JP3139756B2 - Protective relay - Google Patents

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial application field) The present invention relates to a protective relay device capable of performing a function test of the device itself and confirming the operation of an external output contact.

(Prior Art) In power systems such as transmission lines, various types of protective relay devices according to purposes are used in order to ensure safe operation of the system. By the way, the protective relay used for such a system does not have a function that makes it possible to test the operation state of the device itself, and usually, the final operation of the device is forcibly created to test the external sequence. It was about to do. For this reason, the test of the apparatus itself was hardly performed by connecting a dedicated tester at the time of periodic inspection of the equipment.

(Problems to be solved by the invention) However, if a dedicated tester is prepared and tested for testing the operation of the protective relay device, it takes time to set up a test such as connecting the tester. It takes time and effort,
There was a disadvantage that the operation became complicated. Further, such a dedicated tester is expensive. Further, in a normal device, a failure of the device itself was first discovered at the time of a periodic inspection, and a system accident at the time of the failure resulted in a malfunction and a possibility of the accident spreading.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a protective relay device that can perform a function test and output contact confirmation from the device itself.

[Means for Solving the Problems] In order to achieve the above object, a protection relay device of the present invention includes a means for inputting a quantity of electricity to be protected, and a means for inputting an electricity quantity exceeding a predetermined value. A first judging means for outputting one output signal, a first contact portion operated by the first output signal, a second judging means for outputting a second output signal when the electric quantity has a predetermined characteristic, A second contact portion activated by a second output signal;
In the protective relay device having an exciting means for exciting a trip coil connected in series to an operating power supply together with the first contact portion and the second contact portion, the first contact portion or the second contact portion operates. A test signal generator that generates a test signal to perform the test signal, an on / off unit that sends the test signal so that the test signal can be input to at least one of the first determination unit and the second determination unit, and the first contact unit. A detecting unit for detecting an operation of the second contact unit; and a self-diagnosis unit for outputting an on / off command to the on / off unit and inputting a detection result from the detection unit to perform a self-diagnosis.

(Operation) According to the above configuration, when an accident occurs and the amount of electricity to be protected changes in a normal state, the first determination means outputs a first output signal to operate the first contact portion when the amount of electricity exceeds a predetermined value. When the second determining means detects that the electric quantity has a predetermined characteristic, it outputs a second output signal to operate the second contact portion. The trip coil is excited by the operation of the first contact portion and the second contact portion, and the circuit breaker is tripped to protect the protection target. At the time of the test, the test signal from the test signal generator is first input to either the first determining means or the second determining means by the on / off means to detect whether the first contact portion or the second contact portion operates normally. The test means judges from the detection result from the part. Next, a test signal is input to the first determination means and the second determination means simultaneously, and it is determined whether or not both the first contact part and the second contact part operate based on the detection result from the detection part. The trip coil should not be activated by the current flowing during the test. Even if an accident occurs during such a test, the input means always inputs the amount of electricity to be protected to the first and second determination means, so that the steady-state operation is performed and the trip coil operates. , The protected object is always protected.

Embodiment An embodiment of the present invention will be described below with reference to FIGS. FIG. 1 is a diagram showing a circuit configuration of a first embodiment of the present invention. In FIG. 1, reference numeral 1 denotes a power system to which a current transformer 2 is connected. An auxiliary current transformer 3 is connected to the output side of the current transformer 2. This auxiliary current transformer 3
Detects the secondary current of the current transformer 2. A resistor 4 is connected to the output side of the auxiliary current transformer 3 to convert the secondary current of the auxiliary current transformer 3 into a voltage.

The output of the resistor 4 is provided to an operation value comparison circuit 5 and an amplification circuit 7. The operation value comparison circuit 5 generates an output when the voltage value of the resistor 4 according to the amount of electricity of the power system 1 exceeds a preset value, and outputs the microcomputer 6, the display circuit 12, the output Input to the circuit 13.

Reference numeral 9 denotes a test signal generation circuit (test signal generator).
It is supplied to the operation value comparison circuit 5 and the amplification circuit 7 via 101 and 102, respectively. The test signal in this case is equivalent to the amount of electricity when the power system 1 is abnormal.

The microcomputer 6 has a function of determining the operation state of the operation value comparison circuit 5 and the digital value of the A / D conversion circuit 8. The microcomputer 6 inputs the setting contents of the setting switch 11, self (programming) or a command from the remote monitoring device 19 through the transmission device 18 and the interface 17 to the switches 101 and 102 of the switch section 10. An operation command is given to it. Abnormality judgment of power system 1 of microcomputer 6, switch 102
Is given to the display circuit 14 and the output circuit 15. Here, the display circuit 12 displays the operation of the operation value comparison circuit 5,
The output circuit 13 is connected to the output contact 13 by the operation of the operation value comparison circuit 5.
Make one work. Similarly, the display circuit 14 displays the contents of the digital value of the A / D conversion circuit 8 confirmed by the microcomputer 6. The output circuit 15 operates the output contact 151 by the output circuit 15 in accordance with the contents of the digital value of the A / D conversion circuit 8 confirmed by the microcomputer 6 like the display circuit 14.

Further, the output contacts 131 and 151 and the trip coil 20 are connected in series, and the trip coil 20 is excited when the output contacts 131 and 151 operate simultaneously. The trip coil 20 trips a circuit breaker (not shown). Further, the operating states of the output contacts 131 and 151 are detected by the detection circuit 16 and taken into the microcomputer 6.

Next, the detection circuit 16 will be described with reference to FIG. The detection circuit 16 includes a first detection unit 161 and a second detection unit 162. The first detection unit 161 detects opening / closing of an output contact 131 operated by the output circuit 13 and notifies the microcomputer 6 of the opening / closing. The unit 162 detects opening and closing of the output contact 151 operated by the output circuit 15 and communicates with the microcomputer 6. The detection of opening and closing of the output contacts 131 and 151 is performed as follows. Both the current I _P flows through the first and second detecting units 161 and 162 when the output contacts 131 and 151 are both open, the output contacts 1
If only one of the contact points 31 and 151 is closed, no current flows through the first or second detecting section 161, 162 corresponding to the closed contact, and the first or second detecting section corresponding to the open contact. the 161 and 162 flows through a current of 2I _P. Output contact 131,151
When both are closed, the first and second detectors 161, 16
No current flows through 2. Using this property, the output contact 13
The 1,151 states are detected by one of the following two methods.

Detection circuit 16 is a current of I _P is not turned on.

First detecting circuit 2I _P current 16 is turned on.

That is, when the output contact 131 is closed, the second detection unit 162 is turned on,
The detection unit 161 turns off.

When the output contact 151 is closed, the first detector 161 is turned on, and the second detector is turned on.
162 turns off.

When the output contacts 131 and 151 are both closed or both are open, the first and second detection units 161 and 162 are turned off.

Detection circuit I _P following current 16 is turned on.

 When no current flows, the detection circuit 16 is turned off.

That is, the output contacts 131 and 151 are both open and the first and second
The detection unit turns on.

When the output contact 131 is closed, the first detection unit 161 turns off, and the second detection unit
162 turns on.

When the output contact 151 is closed, the second detector 162 is turned off, and the first detector is turned off.
161 turns ON.

The output contacts 131 and 151 are both closed and the first and second detectors 161.1
62 turns off.

In the I _P, 2I _P current is set so that the trip coil 20 does not operate.

With these circuits, the protection device itself such as the microcomputer 6, the operation value comparison circuit 5, the amplification circuit 7, the A / D conversion circuit 8, the output contacts 131 and 151, and the output circuits 13 and 15 can be inspected.

Next, the operation of the first embodiment configured as described above will be described. The amount of electricity in the power system 1 is extracted via the current transformer 2 and the auxiliary current transformer 3, converted into a voltage value by the resistor 4, and supplied to the operation value comparison circuit 5 and the amplification circuit 7. Here, when the power system 1 is in a normal state, the voltage value of the resistor 4 is a sufficiently small value, no output is generated from the operation value comparison circuit 5, and the digital value of the A / D conversion circuit 8 is equal to or less than a predetermined value. Thus, the microcomputer 6 does not determine a system abnormality. When an abnormality occurs in the power system 1 and the voltage value of the resistor 4 rises, the operation value comparison circuit 5 generates an output when the set value exceeds a preset value, activates the output circuit 13 and closes the output contact 131. And Further, the output of the amplification circuit 7 also increases, and the digital value of the A / D conversion circuit 8 also becomes a large value.
As a result, the microcomputer 6 determines a system abnormality from the result of the characteristic operation of the digital value of the A / D conversion circuit 8. Then, the result of the system abnormality determination of the microcomputer 6 operates the output circuit 15, closes the output contact 151, excites the trip coil 20, and trips the circuit breaker (not shown).

Next, when a test of the device is performed, the set contents are received from the set switch 11, and further, automatically (in a self-programming manner) at a fixed period or a command from the remote monitoring device 19 is transmitted through the transmission device 18 and the interface 17. The switch of the switch unit 10 is received by the microcomputer.
When an operation command is given to 101, a test signal of test signal generation circuit 9 is given to operation value comparison circuit 5 via switch 101. In this case, since the test signal is equivalent to the amount of electricity at the time of abnormality of the power system 1, an output is generated from the operation value comparison circuit 5, and this output is displayed on the display circuit 12, and is displayed on the output circuit 12. 13, the output contact 131 operates. This operation is sensed by the microcomputer 6. Further, the operation of the output contact 131 is detected by the second detection unit 162 of the detection circuit 16 and transmitted to the microcomputer 6, whereby the operation value proportional circuit 5, the output circuit 13, and the output contact 131 are self-checked.

Next, when an operation command is given to the switch 102 from the microcomputer 6 automatically (by self-programming) at a fixed cycle (this operation is performed manually), or at a fixed cycle, a test of the test signal generation circuit 9 is performed. The signal is provided to the amplifier circuit 7 via the switch 102. Then, the output of the amplifier circuit 7 is provided to an A / D conversion circuit 8, converted into a digital signal, and input to the microcomputer 6. In this case, the test signal is equivalent to the amount of electricity at the time of abnormality of the power system 1, and under this condition, the digital value of the A / D conversion circuit 8 is determined, and the characteristic is calculated and the display circuit 14 is operated.
And the output circuit 151 operates the output contact 151. Further, the operation of the output contact 151 is detected by the first detection unit 161 of the detection circuit 16 and transmitted to the microcomputer 6, so that the amplification circuit 7, the A / D conversion circuit 8, the output circuit 15,
The output contact 151 and the microcomputer 6 are self-checked. Next, when the microcomputer 6 gives an operation command to the switches 101 and 102 at the same time, the output contacts 131 and 151 are closed in the same manner as described above, and the trip coil 2 is closed.
When 0 is excited (operated), an external sequence test can be performed.

If an abnormality occurs in the power system 1 during such a test, as described above, the microcomputer 6
Since the system abnormality is determined based on the output of the operation value comparison circuit 5 and the system abnormality is determined from the result of the characteristic operation of the digital value of the A / D conversion circuit 8, the protection is not performed. Absent.

As described above, the inspection test from the detection unit of the device itself to the final output contact can be performed, and the failure of the device itself can be notified externally (via the interface 17) by an alarm or the like, and the abnormality can be reliably confirmed. . Furthermore, even if a system abnormality occurs during these self-checks, it can be dealt with reliably, so that the operation as a protective relay is not impaired at all. Further, the system abnormality is detected by the operation value comparison circuit 5 and the system abnormality is detected via the amplification circuit 7 and the A / D conversion circuit 8, and the double AND output configuration is employed, so that malfunctions due to surge, noise, etc. Can be reduced, and stability can be improved.

Next, a second embodiment will be described with reference to FIG. In the second embodiment, the operation value comparison circuit 5 in the first embodiment is
1, composed of an A / D conversion circuit 22 and a microcomputer 23, outputs with characteristics determined by the magnitude of the amount of electricity to be protected, and enables more detailed self-inspection than in the first embodiment. is there.

[Effects of the Invention] As is clear from the above description, the present invention makes it possible to apply a test signal to the trip operating mechanism in a steady state, perform an operation check of the components by the test signal, and detect an abnormal situation even during the test. A protective relay device capable of performing a trip can be provided.

[Brief description of the drawings]

FIG. 1 is a circuit diagram showing a first embodiment of the present invention, FIG. 2 is a diagram showing an output contact, a detection circuit and a trip sequence of FIG. 1 in detail, and FIG. 3 is a second embodiment of the present invention. FIG. 3 is a circuit configuration diagram showing an example. DESCRIPTION OF SYMBOLS 1 ... Power system, 2 ... Current transformer, 3 ... Auxiliary current device, 4 ... Resistance, 5 ... Operation value comparison circuit, 6,23 ... Microcomputer, 7,21 ... Amplification circuit, 8 , 22 …… A / D conversion circuit, 9 …… Test signal generator circuit (test signal generator), 10 ……
Switch section, 11 Setting switch, 12, 14 Display circuit, 13, 15 Output circuit, 16 Detection circuit, 17 Interface, 18 Transmission device, 19 Remote monitoring device, 20 ...... Trip coil.

Continuation of the front page (56) References JP-A-63-56122 (JP, A) JP-A-3-32317 (JP, A) JP-A-3-173311 (JP, A) JP-A-2-136020 (JP) , A) JP-A-60-43015 (JP, A) JP-A-60-239681 (JP, A) Japanese Utility Model Publication No. 58-108725 (JP, U)

Claims (1)

(57) [Claims] 1. A means for inputting a quantity of electricity to be protected, a first judging means for outputting a first output signal when the quantity of electricity exceeds a predetermined value, and a first contact portion operated by the first output signal A second determination unit that outputs a second output signal when the amount of electricity has a predetermined characteristic; a second contact unit that is activated by the second output signal; a first contact unit and the second contact unit And an exciting means for exciting a trip coil connected in series with the operating power supply, wherein a test signal generating a test signal for operating the first contact portion or the second contact portion. A detector, an on / off means for transmitting the test signal so as to be able to be input to at least one of the first determination means and the second determination means, and a detection for detecting an operation of the first contact part and the second contact part. And an on / off command to the on / off means Protective relay apparatus comprising: the self-diagnosis means for performing a self-diagnosis inputs the detection results from Rutotomoni the detecting unit.