KR20210041824A - Apparatus for protecting on load tap changer of transformer - Google Patents

Abstract

The present invention discloses a transformer OLTC protection device and a control method thereof. According to present invention, an OLTC protection device includes: a flow rate sensing unit for measuring a flow rate of insulating oil between an oil compartment and a conservator; a pressure sensor for measuring pressure between the oil compartment and the conservator; a circuit breaker to stop an operation of the transformer; a storage unit for storing the flow rate and pressure measured by the flow rate sensing unit and the pressure sensing unit, and storing a reference value for operating the circuit breaker; a control unit receiving the flow rate and pressure respectively from the flow rate sensing unit and the pressure sensing unit, comparing them with reference values stored in the storage unit, and operating the circuit breaker; and a warning unit which generates an alarm according to the operation of the control unit, thereby securing operational reliability by eliminating malfunction factors.

Description

Transformer OLTC protection device and its control method {APPARATUS FOR PROTECTING ON LOAD TAP CHANGER OF TRANSFORMER}

The present invention relates to a protection device of a transformer OLTC and a control method thereof, and more particularly, to a protection device of a transformer OLTC that operates a circuit breaker of a transformer by sensing a change in flow rate and pressure of an insulating oil in the transformer OLTC, and a control method thereof. .

In general, since the voltage of the transformer changes according to the fluctuation of the voltage of the primary side, when the voltage change of the primary side is severe or depending on the type of load, the load equipment connected to the same transformer is greatly affected. Therefore, the transformer needs to adopt an On Load Tap Changer (OLTC) when the transformer is loaded in order to actively cope with the change in voltage.

When such OLTC is in operation, the driving current of the motor for driving the diverter and the operating time of the motor are changed, and an arc is generated by the internal contact operation, and metal contaminated particles are generated due to contact wear. At the same time, moisture naturally penetrates or is generated internally by chemical changes, resulting in arcing.

In addition, when the OLTC is not driven but the transformer is in operation, partial discharge and ultrasonic waves are generated due to a defective internal contact or a defective contact of a transition resistor.

However, in the past, it was not possible to detect signs of initial failure such as arcing and partial discharge in the OLTC. In other words, conventionally, there was no diagnostic technology for OLTC internal failure as a mechanical drive device for voltage transformation of a transformer, and only the method of notifying the occurrence of OLTC failure using mechanical/electrical protection relays (96T, 87T) is widely used. It is the actual situation.

These 96T protection relays are installed between the OLTC oil compartment and the OLTC conservator at the top of the transformer, a permanent magnet to fix the buoy, a buoy responsive to the flow of flow, a contact that forms a circuit electrically by the buoy, and test. It is composed of a terminal and a terminal block, and when the insulating oil in the oil compartment rapidly flows toward the conservator, the buoy vertically erected by the permanent magnet and spring is pushed back by this flow rate, and the contact is operated.

Therefore, when the protection relay is operated, it is electrically connected to separate the OLTC from the faulty state, the 96T alarm indicator of the switchboard is turned on, and the power is applied to the operating elements of the 86T relay to open the transformer 1st and 2nd circuit breakers.

The background technology of the present invention is disclosed in Korean Patent Publication No. 1993600 (announced on June 27, 2019, a 96T protection relay capable of remote reset of a power transformer).

However, these OLTC protection relays frequently malfunction even if they are not internal failures of the OLTC oil compartment, so most current protection relays do not generate trip signals that block the transformer during operation, and only alarm operation.

In addition, these OLTC protection relays must operate at 1.2m/s (based on oil temperature of 20℃) or higher based on a 154kV transformer, but the operating standards cannot be accurately set. There was a problem that frequent malfunctions were caused by external factors such as.

The present invention was conceived to improve the above problems, and an object of the present invention according to an aspect of the present invention is to operate a circuit breaker of a transformer by sensing a change in flow rate and pressure of an insulating oil in a transformer OLTC, thereby removing a cause of malfunction, thereby improving operational reliability. In addition to securing, it is to provide a protection device for OLTC and a control method for the transformer that predicts failure based on measurement data and analyzes the cause of the failure.

A protection device for a transformer OLTC according to an aspect of the present invention includes: a flow rate detector configured to measure a flow rate of insulating oil between an oil compartment and a conservator; A pressure sensing unit that measures a pressure between the oil compartment and the conservator; A breaker that stops the operation of the transformer; A storage unit that stores the flow rate and pressure measured from the flow rate detection unit and the pressure detection unit, and stores a reference value for operating the circuit breaker; A control unit for operating a circuit breaker by receiving a flow rate and a pressure from the flow rate detection unit and the pressure detection unit, respectively, and comparing the reference value stored in the storage unit; And a warning unit for generating an alarm according to the operation of the control unit.

The present invention is characterized in that it further comprises a communication unit for transmitting the operating state of the control unit and the flow rate and pressure stored in the storage unit to the protection server, and receiving the operating conditions from the protection server.

In the present invention, the reference value is characterized in that it includes a reference flow rate, a reference pressure, and an upward trend of data.

In the present invention, the control unit is characterized in that the circuit breaker is operated when both the flow rate and the pressure exceed the reference value.

A method of controlling a protection device for a transformer OLTC according to another aspect of the present invention includes the steps of: receiving, by a controller, a flow rate and a pressure from a flow rate detection unit and a pressure detection unit, respectively; Determining, by the controller, whether the input flow rate and pressure exceed a reference value; Determining, by the controller, whether the flow rate and pressure satisfy the reference value, and operating a circuit breaker when the flow rate and pressure exceed the reference value; And generating an alarm after the control unit operates the circuit breaker.

In the present invention, the control unit determines whether the flow rate and pressure exceed a reference value, and when the flow rate and pressure do not exceed the reference value, determining whether the flow rate and pressure satisfy an upward trend; And generating an alarm when the control unit determines whether the flow rate and the pressure satisfy the rising trend, and when the rising trend is satisfied, the controller further comprises.

The present invention is characterized in that it further comprises the step of storing the flow rate and pressure input by the control unit in the storage unit and transmitting it to the protection server through the communication unit.

In the present invention, the step of determining whether the flow rate and pressure satisfy the reference value is characterized in that the control unit determines whether both the flow rate and pressure satisfy the reference value.

The protection device of the transformer OLTC and its control method according to an aspect of the present invention is to operate the circuit breaker of the transformer by sensing the flow rate and pressure change of the insulating oil in the transformer OLTC, thereby removing the cause of malfunction and securing operation reliability as well as measuring data. It can be provided to predict the occurrence of a failure and analyze the cause of the failure based on.

1 is a block diagram showing a protection device of a transformer OLTC according to an embodiment of the present invention.
2 is a flowchart illustrating a method of controlling a protection device for a transformer OLTC according to an embodiment of the present invention.

Hereinafter, a protection device for a transformer OLTC and a control method thereof according to the present invention will be described with reference to the accompanying drawings. In this process, the thickness of the lines or the size of components shown in the drawings may be exaggerated for clarity and convenience of description. In addition, terms to be described later are terms defined in consideration of functions in the present invention, which may vary according to the intention or custom of users or operators. Therefore, definitions of these terms should be made based on the contents throughout the present specification.

1 is a block diagram showing a protection device of a transformer OLTC according to an embodiment of the present invention.

As shown in Fig. 1, the protection device of the transformer OLTC according to an embodiment of the present invention includes a flow rate detection unit 10, a pressure detection unit 20, a circuit breaker 40, a storage unit 60, and a control unit 30. ) And a warning unit 50.

The flow rate detection unit 10 may measure the flow rate of the insulating oil between an oil compartment (not shown) of an On Load Tap Changer (OLTC) and a conservator (not shown) and provide it to the control unit 30.

The pressure sensing unit 10 may measure pressure between the oil compartment and the conservator and provide it to the control unit 30.

The circuit breaker 40 may include primary and secondary circuit breakers 40 for stopping the operation of a transformer (not shown).

The storage unit 60 may store the flow rate and pressure measured from the flow rate detection unit 10 and the pressure detection unit 20 to determine the trend, and may store a reference value for operating the circuit breaker 40.

Here, the reference value may include a reference flow rate and a reference pressure for stopping the transformer by operating the circuit breaker 40 for OLTC protection, and the rising trend of data that can predict a failure situation based on the trend of flow rate and pressure change. May include the criteria of.

In this case, the reference value may be arbitrarily set, and the protection server 80 may receive and store the set reference value by analyzing the correlation between flow velocity and pressure change through big data analysis.

The control unit 30 operates the circuit breaker 40 to stop the transformer by receiving the flow rate and pressure from the flow rate sensing unit 10 and the pressure sensing unit 20, respectively, and comparing it with a reference value stored in the storage unit 60 to stop the OLTC. Can be protected.

At this time, the control unit 30 may operate the circuit breaker 40 when both the flow rate and the pressure exceed the reference value. In addition, even if the flow rate and pressure do not exceed the reference value, the controller 30 may generate an alarm to predict and check the failure of the OLTC by generating an alarm when the rising trend of the data is satisfied.

Here, the upward trend may be set as a ratio of an increase compared to the previous value.

The warning unit 50 may generate an alarm according to the operation of the control unit 30 so that the driver can recognize it.

The communication unit 70 may transmit the operating state of the control unit 30 and the flow rate and pressure stored in the storage unit 60 to the protection server 80, and receive an operating condition from the protection server 80.

Accordingly, the protection server 80 may construct correlation big data based on the flow rate and pressure of the transmitted OLTC insulating oil, calculate the optimal operation setting value of the OLCT protection device using a machine learning algorithm, and provide it as a reference value.

In addition, it is possible to predict the occurrence of a failure of a transformer by analyzing the trend of flow velocity and pressure change, and to establish a countermeasure to prevent recurrence by analyzing the cause of OLTC failure.

As described above, according to the protection device of the transformer OLTC according to the embodiment of the present invention, the transformer OLTC detects changes in the flow rate and pressure of the insulating oil and operates the circuit breaker of the transformer, thereby removing the cause of malfunction and securing operation reliability. In addition, it can be provided so that failure occurrence can be predicted and the cause of failure can be analyzed based on measurement data.

2 is a flowchart illustrating a method of controlling a protection device for a transformer OLTC according to an embodiment of the present invention.

As shown in Fig. 2, in the control method of the protection device of the transformer OLTC according to an embodiment of the present invention, first, the control unit 30 includes an oil compartment (not shown) and a conservator (not shown) of an OLTC (On Load Tap Changer). The flow rate and pressure measured from the flow rate detection unit 10 and the pressure detection unit 20 for measuring the flow rate and pressure of the insulating oil are respectively input (S10).

After each input of the flow rate and pressure in step S10, the controller 30 determines whether the input flow rate and pressure exceed a reference value (S20).

Here, the controller 30 may compare the flow rate and the reference flow rate, and compare the pressure and the reference pressure to determine whether they are all exceeded.

In this case, the reference value may be arbitrarily set, and the protection server 80 may receive and set the set reference value by analyzing the correlation between the flow rate and pressure change through big data analysis.

In step S20, after determining whether the flow rate and pressure exceed the reference value, if it exceeds the reference value, the control unit 30 operates the circuit breaker 40 to stop the transformer (S30).

In addition, the control unit 30 generates an alarm through the warning unit 50 (S40).

On the other hand, if the flow rate and pressure do not exceed the reference value after determining whether the flow rate and pressure exceed the reference value in step S20, the controller 30 determines whether the flow rate and pressure satisfy the rising trend (S40).

That is, it can be determined whether the rate of increase in flow rate and pressure compared to the previous value satisfies the upward trend.

Here, the upward trend may be set as a criterion for predicting a failure situation by analyzing a correlation between a flow rate and a pressure change through big data analysis in the protection server 80.

In step S40, it is determined whether the flow rate and pressure satisfy the rising trend, and when the rising trend is satisfied, the controller 30 may generate an alarm to predict and check the failure of the OLTC in advance.

After generating the alarm in step S50, the control unit 30 stores the flow rate and pressure input to the storage unit 60 in the storage unit 60 and transmits it to the protection server 80 through the communication unit 70 (S60). .

Accordingly, the protection server 80 may construct correlation big data based on the flow rate and pressure of the transmitted OLTC insulating oil, calculate the optimal operation setting value of the OLCT protection device using a machine learning algorithm, and provide it as a reference value.

In addition, it is possible to predict the occurrence of a failure of a transformer by analyzing the trend of flow velocity and pressure change, and to establish a countermeasure to prevent recurrence by analyzing the cause of OLTC failure.

As described above, according to the control method of the protection device of the transformer OLTC according to the embodiment of the present invention, the transformer OLTC detects a change in the flow rate and pressure of the insulating oil and operates the circuit breaker of the transformer, thereby eliminating the cause of malfunction and improving the operation reliability. In addition to securing, it can be provided so that failure occurrence can be predicted and the cause of failure can be analyzed based on measurement data.

The implementation described herein may be implemented in, for example, a method or process, an apparatus, a software program, a data stream or a signal. Although discussed only in the context of a single form of implementation (eg, only as a method), the implementation of the discussed features may also be implemented in other forms (eg, an apparatus or program). The device may be implemented with appropriate hardware, software and firmware. The method may be implemented in an apparatus such as a processor, which generally refers to a processing device including, for example, a computer, a microprocessor, an integrated circuit or a programmable logic device, or the like. Processors also include communication devices such as computers, cell phones, personal digital assistants ("PDAs") and other devices that facilitate communication of information between end-users.

The present invention has been described with reference to the embodiments shown in the drawings, but these are only exemplary, and those of ordinary skill in the field to which the technology pertains, various modifications and other equivalent embodiments are possible. I will understand.

Therefore, the true technical protection scope of the present invention should be determined by the following claims.

10: flow rate detection unit 20: pressure detection unit
30: control unit 40: circuit breaker
50: warning unit 60: storage unit
70: communication unit 80: protection server

Claims (8)

A flow rate detector for measuring a flow rate of the insulating oil between the oil compartment and the conservator;
A pressure sensing unit that measures a pressure between the oil compartment and the conservator;
A circuit breaker that stops the operation of the transformer;
A storage unit for storing the flow rate and the pressure measured by the flow rate detection unit and the pressure detection unit, and storing a reference value for operating the circuit breaker;
A control unit receiving the flow rate and the pressure from the flow rate detection unit and the pressure detection unit and comparing the reference value stored in the storage unit to operate the circuit breaker; And
And a warning unit that generates an alarm according to the operation of the control unit.
The transformer OLTC of claim 1, further comprising a communication unit for transmitting the operating state of the control unit and the flow rate and the pressure stored in the storage unit to a protection server, and receiving an operating condition from the protection server. Protective device.
The apparatus of claim 1, wherein the reference value includes a reference flow rate, a reference pressure, and an upward trend of data.
The apparatus of claim 1, wherein the control unit operates the circuit breaker when both the flow rate and the pressure exceed the reference value.
Receiving, by a controller, a flow rate and a pressure from the flow rate detection unit and the pressure detection unit, respectively;
Determining, by the control unit, whether the input flow rate and the pressure exceed a reference value;
Determining, by the control unit, whether the flow rate and the pressure satisfy the reference value, and operating a circuit breaker when the flow rate and the pressure exceed the reference value; And
And generating the alarm after the control unit operates the circuit breaker.
6. The method of claim 5, further comprising: determining, by the controller, whether the flow rate and the pressure exceed the reference value, and when the flow rate and the pressure do not exceed the reference value, determining whether the flow rate and the pressure satisfy an upward trend; And
And generating an alarm when the control unit determines whether the flow rate and the pressure satisfy the rising trend, and when the rising trend is satisfied, generating an alarm.
The method of claim 5, further comprising the step of storing the flow rate and the pressure input by the control unit in a storage unit and transmitting it to a protection server through the communication unit.
The control of a protection device for a transformer OLTC according to claim 5, wherein the determining whether the flow rate and the pressure satisfy the reference value, wherein the controller determines whether both the flow rate and the pressure satisfy the reference value. Way.

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