JPH0142388B2 - - Google Patents

Description

[Detailed Description of the Invention] This invention monitors the operating status of switching equipment in daily operating conditions, and when the operating status deviates from the normal operating status, an alarm is issued to detect an operational failure of the switching equipment in advance. , relates to an abnormal operation monitoring device for switching equipment for preventive maintenance.

Conventionally, during installation or periodic inspection of switchgear equipment, a travel recorder that fully interlocks with the main contacts is temporarily installed to check the operating characteristics of the main contacts, or to check the expected operation of the switchgear during daily operation. A method was adopted in which a protective relay system was used to operate other related switching equipment as a backup only when the switch did not operate after several times the time.

The method of attaching a travel recorder has the disadvantage that the operating characteristics of the opening/closing equipment can be checked only at the time of installation or periodic inspection, but no checks can be made during daily operation. Furthermore, the backup method of the protective relay system has the disadvantage that abnormal switching operations cannot be discovered until after the switching equipment has completely failed.

The present invention has been made in view of the above, and it monitors the operational aspects of switching equipment during daily operation, and detects an abnormality when it shows a tendency to deviate from a perfect state, although this does not pose a problem for daily operation. Provided is an abnormal operation monitoring device for switching equipment that provides an opportunity to repair abnormal operation through planned power outages.

When the switching device is in the closed state, it receives a trip command and performs an opening operation to reach the open state.
Since there is no difference in explaining the configuration of the present invention from the case where the opening state changes to the closed state, an example of the operation in the former case will be described.

FIG. 1 is a simulated explanation of the operating conditions of the switching equipment. Curve a is a so-called opening/closing characteristic curve that shows the movement of the movable electrode of the main contact. Curve b shows the trip command signal current. Curve c indicates the opening point of the main contact. It is assumed that time passes in the direction of the arrow in the figure. There is a time delay after the trip command signal current begins to flow at time A until time B when the movable electrode of the main contact begins to move. This is, for example, the time required for the trip electromagnet to be excited and operated by the trip command signal current to open a so-called catch, or the time required for the solenoid valve, control valve group, etc. to operate and drive the movable electrode of the main contact. This is because there is a time required for the main cylinder to start moving. When the movable electrode of the main contact starts moving from the closed position u at time B and reaches the _a0 position, the main contact opens at time C and reaches the open position v of the main contact at time D,
A series of opening operations is completed. In order to monitor abnormal operation of switching equipment, one or both of them must be used at times A and B, or when the movable electrode of the main contact is commanded to move a certain distance on the way from the closed position u to the open position v. , and issue an alarm if this time is longer than a preset time. If the time between times A and B becomes abnormally long, this often indicates an abnormal operation of the tripping electromagnet and catch, or of the electrode valve or control valve group. In addition, abnormally slow speed of the movable electrode of the main contact, that is, the time it takes to move a certain distance, is often caused by an abnormal increase in frictional force in the bearing system, etc., and the cause of the abnormality may be different for both cases. Since there are many, it is desirable to monitor both.

FIG. 2 is an electrical circuit diagram showing one embodiment of the present invention.

FIG. 3 shows the movement of the movable electrode of the main contact. In Figure 2, 1 is a tripping coil, 2
is a contact that works in conjunction with the movable electrode of the main contact, and is in the closed position when the main contact is closed, and in the open position when the main contact is open.

Note that the contact 2 changes from closed to open when the movable electrode of the main contact comes to position _a1 in FIG. 3, for example. 3 is a coil of the first time-limited relay, and the delay time is within the range where the trip command voltage is normal, for example, 60~
The time is adjusted to be slightly longer than the normal maximum time for the movable electrode of the main contact to start moving when in the 125V range. 4 is a contact that interlocks with the movable electrode of the main contact, and is in a closed state when the movable electrode is in the closed position u, and a ₁ that has moved very slightly from this closed position u.
It opens at a certain position and remains open thereafter, and is constructed of, for example, a micro switch. Reference numeral 5 denotes a self-holding contact that closes when the coil 3 starts excitation. 6 is a contact that interlocks with the movable electrode of the main contact, which is in an open state when the movable electrode of the main contact is in the closed position u, and performs a closing operation when it comes to a position _a2 slightly moved from the closed position u; From this point on, the closed state is maintained, and is comprised of a micro switch or the like. 7, the movable electrode of the main contact is in the closed state from the closed position u to the position _a3 just before the open position v, performs the opening operation at position _a3 , and remains open from this point on, and the micro switch It is made up of etc. 8 is an auxiliary relay 12 for turning on, which will be described later.
9 is the coil of the second time-limited relay, and the delay time is the time required for the movable electrode of the main contact to move from position _A2 to position _A3 , for example, when the hydraulic operating mechanism In this case, the time is set to be slightly longer than the maximum normal required time within the allowable oil pressure fluctuation range. 10 is the input coil;
11 is a contact that interlocks with the movable electrode of the main contact, which is in the closed state when the movable electrode of the main contact is in the open position v, and in the open state when it is in the closed position u, and the movable electrode of the main contact is in the position a ₂ Opening operation is performed near . Reference numeral 12 denotes an auxiliary relay, which has a self-holding contact 12a. 13 is a contact that interlocks with the movable electrode of the main contact,
Performs opening/closing operations in the opposite direction to opening/closing of the main contacts.

Next, the operation will be explained. In Fig. 2, when a trip command current is applied to the switchgear in the closed state, the contact 4 is in the closed state, so the coil 3 of the first time-limited relay is energized, and even after a preset time has elapsed. Contact 4 does not open, in other words,
If the movable electrode of the main contact does not start to move, the first time-limiting relay is activated, actuating a contact (not shown) and issuing an alarm. The role of the contact 5 is to continue excitation of the first time-limited relay when the trip current relay time is particularly short, and is not necessarily required.

The movable electrode of the main contact begins to move anyway and reaches position a ₂
When the time limit reaches , the contact 6 is closed and the contacts 7 and 8 are in a closed state, so that the second time-limiting relay 9 is energized.
Then, the movable electrode of the main contact reaches position _a3 ,
Excitation continues until contact 7 opens. If this excitation continuation time is longer than the preset delay time, the second time-limited relay 9 operates and an alarm contact (not shown) is activated to issue an alarm. Generally, the moving speed of the movable electrode of the main contact is slow during the closing operation.
It is normal for the opening operation to be fast. Therefore, during the closing operation, the excitation time of the second time-limited relay 9 is long;
In order to prevent an alarm from being erroneously issued, an auxiliary relay 12 is provided which is energized simultaneously with the closing command current and instantaneously operates in the case of a closing operation, and this operation opens the contacts 8. This is not necessarily necessary if there is another determination method.

According to the abnormal operation monitoring device of this embodiment, the deviation of the operation of the switching equipment from the normal state can be monitored for each operation, so it is effective for preventive maintenance.

FIG. 4 is a configuration example showing another embodiment of the present invention. As mentioned above, even if the trip command signal voltage is within the permissible fluctuation range, when the voltage is low, the time until the movable electrode of the main contact starts to move, that is, time A,
Generally, the time for B is longer and shorter for higher voltages. Some time-limited relays also take a long time to operate when low voltage is applied, so
This is convenient because it matches the trend of increase/decrease in time between AB. However, compensation is required when the moving time of the movable electrode of the main contact is independent of the control power supply voltage and is shortened or extended depending on the level of oil pressure, such as in a hydraulic operating mechanism.

In FIG. 4, 6 to 9 are the same as in FIG. 14 and 15 are resistors, and 16 is a constant voltage discharge tube. For example, even if the voltage between the
In this case, the voltage between E and F is always maintained at 10V, so there is no effect of fluctuations in the power supply voltage. The resistor 15 has a low resistance value when the oil pressure is high and a high resistance value when the oil pressure is low by changing the position of the resistance terminal in conjunction with a small hydraulic cylinder that opposes the spring force, thereby achieving the second time limit. Since the actual current flowing through the coil of the relay 6 can be increased or decreased, the operating time can also be varied.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram of the operation status of a switching device, FIG. 2 is a circuit diagram of an abnormal operation monitoring device according to an embodiment of the present invention, and FIG. 3 is an explanatory diagram explaining the operation of FIG. 2.
FIG. 4 is a circuit diagram showing essential parts of another embodiment of the present invention. In the figure, 1 is the tripping coil, 2 is the first
3 is a first time relay, 4 is a second auxiliary contact, 6 is a third auxiliary contact, 7 is a fourth auxiliary contact, and 9 is a second time relay. Note that the same reference numerals in each figure indicate the same or corresponding parts.

Claims (1)

[Claims] 1. A coil that opens the main contact in response to a trip command signal, a first auxiliary contact that is connected in series with this coil and is closed when the contact is closed;
a second auxiliary contact that is closed when the main contact is closed and opens earlier than the first auxiliary contact;
An abnormal operation monitoring device for switching equipment, comprising a first time-limited relay connected in series with the second auxiliary contact and activated by the trip command signal to operate after a predetermined period of time has elapsed. 2 A coil that opens the main contact with a trip command signal, a first auxiliary contact that is connected in series with this coil and is closed when the above contact is closed, and a first auxiliary contact that is open when the above main contact is closed. Separated above first
a third auxiliary contact that closes earlier than the auxiliary contacts open; a fourth auxiliary contact that is connected in series with the third auxiliary contact and opens later than the first auxiliary contact; An abnormal operation monitoring device for switching equipment, comprising a second time-limited relay that is connected in series with a fourth auxiliary contact and operates after a predetermined period of time has elapsed after being energized.