DD254256A1 - OPTOELECTRONIC WAY-TIME MEASURING ARRANGEMENT FOR ELECTRICAL SWITCHGEARS - Google Patents

Abstract

The invention relates to a measuring arrangement for detecting the evaluation of the switching pin or other moving parts of an electrical switching device, in particular suitable for detecting rotational as well as translatory movements. By the invention should u. a. be achieved that a measurement without direct mechanical coupling is made possible, a distortion of the measured values (characteristic curve) is excluded by electromagnetic fields and the measurement is made possible at high speeds. According to the invention, it is provided to transmit continuous light from a light source by means of an optical fiber to a measuring disk attached to the switching device drive or switching rod, which is modulated and reflected by the movement of the measuring disk provided with markings, and fed and processed via two further optical fibers to an evaluation circuit such that the optical signals are converted into electrical, amplified, formed into pulses and counted, as well as a directional decision is made. The counter content is assigned to a time base and can be mapped using suitable recording devices as a path-time characteristic.

Description

Invention description Title of the invention

Optoelectronic path-time measuring arrangement for electrical switching devices

Field of application of the invention

The invention relates to a measuring arrangement for detecting the movement of the switching pin or other moving parts of high-voltage switching devices, in particular suitable for · detection of rotational and translational movements.

Characteristic of the known.technical solutions

For detecting the path-time characteristic of high-voltage switching devices, the measuring arrangements described below are known:

By means of a with the drive of the switching device or the switching pin mechanically coupled potentiometer is a the way proportional electrical size (current, voltage, resistance o. Ä.) Supplied via measuring leads an evaluation device. In this case, the measured value can be falsified by electromagnetic fields. At higher switching speeds (> 5 m / s), measurement errors occur due to the lifting of the sliding contact from the resistance track.

23. S.SS-277183

In another measuring arrangement, the movement of the switching pin is detected by means of inductive pickup such that in the transducer, which is without mechanical coupling in the immediate vicinity of the switching pin, or a switching linkage of the drive, one of the speed of the moving part proportional voltage induced and this an evaluation device is supplied. The type of detection and transmission of the measured values can in turn be influenced by external fields and, like the above method, excludes measuring during operation.

Known from practical application is further a mechanical means for recording the path-time characteristic s = f (t), in which a roller on which a measuring strip is mounted, is moved at a constant speed by a motor. By means of a mechanical coupling to the switching device and the conversion of the rotary motion of a switch shaft into a straight-line motion, a pencil tip is guided axially over the roller and a curve is recorded. The curves obtained are very steep even at speeds of 5 m / s and thus difficult to evaluate and there is also the lack that the measuring arrangement is exposed by the direct mechanical coupling with the switching device in switch tests (type test) the risk of destruction. Furthermore, measuring in practical operation of the switching devices is not possible.

Objective of the invention

The aim of the invention is to develop a measuring arrangement for determining the path-time characteristic of Hochspannungssc.haltgeräten, with the disadvantages of the known technical solutions, in particular their limitation to moving speeds> 5 m / s and their susceptibility is overcome and with the very fast motion sequences (> 5 m / s) can be detected by a suitable sensor, the measured value

Transmission is not influenced by electromagnetic interference fields and destruction of the measuring instrument during device testing is ruled out and thus future superfast switching devices to be tested.

Explanation des.Wesens.der invention

The invention has for its object to provide a path-time measuring arrangement for electrical switching devices, 'in the free of mechanical coupling of the measuring device with the switching device recording the characteristic s = f (t) for switching devices with speeds> 5 m / s is enabled, the meter and the evaluation devices can be installed outside the Danger range in switch tests and the measured value transmission from the test object to the meter can be done free of interference from Premdfelder and in practical operation of the switching device.

According to the invention, this is achieved by using a measuring arrangement for detecting the path-time characteristic, which consists of a measuring disk with light-dark markings, a fiber optic sensor, an evaluation device and a measuring cable made of a plurality of optical fibers.

The measuring disk with the markings is firmly attached to the switching pin or the switch shaft of the device and scanned by the fiber optic sensor, which together with the measuring disk a reflex light barrier, contactless. In the measuring instrument, the light signal is converted by an optical receiving element (photodiode or the like) into an electrical signal and after appropriate amplification, the pulses resulting from the hot-dark marking of the measuring disc are shaped by means of a comparator into TTL-compatible L / O pulses and these added by means of counting. If the counting content is continuously queried, the cycle time characteristic curve of the switching device is obtained from the pulses registered per unit of time.

According to the invention, a transient storage in conjunction with an xy recorder for recording the characteristic f = s (t) can be used for this purpose or, when using a D / A converter, the characteristic curve can be imaged directly by means of a storage oscilloscope and an accelerator can be used for slow switching operations calibration of the characteristic using a light beam oscilloscope. Since the bouncing of the switching pin or linkage occurring in a switching device would distort the path-time characteristic, it is necessary to evaluate the direction of movement of the measuring disk.

According to the invention this is achieved in that a further fiber is arranged such that light pulses of the same amplitude are coupled into both fibers at different times. In the evaluation device, the directional decision is made from the applied signals by means of a discriminator, which can be used either to control the respective recording devices or to abort the recording process.

By switching the switching device is generally very much shaken, with the result that repercussions on the very sensitive sensor are possible. According to the invention, these repercussions are compensated for by the fact that optical lenses (preferably rod lenses) are mounted in front of the fiber ends in the sensor, whereby at the same time the adjustment of the sensor is simplified and facilitated.

embodiment

The invention will be explained in more detail below with reference to an exemplary embodiment. In the accompanying drawing show:

Fig. 1: Block diagram of the evaluation device.

Fig. 2: possibilities of arrangement of the measuring

disc on the switchgear

Fig. 3a, b, c: Structure of a measuring cable and the op- ^! table sensor.

As shown in FIG. 1, light is coupled into an optical fiber 11a by a light source 12 and emitted at the other end of the fiber, which is encapsulated here in an optical sensor 14 for mechanical support. From a mounted on the switch drive shaft of the switching device (13) measuring disc (8) this light is modulated in their movement according to the distances of the light-dark marks and the switching speed, reflected and coupled into a second optical fiber (11b). This modulated light signal is converted into a corresponding electrical signal in a receiver circuit (1a), amplified in an amplifier (2a), shaped by means of comparator (3a) into defined H / L pulses and added by a counter (4).

The counter content is recorded by means of transient memory (6). The memory contents can be represented with an xy-recorder as a characteristic s = f (t).

To compensate for the bouncing of the moving parts of the switch during the switching process, another optical fiber (11c) is arranged in the sensor (14) so that, as shown in FIG. 3b, the reflected light pulses have equal amplitudes at a time shift Δt. In a discriminator (5), the chronological order of the incoming pulses is evaluated and is available as a control signal.

As can be seen from FIG. 1, the measuring disk can be designed as a circular disk (8a) or as a ruler (8b), depending on the type of movement. , *

Fig. 2 shows the possible arrangement of the measuring disc (8) on a medium voltage switch (13) on the switch drive shaft (15) by means of screw, wherein in the drive shaft, a corresponding threaded hole is provided and thus the switch drive (16) does not have to be opened , d. H. even during practical operation, a measurement is possible.

Fig. 3a shows the structure of a measuring cable (17), in which the optical fibers (11a, b and c) are located, the spatial arrangement in the sensor (14-) Fig. 3b shows. The use of rod lenses (20) illustrates Fig. 3a.

The other ends of the optical fibers are connected via suitable optical connectors (18) to a light source (12), preferably an LED, or to optical receiving elements (1a and b) (photodiodes).

It is also possible to pour the transmitting and receiving elements directly to the respective fiber ends and to realize the input of the evaluation by conventional electrical plug contacts.

Claims (4)

invention claim 1. Optoelectronic path-time measuring arrangement for electrical switching devices characterized in that the measuring arrangement consists of a measuring disc with applied light-dark markers, an optical sensor, an evaluation device and a measuring cable with multiple optical fibers, wherein the measuring cable, the connection between the sensor and Indicator represents, while the measuring disc is firmly connected to the switching pin or shaft of the electrical switching device and the sensor with the 3 optical fibers and the measuring disc is a reflection light barrier, emitted from the one optical fiber light and coupled into the other fibers, the reflected and modulated light is, wherein the optical fibers are arranged in the sensor so that while in the one fiber maximum light power is coupled, in the other fiber, a minimum of light is coupled. 2. Measuring device according to item 1, characterized in that the dependence of the sensitivity of the sensor from the distance to the measuring disk by the use of optical lenses, preferably rod lenses, is reduced, which simultaneously contributes to the simplification of the adjustment of the sensor on the switching device. 3. Measuring arrangement according to item 1, characterized in that a beam splitter is arranged with simultaneous use of the optical fiber for irradiating the measuring disk and for returning the reflected light pulses between the optical fiber and the evaluation device. 4. Measuring arrangement according to item 1, characterized in that the evaluation device from the modules light source, opto-electrical converter, amplifier, comparator, discriminator, counters and memories with time base and arranged at the output recording devices for the path-time characteristic or a characteristic derived therefrom are. For this purpose, see page η