JP2002051452A - Distance relay - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a distance relay which can set a settling value properly according to the change of the numbers of transformers in operation. SOLUTION: Open/close states of breakers 5 and 6 on respective primary and secondary sides of a plurality of transformers 4 are inputted to an external signal input module 16 and stored in a memory module 18. The impedances of the respective transformers 4 and a transmission line, which are set by external switches 19, are inputted to an external setting module 20 and stored in the memory module 18. An impedance calculation module 21 calculates the total impedance from an installation point to a settling point, according to the impedances of the transformers 4 in operation and the transmission line. A settling value calculation module 22 calculates a settling value according to the total impedance. A relay calculation module 23 calculates for the relay decision according to the calculated settling value.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a distance relay device which is installed in a substation facility including a plurality of transformers and detects an accident from an installation point to a set point based on voltage and current at the installation point.

[0002]

2. Description of the Related Art In general, a distance relay detects an accident from a set point to a set point based on the voltage and current at its installation point, and an impedance Z (= V) from the installation point to the accident point.
/ I) (distance) is electrically calculated, and operates when the calculated impedance is equal to or less than a preset impedance. The impedance set in advance is determined as a set value up to a set point that defines a protection section of the distance relay device.

[0003] The distance relay device is characterized in that it has a high ability to discriminate between a normal state and a failure state, and has a high ability to judge where a failure point is, without being affected by the magnitude of a failure current. Since the operating limit is determined by the impedance, the protection section is clearly determined.

[0004] For this reason, a distance relay is applied to a substation facility having a plurality of transformers and a private generator. That is, the impedance Z (= V) from the installation point to the accident point is obtained by the voltage and current at the installation point of the distance relay apparatus of the receiving and transforming equipment having a plurality of transformers from the installation point of the distance relay apparatus to the settling point. / I) (distance) is electrically calculated to detect an accident point.

FIG. 4 is a system diagram in which a distance relay device is applied to a power receiving and transforming facility having a plurality of transformers and a private generator.

[0006] The power generated by the power generator 1 as a power company facility is supplied to a transmission line via a sending-out circuit breaker 2 and transmitted to a customer. Then, it is connected to the power receiving and transforming equipment via the power receiving circuit breaker 3 of the power receiving and transforming equipment. A plurality of transformers 4a to 4n are provided in the power receiving and transforming equipment, and primary side circuit breakers 5a to 5n are provided on the primary sides of the respective transformers 4a to 4n.
n are connected, and the secondary circuit breakers 6a to 6n are connected to the secondary side.

[0007] An in-house power generation facility 8 is connected to a bus 7 of the power receiving and transforming facility via a link breaker 9, and a distance relay device 10 is installed on the bus 7. Distance relay device 10
, The current I at the installation point is input via the current transformer 11 for the instrument, and the voltage V at the installation point is input via the transformer 12 for the instrument.

The distance relay device 10 calculates an impedance Z (= V / I) from the installation point to the fault point from the input current I and voltage V, and operates when the impedance Z is equal to or less than a set value. Then, a cut-off (disconnect) signal is output to the power receiving circuit breaker 3 and the connecting circuit breaker 9.

[0009]

However, in a substation having a plurality of transformers, not all of the transformers 4a to 4n are operated, and the operated transformers 4a to 4n are not always operated. The impedance up to the set point changes depending on the number of 4n.

As described above, the distance relay device 10 detects the impedance from the installation point to determine an accident. Therefore, when the total impedance of the power receiving and transforming equipment changes when it is healthy, the change is made. Unless a set value according to the total impedance of the state is set, a malfunction may occur.

In the conventional distance relay device 10, there is no function of changing a set value with respect to a change in impedance due to the number of operating transformers 4a to 4n, and an optimum set value cannot be obtained. .

It is an object of the present invention to provide a distance relay device capable of appropriately setting a set value in accordance with a change in the number of operating transformers.

[0013]

The distance relay device according to the first aspect of the present invention is installed in a substation facility including a plurality of transformers and a private power generation facility, and is installed at an installation point based on the voltage and current at the installation point. In a distance relay device for detecting an accident from a set point to a set point, an external signal input module for inputting the open / closed state of a primary circuit breaker and a secondary circuit breaker of each of a plurality of transformers and storing in a storage module, An external setting module for inputting the impedance of each transformer and transmission line set by the switch and storing the impedance in the storage module, and determining the operating transformer based on the open / closed state of the circuit breaker to determine the operating transformer. Calculation module that calculates the total impedance from the installation point to the settling point based on the impedance of the equipment and the impedance of the transmission line A set value calculation module that calculates a set value based on the total impedance calculated by the impedance calculation module; and a relay calculation module that performs a relay determination calculation based on the set value calculated by the set value calculation module. It is characterized by.

In the distance relay device according to the first aspect of the present invention, the external signal input module inputs the open / closed state of the primary and secondary circuit breakers of each of the plurality of transformers and stores them in the storage module. The external setting module inputs the impedance of each transformer and transmission line set by the external switch and stores the impedance in the storage module. The impedance calculation module determines the operating transformer based on the open / closed state of the transformer circuit breaker, and calculates the total impedance from the installation point to the settling point based on the operating transformer impedance and the transmission line impedance. Calculate. The set value calculation module calculates a set value based on the total impedance, and the relay calculation module performs a relay determination calculation based on the calculated set value.

According to a second aspect of the present invention, there is provided a distance relay device,
According to the first aspect of the present invention, the closing / closing time of the circuit breaker is stored in a storage module in advance, and when a circuit breaker closing / closing command is received from an external signal input module, the set value calculation module performs A set value is calculated based on the total impedance in the closed / closed state and stored in the storage module, and the relay calculation module uses the set value calculated and stored after the lapse of the closed / closed time. I do.

In the distance relay device according to the second aspect of the present invention, in addition to the operation of the first aspect, the setting value calculation module is configured to switch on / off of a circuit breaker from an external signal input module.
When a shutoff command is received, a set value is calculated based on the total impedance in the closed and turned on state. The relay operation module determines whether or not an accident has occurred by using the set value calculated and stored after the lapse of the closing / closing time.

[0017]

Embodiments of the present invention will be described below. FIG. 1 is a configuration diagram of a distance relay device according to a first embodiment of the present invention.

The current I at the installation point detected by the current transformer 9 and the voltage V at the installation point detected by the transformer 10 are converted into the input conversion module 13 and the analog-to-digital conversion module of the distance relay device 10. The digital signal is converted into a digital signal via the system bus 14 and is loaded on the system bus 15.

Primary circuit breaker 5 for a plurality of transformers 4a to 4n
a to 5n and the secondary circuit breakers 6a to 6b of the transformers 4a to 4n.
The open / close state of 6n is taken in by the external signal input module 16 as a contact signal of the circuit breaker contact 17, and the open / close state of the contact signal is stored in the storage module 18 via the system bus 15.

The external switch 19 is a switch of the relay device panel or a switch of the relay device main body. The impedance of the plurality of transformers 4a to 4n and the impedance of the transmission line are set from the external switch 19. The external setting module 20 takes in the impedances of the plurality of transformers 4 a to 4 n set in the external switch 19 and the impedance of the transmission line, and stores them in the storage module 18 via the system bus 15.

The impedance calculation module 21 monitors the open / close state of the primary circuit breakers 5a to 5n and the secondary circuit breakers 6a to 6n stored in the storage module 18 and operates the transformer. The relays 4a to 4n are determined, and the total impedance from the installation point of the distance relay device 10 to the settling point is calculated based on the impedance of each operating transformer 4a to 4n and the impedance of the transmission line.

The set value calculation module 22 calculates a set value according to the total impedance and stores it in the storage module 18. The relay operation module 23 calculates an impedance Z (= V / I) based on the input current I and voltage V at the installation point, and if the impedance is smaller than the set value calculated by the set value operation module 22, the protection is performed. It is determined that an accident has occurred in the section, and a breaker trip output command is sent to the trip output module 24.
The trip output module 24 outputs a cut-off (disconnect) signal to the power receiving circuit breaker 2 or the continuous circuit breaker 12.

FIG. 2 is an impedance map of the system diagram shown in FIG. From the installation point A of the distance relay device 10 to the settling point B, the transformers 4a to 4
There are 4n impedances Z1-Zn and transmission line impedance ZL. The sum of these impedances is the total impedance Zt from the setting point A to the settling point B. When all the transformers 4a to 4n are connected, the total impedance Zt
Is Zt = ZL + 1 / (1 / Z1 + 1 / Z2 +... + 1 /
Zn).

When the transformer 4a is disconnected, the total impedance Zt becomes Zt = Z
L + 1 / (1 / Z2 + 1 / Z3 +... + 1 / Zn), and when the transformers 4a and 4b are disconnected, the total impedance Zt becomes Zt = ZL + 1 /
(1 / Z3 + 1 / Z4 +... + 1 / Zn). The impedance calculation module 21 performs such calculation.

The set value calculation module 22 calculates a set value based on the total impedance obtained in this way and performs a relay determination calculation based on the set value, so that the number of transformers 4 to be operated can be changed. Even if there is, a relay determination operation can be performed using an appropriate set value.

According to the first embodiment, the set value can be properly set even if the number of the power receiving equipment operated for a plurality of transformers is changed. A distance relay device capable of appropriately determining an accident in a section can be provided.

Next, a second embodiment of the present invention will be described. FIG. 3 is a configuration diagram of a distance relay device according to a second embodiment of the present invention. In contrast to the first embodiment shown in FIG. 1, the external switch 19 is a switch for setting the on / off time of the circuit breaker in addition to the switch 19a for setting the impedance of the transformers 4a to 4n and the transmission line impedance. 19b, and circuit breakers 5a to 5n, 6
A command contact 25 that operates when a closing / shut-down command is output to any of a to 6n is additionally provided.

That is, the external signal input module 16 receives from the command contact 25 a command to turn on / off the circuit breakers 5a to 5n and 6a to 6n. The switch 19b of the external setting module 19 sets in advance the on / off time from the on / off command to the on / off of the circuit breakers 5a to 5n and 6a to 6n, and sets the on / off time.
The interruption time is stored in the storage module 18 in advance.

Since the other structure is the same as that of the first embodiment shown in FIG. 1, the same elements are denoted by the same reference numerals, and overlapping description will be omitted.

When a command to turn on / off the circuit breakers 5a to 5n and 6a to 6n is input to the external signal input module 16,
The impedance calculation module 21 obtains the total impedance in the system in which the circuit breaker 5 to which the command to turn on / off is given is turned on or turned off. The set value calculation module 22 calculates a set value from the total impedance and stores it in the storage module 18.

The set value at this time is still the distance relay device 1
The setting value stored in the storage module 18 after the command to turn on / off the circuit breaker 5 is input instead of the set value of 0.
After the elapse of the cutoff time, the final setting value of the distance relay device 10 is set. By doing so, it is possible to set an appropriate set value at the same time when the system state is adjusted.

[0032]

As described above, according to the present invention, it is possible to detect a change in impedance due to a change in the number of operating transformers and to set an optimum set value. Can be reliably detected.

Further, since the set value is changed after the ON / OFF time from when the ON / OFF command is output until the circuit breaker operates, the timing for returning the set value should also be adjusted at the time of ON / OFF of the circuit breaker. Can be.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a distance relay device according to a first embodiment of the present invention.

FIG. 2 is an explanatory diagram of a total impedance map of a system to which the distance relay device according to the first embodiment of the present invention is applied;

FIG. 3 is a configuration diagram of a distance relay device according to a second embodiment of the present invention.

FIG. 4 is a system diagram in which a distance relay device is applied to a power receiving and transforming facility having a plurality of transformers and a private generator.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Generator, 2 ... Sending out circuit breaker, 3 ... Power receiving breaker, 4
... Transformers, 5 ... Primary circuit breakers, 6 ... Secondary circuit breakers, 7 ...
Bus 8; private power generation equipment 9; connection breaker 10; distance relay 10; current transformer 12; transformer 12; input conversion module 14; analog-digital conversion module 14 15: System bus, 16: External signal input module, 17: Circuit breaker contact, 18: Storage module, 19: External switch, 20: External setting module, 21 ..., 22: Set value calculation module, 23: Relay calculation module, 24 ... trip output module, 2
5 Command contact

Claims (2)

[Claims] Claims: 1. A distance relay device installed in a power receiving and transforming facility including a plurality of transformers and a private power generating facility and detecting an accident from the installation point to a set point based on the voltage and current at the installation point. Input the open / closed state of the primary and secondary circuit breakers of each transformer and store them in the storage module, and input the impedance of each transformer and transmission line set by the external switch. An external setting module to be stored in the storage module and a transformer operated based on the open / closed state of the circuit breaker, from an installation point to a set point based on the impedance of the operating transformer and the impedance of the transmission line. And a total impedance calculated by the impedance calculation module. A distance relay device comprising: a set value calculation module that calculates a set value based on impedance; and a relay calculation module that performs a relay determination calculation based on the set value calculated by the set value calculation module. 2. The closing / closing time of a circuit breaker is stored in a storage module in advance, and when a circuit breaker closing / closing command is received from an external signal input module, the setting value calculation module sets the closing / closing time. The relay module calculates a set value based on a total impedance in a cut-off state and stores the set value in a storage module, and the relay calculation module uses the set value calculated and stored after the lapse of the closing / cutting time. Item 2. The distance relay device according to Item 1.