Testing device for characteristic test of overvoltage and undervoltage protector

Abstract

The utility model discloses a test device for overvoltage and undervoltage protector characteristic test, which comprises a main switch, a first transformer, a second transformer, a first relay, a second relay and a self-locking circuit, the first transformer and the second transformer are both connected with a power supply, the first transformer is connected with the first relay, and the second transformer is connected with the second relay. The second transformer is connected with a second relay, and the first relay and the second relay are used for adjusting and increasing secondary side voltages of the first transformer and the second transformer; the first transformer is further connected with a self-locking circuit, and the self-locking circuit can control the first transformer to be disconnected from or connected with the circuit. The test device can meet the requirement that under the rated working voltage of the overvoltage and undervoltage protector, the overvoltage and undervoltage protector jumps to an overvoltage or undervoltage state instantly; and the protector can also instantly jump from an overvoltage or undervoltage state to a rated voltage of the overvoltage and undervoltage protector, so that the requirement of a test for verifying the characteristics of the protector is met.

Description

Technical Field

[0001] This utility model belongs to the field of testing, specifically a test device for testing the characteristics of over- and under-voltage protectors. Background Technology

[0002] Over / under voltage protectors are commonly used in power distribution circuits. When an overvoltage or undervoltage condition occurs at the power supply end, the electrical equipment must be disconnected within a specified time to protect it. The reliable protection provided by over / under voltage protectors is crucial for the safe operation of electrical equipment. According to national standards, it is necessary to verify whether the over / under voltage protector can automatically disconnect the line within a specified time when the normal operating voltage jumps to a fault voltage (overvoltage or undervoltage), and whether it can automatically reconnect the line within a specified time after the fault voltage disappears. Furthermore, the voltage change (from normal voltage to fault voltage, and from fault voltage back to normal voltage) must be instantaneous. This necessitates the development of a testing device to simulate the corresponding operating conditions and verify whether the characteristics of the over / under voltage protector meet the requirements of national standards. Currently, there is a lack of testing equipment specifically for undervoltage protectors. Utility Model Content

[0003] Based on the above background technology, in order to overcome the shortcomings and deficiencies of the existing technology, this application proposes a test device for testing the characteristics of over- and under-voltage protectors, which is simple to operate and safe and reliable.

[0004] To solve the above-mentioned technical problems, this application provides the following technical solution:

[0005] A test apparatus for testing the characteristics of over / under voltage protectors is characterized by comprising a main switch, a first transformer, a second transformer, a first relay, a second relay, and a self-locking circuit. Both the first and second transformers are connected to a power source. The first transformer is connected to the first relay, and the second transformer is connected to the second relay. The first and second relays are used to increase the secondary side voltage of the first and second transformers. The first transformer is also connected to a self-locking circuit, which can control the first transformer to be disconnected from or connected to the line.

[0006] Moreover, the self-locking circuit includes a contactor, a first switch, and a second switch connected in series. When the coil of the contactor is energized, the contacts of the contactor close, which can form a self-locking circuit to disconnect the first transformer.

[0007] Furthermore, the power supply location is equipped with a main switch and a fuse.

[0008] Furthermore, the first transformer and the second transformer can be connected to a voltmeter via a switching switch.

[0009] Furthermore, the experimental device is housed inside a suitcase, which contains a control panel.

[0010] The advantages and positive effects of this utility model are:

[0011] 1. This test apparatus can instantly switch from the overvoltage or undervoltage state under the rated operating voltage of the overvoltage and undervoltage protector; it can also instantly switch from the overvoltage or undervoltage state to the rated voltage of the overvoltage and undervoltage protector, thus meeting the requirements for verifying the characteristics of the protector.

[0012] 2. The design of this test device is simple and safe to operate, and meets the national standard requirements for over- and under-voltage protectors. It can verify both the under-voltage protection function and the over-voltage protection function. Attached Figure Description

[0013] To more clearly illustrate the technical solution of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0014] Figure 1 This is the electrical schematic diagram of the test device.

[0015] Figure 2 This is a schematic diagram of the experimental setup. Detailed Implementation

[0016] To make the structure and advantages of this utility model clearer, the structure of this utility model will be further described below with reference to the accompanying drawings.

[0017] A test apparatus for testing the characteristics of over / under voltage protectors, see attached. Figure 1 As shown, it includes a main switch, a first transformer, a second transformer, a first relay, a second relay, a contactor, and a voltmeter.

[0018] The QF switch is the main switch of the test device. The first transformer T1 and the second transformer T2 are both connected to the power supply. The first transformer T1 is connected to the first relay TL1, and the second transformer T2 is connected to the second relay TL2. TL1 and TL2 are used to increase the secondary voltage of the first transformer T1 and the second transformer T2.

[0019] The first transformer T1 is also connected to a contactor K1 branch. When the coil of contactor K1 is energized, K1 closes, forming a self-locking circuit to disconnect the first transformer from the line. A first switch SB1 and a second switch SB2 are connected in series in the contactor K1 branch. When SB1 is pressed, the coil of K1 is energized, and the normally open contact of K1 closes, forming a self-locking circuit. At this time, the first transformer is disconnected, and the test voltage in the line is the secondary voltage of the second transformer. When SB2 is pressed, the coil of K1 is de-energized, and the K1 contact returns to its normal state. At this time, the first transformer is engaged, and the test voltage in the line is the sum of the voltages of the first and second transformers.

[0020] The circuits of the first transformer T1 and the second transformer T2 can be selectively connected to a voltmeter via a switch SA. The voltmeter is used to display the current voltage of the first transformer T1 or the second transformer T2. The voltage value is displayed on the screen, making it easy to observe and adjust the secondary voltage value of the corresponding line.

[0021] A circuit breaker QF is installed near the power source to control the on / off state of the entire circuit; a fuse FU is also connected near the power source to protect the circuit.

[0022] Verification of undervoltage protection:

[0023] Press switch SA and adjust TL2 so that the secondary voltage of the second transformer is the undervoltage test voltage. Press switch SA again and adjust the value of transformer TL1 so that the sum of the secondary voltages of the first and second transformers is the rated voltage of the over / undervoltage protector. After connecting the over / undervoltage protector, turn on switch QF. At this time, the line voltage is normal, and the over / undervoltage protector is normally activated. Press SB1 to disconnect the first transformer, and the line is undervoltage, verifying whether the over / undervoltage protector can disconnect within the specified time. Then press SB2 to connect the first transformer, and the line voltage returns to normal, verifying whether the over / undervoltage protector can activate within the specified time, thus verifying its undervoltage protection performance.

[0024] Overvoltage protection verification:

[0025] Press switch SA and adjust TL2 so that the secondary voltage of the second transformer is the test voltage value of the rated voltage. Press switch SA again and adjust the value of transformer TL1 so that the sum of the secondary voltage values ​​of the first and second transformers is the test voltage value of overvoltage. After connecting the over / under voltage protector, turn on switch QF and press SB1 simultaneously. The first transformer is disconnected, the line is at the rated voltage value, and the over / under voltage protector is normally activated. Then, press SB2, the first transformer is activated, the line is at the overvoltage value, verifying whether the over / under voltage protector can disconnect within the specified time; then press SB1 again, the first transformer is disconnected, the line returns to the normal voltage value, verifying whether the over / under voltage protector can activate within the specified time, thus verifying its overvoltage protection performance.

[0026] See appendix Figure 2 The diagram shows the unfolded state of the device's carrying case. The circuitry of the device is located inside the openable carrying case, and the panel layout is as follows. Figure 2 As shown, the panel is equipped with a screen, TL2 control knob, TL1 control knob, QF switch, SA switch, SB1 switch, SB2 switch, SB3 switch, and terminal blocks for connecting an undervoltage protector.

[0027] The above description is merely an embodiment of this utility model and is not intended to limit this utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A test apparatus for testing the characteristics of over / under voltage protectors, characterized in that, It includes a main switch, a first transformer, a second transformer, a first relay, a second relay, and a self-locking circuit. Both the first and second transformers are connected to a power source. The first transformer is connected to the first relay, and the second transformer is connected to the second relay. The first and second relays are used to adjust the secondary side voltage of the first and second transformers. The first transformer is also connected to a self-locking circuit, which can control the first transformer to be disconnected from or connected to the line.

2. The test apparatus for testing the characteristics of over / under voltage protectors according to claim 1, characterized in that, The self-locking circuit includes a contactor, a first switch, and a second switch, which are connected in series. When the coil of the contactor is energized, the contacts of the contactor close, thus forming a self-locking circuit to disconnect the first transformer.

3. The test apparatus for testing the characteristics of over / under voltage protectors according to claim 1, characterized in that, The power supply location is equipped with a main switch and a fuse.

4. The test apparatus for testing the characteristics of over / under voltage protectors according to claim 1, characterized in that, The first transformer and the second transformer can be connected to a voltmeter via a switching switch.

5. The test apparatus for testing the characteristics of over / under voltage protectors according to claim 1, characterized in that, The experimental apparatus is housed in a suitcase, which contains a control panel.

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