JPH0572167B2 - - Google Patents

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to an inspection circuit for a protective relay device, and in particular automatically inspects one or more protective relay elements and The present invention relates to an inspection circuit incorporating an inspection element that confirms that the element operates and returns within a predetermined operating time.

<Prior Art> FIG. 2 shows the overall connection relationship of the inspection circuit of a protective relay device, which is the object of the present invention.

In FIG. 2, the inspection element 20 includes a test input terminal TEST to which a test switch 22 is connected;
Return input terminal to which return switch 24 is connected
RES, inspection abnormality output terminal NG, inspection start signal output terminal IIS ₀ , inspection end signal input terminal IIE ₀ ,
It has an inspection abnormality output terminal NG.

Each of the E relay elements K ₁ to K _E is duplicated in series either externally or internally, so even if only one is forced to operate, a trip output will not occur unless the other one operates. . Each relay element K ₁ ~
K _E has five input/output terminals. The input and output terminals of the Nth relay element _KN will be described below as a representative.

In the relay element K _N , IN _N is the relay element input terminal, IIS _N is the inspection start signal input terminal, IIE _N is the inspection end signal output terminal, OPA _N is the operation output terminal of element A in this element, OPB _N is also the operation output terminal of the B element. As shown in the diagram, check start signal input terminal
IIS _N is connected to the inspection completion signal output terminal IIE _N-1 of the previous stage, and inspection completion signal output terminal IIE _N is connected to the inspection start signal input terminal IIS _N+1 of the next stage.

The inspection starts by turning on the test switch 22, and the inspection start signal output terminal IIS ₀ of the inspection element 20 is connected to the inspection start signal input terminal of the relay element K ₁ .
A pulse is provided to IIS ₁ , which causes the relay element to
The inspection of _K1 is performed, and when the inspection is completed, a pulse is output from the inspection completion signal output terminal _IIE1 . This pulse is applied to the inspection start signal input terminal IIS ₂ of the relay element K ₂ in the next stage, and inspection of K ₂ begins. When the inspection is finished, a pulse is generated from the inspection end signal output terminal IIE ₂ . Similarly, the pulses are transmitted sequentially to the elements.
Steps are taken sequentially from K ₃ to K _E , and inspections are performed one after another.
When the inspection of the last relay element K _E is completed, a pulse is transmitted from IIE _E to IIE ₀ of the inspection element 20. In response to this, the inspection element 20 confirms that the inspection was normal. This completes the automatic inspection sequence.

FIG. 3 shows the configuration of the inspection element 20. The inspection element 20 is a positive edge trigger monostable multivibrator (hereinafter referred to as PMM) 31 that outputs a one-pulse signal (receives output terminal IIS ₀ ) at the moment the input to the input terminal TEST changes from negative to positive. , a reset-priority flip-flop (hereinafter referred to as FF) 32 which is set by a pulse from the PMM 31 and reset by a pulse from the input terminal IIE ₀ , a timer 33 for overtime and a timer 33 operating in response to the output of the FF32. a timer 34, logic gates 35 and 36,
Consists of FF37.

Let T ₀ be the time from when the inspection start signal pulse is sent from the output terminal IIS ₀ until the inspection sequence is normally completed and the inspection end signal pulse arrives at the input terminal IIE ₀ . The operating time T _L of the overtime timer 33 is set to be slightly larger than T _O.
The operating time T _S of the timer 34 for time shortage is set to be slightly smaller than T _O. Also, timers 33 and 34
Assume that the recovery time when there is no input after each operation is not completely zero, but has an extremely small delay time.

If a pulse is sent to IIS ₀ to start inspection, and the timer 33 times up by the time the end pulse arrives at IIE ₀ , or even if the end pulse arrives at IIE ₀ , the timer 34 does not time up. If not, the time has exceeded and the time has run short, respectively, the FF 37 is set, and an inspection abnormality signal is output from the output terminal NG. This FF37 is an input terminal
It is reset by the return signal applied to RES.

FIG. 4 shows the structure of the conventional relay element _KN .

In FIG. 4, 41 and 42 are A element and B element, respectively.
The level detector of the element sends out a high level signal when the input signal at the terminal IN _N exceeds a predetermined level. 43 and 44 are timers for the A element and B element, respectively, which are operated by the outputs of the level detectors 41 and 42, and their time-up outputs are led out to the terminals OPAN and OPB _N as the operation outputs _of each element. In addition,
The outputs of the timers 43 and 44 are normally converted to contact outputs via auxiliary relays, but the auxiliary relays are omitted in this figure.

Further, 45, 46, and 47 are flip-flops (hereinafter referred to as FF) similar to those described above. However, FF4
The reset input No. 7 is set to negative logic.

50 is a negative edge trigger monostaple multivibrator (hereinafter referred to as NMM), which outputs a one-pulse signal only at the moment the input changes from positive to negative.

48 and 49 are off-delay circuits, which are circuits in which when the input becomes low level, the output becomes low level after a very short delay time.

51, 52, 53, and 54 are logic gates that perform logic operations represented by symbols in the figure.

In the configuration of FIG. 4, the inspection sequence is performed as follows.

When an inspection start pulse is applied to input terminal IIS _N with both A and B elements inactive, FF
45 is set and the inspection start pulse is held. When the FF 45 is set, a check input is applied from the AND gate 51 to the level detector 42 of the B element on the condition that the A element is not operating.
When the timer 44 of the B element operates, the FF 45 is reset by its output, and a one-pulse signal is generated by the off-delay 48 and the AND gate 53, and the FF 46 is set by the one-pulse signal.

When the FF 46 is set, a check input is applied from the AND gate 52 to the level detector 41 of the A element after the B element is restored. When the timer 43 of the A element operates, its output resets the FF 46 (the inspection input disappears), and
A one-pulse signal is created by the off-delay circuit 49 and the AND gate 54, and the one-pulse signal
FF47 is set. This FF 47 is reset when the A element returns. When the FF 47 changes from set to reset, a one-pulse signal is generated by the NMM 50, which is sent to the output terminal IIE _N as a pulse indicating the end of inspection.

<Problems to be Solved by the Invention> The conventional configuration shown in FIG. If there is an electric element, the following problems will occur.

Assume that the automatic inspection sequence has started and the relay elements that are constantly operating have had their turn.
In that case, even if an inspection start pulse is applied to the input terminal IIS _N of that relay element, FF 48 is not set (FF 48 has reset priority). Therefore, the sequential pulse of the inspection operation is lost at this stage, and the inspection sequence does not proceed any further. Therefore, the inspection completion pulse never arrives at the input terminal IIE ₀ of the inspection element 20, and an abnormal signal is output from the output terminal NG.

In order to avoid the above-mentioned inconvenience, the following measures are usually taken.

(1) If there is a relay element that is operating, disable the inspection start signal within the inspection element 20. In other words, the inspection itself is canceled.

(2) Only relay elements that are constantly operating are excluded from automatic inspection.

Countermeasure (1) makes it impossible to perform an overall inspection because only one element is in operation. For example, if a device containing an undervoltage relay element is applied to a protection line, an automatic inspection of the entire unit is not possible. I can't do much anymore.

In addition, in the case of countermeasure (2), it is not possible to automatically inspect undervoltage relay elements, etc., which is extremely undesirable from a reliability standpoint.

This invention was made in view of the above-mentioned conventional problems, and even if one relay element is in operation, it does not interfere with the entire automatic inspection sequence, and other relay elements can be checked. The object of the present invention is to provide an inspection circuit for a protective relay device that allows automatic inspection to be carried out as usual.

<Means for Solving the Problems> Accordingly, in the present invention, a circuit means is provided for sending a simulated pulse indicating the end of inspection to the inspection end signal output terminal when a pulse indicating the start of inspection is applied while the relay element is in operation. Ta.

<Function> In the configuration of the present invention, when the relay element is operating, even if a pulse to start inspection is applied to this element, the element is of course not inspected, but the above simulated pulse is applied. The element therefore behaves as it would normally, and the entire automatic inspection sequence therefore proceeds as normal.

<Embodiment> The overall connection of the inspection circuit according to the present invention is the same as that in FIG. 2 already described. Further, the configuration of the inspection circuit 20 in FIG. 2 may be the same as that in FIG. 3 already described. Relay element K _N in Fig. 2
Conventionally, the relay element KN was constructed as shown in FIG. 4, whereas in one embodiment of the present invention, the relay element _KN is constructed as shown in FIG.

In FIG. 1, the relay element input terminal IN _N , the level detector 41 and timer 43 of the A element, the operation output terminal OPA _N , the level detector 42 and the timer 4 of the B element
4, operation output terminal OPB _N , inspection start signal input terminal
IIS _N , inspection completion signal output terminal IIE _N , FF45 and FF
46 and FF47, off-delay circuits 48 and 49,
NMM50, logic gates 51, 52, 53 and 54
The structure is exactly the same as that of the conventional circuit shown in FIG. 4, and the operation of this part is also the same as that of the conventional circuit.

The circuit of the present invention shown in FIG. 1 is obtained by adding logic gates 60, 61, and 62, an off-delay circuit 63, and an NMM 64 to the conventional circuit shown in FIG. This additional circuit corresponds to the circuit means for generating the simulation completion pulse described above.

In FIG. 1, when both the A element and the B element are operating, the two inputs of the AND gate 60 are at a high level and its output is also at a high level.
When an inspection start pulse is applied to the inspection start signal input terminal IIS _N in this state, the pulse passes through the AND gate 61 and is input to the off-delay circuit 63. The off-delay circuit 63 delays the falling edge of the input pulse by a time T3. next stage
The NMM 64 generates one pulse at the moment the output of the off-delay circuit 63 falls. This one pulse is the simulated pulse at the end of the inspection mentioned above.
Inspection completion signal output terminal IIE _N via OR gate 62
sent to.

That is, when an inspection start pulse is input to the input terminal IIS _N while both the A element and the B element are operating, a simulated inspection end pulse is sent to the output terminal IIE _N after time T3.

The above time T3 starts from the time when the inspection start pulse is input when both the A and B elements are not operating, the A and B elements are inspected in a predetermined sequence, and finally the inspection is completed. It is set equal to the time it takes for the pulse to be sent to the output terminal IIE _N. Note that the operation of the normal inspection sequence is exactly the same as that shown in FIG. 4, so a description thereof will be omitted.

Therefore, even if the relay element is operating, the inspection start and inspection end pulses are sent in the same order as when it is not operating, so everything except the operating element continues as usual. An inspection will be carried out.

Note that the inspection element 20 in FIG. 3 is provided with a timer 34 for insufficient time, and even if the inspection end pulse arrives too early, it is determined to be an abnormality, but the function of the timer 34 for insufficient time is omitted. In some cases, it may be done. In that case, the off-delay circuit 63 and NMM 64 in FIG. 1 may be omitted. In other words,
A pulse to start the inspection may be sent to the output terminal IIE _N through the AND gate 61 and the OR gate 62, and this may be used as a simulated pulse to end the inspection.

<Effects of the Invention> As explained in detail above, according to the inspection circuit of the protective relay device according to the present invention, even if some of the relay elements are in operation, there is no interruption in the automatic inspection sequence. There is no obstruction and automatic inspection can be performed as if all elements were not operating.

[Brief explanation of the drawing]

Fig. 1 is a circuit diagram of the main parts of the inspection circuit according to an embodiment of the present invention (configuration diagram of relay element _KN in Fig. 2), and Fig. 2 is a diagram showing the overall connection relationship of the inspection circuit (this 3 is a diagram showing the configuration of the inspection element in FIG. 2 (common to the present invention and the conventional), and FIG. 4 is a diagram showing the configuration of the inspection element in FIG. 2 _.
FIG. 2 is a diagram showing a conventional configuration. 20... Inspection element, K _N ... Relay element, IIS _N ...
...Inspection start signal input terminal, IIE _N ...Inspection end signal output terminal, 41...A element level detector, 42
...B element level detector.

Claims (1)

[Claims] 1 An inspection element that starts inspection of the protective relay device and outputs an inspection start signal in response to an inspection start command signal, and outputs an inspection abnormality signal when the protective relay device is abnormal, and an inspection element for this inspection element. A signal is input, and at least one first-stage relay element made by duplicating the first element and the second element, or this first-stage relay element is successively connected and sequentially inspects the inspection completion signal of the previous stage. In an inspection circuit consisting of a plurality of relay elements input as a start command signal and inputting an inspection completion output signal of the final stage relay element to the inspection element, an inspection start command input is input to each relay element. An inspection end signal is output based on a logical operation between the signal and the first element or the second element, and a signal obtained through a logical operation between the first element and the second element and the inspection start command input signal. What is claimed is: 1. An inspection circuit for a protective relay device, comprising circuit means for outputting a simulated inspection completion signal obtained by a logical operation.