KR20000042158A - Automatic control apparatus of under frequency relay - Google Patents

Abstract

PURPOSE: An automatic control apparatus of an under frequency relay(UFR) is provided to improve a reliability to a power supply by controlling a plurality of breakers installed at a service wire corresponding to an UFR. CONSTITUTION: An automatic control apparatus comprises first to third UFRs(1-3), a selector(4), a digital frequency meter(5), a control unit(6), first to third switches(7-9) and an alarm part(10). Each of the first to third UFRs(1-3) has a predetermined sense frequency, and outputs an electric signal when a frequency of a corresponding service line corresponds to the predetermined sense frequency. The selector(4) is to make a user switch on and off the first to third UFRs(1-3), and consists of three on switches(S2,S4,S6), three off switches(S1,S3,S5), and a switch(S7) for setting the yes or no of a remote control(SCADA). When a low frequency abnormality of a power system is resolved and is restored into an original state, the digital frequency meter(5) outputs a restoration signal for restoring a breaker related thereto in an operation order. A control unit(6) switches on and off service lines corresponding to the UFRs(1-3) and installed breakers according to whether the first to third UFRs(1-3) are operated. The first switch(7) switches off breakers installed at service lines corresponding to the UFRs(1-3), and the second switch(8) switches on breakers installed at service lines corresponding to the UFRs(1-3). The third switch(9) is switched on and off according to a control signal applied from an output terminal(6c) of the control unit(6).

Description

Low Frequency Relay Automatic Control

The present invention relates to a low-frequency relay automatic control device, in particular, a plurality of circuit breakers installed in the distribution line corresponding to the low-frequency relay at the same time during the operation of the low-frequency relay to perform the function of separating the load from the grid in the event of a frequency abnormality of the power system The present invention relates to a low-frequency relay automatic control device that can be collectively turned on / off control to improve the power supply reliability.

In addition to the current development of living standards that require electricity is used, as well as in most factories and buildings, especially hospitals must be able to supply electricity at all times.

Therefore, the electricity supplier will supply high-quality electricity to the consumer, but set the priority so that when the power is insufficient, the electricity is cut off in order of low priority to high region, and priority when the power is restored normally. Electricity is restored in order from high to low.

For example, if the general residential area is selected as the lowest priority, the factory area is selected as the middle priority area, and the place where people's lives are treated as the highest priority, such as a hospital, When not enough, electricity is cut off in the order of general residential area → factory area → hospital. When power is restored, electricity is restored in order of hospital → factory area → general residential area.

As such, an under frequency relay (UFR) is used to perform a function of separating a load of a distribution line by a system, that is, a priority, in case of an abnormal power system.

However, the conventional low frequency relay switchgear, which performs the function of separating the load in case of frequency abnormality of the power system, is still a non-standard specification, and its functions and specifications are applied differently by each customer, and unmanned and automated substations are rapidly applied. Since 3 ~ 4 substations are operated at power distribution centers, several line breakers must be operated at the same time when low frequency relays are operated. Therefore, it takes a long time. There was a problem.

Accordingly, the present invention for solving the above problems is a batch at the same time a plurality of circuit breakers installed in the distribution line corresponding to the corresponding low frequency relay during the operation of the low frequency relay to perform the function of separating the load from the system when the frequency abnormality of the power system It is an object of the present invention to provide a low-frequency relay automatic control device that can be turned on / off control to improve the reliability of the power supply.

Features of the present invention for achieving the above object,

In the case where the frequency of the power system is abnormal, the load is separated and intermittent by frequency for

First to third low frequency relays for detecting a frequency change of a power system power source and outputting a predetermined electric signal when the detected frequency is out of a preset range of a preset value;

A selection unit comprising a selection switch for selecting whether to operate the low frequency relay and a switch for setting whether to execute remote control;

A digital frequency meter for setting an operating frequency of the low frequency relay;

An alarm unit for displaying an alarm when an operation of the low frequency relay is abnormal;

First and second output terminals are formed to turn off or on circuit breakers installed in distribution lines corresponding to the respective low frequency relays according to power frequency detection results from the first to third low frequency relays. A control unit formed with a third output terminal for outputting a control signal for preventing overcurrent caused by the operation of the re-closing relay of the power company during the operation of the third low-frequency relay;

A first switching unit comprising a plurality of relay switches to be turned on by a control signal output from a first output terminal of the control unit to turn off a circuit breaker installed in a distribution line;

A second switching unit including a plurality of relay switches to be turned on by a control signal output from the first output terminal of the control unit to turn on a circuit breaker installed in a distribution line;

A third switching unit including a plurality of relay switches configured to be connected to or disconnected from a reclosing relay of a power company by operating on / off by a control signal output from a third output terminal of the control unit; It features.

The control unit may operate from the low frequency relay determined as the lowest among the low frequency relays, the priority of which is determined by frequency when the frequency of the power system is abnormal, and the alarm unit operates when the order is not followed.

In addition, the control unit is to operate in order from the low-frequency relay determined as the highest priority among the low-frequency relays, the priority is determined for each frequency when the power line frequency returns to normal, characterized in that for controlling the alarm to operate when the order is not followed. do.

1 is a block diagram showing a low frequency relay automatic control device of the present invention.

Figure 2 is a flow chart showing a breaker off process of the present invention.

Figure 3 is a flow chart showing the breaker recovery process of the present invention.

Figure 4 shows an embodiment of the breaker off process of the present invention.

5 is a view showing an embodiment of the breaker recovery process of the present invention.

※ Explanation of symbols for main parts of drawing

1 to 3: low frequency relay, 4: kiibu,

5: digital frequency meter, 6: control unit,

7-9: switching part, 10: alarm part,

7A, 8A, 9A: relay switch,

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings, FIGS. 1 to 5.

According to the drawings, the present invention provides the first to third low frequency relays 1 to 3, the selector 4, the digital frequency meter 5, the control unit 6, and the first to third switching units 7. 9) It consists of the alarm part 10 roughly.

The first to third low frequency relays 1 to 3 detect the frequency of the power system and output a predetermined electrical signal to the control unit 6 when an abnormality is detected. 3) has a predetermined sensing frequency, and outputs a predetermined electrical signal when the frequency of the distribution line corresponds to a preset sensing frequency.

The first to third low frequency relays 1 to 3 set an operation order when the frequency abnormality of the power system occurs and an operation order when the frequency abnormality is restored, and operate according to the setting procedure.

That is, the first low frequency relay 1 is set to detect 59 Hz, the second low frequency relay 2 is 58 Hz, and the third low frequency relay 3 is 57 Hz, and its operation priority is' first low frequency relay <second. If the low frequency relay is set in the order of <third low frequency relay ', when the frequency abnormality of the power system occurs, it operates from the first low frequency relay (1), and when the frequency abnormality of the power system is restored, the third low frequency relay is performed. It starts from (3).

The selector 4 includes three on-operation switches S2, S4, S6 and off-operation switches S1, S3, and S5, which the user can set whether the first to third low frequency relays 1 to 3 are operated. ), And a switch (S7) for setting whether or not the remote control (SCADA).

The digital frequency meter 5 outputs a return signal so that the breaker associated with the low frequency abnormality of the power system is eliminated and the circuit breaker associated with the power system is returned in the operation order.

The control unit 6 turns on / off a distribution line corresponding to each of the low frequency relays 1 to 3 and a circuit breaker installed according to whether the first to third low frequency relays 1 to 3 operate. The first and second output terminals 6a and 6b for turning on / off the circuit breaker and the third output terminal 6c associated with the operation of the distribution line and the reclose relay corresponding to the respective low frequency relays 1 to 3 are connected. It is configured to include.

On the other hand, the first switching unit 7 is turned on by a control signal input from the first output terminal 6a of the control unit 6 to operate the first to third low frequency relays 1 to 3. It is composed of a plurality of relay switches 7A1 to 7An for turning off (breaking) the circuit breaker provided in the distribution line corresponding to the sensing area.

That is, when the first low frequency relay 1 operates when the frequency of the power system is abnormal and the control signal is output to the first output terminal 6a of the control unit 6, the distribution line corresponding to the first low frequency relay 1 The relay switch 7A1 to 7An connected to the circuit breaker installed in the furnace is turned on, the circuit breaker is turned off to cut off the distribution line, and the second and third low frequency relays are operated to output the first output of the control unit 6. When a control signal is outputted to the terminal 6a, the relay switches 7A1 to 7An are turned on by the control signal and the distribution line is cut off.

The second switching unit 8 is turned on by a control signal input from the second output terminal 6b of the control unit 6 so as to detect the first to third low frequency relays 1 to 3. And a plurality of relay switches 8A1 to 8An which turn on (return) the circuit breaker provided in the distribution line corresponding thereto.

That is, when the frequency abnormality of the power system is restored, when the third low frequency relay 3 operates to output the control signal to the first output terminal 6b of the control unit 6, the third low frequency relay 3 The relay switches 8A1 to 8An connected to the circuit breakers installed in the corresponding distribution lines are turned on, so that the circuit breakers are turned on (return) and the distribution lines are turned on (return).

The third switching unit 9 is turned on / off by a control signal input from the third output terminal 6c of the control unit 6 to detect the first to third low frequency relays 1 to 3. The distribution line corresponding to the area is connected to or disconnected from the reclosing relay of the power company, so if the frequency of the distribution line is abnormal, the overcurrent by the operation of the reclosing relay is not applied to the distribution line when the circuit breaker of the distribution line is blocked. When the frequency of the distribution line is restored, the distribution line is connected to the reclose relay.

The alarm unit 10 includes a lamp BL, a buzzer sound output unit BZ, a switch HS RESET, and the like, which are turned on under the control of the control unit 6.

The operation of the present invention configured as described above will be described with reference to FIGS. 4 and 5.

First, when a low frequency occurs in the power system, the first low frequency relay 1 operates first to output a predetermined electric signal to the control unit 6.

The control unit 6 receiving the electrical signal from the first low frequency relay 1 outputs a predetermined control signal to the first switching unit 7 through the first output unit 6a to provide a corresponding relay switch ( Switching line corresponding to the first low frequency relay 1 by turning on 7A1 to 7An and turning on the corresponding relay switch 9A1 to 9An by outputting a control signal to the third switching unit 9 after a predetermined time delay. The circuit breaker installed in the circuit is turned off so that the corresponding distribution line is blocked, and the blocked distribution line is blocked from the reclosing relay.

Thereafter, when the frequency abnormality of the power system continues, the second low frequency relay 2 having the lowest priority operates next, and the third low frequency relay 3 having the highest priority operates afterwards, and the second And the control unit 6 responds to the operation of the third low frequency relay 2, 3, corresponding relay switches 7A1 to 7An of the first switching unit 7 and the third switching unit 9A1. ~ 9An) to turn off the circuit breakers installed on the distribution lines corresponding to the second and third low frequency relays (2) and (3) to turn off the corresponding distribution lines, as well as to block the disconnected distribution lines from the reclosing relays. do.

If, as described above, the first low frequency relay 1 does not operate in the order of the third low frequency relay 3 and the third low frequency relay 3 operates from the beginning, or the second low frequency relay 2 operates. When the control unit 6 operates the alarm unit 10 so that the alarm sound and the alarm light are turned on, the control unit 6 waits for the first and third low frequency relays 1 to 3 to operate in the normal order again. If no action is taken, the system is stopped.

On the other hand, if the frequency abnormality of the power system is restored after the operation of breaking the power distribution line is completed, as described above, the frequency abnormality occurs,

First, the third low frequency relay 3 having the highest priority is operated, and the control unit 6 is in a blocked state by turning on the corresponding relay switch 8A1 to 8An of the second switching unit 8. The circuit breaker associated with the third low frequency relay 3 was turned on at an interval of about 0.1 to 1 sec to return the distribution line to its original state, and the power was automatically and quickly transferred to the main area such as a hospital through the distribution line. Power is supplied.

After the breaker of the distribution line is returned, the relay switches 9A1 to 9An of the third switching unit 9 associated with the distribution line are turned on so that the reclose relay and the distribution line are connected again.

As described above, after the third low frequency relay 3 is operated, the second low frequency relay 2 and the first low frequency relay 1 are operated in sequence, and the control unit 6 includes the second low frequency. The circuit breaker associated with the relay 2 and the first low frequency relay 1 is turned on at intervals of about 0.1 to 1 sec to return the distribution line to its original state, and at the same time, the third switching unit 9 associated with the distribution line. The relay switches 9A1 to 9An of ON are operated again so that the relay and the distribution line are re-closed again, thereby completely returning the disconnected distribution line to its original state.

Even in the distribution line return operation, the control unit 6 causes the alarm unit 10 to operate if the third to first low frequency relays 3 to 1 do not operate in the normal order.

Since the distribution line blocking and returning operation as described above is automatically performed by the control unit 6, even if a frequency abnormality of the power system occurs, the operator does not need to operate the breaker while circulating one by one.

In the above description, three low frequency relay yarns are used as an example, but more low frequency relays may be used.

As described above, the present invention provides a low frequency relay that performs a function of separating and disconnecting a load from a system in the event of a frequency abnormality of a power system and a plurality of circuit breakers installed in a corresponding distribution line so as to quickly and automatically control on / off. Low-frequency relay automatic control device to improve the power supply reliability.

Claims (3)

In the case where the frequency of the power system is abnormal, the load is separated and intermittent by frequency for First to third low frequency relays 1 to 3 for detecting a frequency change of a power source flowing through the power system power and for outputting a predetermined electric signal when the detected frequency is out of a preset range; A selection unit (4) comprising selection switches (S1 to S6) for selecting whether to operate the low frequency relays (1 to 3), and a switch (S7) for setting whether to execute remote control; A digital frequency meter 5 for setting the return signal output of the low frequency relays 1 to 3; An alarm unit 10 for displaying an alarm when an operation abnormality of the low frequency relays 1 to 3 occurs; A circuit breaker installed in the power distribution line corresponding to each of the low frequency relays 1 to 3 according to a frequency sensing result of the power system from the first to third low frequency relays 1 to 3 to turn off or on; First and second output terminals (6a) and (6b) are formed, the control signal for preventing the overcurrent due to the operation of the re-close relay in the operation of the first to third low frequency relays (1 to 3) is not supplied to the corresponding line A control device unit 6 having a third output terminal 6c for outputting the same; A first switching unit composed of a plurality of relay switches 7A1 to 7An which are turned on by a control signal output from the first output terminal 6a of the control unit 6 to turn off the circuit breaker installed in the distribution line ( 7); A second switching unit composed of a plurality of relay switches 8A1 to 8An which are turned on by a control signal output from the first output terminal 6b of the control unit 6 to turn on a circuit breaker installed in the distribution line. (8); A plurality of relay switches 9A1 to 9An that operate on / off by a control signal output from the third output terminal 6c of the control unit 6 so that the corresponding distribution line is connected to or disconnected from the reclosing relay; Low frequency relay automatic control device, characterized in that consisting of a third switching unit (9) consisting of. According to claim 1, wherein the control unit (6) operates from the low-frequency relay determined as the lowest among the low-frequency relays, the priority is determined for each frequency when the frequency of the power system abnormal, the alarm unit 10 when the order is not followed Low frequency relay automatic control device characterized in that the control to operate. 2. The control unit (6) according to claim 1, wherein the control unit (6) operates in order from the low frequency relay determined as the highest priority among the low frequency relays whose priority is determined for each frequency when the frequency of the power system returns to normal. Low frequency relay automatic control device, characterized in that for controlling to operate the alarm unit (10).