JP3213710B2 - Testing system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention cuts off the supply of power when an overload or short circuit occurs in a transmission line or distribution line constituting a power supply route for supplying power from a power plant to a customer. And a test system for testing a protective relay used as described above.

[0002]

2. Description of the Related Art In a factory of each business site, for example, once a year, protection relays used for interrupting transmission lines and distribution lines are tested. If there is a machine short-circuit accident in the factory and excessive current is applied to the machine side, it is dangerous.If the amount of current is detected and becomes excessive, the output of the protective relay will The circuit breaker provided in the distribution line is operated to interrupt the current.

[0003] In the test of the protective relay, the tester is connected to the protective relay, a test current is supplied from the tester side, and the output operation and time limit of the protective relay for the test current are checked.

[0004]

Conventionally, in such a test of a protection relay, measurement of the operation time from the time when a test current is applied to the protection relay to the time when the protection relay operates is particularly limited. If the protection relay was not operated, the tester determined that the measurement time was too long and stopped supplying the test current, but this determination was made by the tester. If the judgment of the tester is delayed, a large test current will flow through the protection relay for a long time, and there is a risk that the protection relay and the tester may be damaged.

[0005] The present invention has been made in view of the above points, and an object of the present invention is to prevent a protection relay and a tester from being damaged in a test of the protection relay.

[0006]

In order to achieve the above-mentioned object, the present invention is configured as follows.

That is, in the present invention, the measurement of the operation time of the protection relay is limited to a predetermined time.

[0008]

According to the above configuration, since a time limit is set for measuring the operation time of the protection relay, the protection relay and the tester are damaged by continuing to supply the test electricity to the protection relay for a long time. I can't.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 is a block diagram of an embodiment of the present invention. A protection relay 1 is a test electric quantity from a tester 2, and in this embodiment, an input section 4 to which an alternating current is input.
A transmitting and receiving unit 6 for transmitting and receiving information to and from the tester 2, a CPU 8 for controlling each unit and performing an arithmetic operation, and the like;
An output unit 10 that outputs by operating a relay 26 based on a command operation from U8, a setting unit 12 in which various set values are set, and a storage unit 14 in which an operation program of the CPU 8 and various test data are stored. And a test circuit unit 16 provided corresponding to the output unit 10.

The output unit 10 includes an output drive circuit 18 that outputs a drive signal after a predetermined delay time in response to an output command signal from the CPU 8, a transistor 20 that is turned on by the drive signal from the output drive circuit 18,
And a contact 24 for output that is turned on by excitation of the drive coil 22. The drive coil 22 and the output contact 24 form a relay 26. The test circuit section 16
A test contact section 28 that is similarly operated by the drive coil 22 of the output section 10 is provided and configured.

FIG. 2 is a partial front view showing a part of the front surface of the protection relay 1.
A test connector 30 is provided for connection to the test. In the test connector 30, a communication terminal 32 connected to the transmission / reception unit 6 and a test terminal 34 from the test circuit unit 16 are collectively arranged. As shown in FIG. 3, the input terminal 36 connected to the input unit 4 is pulled out to the outside, and a test terminal is provided below a portion of the sub-panel 38 on which the protective relay 1 is provided, where the protective relay 1 is provided. 40. The output terminal 42 connected to the output contact portion 24 is provided on the back surface of the protection relay 1.

The protection relay 1 usually has an input terminal 3
6, when a detection current is provided from a current detector provided in a transmission line or a distribution line, for example, and when the current value reaches a set value set by the settling unit 12, an output command signal is output from the CPU 8 to drive. By being provided to the circuit 18, the drive coil 22 is driven and the output contact portion 24 is turned on, whereby a cutoff command signal is provided from the output terminal 42 to a circuit breaker provided on a power transmission line or a distribution line. I have.

The tester 2 controls each part and, as described later, has a function as a limiting means for limiting the measurement of the operation time of the protection relay 1 for a predetermined time.
U50, a storage unit 51 for storing an operation program of the CPU 50 and various data, a current generating unit 52 for generating a test AC current supplied to the protection relay 1, and a protection relay 1
A transmission / reception unit 54 for transmitting / receiving information to / from, an input unit 56 to which an output signal from the protection relay 1 is input, a display unit 58 for displaying test result contents and the like, and an operation unit 60. I have.

Next, the operation during the test will be described.

FIG. 3 is a diagram showing a test state of the protection relay 1 by the tester 2. At the time of the test, a current supply cable 62 from the tester 2 is connected to the test terminal 40 of the power receiving and changing panel 38. The connection confirmation cable 64 from the tester 2 is connected to the test connector 30.

When a test current is supplied from the tester 2 to the test terminal 40 during the test, the protection relay 1 operates in the same manner as in the normal operation described above, and the relay 26 whose current value exceeds the set value is activated. When the test contact portion 28 is turned ON, an operation signal is supplied to the test device 2 via the test connector 30 and the contact confirmation cable 64.

In this embodiment, when the protection relay 1 does not operate, a large test current is continuously supplied for a long time so that the protection relay 1 and the tester 2 are not damaged. The tester 2 sets a predetermined time limit for the measurement of the instantaneous operation time and the time limit operation time, and displays an error message when the output of the protection relay 1 cannot be obtained after the time limit. At the same time, the supply of the test current is stopped.

First, as shown in FIG. 4, the time limit for measuring the instantaneous operation time is set to 1 second, which is 20 times the instantaneous operation time 50 ms, and a test current of 200% of the set current is applied for 1 second. When the protection relay 1 does not operate even if the current flows, an error message is displayed and the supply of the test current is stopped.

On the other hand, the time limit for measuring the time limit operation time is determined as follows. The protection relay 1 of this embodiment is an overcurrent relay, and has one of the super-restricted time characteristic and the reversible time characteristic shown in FIG. 1 so that the test current can be 200% of the set current.
Up to 400%, as shown by the line A, the operation time of the super-restricted time characteristic at 200% of the set current (indicated by a black circle) is limited, and the test current is 500% to 1% of the set current.
Up to 000%, as shown by the line B, the operation time (represented by a black triangle) of the time limit characteristic at 500% of the set current is limited. In other words, the longer operation time of the super time limit characteristic and the time limit characteristic at 200% and 500% of the set current is set as the time limit.

Normally, the measurement of the time limit operation time is performed at test currents of 300% and 700% of the set current.
In this embodiment, when the test current is 300% of the set current, the operation time of the super-restricted time characteristic at 200% of the set current indicated by the line A is the time limit, and the operation time is 700% of the set current. In the case of the test current, the operation time of the time limit characteristic at 500% of the set current indicated by the line B is the time limit.

Next, the measurement of the instantaneous operation time will be described with reference to the flowchart of FIG.

First, test conditions such as a test current value are set (step n1), and a time limit corresponding to the measurement of the instantaneous operation time, ie, 1 second in this embodiment (step n2), is set. The protection current is passed through the protection relay 1 and time measurement is started (step n3), and it is determined whether or not the time limit has elapsed (step n4). The protection relay 1 operates without the time limit. At this time, the time measurement is terminated (step n5), and when the time limit has elapsed, an error message is displayed, the supply of the test current is stopped, and the measurement is terminated (step n6).

Next, measurement of the time limit operation time will be described with reference to the flowchart of FIG.

First, test conditions such as a test current value are set (step n1), the magnitude of the test current is determined (step n2), and the test current is set to 200% of the set current.
If it is 400%, the corresponding time limit, that is, the operation time of the super-restricted time characteristic at 200% of the set current is set as the time limit (step n7), and the test current becomes 500% of the set current. When it is ~ 1000%, the corresponding time limit, that is, 500% of the set current
Is set as the time limit (step n3), a test current is supplied to the protection relay 1, and time measurement is started (step n4) to determine whether the time limit has elapsed. Judgment is made (step n5), and when the protection relay 1 operates without lapse of the time limit, the time measurement is ended (step n6). When the time limit is lapsed, an error message is displayed and the test current is displayed. Is stopped to terminate the measurement (step n8).

As described above, in the measurement of the operation time, when the protection relay 1 does not operate even after the predetermined time limit has elapsed, an error message is displayed and the supply of the test current is stopped. Damage to the protective relay 1 and the tester 2 due to the continuous supply of test electricity for a long time is reliably prevented.

Conventionally, as in the present invention, the test relay unit 16 and the contact confirmation cable 6 are connected to the protective relay 1.
4 is not provided, and during the test, the contact confirmation cable 64 is connected to the substation 3
8, the protective relay 1 is opened and its output contact 42
According to the present invention, the test can be easily performed simply by connecting the contact confirmation cable 64 to the test connector 30 from the front of the protective relay 1 according to the present invention.

The predetermined time limit is of course not limited to the above embodiment.

[0029]

As described above, according to the present invention, the operation time of the protection relay is limited by a predetermined time.
The protection relay and the tester will not be damaged by supplying the test electricity to the protection relay for a long time.
In addition, the tester is connected to terminals located on the front of the protective relay.
Since it is connected via a cable, the tester
Cable from the back of the protective relay
Tester and protection relay can be easily connected.
It works.

[Brief description of the drawings]

FIG. 1 is a block diagram of one embodiment of the present invention.

FIG. 2 is a partial front view of the protection relay of FIG. 1;

FIG. 3 is an explanatory diagram of a state at the time of the test in FIG. 1;

FIG. 4 is a characteristic diagram showing a limitation on an instantaneous operation time.

FIG. 5 is a characteristic diagram showing a limitation on a time limit operation time.

FIG. 6 is a flowchart of an instantaneous operation time measurement.

FIG. 7 is a flowchart of timed operation time measurement.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Protective relay 2 Tester 16 Test circuit part 50 CPU (limitation means)

Continued on the front page (72) Inventor Toshimori Fujieda 918-1 Minamisayama, Nakagami character, Iruma-shi, Saitama Musashi Electric Instrument Co., Ltd. -1 Musashi Electric Instrument Co., Ltd. (56) References JP-A-1-264524 (JP, A) JP-A-4-244725 (JP, A) (58) Fields studied (Int. Cl. ⁷ , DB G01R 31/327 G01R 31/333

Claims (1)

(57) [Claims] 1. A protection relay and a protection relay connected to the protection relay.
To supply electricity for testing,
Tester with a tester to which the output of the
In the test system, the protection relay is connected to the tester via a communication terminal.
Transmission / reception unit for transmitting and receiving information, and command signal from CPU
The output contact is activated by the
And an output unit for outputting a command signal.
It has a test contact that operates, and a test terminal
A test circuit unit having the communication terminal and the communication terminal
And a test terminal are arranged in front of the protection relay, and the tester is connected to the communication terminal via a cable.
Transmission and reception unit, and the test terminal through a cable
The input part to be connected and the amount of electricity for testing to the protective relay
And then the output of the protection relay is given to the input section.
Measurement of operating time until operation is restricted by a predetermined time
Test system, comprising:
M