215.321-2008 when testing the DC and even harmonic influence test of the electric energy meter. Divide the 4 epitopes into two, the two epitopes form a group, the No. 1 and No. 2 epitopes are used as the forward branch, as the test table, and the No. 3 and No. 4 epitopes are used as the reverse branch, as the To balance the impedance, use the same type of electric energy meter for all the meters in the test to ensure the impedance balance of the two branches. The rectifier diode adopts a fast dual diode module to ensure the consistency of diode characteristics. the

In the past, when doing this test on the verification circuit of the electric energy meter, manual wiring was used, which was cumbersome and the test efficiency was not high. the

Utility model content

The purpose of the utility model is to provide an electric energy meter verification circuit for error test and DC and even-order harmonic test to solve the problems of cumbersome manual wiring and low efficiency when performing tests. the

In order to achieve the above object, the solution of the present utility model is: an electric energy meter verification circuit for error test and DC and even harmonic test, which circuit includes: a basic error test current loop, which includes a standard set in series The meter and the first and second two tested modules, the first tested module includes a series connected first switch (K1) and at least one tested meter seat, the second tested module includes a connected connected second switch (K2) and The same number of tested meters as in the first tested module; the circuit is also equipped with a Y-shaped branch composed of a third switch (K3) and the first and second reversely arranged diodes (D1, D2) , the third switch (K3) end of the Y-shaped branch is connected to the power supply side of the first switch (K1), and the two diode ends are respectively connected to the first switch (K1) in the first module under test and the corresponding meter under test The series point of the socket, and the series point of the second switch (K2) in the second module under test and the corresponding table base under test; there is also a fourth switch (K4) in the circuit; the fourth switch (K4) and the second Try connecting the modules in parallel. the

The verification device of the utility model has an automatic switching function, and can automatically switch the wiring of the basic error test and the direct current and even harmonic test, thereby realizing the automation of the test process and improving the work efficiency. the

Further, a fifth switch ( K5 ) and a sixth switch ( K6 ) are arranged in series on the branches of the Y-shaped branch where the two diodes are located. the

Further, the base of the tested meter is connected with a normally closed self-resetting contact, and when the tested meter is connected, the contact is disconnected, and the tested meter is connected in series in the current loop. the

Further, each of the switches is a relay contact. the

By adopting the circuit of the utility model, manual wiring is unnecessary, and the efficiency is improved.

Description of drawings

Figure 1 is a half-wave rectification test circuit diagram;

Figure 2 is a half-wave rectification waveform diagram;

Figure 3 is a basic error test wiring diagram;

Figure 4 is a wiring diagram for DC and even harmonic tests;

Fig. 5 is a wiring circuit diagram of the utility model.

Detailed ways

Below in conjunction with accompanying drawing, the utility model is described in further detail. the

The circuit of the utility model is shown in Figure 5, as can be seen from the figure, the circuit can switch the wiring of the basic error test and the DC and even harmonic test, thereby realizing the automation of the test process. The circuit includes: a basic error test current loop; the loop includes a standard meter set in series and the first and second two tested modules, the first tested module includes the first switch K1 connected in series and two tested meters seat, the second tested module includes the second switch K2 connected in series and two tested meter seats, each tested meter seat includes two current terminals for connecting a corresponding tested meter in series in the loop, And, when no tested meter is loaded, the two current terminals of the corresponding tested meter base are shorted; in this embodiment, the tested meter base is realized with a normally closed self-resetting mechanical shrapnel contact. When entering the meter under test, the contacts are disconnected, and the meter under test is connected in series in the current loop. There is a test table for the two test table seats of each test module (as shown in the figure, test table 1, test table 2, test table 3, and test table 4);

The circuit is also provided with a Y-shaped branch composed of a third switch K3 and the first and second reversely arranged diodes (D1, D2). The end of the third switch K3 of the Y-shaped branch is connected to the first switch On the power supply side of K1, the two diode ends are respectively connected to the series connection point between the first switch K1 in the first module under test and the corresponding table base under test, and the connection point between the second switch K2 in the second module under test and the corresponding table base under test. A series point; a fourth switch K4 is also provided in the circuit; the fourth switch K4 is connected in parallel with the second module under test. Further, a fifth switch K5 and a sixth switch K6 are arranged in series on the branches where the two diodes are located, respectively controlling the on-off of the two diode branches.

All the above-mentioned switches are realized by relays. Two diodes form a diode module, each of which consists of a fast diode. the

When the error test is carried out, the relay control switches K1 and K2 are closed, and the switches K3 and K4 are disconnected, so the tested meter 1 and the tested meter 4 are connected in series, which meets the connection requirements of the four-position basic error test. the

When conducting DC and even-order harmonic tests, the relay control switches K3, K5, K6, and K4 are closed, and K1 and K2 are opened, so the tested meter 1 and the tested meter 2 are connected in series to the forward branch of the diode module. The tested meter 3 and the tested meter 4 are connected in series to the reverse branch of the diode module, which meets the requirements of DC and even harmonic test wiring. the

In this embodiment, each tested module is composed of two tested meter seats. As other embodiments, there may be more than one seat to be tested. When conducting tests on DC and even harmonics, it should be ensured that the number of tested meters connected to the two tested modules is equal to meet the test wiring requirements. the

Claims (4)

1. the electric energy meter calibration circuit of error test and direct current and even-order harmonic test usefulness; It is characterized in that; This circuit comprises: a fundamental error test current loop; Standard scale that this loop comprises that series connection is provided with first, second two first is comprised first switch (K1) and at least one seat of being taken temperature of series connection by the die trial piece by the die trial piece, second by the die trial piece comprise the second switch (K2) of series connection reach with first by the quilt that quantity is identical in the die trial piece seat of taking temperature;

Also be provided with the 3rd switch (K3) and first, second two the Y shape branch roads that the reverse diode (D1, D2) that is provided with constitutes on the circuit; The 3rd switch (K3) end of this Y shape branch road is connected to the mains side of first switch (K1); Two diode ends are connected respectively to first by the series connection point of first switch (K1) in the die trial piece with the corresponding seat of being taken temperature, and second by a second switch (K2) in the die trial piece and a corresponding series connection point of being taken temperature;

Also be provided with the 4th switch (K4) in the circuit; The 4th switch (K4) is parallelly connected by the die trial piece with second.

2. the electric energy meter calibration circuit of a kind of error test according to claim 1 and direct current and even-order harmonic test usefulness; It is characterized in that, also go here and there respectively in the Y shape branch road branch at said two diodes place and be provided with the 5th switch (K5) and the 6th switch (K6).

3. the electric energy meter calibration circuit of a kind of error test according to claim 1 and direct current and even-order harmonic test usefulness; It is characterized in that, be connected with normally closed on the said seat of being taken temperature from resetting contact, when access is taken temperature; Contact is disconnected, and will be taken temperature to be connected in the said current return.

4. the electric energy meter calibration circuit of a kind of error test according to claim 1 and direct current and even-order harmonic test usefulness is characterized in that said each switch is relay contact.

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