JP3227477B2 - Protection relay and tester and test 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. Relay, a tester for testing the protective relay, and a test system including the same.

[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] Such a protective relay, for example, an overcurrent relay has two relay elements, a time limit function and an instantaneous function. Therefore, when measuring the operating value and operating time of the overcurrent relay, For example, when measuring the instantaneous operating current value, one of the functions may be stopped to measure the operating value and operating time of each function, such as to prevent the timed function from operating first. Alternatively, it is necessary to perform measurement by performing an operation such as lowering the operation sensitivity.

For this reason, conventionally, as shown in the front view of the overcurrent relay of FIG. 7, for example, a time limit lock switch 75 and an instantaneous lock switch 76 for stopping the time limit function and the instantaneous function, respectively, are provided. These function lock switches 75 and 76 lock one function and measure the other function. In FIG. 7, reference numeral 77 denotes a time limit current setting switch, and 78
Is a time limit switch, 79 is an operation indicator, and 80 is a start / elapsed time indicator.

[0006]

However, in the protection relay of the related art which locks a relay element such as a time limit function or an instantaneous function by operating a function lock switch as described above, a function lock switch is provided when the measurement is completed. If you forget to release the lock by returning to the original position, the protection relay will not operate.For example, if the instantaneous function remains locked, short-circuit protection with an overcurrent There is a drawback that the protection function in the place works, leading to a spillover accident in which all consumers lose power.

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and enables a relay element to be locked and unlocked without operating a function lock switch. The purpose is to prevent serious accidents.

[0008]

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

That is, in the present invention, a lock signal is transmitted from a tester to a protection relay via a connection cable.
And release of the lock signal is unlocked.
The protection relay locks or releases the relay element based on those signals, and when the connection cable is disconnected from the protection relay, the lock signal is output . By stopping transmission
Thus, the lock of the relay element is forcibly released.

[0010]

[Function] During the test, the tester supplies electricity to the protective relay and the output of the protective relay is taken into the tester, so that both are connected to each other by a connection cable. , The connection is disconnected, so even if the lock signal is sent from the tester,
Since the signal transmission is forcibly stopped, the lock of the relay element of the protection relay is forcibly released, and it is not necessary to operate the function lock switch as in the conventional example.

[0011]

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 test system according to this embodiment includes an overcurrent relay 1 having two relay elements, a time limit function and an instantaneous function, and an overcurrent relay 1 having the same. A tester 2 of the relay 1 and two connection cables 62 and 64 for connecting the two are provided.

The overcurrent relay 1 includes a transmission / reception unit 6 for transmitting and receiving information between the input unit 4 to which a test electric quantity from the test unit 2, in this embodiment, an alternating current is input, and the test unit 2.
And a CPU 8 that controls each unit and performs an arithmetic operation and the like
And an output unit 10 for outputting by operation of a relay 26 based on a command operation from the CPU 8, a setting unit 12 for setting various set values, and a storage for storing an operation program of the CPU 8, various test data, and the like. A test circuit section 16 provided corresponding to the output section 10 and a function lock input section 7 to which a lock control signal for locking or unlocking the relay element is input and the corresponding output is given to the CPU 8
1 is provided.

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 overcurrent relay 1, and a test connector 30 for connection to the tester 2 is provided at a lower portion of the front surface of the overcurrent relay 1. As shown in FIG. 1, the test connector 30
A communication terminal 32 connected to the transmission / reception section 6, a test terminal 34 from the test circuit section 16, and a lock control signal input terminal 73 are collectively arranged.

The input terminal 36 connected to the input section 4 is
As shown in FIG. 3, the overcurrent relay 1
Are disposed as test terminals 40 below the portion of the substation 38 on which the overcurrent relay 1 is provided. The output terminal 42 connected to the output contact portion 24 includes:
It is provided on the back of the overcurrent relay 1.

The overcurrent relay 1 is provided with a detection current from a current detector, which is usually provided on an input terminal 36 on a transmission line or a distribution line.
When the set value set in step (1) is reached, an output command signal is supplied from the CPU 8 to the output drive circuit 18, whereby the drive coil 22 is driven and the output contact portion 24 is turned on. An interruption command signal is given to a circuit breaker provided on an electric wire or a distribution line.

In this embodiment, the CPU 8 as a function lock control unit locks and releases the corresponding relay element based on the output from the function lock input unit 71, and connects the connection cable 64 to the overcurrent relay. When the relay element is removed from 1 and the relay element is locked, the lock is forcibly released.

The tester 2 has a CPU 50 for controlling each unit.
And a storage unit 51 for storing an operation program of the CPU 50 and various data, a current generation unit 52 for generating a test AC current supplied to the overcurrent relay 1, and transmission and reception of information between the overcurrent relay 1. A transmitting / receiving unit 54, an input unit 56 to which an output signal from the overcurrent relay 1 is input, a display unit 58 for displaying test result contents, etc., an operation unit 60, and locking of a relay element of the overcurrent relay 1. Alternatively, it comprises an output unit 74 that outputs a 2-bit lock control signal to be released under the control of the CPU 50.

Next, the operation during the test will be described.

FIG. 3 is a diagram showing a test state of the overcurrent relay 1 by the tester 2. In the test, a connection cable 62 for supplying a current from the tester 2 is connected to the test terminal 40 of the power receiving and changing panel 38. Then, the connection cable 64 for contact confirmation from the tester 2 is connected to the test connector 30 of the overcurrent relay 1.

When a test current is supplied from the tester 2 to the test terminal 40 during the test, the overcurrent 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. As a result, the test contact 28
Is turned on, an operation signal is supplied to the tester 2 via the test connector 30 and the contact confirmation cable 64.

Here, since the overcurrent relay 1 has two relay elements, a time limit function and an instantaneous function, in order to measure an operation value and an operation time in each function,
One of the functions needs to be stopped, that is, locked. In this embodiment, for example, as shown in FIG. 4, the required relay elements to be stopped when performing the measurement are locked and the test is sequentially performed. Can proceed.

That is, the tester 2 outputs a lock signal (for example, one of two bits to a high level) for locking the instantaneous function from the output unit 74 to the overcurrent relay 1.
H, L), which are lock signals of level H, are sent to request the locking of the instantaneous function, the overcurrent relay 1 locks the instantaneous function in response to this lock signal, and the tester 2 The time test is started, the overcurrent relay 1 operates, and the test is completed.

When the test is completed, the tester 2 sends a release signal for releasing the lock of the instantaneous function from the output section 74 to the overcurrent relay 1 (for example, any bit is high).
Stop sending level H lock signal to low level
L , L) is transmitted to request the release of the lock of the instantaneous function, the overcurrent relay 1 releases the lock of the instantaneous function in response to this release signal, and the tester 2 outputs the overcurrent relay. 1
In response to this, a lock signal for locking the time limit function (for example, the other
L, H) as a lock signal for the low level H is sent to request locking of the time limit function, the overcurrent relay 1 locks the time limit function in response to the lock signal, and the tester 2 operates instantaneously. The time test is started, the overcurrent relay 1 operates, and the test is completed.

When the test is completed, the tester 2 sends a release signal (for example, L, L) for releasing the lock of the time limit function from the output unit 74 to the overcurrent relay 1 to send the time limit function. In response to the release signal, the overcurrent relay 1 releases the lock of the time limit function, and the test proceeds in the same manner as described above. When the test is completed, the overcurrent relay 1 releases the lock from the tester 2. The function lock is released by the signal.

Moreover, in this embodiment, the overcurrent relay 1
, When the connection cable 64 for contact confirmation is removed from該継collector 1, release signal (it is in the function lock input unit 71
The shift bit also sends a high-level H lock signal.
The state is the same as when L and L) are stopped and the low level is applied, and when the function is locked, C
The PU 8 forcibly releases the function lock.

Therefore, when the test is terminated and the connection cable 64 is disconnected, the connection cable 64 is disconnected for some reason in a state where the test is not completely completed and the function lock is not released. The function lock of the overcurrent relay 1 is surely released even when the function lock switch is removed. For example, as in the conventional example, forgetting to return the function lock switch to the original state may cause a serious accident. Is prevented.

FIG. 5 is a flowchart showing an operation example of each test proceeding as described above. When a start operation is performed by the operation unit 60, the tester 2 first reads the set value of the overcurrent relay 1 ( Step 1), a corresponding test current is calculated, and the calculated test current is supplied to the overcurrent relay 1 (steps 2 and 3), and then a timer is started (step 4). The reading of the set value in the above is performed via the communication line of the connection cable 64 for contact confirmation, and the overcurrent relay 1 gives the set value to the test device 2 by communication in response to the communication command from the test device 2. This is done by: When the operation signal from the overcurrent relay 1 is obtained (step 5), the timer is stopped (step 6), and when the operation time measured by the timer is within a predetermined time (step 7). The display unit 58 displays that the overcurrent relay 1 has passed the test (step 8). If the activation signal is not obtained within a predetermined time, a rejection is displayed (step 9).

Conventionally, neither the test circuit section 16 nor the test connector 30 for connecting the connection cable 64 for contact confirmation is provided in the overcurrent relay 1 as in this embodiment. Connection cable 64
Was placed in the receiving / transforming board 38 and the overcurrent relay 1 was opened and connected near the output contact portion 42. According to this embodiment, the connection cable 64 for contact confirmation was tested from the front of the overcurrent relay 1 The test can be performed simply by connecting to the test connector 30, wiring for obtaining the test output can be performed very easily, and the work efficiency can be greatly improved.

In this embodiment, the connection cable 64
Although the function is locked or unlocked through the connection cable 64 as another embodiment of the present invention.
The function may be locked or unlocked by communication via the communication line described above. In this case, it is not necessary to increase the number of signal lines even if the number of functions to be controlled increases.

Although this embodiment has been described by applying to the overcurrent relay 1, for example, as shown in FIG.
The present invention can be similarly applied to a composite protection relay having a plurality of relay elements such as a combination of an undervoltage relay and an underfrequency relay.

In FIG. 6, the tester requests the composite protection relay to lock the function of the undervoltage relay, and the protection relay locks the function of the undervoltage relay in response to the request. The tester starts testing the under-frequency relay, and when the protective relay operates and completes the test,
The tester requests the protection relay to release the function lock of the undervoltage relay, and the protection relay releases the function lock in response thereto.
Requests the function lock of the under-frequency relay, the protection relay responds by locking the function of the under-frequency relay, the tester starts the test of the under-voltage relay, the protection relay operates and the test is completed Then, the tester requests the protection relay to release the function lock, and the protection relay releases the function lock in response to the request. Thereafter, the test is sequentially performed in the same manner.

[0034]

As described above, according to the present invention, a lock signal is transmitted from a tester to a protection relay via a connection cable or the transmission of the lock signal is stopped to provide a release signal . Based on the signal, the relay element such as the time limit function and the instantaneous function is locked or unlocked, and when the connection cable is disconnected from the protective relay, the lock of the relay element of the protective relay is forcibly released. Therefore, it is possible to effectively prevent a serious accident from being forgotten to return the function lock switch after the test is completed, as in the conventional example of locking or releasing the function by the function lock switch of the protective relay. Become.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a protection relay and a tester thereof according to an embodiment of the present invention.

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

FIG. 3 is an explanatory diagram of a state during a test.

FIG. 4 is a diagram sequentially showing the operations of a protective relay and a tester during a test.

FIG. 5 is a flowchart for explaining the operation.

FIG. 6 is a diagram corresponding to FIG. 4 of another embodiment.

FIG. 7 is a front view of a conventional overcurrent relay.

[Explanation of symbols]

 1 Overcurrent relay 2 Tester 71 Function lock input unit 74 Output unit

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-1-264526 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H02H 3/05 G01R 31/02

Claims (3)

(57) [Claims] 1. A test system comprising: a protective relay having a plurality of relay elements; a tester for measuring the relay elements; and a detachable connection cable for interconnecting these. A lock signal for locking a required relay element of the protection relay is transmitted via the connection cable to the protection relay.
Sending to the electric appliance and stopping the sending of the lock signal
The have output <br/> force unit to release signal for unlocking the relay element, the protective relay is adapted to lock the relay element corresponding in response to the lock signal, the lock Sending a signal
A function lock control unit that releases the lock of the relay element in response to the stoppage of the connection cable. The function lock control unit transmits the lock signal when the connection cable is disconnected from the protection relay.
A test system for forcibly unlocking a relay element in response to an outage stop . 2. A protective relay having a plurality of relay elements, while locking the corresponding relay elements in response to the lock signal input through a detachable connecting cable, prior to
A function lock control unit that releases the lock of the relay element in response to the release signal as a stop signal for stopping the input of the lock signal , wherein the function lock control unit disconnects the connection cable from the protection relay. Of the lock signal input
A protective relay for forcibly unlocking a relay element in response to a stop . 3. A lock signal for locking a required relay element of a protective relay having a plurality of relay elements is transmitted.
The transmission of the lock signal is stopped when the relay element is locked.
A tester comprising: an output section that serves as a release signal for releasing a lock .