JPH0612949A - Improper vacuum detecting device - Google Patents

Abstract

PURPOSE:To provide an improper vacuum detecting device whereby normal operation and misoperation can be discriminated in detecting an improper vac uum. CONSTITUTION:Of a discharge waveform detected in an improper vacuum, the crest voltage of a discharge waveform component is detected by a discharge waveform detecting circuit 14, and in AC waveform component is detected by an AC component detecting circuit 16, to display an output value of the discharge waveform detecting circuit 14 in a discharge waveform peak value display circuit 15. A vacuum pressure decision circuit 18 calculates a vacuum pressure in an improper vacuum detection range and at improper vacuum detection time based on output signals from these detecting circuit and output circuit 11.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vacuum defect detecting device.

[0002]

2. Description of the Related Art A conventional vacuum valve vacuum defect detecting device for a vacuum circuit breaker is shown in FIG. In the figure, reference numeral 1 is, for example, a copper plate molded with an insulator (not shown), which is a detection sensor for detecting the vacuum pressure of the vacuum valve,
Is a detection impedance circuit for converting an output signal from the detection sensor 1 into an AC component voltage and a discharge pulse voltage,
Reference numeral 3 is a selection switch for selecting the detection impedance circuit 2 and a self-diagnosis circuit 6 described later. 4 receives the AC voltage output from the detection impedance circuit 2 as input
A waveform waveform circuit 5 applies a so-called window to a data window at a position where a discharge pulse is generated from a wave, when a vacuum pressure in the vacuum valve is reduced, and a discharge occurs in a contact and a shield plate in a vacuum valve (not shown). A discharge waveform shaping circuit for shaping the discharge pulse by using the discharge pulse output from the detection impedance circuit 2 as an input, and 6 is a self-check for confirming the soundness of the device by simulating the waveform when the vacuum pressure of the vacuum valve drops. A diagnostic circuit 7 is a discharge waveform determination circuit that receives the output from the discharge waveform shaping circuit 5 and determines a vacuum defect when the input voltage reaches the vacuum defect voltage.

Reference numeral 8 is an AND circuit that receives the outputs from the window waveform circuit 4 and the discharge waveform determination circuit 7 and outputs a signal when both outputs are simultaneously output, and 9 is an AND circuit 8
A counter circuit that counts up the output from the input, 10 is a counter determination circuit that receives the output from the counter circuit as an input and determines whether or not a vacuum defect output is continuously generated for a predetermined time, 11 is a counter It is an output circuit which outputs an output from the circuit 9 and outputs a vacuum defect display or an external vacuum defect output contact when a vacuum defect output is input. Further, 12 is a vacuum circuit breaker, and 13 is a main circuit.

That is, the detection sensor 1 is arranged near a vacuum valve (not shown). AC if the vacuum valve is normal
Although only waveforms are output, if a small hole is created in the vacuum valve, for example, and the pressure inside the vacuum valve changes from high vacuum to atmospheric pressure, the vacuum valve and internal shield plate are discharged. To do. As the output of the detection sensor 1, this discharge is output to the detection impedance circuit 2 along with the AC waveform. With respect to the output from the detection impedance circuit 2 when the vacuum is defective, the window waveform circuit 4 creates a data window for detecting only the discharge portion from the AC waveform, and the discharge waveform shaping circuit 5 and the discharge waveform determination circuit 7 generate the discharge pulse. A vacuum failure signal is determined based on the magnitude of the voltage. Then, when the outputs from the window waveform circuit 4 and the discharge waveform determination circuit 7 are picked up by the AND circuit 8 and continuously output from the AND circuit 8 for a predetermined time, the user is warned that the vacuum valve is defective in vacuum. Can be given.

[0005]

The conventional vacuum defect detecting device has the following problems.

That is, even if the vacuum defect of the vacuum valve of the vacuum circuit breaker is detected by the vacuum defect detection device and an alarm is output, it is not possible to normally operate or determine erroneous detection due to external noise or the like. In addition, after detecting a vacuum defect, the load side of the circuit breaker must be stopped and a commercial frequency withstand voltage test must be performed between the vacuum valve electrodes to check the vacuum pressure of the vacuum valve.
Therefore, it takes a long time to carry out such verification, which imposes a heavy financial burden on the user. An object of the present invention is to provide a highly reliable vacuum defect detecting device capable of determining whether it is a normal operation or an erroneous detection.

[0007]

In order to achieve the above object, the present invention is connected to a vacuum circuit breaker having a pair of electrodes which can be freely contacted and separated in a vacuum container, and is detected when a vacuum in the vacuum container is defective. In a vacuum defect detecting device for detecting an abnormality from a discharge waveform and an AC waveform detected under normal conditions, a first detecting means for detecting a peak value of an AC wave component in the discharge waveform and a discharge wave component in the discharge waveform. The second detecting means for detecting the start time of the vacuum defect from the peak value, the third detecting means for detecting the continuous generation of the discharge waveform, and the first, second and third detecting means. The gist is that it is constituted by a discriminating means for detecting a vacuum pressure value within the vacuum defect detection range and at the time of vacuum defect detection based on the output signal.

[0008]

In such a structure, the first detecting means for detecting the AC wave component in the discharge waveform, the second detecting means for detecting the start time of the vacuum defect, and the discharge waveform are continuously generated. By the output signal of each of the third detecting means for detecting
Since the determination means detects the vacuum pressure value within the vacuum defect detection range and at the time of vacuum defect detection, erroneous detection can be prevented and reliability is improved.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the drawings. The same components and circuits as those in the related art are designated by the same reference numerals as those in FIG. 6 and their description is omitted.

FIG. 1 is a block diagram of a vacuum defect detecting device of the present invention. In the figure, reference numeral 14 is a discharge waveform detection circuit for detecting a discharge pulse crest value generated when a vacuum failure is caused by a signal output from the selection switch 3, and 15 is an output of the discharge waveform detection circuit 14, Discharge waveform peak value display circuit for displaying an LED numerical value, 16 is an AC minute detecting circuit for detecting an AC minute waveform by the signal output from the selection switch 3, and 17 is an input of the output of the AC minute detecting circuit 16, for example, an LED numerical value display It is an AC demultiplexing value display circuit.

Further, 18 receives the signal from the output circuit 11 and the outputs of the discharge waveform detection circuit 14 and the AC component detection circuit 16 to determine the vacuum pressure at the vacuum defect detection point or the vacuum pressure within the vacuum defect detection range. Vacuum pressure determination circuit, 19 is a vacuum pressure display circuit that displays the vacuum pressure within the vacuum defect detection range, for example, with an LED numerical value, and 20 is a vacuum pressure display that displays the vacuum pressure at the vacuum defect detection point, for example, with an LED numerical value when vacuum defect is detected Circuit. Next, the operation of the embodiment configured as described above will be described.

The detection sensor 1 arranged near the contact of a vacuum valve (not shown) has a high vacuum pressure regardless of whether the contact of the vacuum valve is open or closed. While changing from vacuum to atmospheric pressure, detect the discharge waveform when discharging to the vacuum valve contact and the shield plate. The output from the detection sensor 1 is integrated by the detection impedance circuit 2 and converted into a signal that is easy to detect.
The output waveform of the detection impedance circuit at this time is a waveform in which the discharge waveform is added to the AC wave whose phase is advanced by 90 ° from the frequency of the main circuit voltage. The output signal from the detection impedance circuit 2 is output to the selection switch 3. When the selection switch 3 is turned on to the vacuum defect detection side, it is output to the window waveform circuit 4, the discharge waveform shaping circuit 5, and the discharge waveform detection circuit 14 and the AC component detection circuit 16. The discharge waveform detection circuit 14 detects the peak value of the discharge pulse generated when a vacuum defect is reached, and outputs it to the discharge waveform peak value display circuit 15 and the vacuum pressure determination circuit 18. Discharge waveform peak value display circuit 15
Then, the peak value of the discharge pulse is displayed on the LED numerical value to indicate that the detection is started. In the AC minute detection circuit 16,
The AC peak value is detected and output to the AC peak value display circuit 17 and the vacuum pressure determination circuit 18. The AC peak value display circuit 17 displays the AC peak value in LED numerical values. In the vacuum pressure determination circuit 18, the outputs of the output circuit 11, the discharge waveform detection circuit 14, and the AC component detection circuit 16 are calculated, and the vacuum pressure when the vacuum defect is detected is the vacuum pressure display circuit 20 when the vacuum defect is detected, and the vacuum defect. It outputs to the vacuum pressure display circuit 19 which displays the vacuum pressure within the detection range. Both the vacuum pressure display circuit 19 and the vacuum pressure display circuit 20 when a vacuum defect is detected display the vacuum pressure in LED numerical values. A time chart showing these relationships is as shown in FIG.

That is, the main circuit voltage waveform A is always applied when the vacuum circuit breaker is in the open and closed states. When the vacuum is defective, an output waveform B of the detection impedance circuit 2 is obtained with respect to the main circuit voltage, and the waveform is such that a discharge pulse is added to the AC portion by 90 °. Where C
Is a window waveform, D is the output of the discharge waveform determination circuit 7, and E is the output of the AND circuit 8.

Further, FIG. 3 shows the vacuum pressure and the discharge voltage between the valve poles, and FIG. 4 shows the vacuum pressure and the AC demultiplexed high voltage of the vacuum failure signal.
FIG. 5 shows the relationship between the vacuum pressure and the discharge pulse wave high voltage. Note that x and y in FIGS. 3 to 5 indicate vacuum defect detection points.

In this embodiment, the output waveform of the detection impedance circuit 2 of FIG. 2 is a2 as shown in FIGS. 4 and 5 due to the vacuum pressure.
Vacuum pressure judgment circuit 18 by applying the characteristics of a3
It is possible to display the vacuum pressure when the vacuum is defective and the vacuum pressure within the detection range.

Therefore, when a vacuum failure occurs in the vacuum valve of the vacuum circuit breaker, it can be determined that the numerical value display LED of the discharge waveform crest value display circuit 15 has started displaying and the vacuum failure detection device has started detection. . When the vacuum pressure further rises, detection operation is performed at a certain operating point, and the vacuum pressure is numerically displayed and held by the vacuum pressure display circuit 20 when a vacuum defect is detected. The vacuum pressure within the vacuum defect detection range is always displayed numerically by the vacuum pressure display circuit 19.

From each of these indications, it can be determined that the vacuum defect detection device is operating normally, and the commercial frequency withstand voltage test is not performed between the vacuum valve poles after the detection of the vacuum defect. It becomes possible to reduce the disadvantages.

[0018]

As described above, according to the present invention, when the vacuum valve used in the breaking portion of the vacuum circuit breaker has a defective vacuum, the defective vacuum can be surely detected, and after the defective vacuum occurs, It is possible to obtain a vacuum defect detection device that does not require a great deal of time for investigation and can reduce the user's time and financial burden.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of an embodiment of a vacuum defect detecting device of the present invention.

FIG. 2 is a diagram for explaining the operation of FIG.

FIG. 3 is a characteristic diagram of the vacuum pressure in FIG. 1 and the discharge voltage between the valve poles.

FIG. 4 is a characteristic diagram of the vacuum pressure of FIG. 1 and the AC demultiplexing high voltage of the vacuum defect signal.

FIG. 5 is a characteristic diagram of the vacuum pressure and the discharge pulse wave high voltage of FIG. 1.

FIG. 6 is a block diagram showing a configuration of a conventional vacuum defect detecting device.

[Explanation of symbols]

1 ... Detection sensor, 2 ... Detection impedance circuit, 11 ... Output circuit, 14 ... Discharge waveform detection circuit, 16 ... AC component detection circuit,
18 ... Vacuum pressure judgment circuit.

Claims (1)

[Claims] 1. A vacuum circuit breaker having a pair of electrodes which can be freely contacted and separated from each other in a vacuum container, and detects an abnormality from a discharge waveform detected when the vacuum in the vacuum container is defective and an AC waveform detected when the vacuum container is normal. In a vacuum defect detecting device for detecting, a first detecting means for detecting a peak value of an AC wave in the discharge waveform and a start time of the vacuum defect from a peak value of a discharge wave in the discharge waveform. Second detecting means, and third detecting means for detecting that the discharge waveform is continuously generated,
Vacuum defect detection, comprising: a determination unit that detects the vacuum pressure value within the vacuum defect detection range and the vacuum pressure value when the vacuum defect is detected based on the output signals from the first, second, and third detection units. apparatus.