CN206470330U - A kind of loop resistance test device of high-voltage switch gear two-terminal-grounding - Google Patents

Abstract

The utility model discloses a loop resistance testing device with both ends of a high-voltage switch grounded, which comprises a direct current source DC, a current measuring device A, a voltage measuring device V, a current sensor CT and an A/D sampling module; the direct current source DC and voltage measuring device V are connected in parallel at both ends of the parallel circuit composed of main circuit resistance R1 and grounding circuit resistance R2; the current sensor CT is connected in series with main circuit resistance R1 or grounding circuit resistance R2; the current sensor CT The measured current value output end is connected to the corresponding acquisition end of the A/D sampling module; the current measurer A is connected in series with the direct current source DC; the measurement output ends of the current measurer A and the voltage measurer V are respectively connected to the The corresponding acquisition terminal of the above-mentioned A/D sampling module. The utility model has the advantages of good safety and easy operation.

Description

A loop resistance testing device with both ends of a high voltage switch grounded

technical field

The utility model relates to a loop resistance testing device with both ends of a high-voltage switch grounded.

Background technique

According to the electrical work standard, it is necessary to regularly overhaul and test the high-voltage switchgear, among which the contact circuit resistance measurement of the high-voltage switch is an important test item. Both sides of the switch must be grounded.

Existing loop resistance testers apply a DC source on both sides of the high-voltage switch contact and measure the voltage at the same time when both ends of the high-voltage switch contact are not grounded or one end is grounded, so as to obtain the resistance value. Dismantling the grounding device at one end increases the workload and potential safety hazards on site. If both sides of the high-voltage switch contact are grounded at the same time, a closed loop is formed between the grounds on both sides of the contact, and the current in the DC source includes both the current flowing into the contact and the current flowing into the grounding loop, so the resistance value cannot be measured.

Therefore, how to measure the loop resistance when both sides of the high-voltage switch contact are grounded is a problem to be solved in this field.

Utility model content

The technical problem to be solved by the utility model is to provide a high-voltage switch circuit resistance testing device with good safety and easy operation.

The utility model adopts the following technical solutions:

A loop resistance testing device with both ends of a high-voltage switch grounded, which includes a direct current source DC, a current measurer A, a voltage measurer V, a current sensor CT and an A/D sampling module; the direct current source DC and the voltage measurer V is connected in parallel at both ends of the parallel circuit composed of the main circuit resistance R1 and the grounding circuit resistance R2; the current sensor CT is connected in series with the main circuit resistance R1 or the grounding circuit resistance R2; the measured current value output terminal of the current sensor CT Connect to the corresponding acquisition end of the A/D sampling module; the current measurer A and the direct current source DC are connected in series; the measurement output terminals of the current measurer A and the voltage measurer V are respectively connected to the A/D sampling The corresponding acquisition terminal of the module.

The beneficial effects of the utility model are as follows:

The utility model utilizes the closed circuit formed by the contact main circuit of the high-voltage switch itself and the shell of the high-voltage switch contact K and the grounding circuit to measure the circuit resistance when both sides of the high-voltage switch contact K are grounded, which has good safety and The operation is simple, the workload of the test is reduced, and it is safe and accurate. When the utility model is in use, according to the different structures of the high-voltage switch contacts, the current sensor CT can be connected to the circuit where the main circuit resistance is located; when the current sensor CT cannot be connected to the circuit where the main circuit resistance is located, the high-voltage switch can The current sensor CT is connected to the grounding circuit on both sides of the contact, which is convenient and flexible to use, the required equipment is simple, easy to install and carry, and is very suitable for on-site operation.

Description of drawings

FIG. 1 is a schematic structural diagram of an equivalent circuit of Embodiment 1 of the present invention.

FIG. 2 is a schematic structural diagram of an equivalent circuit of Embodiment 2 of the present invention.

Fig. 3 is a schematic diagram of the grounding state on both sides of the high voltage switch.

Among them, 1 represents the main circuit of the contact, 2 represents the closed circuit formed by the shell of the high-voltage switch contact K and the grounding circuit, S1 and S2 represent the grounding knife switch; K represents the high-voltage switch contact; R1 represents the high-voltage switch contact K in In the closed state, the main circuit resistance of the main circuit of the contact when both sides are grounded; R2 represents the grounding circuit resistance of the closed circuit formed by the shell of the high-voltage switch contact K and the grounding circuit when both ends of the high-voltage switch contact K are grounded ; CT represents the current sensor; A represents the current measuring device; V represents the voltage measuring device; I ₀ represents the output current of the direct current source DC, I ₁ represents the current measured when the current sensor CT is connected in series with R1, and I ₂ represents the current sensor CT Current measured when in series with R2.

detailed description

Below in conjunction with Fig. 1 ~ Fig. 3 the utility model is described further.

As shown in Figure 1, Embodiment 1 relates to a loop resistance testing device with both ends of a high-voltage switch grounded, which includes a direct current source DC, a current measuring device A, a voltage measuring device V, a current sensor CT and an A/D sampling module ; The direct current source DC is connected in parallel to the two ends of the parallel circuit composed of the main circuit resistance R1 and the grounding circuit resistance R2, and the voltage measuring device V is also connected in parallel to the circuit composed of the main circuit resistance R1 and the grounding circuit resistance R2 The two ends of the parallel circuit; the current sensor CT is connected in series with the main loop resistance R1; the current measurer A is connected in series with the direct current source DC; the corresponding acquisition ports of the A/D sampling module are respectively connected to the measurement of the current measurer A The output terminal, the measurement output terminal of the voltage measuring device V and the measurement current value output terminal of the current sensor CT.

As shown in Figure 2, Embodiment 2 relates to a loop resistance testing device with both ends of a high-voltage switch grounded, which includes a direct current source DC, a current measuring device A, a voltage measuring device V, a current sensor CT and an A/D sampling module ; The direct current source DC is connected in parallel to the two ends of the parallel circuit composed of the main circuit resistance R1 and the grounding circuit resistance R2, and the voltage measuring device V is also connected in parallel to the circuit composed of the main circuit resistance R1 and the grounding circuit resistance R2 The two ends of the parallel circuit; the current sensor CT is connected in series with the ground loop resistance R2; the current measurer A is connected in series with the direct current source DC; the corresponding acquisition ports of the A/D sampling module are respectively connected to the measurement of the current measurer A The output terminal, the measurement output terminal of the voltage measuring device V and the measurement current value output terminal of the current sensor CT.

The working principle of embodiment 1-embodiment 2 is as follows:

The direct current source DC is a current source that outputs a current of 100A to 300A, and it is connected to both ends of a parallel circuit composed of a main circuit resistance R1 and a grounding circuit resistance R2; the current measuring device A and the direct current source DC are connected in series, The current measuring device A is used to measure the output current I ₀ of the direct current source DC; the main circuit resistance R1 is the resistance value of the high-voltage switch contact K in the closed state; the ground circuit resistance R2 is the resistance value of the high-voltage switch contact K when When both ends are grounded, the resistance value of the closed loop formed by the shell of the high-voltage switch contact K and the grounding loop; the current sensor CT is connected in series in the loop where the main loop resistance R1 is located, and it is used to measure the resistance of the loop where the main loop resistance R1 is located. current value; or the current sensor CT is connected in series in the loop where the ground loop resistance R2 is located, and it is used to measure the current value of the loop where the ground loop resistor R2 is located; the voltage measuring device V is connected in parallel with the main loop resistor R1, the ground loop resistor The two ends of the parallel circuit composed of R2 are used to measure the voltage value U at both ends of the parallel circuit composed of the main circuit resistance R1 and the grounding circuit resistance R2; the A/D sampling module utilizes the current measuring device A, the voltage measuring device V, The current sensors CT are respectively connected to transmit the output current I ₀ of the direct current source DC, the current value in the current sensor CT, and the voltage value U at both ends of the main circuit resistance R1 and the grounding circuit resistance R2.

The method that utilizes this technical scheme to test is as follows:

(1) The test method using Example 1 is as follows: Due to the different structure of the high-voltage switch contact K, when the current sensor CT is conveniently connected to the circuit where the main circuit resistance R1 is located, the steps are as follows, see Figure 1 and Figure 1 3:

1. Keep both sides of the high-voltage switch contact K in a grounded state to form a conductive circuit;

2. Connect a direct current source DC to both ends of the main circuit resistance R1, connect a current sensor CT to the circuit where the main circuit resistance R1 is located, and connect the voltage measuring device V to both ends of the main circuit resistance R1 in parallel ;

3. According to Ohm's law, the resistance value of the main circuit resistance R1 can be obtained by using the A/D sampling module to collect the measured voltage U of the voltage measuring device V and the current I ₁ measured by the current sensor CT, R1=U/ I ₁ .

(2) The method of testing using Example 2 is as follows: When the current sensor CT cannot be connected to the circuit where the main circuit resistance R1 is located, the current sensor CT can only be connected to the grounding circuit on both sides of the high-voltage switch contact K. The specific steps are as follows, see Figure 2 and Figure 3:

1. Keep both sides of the high-voltage switch contact K in a grounded state to form a conductive circuit;

2. A direct current source DC is connected to both ends of the parallel circuit composed of the main circuit resistance R1 and the grounding circuit resistance R2, and its output current is I ₀ , and a current sensor CT is connected to the circuit where the grounding circuit resistance R2 is located. The voltage measuring device V is connected to the two ends of the parallel circuit composed of the main circuit resistance R1 and the grounding circuit resistance R2;

_3. Use the A/D sampling module to measure the current value of the DC output of the direct current source DC as I ₀ , the current sensor CT measures the current value in the loop where the grounding loop resistance R2 is located, and the voltage measuring device V measures the main loop The voltage value U across the parallel circuit composed of resistor R1 and ground loop resistor R2.

4. Calculate the current value I ₁ in the circuit where the main circuit resistance R1 is located: I ₀ -I ₂ =I ₁ ;

The resistance value of the main loop resistor R1 is: U/I ₁ =R1.

Although the utility model has been specifically shown and described in conjunction with preferred embodiments, those skilled in the art should understand that, without departing from the examined scope of the utility model defined by the appended claims, changes in form and details may be made. Making various changes to the utility model is within the protection scope of the utility model.

Claims (1)

1. a kind of loop resistance test device of high-voltage switch gear two-terminal-grounding, it is characterised in that：It includes DC current source DC, electricity Flow measurer A, Voltage measure V, current sensor CT and A/D sampling module；The DC current source DC and Voltage measure V It is parallel to by the two ends of major loop resistance R1 and ground loop resistance the R2 parallel circuit constituted；The current sensor CT with Major loop resistance R1 or ground loop resistance R2 series connection；The measurement current value output end of the current sensor CT accesses the A/ The corresponding collection terminal of D sampling modules；Current measurer A and DC current source the DC series connection；The current measurer A and voltage Measuring appliance V measurement output end connects the corresponding collection terminal of the A/D sampling modules respectively.