JPS643297B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an interlock condition determining device, and particularly to an interlock condition determining device that uses a microcomputer to determine whether or not a disconnector connected to a busbar can be opened or closed. It is something.

Conventionally, the method for determining the interlock condition of a disconnector is to use a combination of the contacts of the circuit breaker and the disconnector, or to once amplify each of these contacts with an auxiliary relay, and to determine the interlock condition of the disconnector by the combination of these contacts. It was like judging.

In the conventional method described above, whenever a circuit breaker or disconnector is added or the electrical position is changed, wiring changes and auxiliary relays are necessarily added or removed. Furthermore,
As the scale of substations expands in recent years,
These interlock condition determination circuits are complex and require the manufacture of unique hardware each time.

On the other hand, these interlock condition judgment circuits applied to microcomputers can also be considered as software targets, but since operational errors cannot be tolerated in these circuits, interlock condition determination circuits applied to microcomputers with higher reliability are considered. A condition determination device must be obtained. The most common method to obtain a highly reliable device is to duplicate the device, but if it is used with the same type of software, simply duplicating the device will not cause an error in the interlock judgment stage. The probability of it being done increases.

The present invention was made with the aim of solving the above-mentioned problems, and it prevents errors in judgment conditions,
The object of the present invention is to provide a microcomputer-applied interlock condition determination device with higher reliability.

That is, in the present invention, the determination results are derived in parallel using two different condition routes, and the final disconnector operation signal is determined by the coincidence of these two determination results.

Examples will be described below with reference to the drawings. 1st
The figure is a block diagram of an embodiment of a disconnector interlock condition determination device using a microcomputer according to the present invention, FIG. 2 is a system diagram to which it is applied, and FIG. 3 is a flowchart used for calculation. be.

In FIG. 1, 1 is a normally open contact and is an auxiliary contact of an associated disconnector or circuit breaker, and 2 is a normally closed contact of the associated disconnector or circuit breaker. Numerals 3 and 4 are photocouplers, respectively. The photocoupler 3 receives the open/closed state of the normally open contact 1, and the photocoupler 4 receives the open/closed state of the normally closed contact. Reference numeral 5 denotes a process input/output device into which signals interfaced with the photocouplers 3 and 4 described above are introduced. 6 is a central processing unit that judges whether or not the interlock condition of the disconnector is satisfied based on the interfaced signal according to a pre-installed interlock condition judgment program; The result is output to the relay driver 7 via the process input/output device 5, and the output relay 8 is further activated. The operation of the output relay 8 is used as an output as an interlock condition determination device.

FIG. 2 shows a system diagram in which interlock conditions are applied. That is, as shown in the second figure,
A circuit breaker 12 is connected via disconnectors 10 and 11, and a power transmission line is further connected to the circuit breaker 12 via another disconnector. On the other hand, disconnectors 13 and 15 are connected to the busbar, and a busbar communication circuit breaker 14 is provided between them. Therefore, the operating conditions of the disconnector 10 in this system will be considered. Here, the disconnector 10 can be operated if the disconnector 11 is open and the circuit breaker 12 is also open, and even if the disconnector 11 is closed, the busbar connection condition is closed, that is, the disconnectors 13, 15
and if the busbar communication circuit breaker 14 is closed, the disconnector 1
0 is operational. Therefore, its operation will be explained below while taking into account the above-mentioned conditions.

When determining the interlock condition of the disconnector 10, the disconnectors 11, 13, 15 and the circuit breakers 12, 1
The normally open contacts and normally closed contacts of 4 are input to the process input/output device 5 via photocouplers 3 and 4, respectively. Then, it is sufficient to create a program having two determination routes for determination based on signals from each of these normally open contacts and normally closed contacts. That is, in the determination route using only the normally open contact, it is first considered whether or not the disconnector 11 is off, but in this case, the normally open contact is open and the disconnector 11 is considered to be off. Next, since the normally open contact of the circuit breaker 12 is open, the circuit breaker 12 is considered to be off, so that the interlock determination based on the normally open contact route determines that the disconnector 10 can be operated.

On the other hand, in the determination route using only normally closed contacts, it is first considered whether or not the disconnector 11 is on.
In this case, it is assumed that the normally closed contact is closed and the disconnector 11 is not on. Next, it is assumed that the normally closed contact of the circuit breaker 12 is closed and the circuit breaker 12 is not on, and thereby, the interlock determination based on the normally closed contact route determines that the disconnector 10 can be operated.

Therefore, these matters will be explained with reference to the flowchart shown in FIG. Now, when operating the disconnector 10, in determination route _A1 using normally open contacts, it is examined whether the disconnector 11 is off, and if it is off, it is determined whether the circuit breaker 12 is off. will be considered sequentially. If both the disconnector 11 and the circuit breaker 12 are off, the disconnector 10 is operable, so one input of the step for examining output matching is derived. Similarly, in determination route B ₁ using normally closed contacts, it is examined whether or not the disconnector 11 is on, and if it is determined that it is not on, it is sequentially examined whether or not the circuit breaker 12 is on. . If both the disconnector 11 and the circuit breaker 12 are not on, the disconnector 10 is operable, so the other input of the step for examining output matching is derived, and here the normally open contact and the normally closed contact are used. When the respective operable inputs match, the output relay 8 operation step is activated, and it is finally determined that the disconnector can be operated.

Next, if it is determined that the disconnector 11 is not off in the normally open contact route _A1 , other busbar connection conditions must be considered, so the normally open contact route
Move to _A2 . If the disconnectors 13 and 15 and the busbar communication circuit breaker 14 are all off, the disconnector 1
Since 0 is operational, one input of the step that considers the output match is derived. Similarly, the normally closed contact route _B1 is assumed to have the disconnector 11 on, and moves to _B2 , and similarly, since the disconnectors 13, 15 and the busbar communication circuit breaker 14 are all on,
The other input of the step for examining output matching is derived, and it is finally determined that the disconnector can be operated.
In this case, each route of normally open contact and normally closed contact
It is clear that if any of the disconnectors and circuit breakers at A ₂ and B ₂ are open, the disconnector 10 becomes inoperable.

That is, it examines whether the judgment results based on the normally open contact route and the judgment results based on the normally closed contact route match or do not match, and if they match in the operation direction, the output relay 8 is operated and an operation enable signal is sent to the disconnector 10. is being used. Furthermore, busbar connection conditions (on/off conditions for circuit breaker 14 and disconnectors 13 and 15)
A comprehensive judgment of the interlock will be made based on the combination of the two.

As explained above, according to the present invention, a determination circuit having a program for determining the state of one device using only normally open contact signals and a determining circuit having a program for determining the status of one device using only normally closed contact signals are provided in parallel. Since the interlock determination device is configured to derive the operable signal only when both of them generate the same output in the operable direction, malfunctions and malfunctions of the electronic circuit due to input signal errors, program errors, and disturbances are avoided. It is possible to prevent erroneous judgments due to non-operation, provide a more reliable interlock judgment device, and achieve the following effects.

Since different contact signals are input through independent and different routes, it is possible to prevent erroneous judgments in the event of erroneous signal input.

Since there are two determination routes that are determined by different programs, even if an erroneous determination is made in one determination route, the interlock determination device will not produce an erroneous output.

Since it has two different inputs and each program to process them, and the judgment condition is that the processing outputs of both match, erroneous outputs due to errors in the process are eliminated, and highly reliable interlocking is achieved. A determination device is obtained.

A device abnormality can be detected by detecting a discrepancy between the outputs of the two determination routes.

[Brief explanation of drawings]

FIG. 1 is a block diagram of an embodiment of a disconnector interlock condition determination device using a microcomputer according to the present invention, FIG. 2 is a system diagram to which the device is applied, and FIG. 3 is a flowchart used for calculation. 1... Normally open contacts such as circuit breakers and disconnectors, 2... Normally closed contacts such as circuit breakers and disconnectors, 3, 4... Photocoupler, 5... Process input/output device, 6... Central processing unit, 7... Relay driver, 8... Output relay, 9... Output relay contact, 10, 11, 1
3, 15... Disconnector, 12, 14... Circuit breaker.

Claims (1)

[Claims] 1. In an interlock condition determination device that determines whether or not a circuit breaker can be operated based on the open/closed state of the circuit breaker or disconnector, there are two contradictory types of normally open contact and normally closed contact caused by the circuit breaker or disconnector, etc. By inputting the contact conditions into one arithmetic unit and performing logical operations on the input signal from the normally open contact and the input signal from the normally closed contact using independent and separate programs installed in advance, the two An interlock condition determining device that compares logical operation outputs and determines whether or not the disconnector can be operated based on whether or not the logical operation outputs from each of the independent programs agree in the respective operable directions. .