JPH03218216A - Protective relay - Google Patents

Abstract

PURPOSE:To perform protection output from a relay to an alarm output contact with the quantity of electricity of an electric power system during normal operation and improve the test efficiency by lowering the alarm output value. CONSTITUTION:The main current transformer 2 of a protective relay 3 is fixed to the cable 1 of a protected electric power system and a command to set the alarm output value stored in a setting memory 11 lower than a voltage signal value corresponding to the normal current value passed through the cable 1 is transmitted from a remote monitoring device 18 to the microcomputer 9 of the protective relay 3, while a normal current is passing through the cable 1. Then the alarm output value stored in the setting memory 11 lowers, therefore, the microcomputer 9 judges that a voltage signal transmitted from an analogue-to-digital conversion circuit 8 exceeds the alarm output value and transmits a protection output signal to an output circuit 13. Then the output circuit 13 operates an alarm output contact 14.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) The present invention relates to a protective relay device that protects a power system such as a load or an electric circuit, and particularly relates to a protective relay device that protects a power system such as a load or an electric circuit, and in particular, a protective relay device that enables testing of the device by remote control. This invention relates to a protective relay device.

(Prior Art) Power systems such as power transmission lines and distribution lines are equipped with various protective relay devices depending on the purpose to ensure safe operation of the power system. In order to more reliably perform this safe operation, the protective relay device is required to operate normally at all times. Therefore, it is necessary to periodically test whether the maintenance relay device operates normally.

In order to perform this periodic test, it is necessary to apply multiple types of electrical quantities from below the operating value to above the operating value to this protective relay device. For example, a dedicated test device such as a high voltage generator is used in a state where the connected power system to be protected is cut off by separating it from other power systems. In addition, if it is not possible to cut off power to the power system to be protected for a long period of time, remove the protective relay device to be tested from the power system and use the test-dedicated equipment mentioned above to test the amount of electricity that exceeds the operating value. Apply.

In this way, protection l! Since it takes a great deal of time and effort to test electrical equipment, there has been a problem in that periodic tests cannot be carried out frequently. Therefore, for example, in a case where the test can be carried out only once a year, the device will be used in a faulty state for up to nearly one year even if a fault occurs.

Therefore, if an abnormal voltage occurs in the power system during that time, it will be impossible to deal with the situation. Therefore, there is a concern that reliability may deteriorate.

Furthermore, it is necessary to prepare a test-only device such as the high voltage generator described above, but this test-only device is expensive, and as a result, there is a problem in that the cost required for periodic tests increases.

(Problems to be Solved by the Invention) As described above, in conventional protective relay devices, it requires a great deal of time and effort to regularly test whether they operate normally, and additionally, expensive tests are required. Special equipment? ! I1
It was necessary to prepare.

The present invention was made in view of these circumstances, and
Instead of externally applying multiple types of electrical quantities ranging from below the operating value to above the operating value, by changing the operating value from the outside, the electrical quantity applied from the outside can be equivalently changed. Therefore, it is an object of the present invention to provide a protective relay device that allows testing of the device itself while the power system is normally energized and improves test work efficiency.

[Configuration of the Invention (Means for Solving the Problems) In order to solve the above problems, the present invention detects the amount of electricity in the power system to be protected, and detects the amount of electricity in the power system to be protected, and sets the detected amount of electricity to a preset operating value. A protective relay device that outputs a protective output for a characteristic time corresponding to the exceeded amount of electricity when the amount of electricity is exceeded, comprising an alarm output contact and a trip output contact as a means for outputting the protective output, and a storage means for storing the operating value, The apparatus includes an operation value changing means for changing the alarm output operation value among the operation values stored in the storage means in response to a command from the remote monitoring device.

(Function) According to the protective relay device configured as described above, the operating value stored in the storage means, which determines whether to output an alarm, is not a fixed value, but can be changed to an arbitrary value from the remote monitoring device. Therefore, by lowering the alarm output operating value of the operating values, it becomes possible to cause the relay device to output protective output to the alarm output contact using the amount of electricity of the power system during normal operation. Therefore, there is no need to prepare a test-dedicated device for applying the test amount of electricity.

(Example) An embodiment of the present invention will be described below with reference to the drawings.

In the figure, reference numeral 1 denotes one electric line constituting the power system, and a main current transformer 2 is attached to this electric line 1 in a non-contact manner. An auxiliary current transformer 4 is attached to the output side of the main current transformer 2 within the protective relay device 3 . This auxiliary current transformer 4 detects the secondary current of the main current transformer 2. A resistor 5 is connected between the output terminals of the auxiliary current transformer 4, and the voltage between the terminals of the resistor 5 is input to a filter 6. That is, a voltage corresponding to the current flowing through the electric line 1 is input to the filter 6.

The voltage signal corresponding to the current has high frequency noise components removed by a filter 6, is amplified by an amplifier circuit 7, and then sent to an A/D
The conversion circuit 8 samples the signal at a constant frequency and converts it into a digital value. The voltage signal converted into a digital value is input to a microcomputer 9 that performs various data processing and judgment processing.

In addition to voltage signals converted into digital values, the microcomputer 9 also contains alarm output operating values, trip output operating values, and operating time values that serve as criteria for sending out protective outputs to the power system as a protection target. A setting signal is input from a setting circuit 10 that sets the . When a settling signal is inputted to the microcomputer 9, the microcomputer 9 writes each setting value specified by the setting signal, such as the operation value and the operation time value, into the setting memory 1 as a storage means. Further, a display circuit 12 and an output circuit 13 are connected to the microphone port computer 9.

The microcomputer 9 converts the voltage signal input from the A/D 6 conversion circuit 8 into the setting memory 1.
It is determined whether or not the current value of the electric line 1 of the electric power system is an abnormal value by comparing and judging with each set value such as the alarm output operation value, trip output operation value, and operation time value stored in the electric power system 1. Then, the determination result is displayed on the display circuit 12. Also,
If the determination result is an abnormality, a protection output signal corresponding to the type of abnormality is sent to the output circuit 13.

When the protection output signal is input, the output circuit 13 operates one or both of the alarm output contact 14 and the trip output contact 15 depending on the type of abnormality.

Furthermore, the microcomputer 9 has an interface 1.
A remote monitoring device 18 is connected to this interface 16 via a transmission device 17. The remote monitoring device 18 is also composed of a kind of computer system, and this remote monitoring device 18 and the protective relay device 3
It is possible to freely transmit data to the microcomputer 9 inside via a transmission device 17 such as a public line.

In this embodiment, each set value such as the alarm output operation value, trip output operation value, and operation time value stored in the differential memory 1 is changed to an arbitrary value by a change command from the remote monitoring device 18. It can be changed to

In the protective relay device configured in this way, when testing whether the protective relay device operates normally, connect the main current transformer 2 of the protective relay device to the power line 1 of the power system to be protected. Leave it in the attached state and in a state where normal current is flowing through the electric circuit 1.

In such a state, the remote monitoring device 18 sends the alarm output operation value stored in the setting memory 11 to the microcomputer 9 of the protective relay device 3 as a voltage signal corresponding to the normal current value flowing through the electrical circuit 1. Sends a command to set the value lower than the value.

As a result, the alarm output operation value stored in the setting memory 11 decreases, so the microcomputer 9
It is determined that the voltage signal output from the conversion circuit 8 exceeds the alarm output operating value, and a protection output signal is sent to the output circuit 13. Thus, the output circuit 13 activates the alarm output contact 14.

Note that in order to accurately verify the actual alarm operation value, the remote monitoring device 18 sets a plurality of alarm output operation values near the voltage signal value corresponding to the normal current value in the setting memory 1. Then, it is only necessary to check whether the alarm output contact 14 actually operates for each alarm output operation value.

In this case, since the trip output operating value in the setting memory 7 is not changed, the trip output contact 15 is not operated. That is, in this embodiment, the alarm output test is used in place of the trip output test. Therefore, this test of the protective relay device 3 does not actually cause any protective operation to be applied to the power system. Therefore, this test will not cause any hindrance to normal operations in the power system.

Furthermore, there is no need to separately prepare expensive test-specific equipment to conduct the test.

Furthermore, the test is automatically executed by simply sending a command to change the alarm operation value from the remote device 18, so that the efficiency of the test work can be greatly improved.

[Effects of the Invention] As explained above, according to the protective relay device of the present invention, instead of applying from the outside multiple types of electrical quantities ranging from below the operating value to above the operating value, the operating value is I am trying to change it from outside. Therefore, it is possible to equivalently change the amount of electricity applied from the outside, thereby making it possible to test the device itself while the power system is normally energized, and to improve the efficiency of the test work.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing a schematic configuration of a protective relay device according to an embodiment of the present invention. DESCRIPTION OF SYMBOLS 1... Electric circuit, 2... Main current transformer, 3... Protective relay device, 4... Auxiliary current transformer, 8... A/D conversion circuit, 9
...Microcomputer, 11...Setting memory,
13... Output circuit, 14... Alarm output contact, 15.
...Trip output contact, 16...Interface,
17... Transmission device, 18... Remote monitoring device. 10 Procedural Amendment December 1990

Claims (1)

[Claims] The protective relay device detects the amount of electricity in the power system to be protected and, when the detected amount of electricity exceeds a preset operating value, outputs a protective output for a characteristic time corresponding to the amount of electricity that exceeds the amount of electricity. It is equipped with an alarm output contact and a trip output contact as a protection output means, and a storage means for storing the operation value, and the alarm output operation value among the operation values stored in the storage means is used in response to a command from a remote monitoring device. 1. A protective relay device comprising: operating value changing means for changing an operating value.