CN204142921U - Vacuum circuit breaker contact proving installation - Google Patents

Abstract

The utility model discloses a kind of vacuum circuit breaker contact proving installation, comprising: Linear displacement transducer, in order to detect the stroke of the moving contact of a vacuum circuit breaker, and change voltage signal output into; Sample/hold circuit, connecting linear displacement transducer, samples to voltage signal or keeps; Analog to digital conversion circuit, connects sample/hold circuit, carries out analog to digital conversion to the output of sample/hold circuit; The external interrupt input end of the opening of vacuum circuit breaker, break signal input analog to digital conversion circuit, in order to detect the opening of vacuum circuit breaker, break time.

Description

Vacuum circuit breaker contact test device

technical field

The utility model relates to the technical field of measurement and measurement, in particular to a contact testing device for a vacuum circuit breaker.

Background technique

Vacuum circuit breaker is the most important electrical equipment in high-voltage transmission and distribution lines, and its performance is directly related to the safety and reliability of line operation. Vacuum circuit breaker uses "vacuum" as insulation and arc extinguishing medium, not only can switch normal load current and overload current, but also can switch a certain short-circuit current, especially when a short-circuit fault occurs in the circuit, it can automatically trip and start to protect lines and equipment.

In order to improve the performance of the vacuum circuit breaker, a device is needed to test and adjust the main technical parameters such as the stroke, opening distance, overtravel, opening time and closing time of the three-phase contact of the vacuum circuit breaker during the production process. To improve reliability, reduce electrical wear and prolong service life.

Utility model content

The utility model provides a vacuum circuit breaker contact testing device aiming at the above-mentioned shortcomings in the prior art. The utility model is realized through the following technical solutions:

A contact test device for a vacuum circuit breaker, comprising:

The linear displacement sensor is used to detect the stroke of the moving contact of a vacuum circuit breaker and convert it into a voltage signal output;

Sample/hold circuit, connected with linear displacement sensor, to sample or hold the voltage signal;

The analog-to-digital conversion circuit is connected to the sampling/holding circuit, and performs analog-to-digital conversion on the output of the sampling/holding circuit; the on-off signal of the vacuum circuit breaker is input to the external interrupt input terminal of the analog-to-digital conversion circuit to detect the opening and closing of the vacuum circuit breaker , Break time.

Preferably, there are three linear displacement sensors, which are respectively connected to the strokes of the U, V, and W phase moving contacts of the vacuum circuit breaker.

Preferably, the number of sample/hold circuits is three, and three linear displacement sensors are respectively connected.

Preferably, it also includes a potentiometer connected to the linear displacement sensor to stabilize the voltage and reduce the influence of temperature drift.

Preferably, the sample/hold circuit includes:

A sample/hold device, the input terminal is connected to a linear displacement sensor;

The potentiometer is connected to the zero adjustment terminal of the sample/hold device to adjust the drift voltage.

Preferably, it also includes a serial port circuit connected between the analog-to-digital conversion circuit and a host computer.

Description of drawings

Figure 1 is a schematic diagram of the contact action position of the vacuum circuit breaker;

Figure 2 shows the schematic diagram of the linear displacement sensor and the sample/hold circuit;

What Fig. 3 shows is the schematic diagram of the analog-to-digital conversion circuit.

Detailed ways

The following will be combined with the accompanying drawings of the utility model to clearly and completely describe and discuss the technical solutions in the embodiments of the utility model. Obviously, what is described here is only a part of the utility model, not all examples, based on The embodiments of the present utility model and all other embodiments obtained by persons of ordinary skill in the art without making creative efforts all belong to the protection scope of the present utility model.

In order to facilitate the understanding of the embodiments of the present utility model, the following will further explain and illustrate by taking specific embodiments as examples in conjunction with the accompanying drawings, and each embodiment does not constitute a limitation to the embodiments of the present utility model.

As shown in Figure 1, the schematic diagram of the dynamic and static contacts of the vacuum circuit breaker. In the figure: L is the stroke: the distance between the opening position and the closing position. L1 is the opening distance: the distance between the opening position and the just closing position. L2 is the overtravel (contact stroke): the distance between the just-closed position and the closed position.

A contact testing device for a vacuum circuit breaker provided in this embodiment includes: a linear displacement sensor, a sample/hold circuit, and an analog-to-digital conversion circuit.

The sliding end of the linear displacement sensor moves synchronously with the moving contact of the vacuum circuit breaker. Through the linear displacement sensor, the mechanical displacement of the moving contact of the vacuum circuit breaker is converted into a voltage signal output. The reference value added to the linear displacement sensor can be changed by adjusting the potentiometer. Voltage, in order to ensure the stability of the voltage applied to the linear displacement sensor and reduce the influence of temperature drift, the resistor R17 adopts a precision resistor with low temperature drift, and the potentiometer adopts a wire-wound potentiometer. The linear displacement sensor adopts WDL50-2 straight sliding conductive plastic potentiometer, which has simple structure, stable performance and high resolution. Its maximum displacement distance is 50±2mm, resistance value is 5kΩ, and linearity is 0.1%.

Sample / hold circuit adopts LF398. The device is a monolithic integrated sampling/holding device with high sampling speed, slow voltage drop rate and high precision, and it has 8 pins. In the figure, pin 2 is connected to the potentiometer RW1, which is used to adjust the drift voltage. Pin 7 and pin 8 are two control terminals, which control the LF398 to be in the sampling or holding state. Pin 7 is connected to the reference voltage, and pin 8 is connected to the control signal. If pin 7 is grounded, when the control signal connected to pin 8 is greater than 1.4V, LF398 is in sampling state; if pin 8 is low level, LF398 is in hold state. The 6-pin external holding capacitor C1 is 200P. Pin 1 and pin 4 are the power supply terminals, pin 3 is the signal input terminal, and pin 5 is the signal output terminal. Figure 2 is a schematic diagram of the U-phase displacement sensor detection and sampling/holding circuit, and the displacement sensors and sampling/holding circuit schematic diagrams of the V-phase and W-phase are the same as those of the U-phase. The mechanical displacement of the moving contact of the vacuum circuit breaker is converted into a voltage signal and input from pin 3 of the sample/hold circuit LF398.

The output signals OUT-u, OUT-v and OUT-w of the three-phase sampling/holding circuit are respectively sent to the built-in 8-way 10-bit high-speed A/D conversion input terminals of LPC2132. The three-phase dynamic and static contact opening and breaking signals are respectively sent to the external interrupt input terminal of LPC2132, so the three-phase dynamic and static contact displacement signals are respectively A/D converted by means of interruption, and the three-phase dynamic and static contact The opening and closing of the head are time detected, as shown in Figure 3.

The serial communication between LPC2132 and the upper computer is converted to RS-232, and the test results are sent to the upper computer.

The above is only a preferred embodiment of the utility model, but the scope of protection of the utility model is not limited thereto, and any person familiar with the technical field can easily think of All changes or replacements should fall within the protection scope of the present utility model. Therefore, the protection scope of the present utility model should be based on the protection scope of the claims.

Claims (6)

1. A vacuum circuit breaker contact testing device, characterized in that, comprising: The linear displacement sensor is used to detect the stroke of the moving contact of a vacuum circuit breaker and convert it into a voltage signal output; a sample/hold circuit, connected to the linear displacement sensor, to sample or hold the voltage signal; an analog-to-digital conversion circuit, connected to the sampling/holding circuit, and performing analog-to-digital conversion on the output of the sampling/holding circuit; the opening and closing signals of the vacuum circuit breaker are input to the external interrupt input terminal of the analog-to-digital conversion circuit, It is used to detect the on-off time of the vacuum circuit breaker. 2. The vacuum circuit breaker contact testing device according to claim 1, wherein the number of said linear displacement sensors is three, which are respectively connected to the U, V and W phase moving contacts of said vacuum circuit breaker. journey. 3. The vacuum circuit breaker contact testing device according to claim 2, characterized in that there are three sample/hold circuits, which are respectively connected to the three linear displacement sensors. 4. The vacuum circuit breaker contact testing device according to claim 1, further comprising a potentiometer connected to the linear displacement sensor to stabilize the voltage and reduce the influence of temperature drift. 5. The vacuum circuit breaker contact testing device according to claim 1, wherein the sample/hold circuit comprises: A sample/hold device, the input end of which is connected to the linear displacement sensor; The potentiometer is connected to the zero adjustment terminal of the sample/hold device to adjust the drift voltage. 6. The vacuum circuit breaker contact testing device according to claim 1, further comprising a serial port circuit connected between the analog-to-digital conversion circuit and a host computer.