JPH0584615B2 - - Google Patents

Description

Detailed Description of the Invention [Technical Field of the Invention] The present invention relates to a switching device used for self-diagnosing malfunctions of a power switch operating device that opens and closes a power switch used in a power system, for example. The present invention relates to a container opening/closing time detection device.

[Technical Background of the Invention and Problems Therewith] Generally, important power switches, particularly protective circuit breakers, are opened and closed using hydraulic operating devices or the like. This type of circuit breaker must not only be able to switch on and off the load current, but also have the ability to quickly and reliably cut off the fault current in the event that an abnormality occurs in the power system and fault current flows. . Therefore, there is a need for maintenance measures to prevent circuit breaker failures in advance.

Generally, the majority of circuit breaker failures are due to malfunctions in the mechanical operating parts of the operating device, and in particular there are cases where the circuit breaker is unable to operate due to "galling" or "lack of lubricant" in the rotating or sliding parts. However, in this case, the device does not become inoperable all at once, but the opening/closing time gradually becomes longer, which may eventually lead to a serious accident.

Conventionally, the following first, second, and third preventive maintenance measures have been taken in response to the occurrence of serious accidents as described above. The first example is to electrically measure the normal opening/closing time of a circuit breaker using a switching time detection device in the early stages of use, store this as a reference value, and then perform the opening/closing operation during periodic inspections of the circuit breaker. There is a device in which the opening/closing time at that time is compared with the above-mentioned reference value, and if the difference exceeds an allowable range, it is determined that there is an abnormality.

As a second example, recently, as opening/closing time detection means used in the above-mentioned preventive maintenance measures, a position detection index attached to a connecting part of a movable contact of a power switch and a switch operating mechanism, There is a device that uses a position detection sensor that is provided at a predetermined position along the movement route of the index for electrically detecting the position and detects the opening/closing time based on the output of the position detection sensor.

Further, as a third example, there is a method in which the position detection index and the position detection sensor of the second example are used to optically detect the position detection index.

However, the first to third examples have the following problems. In other words, periodic inspections of circuit breakers are usually carried out at very long intervals of 6 months to several years, and malfunctions that occur during the period up to the next periodic inspection will not be considered in any of the first to third examples above. However, it could not be detected even during this period, and there was a risk that a serious accident could occur during that time.

Furthermore, in the second example, since the opening/closing time is detected electrically by the opening/closing time detection means, it has the disadvantage that it is easily influenced by induction caused by switching surges, etc. when used in a substation, for example. It was hot. Furthermore, in the third example, the second
Although the drawbacks of the above example can be removed, the position detection index, position detection sensor, etc. will become dirty due to the adhesion of oil and dirt, and if the contamination progresses, it will become impossible to detect the position detection index during the switch opening/closing operation. An opening/closing abnormality may be detected even though the operation is normal.

[Object of the Invention] The present invention has been made based on the above-mentioned circumstances, and is a device that uses an optical method to determine the presence or absence of an abnormality in the opening/closing operation, and has a function of self-diagnosing the presence or absence of an abnormality in the optical system. It is an object of the present invention to provide a switching time detection device for a power switch which is capable of accurately detecting the occurrence of an abnormality in a switch at any time, saves labor in maintenance and maintenance of the switch, and has excellent reliability.

[Summary of the Invention] The present invention has been made to achieve the above-mentioned object, and includes a reflecting plate attached to a connecting portion that connects a movable contact and a movable arc contact of a switch to an operating mechanism thereof, and A plurality of optical fiber heads for position detection are arranged along the movement path to project light onto the reflector and to receive the light reflected by the reflector, and the reflector has a reflectance different from that of the other parts for position detection. An indicator is carried on the switch side at a position that is less than or equal to the wiping distance of the movable main contact from a position facing the position detection optical fiber head disposed on the switch side when the switch is closed. , the time from when the switch tripping command is issued until the position detecting optical fiber head on the switch side detects the position detecting index, and the time between the position detecting optical fiber heads. The time required for the index to pass is measured, and these measured times are compared with a reference value to constantly monitor the presence or absence of any abnormality in operation, and the level of light reflected by the reflector plate at the position detection optical fiber head is determined. An opening/closing time detection device for a switch, characterized in that means for constantly monitoring and determining the presence or absence of an abnormality in the optical system is installed outside the switch, and is connected to a plurality of the position detection optical fiber heads via optical fibers. be.

[Embodiment of the Invention] FIG. 1A is a schematic diagram of an embodiment of the present invention.
In this figure, 1 is the main part of the circuit breaker, and the main part 1 includes a gas tank 2 filled with insulating gas and a fixed main contact 3 housed in this gas tank 2.
, a movable main contact 4, a fixed arc contact 5, and a movable arc contact 6, which are separated from each other.

On the other hand, the opening/closing operation device 7 includes a hydraulic cylinder such as a hydraulic cylinder 8, a piston 9 that is slidably provided in the hydraulic cylinder 8 and is driven by a drive hydraulic circuit to be described later, and a piston 9 and the movable piston 9. It consists of an operating rod 10 that connects the main contactor 4.

The hydraulic circuit for driving the hydraulic cylinder 8, for example, the hydraulic circuit, is pressurized by an oil tank 11, a pipe line 12 connecting the oil tank 11 and the bottom end of the hydraulic cylinder 8, and a pump 13 from the oil tank 11. an accumulator 14 for accumulating hydraulic oil, a pipe line 15 leading to the accumulator 14, a pipe line 16 connecting the discharge side of the pump 13 and the front side of the piston 9 in the hydraulic cylinder 8, and the pipe line A branch pipe line 17 that communicates between the pipe line 12 and the pipe line 16;
A solenoid valve 18 having an actuating coil 18a provided in this branch line 17, and an actuating coil 19a provided between the branch part of the branch line 17 and the oil tank 11.
a solenoid valve 19 having a branch pipe 1 of the pipe line 16;
A solenoid valve 64 having an actuating coil 64a provided at a portion closer to the hydraulic cylinder 8 than the branching portion of the valve 7;
The solenoid valve 65 has an operating coil 65a provided on the drain (not shown) side of the front surface of the piston 9 in the hydraulic cylinder from the solenoid valve 64. Note that the accumulator 14 has a free piston 14a, and this free piston 14
An inert gas 14b is sealed on the side opposite to the hydraulic oil a. In addition to the above configuration, an opening/closing time detection means having the following configuration is provided. That is, a light reflecting plate 20 is attached to the operating rod 10, as shown in the perspective view of FIG. 1B. This light reflecting plate 20 has a surface with high reflectance as a whole,
This surface has a band-shaped position detection index 2 with low reflectance.
1a and a position detection indicator 21b are provided, of which the position detection indicator 21a is provided on the movable contact side.

Further, above the operating rod 10, as shown in FIG. 1A, there is an optical fiber head 22 for detecting the closed circuit position.
An optical fiber head 23 for detecting an intermediate position and an optical fiber head 24 for detecting an open circuit position are provided.
Each of the optical fiber heads 22 to 24 has a light projecting section 22a and a light receiving section 22b, 23a and 23b, 2, respectively.
4a and 24b. Each optical fiber head 22
-24 light projecting units 22a to 24a are E/O conversion units 28a that convert optical signals provided to the detection unit 28 through light projecting optical fibers 25, 26, and 27 into electrical signals.
The light receiving section is connected to the light receiving optical fibers 29, 3.
0 and 31, it is connected to an O/E conversion section 28b provided in the detection section 28, which converts light into electricity. The detection section 28 is provided with a calculation section 28c that controls the energization of the light projecting sections 22a to 24a and compares the outputs of the light receiving sections 22b to 24b with a reference value. This arithmetic unit 28c is configured such that each of the position detection optical fiber heads 22 to 24 corresponds to the position detection index 21.
When a, 21b is detected, an off signal is generated, and when not detected, an on signal is generated, and this is used to calculate an electrical signal through signal lines 60, 61, 62 corresponding to each of the position detection optical fiber heads 22 to 24. It is sent to the processing device 33. Further, the arithmetic unit 28c has a function of sending an alarm to the terminal 34 when the outputs of the light receiving units 22b to 24b are smaller than the reference value.

The arithmetic processing unit 33 also has terminals 35 and 3.
6, a tripping command S1 and a closing command S2 are given.

The arithmetic processing unit 33 has a position detection index 21a,
The time when the circuit breaker 1 was actually tripped or closed is determined from the detection output of the circuit breaker 21b, and these times and the terminal 3
The time required for tripping or closing is determined from the time when the trip command S1 from 5 or the closing command S2 from terminal 36 is received, and if these times are greater than the reference value, an alarm is sent from terminal 37. I'm starting to do that.

Next, each movable main contactor 4, movable arc contactor 6
wiping will be explained. Assume now that a tripping command S1 is received. Then, the movable main contact 4,
Since the movable arc contactor 6 starts to move from a stationary state, the contact state is followed, that is, wiped, in accordance with the acceleration force after tripping, in order to set the opening speed to the required value. This wiping is the same in the closing operation. However, in this case, the problem is deceleration force instead of acceleration force. This situation is shown in FIGS. 2A and 2B. FIG. 2A shows the tripping operation, and FIG. 2B shows the closing operation. As can be seen from this figure, unlike the wiping distance | _A of the normal movable main contactor 4 and the wiping distance | _B of the movable arc contactor 6, | _A <| _B . Further, it is considered that the wiping distances |' _A and |' _B during the tripping operation and the closing operation are approximately equal. That is, | _A = |′ _A and | _B = |′ _B. Each of the position detection optical fiber heads 22 to 24 described above is installed at a position that takes into consideration the above-mentioned wiping.

Further, the distance between the optical fiber head 22 for detecting the closed circuit position and the optical fiber head 23 for detecting the intermediate position is selected to be narrower than the distance between the position detecting indicators 21a and 21b. The distance between the intermediate position detection optical fiber head 23 and the open circuit position detection optical fiber head 24 is determined by the position detection index 21a,
21b is selected to be wider than the spacing between 21b.

The position of the intermediate position detection optical fiber head 23 is such that when the circuit breaker 1 is in the closed state, the position detection index 21b is located at the intermediate position detection optical fiber head 2.
It is selected so that it is within the detection range of 3.

As described above, each position detection optical fiber head 2
Since the positions of 2 to 24 are determined, when the movable main contact 4 is in the closed state, the position detection indicator 21a on the movable main contact 4 side is used for detecting the closed circuit position, as shown in FIG. 4A. It is located closer to the movable main contactor 4 than the optical fiber head 22. When the movable main contact 4 is in the tripped state, the position detection indicators 21a and 21b are both located on the opposite side of the open circuit position detection optical fiber head 24 from the movable main contact 4, as shown in FIG. 4B. be.

Therefore, when the movable main contactor 4 is in the closed state, the signal of the position detection optical fiber head 22 is on.
The 23rd signal is off, and the 24th signal is on.

As shown in FIG. 3-1, it is assumed that a trip command S1 is issued at a certain point in time. This allows the third
A tripping operation is performed during period TA in the figure.

First, the operating coil 19a of the electromagnetic valve 19 in the conduit 12 shown in FIG.
Connect 1. At the same time, the actuating coil 64a of the solenoid valve 64 is energized to open the solenoid valve 64. In this case, the solenoid valve 18 is in a closed state. As a result, the piston 9 rapidly moves toward the right side in the drawing due to the hydraulic pressure within the accumulator 14 acting on the front surface of the piston 9 within the hydraulic cylinder 8.

On the other hand, an operating rod 10 connected to a piston 9
The movable main contactor 4 connected to the main contactor 4 starts rapid movement in the contact separation direction with a stroke as shown in FIG. 3-2. One position detection indicator 2 on the reflector 20
1a rapidly passes through the optical fiber head 22 for closed circuit position detection, and the other position detection indicator 21b is
It quickly leaves the detection range of the optical fiber head 23 for intermediate position detection. This position detection index 21b
When the intermediate position detection optical fiber head 23 leaves the detection range, the intermediate position detection head 23
generates an on signal, and this signal is sent to the arithmetic processing unit 33 through the signal line 61. Then the third
As shown in FIG. 3-3, the position detection index 21a
When the optical fiber head 22 for detecting the closed circuit position passes through, an off signal SA _A is generated. This signal is signal line 60
The data is sent to the arithmetic processing unit 33 through. After the position detection index 21b leaves the detection range of the intermediate position detection optical fiber head 23, it passes through the open circuit position detection optical fiber head 24 and an off signal is generated, but before that, the position detection index 21a has moved to the intermediate position. After passing through the detection optical fiber head 23,
An off signal SA _B is generated as shown in -4. These off signals are sent to the arithmetic processing unit 33 through the signal lines 32 and 30;
3 ignores the signal from the optical fiber head 24 for detecting the open circuit position that arrives from the signal line 32 after a delay, and ignores the signal from the optical fiber head 24 for detecting the intermediate position.
Incorporate SA _B. Finally, as shown in FIG. 3-5, the position detection indicator 21a passes through the open circuit position detection optical fiber head 24, and an off signal _SAC is generated. This signal is sent to the arithmetic processing unit 33 through the signal line 62.

Off signals SA _A , SA _B , and SA _C are sent to the arithmetic processing unit 33
, from the time of input of the trip command S1 that has already been input in the arithmetic processing unit 33,
Based on the time T ₁ (opening time) until the off signal SA _B output from the optical fiber head 23 for intermediate position detection is input, and the input time of the signal SA _A output from the optical fiber head 22 for closed position detection, the open position can be determined. Off signal SA _C output from detection optical fiber head 24
The time T ₂ (open circuit time) up to the input point of time is calculated, and the open circuit time required for the position detection indicator 21a to reach a predetermined position is detected.

On the other hand, at a certain point in the above-mentioned open state, the closing command S
Suppose that 2 is given. As a result, the closing operation is performed during the period TB in FIG. 3. First, actuating coil 18a is deenergized and actuating coil 19a is energized.

Simultaneously with the activation of the activation coil 19a, the activation coil 65a is activated, and the activation coil 64a is also activated.
is deenergized, so that the electromagnetic valve 65 is opened, the front surface of the piston 9 of the hydraulic cylinder 8 is communicated with the drain, and the hydraulic pressure is applied to the rear surface of the piston 9 of the hydraulic cylinder 8. As a result, the piston 9 is driven in the opposite direction to the aforementioned operation, and the operating rod 10 and the movable main contact 4 also begin to move toward the fixed main contact 3 at high speed.

With this movement, the position detection index 21a passes through the detection ranges of the optical fiber head 24 for open circuit position detection, the optical fiber head 23 for intermediate position detection, and the optical fiber head 22 for closed circuit position detection in this order, and the off signals SB _C and SB are detected. _B and SB _A are generated (right side of Figure 3 3-3 to 3-5). Further, the position detection indicator 21b is also connected to the optical fiber head 2 for open circuit position detection.
4, an off signal is generated upon passing, but this signal is ignored.

When the above-mentioned off signals SB _A to SB _C are input to the arithmetic processing unit 33 to which the input command S2 has already been input, the processing from the time when the input command S2 is input to the time when the off signal SB _B is input in the arithmetic processing unit 33 time of
T ₃ (turning time) is calculated, and the time T ₄ from the time when the off signal SB _C is input to the time when the off signal SB _A is input
(Closing time) is calculated. Thereby, the time required for the position detection index 21a to reach the predetermined position is detected.

The arithmetic processing unit 33 compares the opening time T ₁ , opening time T ₂ , closing time T ₃ , and closing time T ₄ obtained as described above with their respective reference values, and determines that the difference is within the allowable range. The presence or absence of an abnormality in operation is determined based on whether or not the operation is abnormal. If it is determined that there is an abnormality, an alarm is sent from the terminal 37.

By the way, the reflector 20 has a surface with a high reflectance and a position detection index 21 with a low reflectance.
a and 21b exist. The light emitted by the E/O converter 28a is transmitted into the optical fibers 25-27 and is projected toward the reflecting plate 20 from the light projectors 22a-24a of the position detection optical fiber heads 22-24. The light reflected on the surface of the reflecting plate 20 is transmitted to the light receiving section 22 of each of the optical fiber heads 22 to 24.
b~24b, optical fibers 29~3
1 and is converted into an electrical signal by the O/E converter 28b. When the high reflectance portion of the reflector plate 20 is within the detection range of the position detection optical fiber heads 22 to 24, the light reception level _PW is in the H state as shown in FIG. 5A. Further, the electric signal is also in the H state as shown in FIG. 5B. Position detection index 21 with low reflectance as the circuit breaker 1 opens and closes
a, 21b are position detection optical fiber heads 22~
When the light enters the detection range of 24, the received light level naturally decreases. When the above-mentioned reduction in the light reception level reaches a predetermined operating level P _A , the level of the electric signal becomes an L state. However, the reflective plate 20 is damaged by dust and other debris generated by long-term use.
The high-reflectance portion of the light is contaminated, and the received light level P _W gradually decreases. In the worst case, the operating level P _A
It may even drop to .

In such a state, the position detection index 21
Detection of a, 21b becomes uncertain or impossible,
This will result in malfunction. Therefore, in the above embodiment, the alarm level P _B is set to n times the operation level P _A.
It is said that Further, when the duration of the decrease in the electrical signal becomes m times T _W of the maximum pulse width generated by the passage of the position detection indicators 21a and 21b through the respective position detection optical fiber heads 22 to 24,
The arithmetic processing unit 33 determines whether the reflection plate 20 is contaminated.

By setting the alarm level P _B , the operation level P _A , and the level drop duration T _W in this way, it is possible to determine whether the received light level P _W is below the alarm level P _B , above the operation level P _A , and when the level drop duration is above T _W. Depending on whether or not the optical system is contaminated, it is determined whether or not the optical system is contaminated. As mentioned above, since the time T _W is added to the determination factor, the light reception level P _W decreases due to the passage of the position detection indicators 21 a and 21 b during the opening/closing operation, and the reflection plate 20
It is possible to distinguish between a decrease in the light reception level due to surface contamination. In this manner, when it is determined that the reflector 20 is contaminated, an alarm is issued from the terminal 34.

According to the embodiment described above, by optically detecting the position detection indicators 21a and 21b formed on the reflection plate 20 attached to the operating rod 10 that drives the possible main contactor 4 and the movable arc contactor 6. ,
Tripping command S is issued every time the circuit breaker is opened or closed.
The time required for each movable contact to move to a predetermined position is constantly monitored from the time when the closing command S1 and closing command S2 are issued.

In this case, since the total time required to shut off or close the connection and the time required to move to a predetermined intermediate position is monitored, even subtle abnormalities can be detected accurately and with relatively high sensitivity. and exhibits excellent self-diagnosis capabilities. In addition, the light receiving lens is constantly monitored, and if the received light level becomes lower than a predetermined standard or the duration of the level drop becomes longer than a predetermined time, it is determined that the reflector 20 is contaminated and an alarm is issued. This makes it possible to prevent malfunctions caused by contamination of the optical system. Furthermore, since the device uses an optical system, it is less susceptible to the effects of induction such as switching surges when used in a substation.

In addition, the level of light received by the optical fiber heads 22 to 24 for detecting the position of the reflected light from the reflector plate 20 is constantly monitored, and the E/O section 28a, O/E section 28b, calculation section 28c, and calculation processing device 33 are connected to the outside of the switch. Because it is installed, the influence of induction (surge, etc.) is reduced and detection accuracy is improved.

FIG. 6, in which the same parts as in FIG. 1 are denoted by the same reference numerals, is a schematic diagram showing another embodiment of the present invention. In this embodiment, a hydraulic sensor 38 is provided to detect the hydraulic pressure of the conduit 15 of the hydraulic drive circuit, that is, the accumulator 14, as an electrical signal, and a temperature sensor 39 is further provided to detect the ambient temperature of the circuit breaker 1 as an electrical signal. ing. Further, the solenoid valve 1
Voltage sensors 40, 4 detecting the control voltage applied across the actuating coils 18a, 19a of 8, 19.
1 is provided. Thus, each sensor 38
The outputs of -41 are converted into optical signals by E/O converters 42-45 and sent to O/E converter 50 via optical fibers 46-49.

The electrical signals converted by this O/E converter 50 are input to the arithmetic processing unit 33 through signal lines 51 to 54. Other than the above points, the configuration is the same as that of the embodiment shown in FIG. 1 described above.

In an embodiment with such a configuration, the time t required for the position detection index to reach a predetermined position from the time when the tripping command or the closing command is issued depends on the oil pressure P, the ambient temperature T, and the control voltage. It fluctuates under the influence of E. These relationships can be expressed as a function t=F(P,T,E) based on test data. Therefore, if each measurement value obtained in the same manner as in the embodiment shown in FIG. 1 is corrected by the output of each sensor to determine the time required for opening and closing, then the embodiment shown in FIG. In addition to its effects, more accurate self-diagnosis becomes possible.

Note that the present invention is not limited to the above embodiments. For example, it can also be applied to switches other than the illustrated circuit breaker 1. Furthermore, the position detection indicators 21a and 21b on the reflecting plate 20 may have higher reflectance than other parts.

[Effects of the Invention] As described above, the switching time detection device for a switch of the present invention allows the movable contact to be at a predetermined position from the time the tripping command or closing command is issued every time the switch is opened or closed. The time required to travel to the destination will be constantly monitored.

In the present invention, since both the total time required for shutting off or closing and the operation time to a predetermined intermediate position are monitored, even subtle abnormal operations can be detected accurately and with relatively high sensitivity. It can perform excellent self-diagnosis functions.

Furthermore, since the received light level is constantly monitored, the drawbacks of using an optical detection method are eliminated, resulting in a highly reliable opening/closing time detection sensor.

Furthermore, since it employs an optical detection method, it is less susceptible to the effects of induction such as switching surges when used inside a substation or the like.

The influence of induction (surge, etc.) is reduced because a means is installed outside the switch to constantly monitor the level of light received by the optical fiber head for detecting the position of the reflected light from the reflector and determine whether there is an abnormality in the optical system. , the detection accuracy is improved.

In this way, it is possible to early and accurately detect the presence or absence of an abnormality in a switch such as a circuit breaker without waiting for periodic inspection. As a result, it becomes possible to save labor in maintaining and maintaining the switch.

[Brief explanation of the drawing]

Figure 1A is a schematic diagram of one embodiment of the present invention, Figure 1B
is a perspective view showing an enlarged part of it, Figures 2A and B
is a diagram showing the movement stroke of the movable contact, the third
The figure is a diagram showing the relationship between the opening/closing stroke and various signals, Figures 4A and B are diagrams showing the relationship between closing and tripping states and position detection indicators, and Figure 5 is the relationship between the received light level and electrical signals. FIG. 6 is a schematic diagram of another embodiment of the present invention. 1... Circuit breaker, 3... Fixed main contact, 4... Movable main contact, 5... Fixed arc contact, 6... Movable arc contact, 7... Opening/closing operation device, 8... Hydraulic cylinder , 9... Piston, 10... Operation rod, 11... Oil tank, 12, 15, 16... Pipe line, 17... Branch pipe line, 18, 19, 64, 65...
...Solenoid valve, 18a, 19a, 64a, 65a...
Operating coil, 20...Reflector, 21a, 21b...
... Indicator for position detection, 22 ... Optical fiber head for detecting closed circuit position, 23 ... Optical fiber head for detecting intermediate position, 24 ... Optical fiber head for detecting open circuit position, 22a, 23a, 24a ... Light projecting section, 22
b, 23b, 24b...light receiving section, 25-27, 2
9-31... Optical fiber, 28... Detection section, 28
a...E/O conversion section, 28b...O/E conversion section,
28c... calculation section, 32, 35, 36, 37...
Terminal, 33...Arithmetic processing unit.

Claims (1)

[Claims] 1. A reflecting plate is attached to a connecting part that connects a movable main contact and a movable arc contact of a switch to its operating mechanism, and light is projected onto the reflecting plate along a movement path of the connecting part, and the reflecting plate A plurality of position detection optical fiber heads are arranged to receive reflected light from the switch, and a position detection index having a reflectance different from that of the other parts is disposed on the reflector plate, and the position detection index is arranged on the switch side when the switch is in the closed state. It is carried on the switch side at a position that is less than the wiping distance of the movable main contact from a position facing the position detection optical fiber head, and from the time when the switch tripping command is issued, the switch side Measure the time until the position detection optical fiber head detects the position detection index and the time required for the position detection index to pass between the position detection optical fiber heads, and set these measured times as a reference. The switch includes a means for constantly monitoring the presence or absence of an abnormality in operation by comparing with the value, and further constantly monitoring the level of light reflected by the reflection plate at the optical fiber head for position detection, and determining whether or not there is an abnormality in the optical system. 1. An opening/closing time detection device for a switch, characterized in that the opening/closing time detection device for a switch is installed outside the device and connected to the plurality of position detection optical fiber heads through optical fibers.