KR101888409B1 - Feeder remote terminal unit - Google Patents

Abstract

According to an embodiment of the present invention, there is provided a power supply apparatus including: a measuring unit disposed in a distribution line to measure a current and a voltage; A sampling unit for sampling the current and the voltage measured by the measuring unit; And a determination unit comparing the sampled current and voltage with a predetermined reference range to determine whether an abnormal waveform has occurred.

Description

[0001] FEEDER REMOTE TERMINAL UNIT [0002]

One embodiment of the present invention relates to a distribution intelligent terminal device.

Generally, electricity generated from various power plants is boosted to ultra-high pressure (154 kV to 745 kV) suitable for transmission at the first substation and transmitted through the transmission system. Then, the power is further reduced to a special high voltage (22.9 kV) (230kV or 380kV) which can be used in the customer by the pillar transformer installed in the pole, and it is distributed through the processing power distribution system installed in the pole.

The super high voltage transmission system is transmitted through the processing transmission line supported by the transmission tower installed in a rare mountain area and the special high pressure transmission system is transmitted through the processing transmission line supported on the pole or the underground transmission line installed in the ground, It is distributed through a supported distribution line or an underground distribution line installed in the ground.

In a distribution line for distributing commercial electricity of such a commercial voltage, the voltage is increased or decreased according to the increase or decrease of the receiving load, which affects the use of the consumer electronic device. Therefore, the voltage of the distribution line is monitored to maintain the voltage of the distribution line at a normal voltage.

On the other hand, the power distribution system constructs a distribution intelligence system to acquire the state information, event, and power data of the line switchgear from the terminal device, and transmits it to the distribution intelligence server (master value) And to minimize the power outage time through the sectionalize function using communication between the terminals. However, it is impossible to fundamentally prevent the occurrence of power outage by predicting the failure of the system, and the algorithm of the terminal device needs a function to judge the failure of the system in advance by measuring the rate of change of the RMS and the instantaneous value change within one cycle .

An object of the present invention is to provide a distribution intelligent terminal apparatus capable of preventing a failure or an accident that may occur in a distribution system by using a current and a voltage waveform of a distribution line.

Another object of the present invention is to provide a distribution intelligent terminal device capable of acquiring and analyzing a specific waveform that occurs when a failure of a power distribution system or an accident occurs for each power parameter.

According to an embodiment of the present invention, there is provided a power supply apparatus including: a measuring unit disposed in a distribution line to measure a current and a voltage; A sampling unit for sampling the current and the voltage measured by the measuring unit; And a determination unit comparing the sampled current and voltage with a predetermined reference range to determine whether an abnormal waveform has occurred.

The determination unit may determine that an abnormal waveform has occurred when the sampled current value or the voltage value has occurred n ₁ or more times in succession from the first reference range.

The determination unit compares the current RMS value of each cycle with the current RMS value of the previous cycle to depart from the second reference range. If the current value falls within the second reference range within n ₂ cycles from the cycle out of the second reference range, If it occurs more than ₃ times within the time, it can be judged that an abnormal waveform has occurred.

The determination unit compares the RMS value of the sampled current value with the RMS value of the previous sampled current value, and determines that an abnormal waveform has occurred when the difference exceeds a reference value (R2) according to Equation (1).

[Equation 1]

, s는 1,2,3···샘플링 수, K는 1 내지 100에서 설정되는 수)(I is the current RMS value per cycle, f is frequency, step is

, s is the number of 1, 2, 3 ... sampling, and K is a number set in the range of 1 to 100)

The determination unit calculates the harmonic content rate of each cycle using the measured current and voltage, and determines that an abnormal waveform has occurred when the harmonic content rate per cycle exceeds n ₃ times within a specified time .

The determination unit may calculate the third harmonic value using the measured current and voltage, and may determine that an abnormal waveform has occurred when the third harmonic value deviates from the fourth reference range by n5 times or more within a designated time.

The controller may further include a controller for extracting the waveform and a waveform for a predetermined period of time and storing the extracted waveform in a database when the determination unit determines that an abnormal waveform has occurred.

And a communication unit for transmitting the waveform and the past waveform to the main server.

The control unit receives the control command from the main server and can control equipment installed in the distribution line.

The power distribution terminal device of the present invention can prevent a failure or an accident that may occur in the power distribution system by using the current and voltage waveforms of the power distribution line.

In addition, the specific waveforms that occur when a power system failure or an accident occurs can be obtained for each power parameter and used for analysis.

1 is a diagram for explaining a connection relationship between a distribution intelligent terminal device and an external device according to an embodiment of the present invention;
2 is a block diagram of a configuration of a distribution < RTI ID = 0.0 > intelligence < / RTI > terminal apparatus according to an embodiment of the present invention;
3 to 6 are views for explaining the operation of the power distribution terminal according to the embodiment of the present invention.

The present invention is capable of various modifications and various embodiments, and specific embodiments are illustrated and described in the drawings. It should be understood, however, that the invention is not intended to be limited to the particular embodiments, but includes all modifications, equivalents, and alternatives falling within the spirit and scope of the invention.

The terms including ordinal, such as second, first, etc., may be used to describe various elements, but the elements are not limited to these terms. The terms are used only for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, the second component may be referred to as a first component, and similarly, the first component may also be referred to as a second component. And / or < / RTI > includes any combination of a plurality of related listed items or any of a plurality of related listed items.

It is to be understood that when an element is referred to as being "connected" or "connected" to another element, it may be directly connected or connected to the other element, . On the other hand, when an element is referred to as being "directly connected" or "directly connected" to another element, it should be understood that there are no other elements in between.

The terminology used in this application is used only to describe a specific embodiment and is not intended to limit the invention. The singular expressions include plural expressions unless the context clearly dictates otherwise. In the present application, the terms "comprises" or "having" and the like are used to specify that there is a feature, a number, a step, an operation, an element, a component or a combination thereof described in the specification, But do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, or combinations thereof.

Unless defined otherwise, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Terms such as those defined in commonly used dictionaries are to be interpreted as having a meaning consistent with the contextual meaning of the related art and are to be interpreted as either ideal or overly formal in the sense of the present application Do not.

1 is a view for explaining a connection relationship between a distribution intelligent terminal device and an external device according to an embodiment of the present invention.

A power distribution terminal unit (FRTU) 200 is installed together with the power distribution intelligent switch 300 to measure the current and voltage flowing in the power distribution line in real time, calculates various power amounts, When a fault occurs, it can be detected and transmitted to the remote power distribution room. The distribution intelligent terminal device 200 can receive the control command of the switch 300 and open the distribution line of the failure point to minimize the failure range (power failure, etc.). In addition, all events occurring in the distribution line can be stored to provide information for analyzing the cause of the failure, and the remote state monitoring and control of the distribution line can be performed by transmitting the state of the distribution line to the remote site using the DNP3.0 Protocol .

The distribution switch 300 can detect and isolate a failure occurrence section of the distribution line (cooperate with a distribution line), reduce the static section when working the line, and overload the line through load switching.

The distributing switch 300 may be divided into a manual switch and an automatic switch according to the operation mode, and may be divided into a gas insulated switch, an inflow switch, and a vacuum switch according to the internal insulation. In the manual switch, the operator opens or closes the switch directly from the ground, and the automatic switch (distribution switch) opens or closes the switch by opening or closing the switch via the distribution intelligence network at the distribution center of the remote place A CT (Current Transformer) and a PT (Potential Transformer) for measuring current and voltage, and various status monitoring contacts and sensors.

The main server 100 monitors in real time the failure occurrence signals such as a ground fault or a short circuit to the power distribution line, the status information of the power distribution intelligent switch 300, the current and voltage signals to the power distribution line, . The main server 100 can detect a failure occurrence period and monitor the operation status of the distribution intelligent switch 300 in real time and send a control command for controlling the failure occurrence interval to be released by the distribution intelligent switch 300 to the distribution intelligent terminal & To the device (200).

2 is a block diagram showing the configuration of a power distribution terminal according to an embodiment of the present invention. 2, a power distribution terminal device 200 according to an embodiment of the present invention includes a measurement unit 210 disposed in a power distribution line to measure a current and a voltage, a controller 210 for sampling the current and voltage measured by the measurement unit 210, A determination unit 230 for determining whether an abnormal waveform has been generated by comparing the sampled current and voltage with a preset reference range; and a determination unit 230 for determining whether an abnormal waveform has occurred in the determination unit 230, A controller 240 for extracting a waveform for a certain period of time and storing the waveform in a database 250, and a communication unit 260 for transmitting the waveform and a waveform for a certain period of time to a main server.

The measuring unit 210 may include a CT (Current Transformer), a PT (Potential Transformer), and various status monitoring contacts or sensors that are disposed in the distribution line and can measure current and voltage.

The sampling unit 220 may convert the current and voltage signals measured by the measuring unit 210 into digital values using frequency data values. The sampling unit 220 can digitally convert an analog signal at a sampling rate of 128 samples / cycle. The sampling unit 220 may perform Fast Fourier Transform (FFT) to sample current and voltage.

The determination unit 230 may determine that an abnormal waveform has occurred when the sampled current value or the voltage value has occurred n ₁ or more times in succession from the first reference range.

The determination unit 230 if a group occurs more than n ₃ times within a specified time when returning to the second reference range of the current RMS value per cycle as compared to the current RMS value of the previous cycle to get out of the second reference range within n2 cycles It can be determined that an abnormal waveform has occurred.

The determination unit 230 compares the RMS value of the sampled current value with the RMS value of the previous sampled current value, and determines that an abnormal waveform has occurred when the difference exceeds a reference value (R2) according to Equation (1) .

 [Equation 1]

, s는 1,2,3···샘플링 수, K는 1 내지 100에서 설정되는 수)(I is the RMS value of the previous cycle, f is frequency, step is

, s is the number of 1, 2, 3 ... sampling, and K is a number set in the range of 1 to 100)

In Equation (1), K is an allowance value for setting the second reference range. By adjusting the K value, the condition for determining the abnormal waveform can be variously changed according to the situation. As the K value is set close to 1, the second reference range is narrowly set to increase the probability of being judged as an abnormal waveform. As the K value is set closer to 100, the second reference range is set wider, Is relatively low.

The determination unit 230 calculates the harmonic content rate of each cycle using the measured current and voltage. If the harmonic content rate per cycle deviates from the third reference range by n ₄ or more within a designated time, an abnormal waveform is generated It can be judged.

The determination unit 230 may calculate the third harmonic value using the measured current and voltage, and may determine that an abnormal waveform has occurred when the third harmonic value deviates from the fourth reference range by n5 times or more within a specified time have.

The control unit 240 receives a control command from the main server and can control equipment installed in the distribution line. The control unit 240 can prevent an accident by blocking the fault occurrence period before a failure or an accident occurs in the power distribution system using the control command.

The database 250 may store a past waveform within a predetermined period from the abnormal waveform and the abnormal waveform under the control of the control unit.

The communication unit 260 may perform data communication with the main server to transmit waveform data or receive a control command.

3 to 6 are views for explaining the operation of the power distribution terminal according to the embodiment of the present invention.

Referring to FIG. 3, the distribution intelligent terminal apparatus can determine that an abnormal waveform has occurred when the sampled current value has occurred three or more times in succession over a period in which the magnitude of the current value deviates from the first reference range. In FIG. 3, n ₁ is set to 3 but can be set differently according to the external input.

3 (a) can be used as a reference waveform for setting the first reference range to the current waveform measured in the distribution line in the normal case. The first reference range can be set at a predetermined ratio from the sampling value of the normal waveform. For example, a range within 20% of the maximum value and the minimum value of the normal waveform can be set as the first reference range. In FIG. 3A, the first reference range can be set within 72 A, which is 20% of the maximum value 60A of the normal waveform, and -72A, which is 20% of the minimum value 60A.

FIG. 3 (b) shows an example of detecting the period when the sampled current waveform is out of the first reference range and counting consecutive periods. In FIG. 3 (b), since the first and second periods are out of the first reference range but are not out of the first reference range in the third period, they are not judged as abnormal waveforms.

FIG. 3 (c) shows an example in which an abnormal waveform is determined. In (c) of FIG. 3, it is determined that an abnormal waveform has occurred because the sampling values continuously out of the first reference range are detected in the first period, the second period, and the third period. If an abnormal waveform occurs, the abnormal waveform and waveforms corresponding to the following 20 periods are extracted and stored.

Referring to FIG. 4, when the distribution intelligent terminal device compares the current RMS value of each cycle with the current RMS value of the previous cycle and returns to the second reference range within three cycles from the second reference range and out of the second reference range It is judged that an abnormal waveform has occurred when three or more times occur within 180 minutes of the designated time. 3, n ₂ and n ₃ are set to 3, and the designated time is set to 180 minutes, but they can be set differently according to the external input.

4 (a) shows a case where the current RMS value of the specific period increases from the current RMS value of the previous period to the second reference range or more. The second reference range may be set to 10% of the current RMS value of the previous period. That is, when the current RMS value of the specific period is compared with the current RMS value of the previous period, a change of 10% or more is detected. However, in (a) of FIG. 4, since it has not returned within the second reference range within 3 cycles, counting is not performed.

FIG. 4 (b) shows a case in which a variation of 10% or more is generated by comparing the current RMS value of the specific period with the RMS value of the previous cycle, but the variation is within the second reference range within 3 cycles. In the case of (b) of FIG. 4, counting is performed when it returns to the second reference range within three cycles.

FIG. 4 (c) shows an example in which an abnormal waveform is determined. In (c) of FIG. 4, it is determined that an abnormal waveform has occurred because three cases corresponding to FIG. 4 (b) occur within 180 minutes that is the designated time. If an abnormal waveform occurs, the abnormal waveform and waveforms corresponding to the following 20 periods are extracted and stored.

5 calculates the RMS value based on the sampling data of the current value and calculates the reference (R ₂ ) value according to Equation (1). It is determined that an abnormal waveform has occurred when the difference value of the continuous instantaneous sampling data exceeds the reference value. FIG. 5 is a diagram for explaining a reference value. As the margin K value approaches 100, the second reference range approaches 40 A and the second reference range is set wider. On the other hand, as the margin K value approaches 1, the second reference range is close to 20A and the second reference range is narrowed.

Referring to FIG. 6, the distribution intelligent terminal device calculates the harmonic content rate of each cycle by using the measured current and voltage, and when the case where the harmonic content rate per cycle deviates from the third reference range occurs more than three times within 180 minutes, It can be judged that an abnormal waveform has occurred. In Figure 5 n ₄ has been set to 3, the point-in-time has been set to 180 minutes may be set differently according to external input.

6 (a) can be used as a reference waveform for setting the third reference range to the current waveform measured in the distribution line in the normal case. For example, the third reference range may be set within a range of 10% of the harmonic content rate of the normal waveform.

FIG. 6 (b) shows a case in which a cycle in which the harmonic content rate per cycle deviates from the third reference range is detected twice within 180 minutes. In FIG. 5 (b), since the period exceeding the third reference range is not generated more than three times within 180 minutes, it is not judged as an abnormal waveform.

FIG. 6 (c) shows an example in which an abnormal waveform is determined. In (c) of FIG. 6, it is judged that an abnormal waveform has occurred because the case where the harmonic content rate per cycle deviates from the third reference range is detected three times within 180 minutes. If an abnormal waveform occurs, the abnormal waveform and waveforms corresponding to the following 20 periods are extracted and stored.

Referring to FIG. 7, the distribution intelligent terminal device calculates the third harmonic value using the measured current and voltage. If the third harmonic value deviates from the fourth reference range by more than three times within 180 minutes, which is the designated time, It can be judged that a waveform has occurred. 7, n ₅ is set to 3, and the designated time is set to 180 minutes, but it can be set differently according to the external input.

7 (a) can be used as a reference waveform for setting the fourth reference range to the current waveform measured in the distribution line in the normal case. For example, the fourth reference range may be set within a range of 10% of the third harmonic value of the normal waveform.

FIG. 7 (b) shows a case where the period in which the third harmonic value deviates from the fourth reference range is detected twice. In FIG. 6 (b), since the period exceeding the fourth reference range is not generated more than three times within 180 minutes, it is not judged as an abnormal waveform.

FIG. 7C shows an example in which an abnormal waveform is determined. In (c) of FIG. 7, it is judged that an abnormal waveform occurs because the third harmonic value is detected three times within 180 minutes when the third harmonic value is out of the fourth reference range. If an abnormal waveform occurs, And extracts it.

As used in this embodiment, the term " portion " refers to a hardware component such as software or an FPGA (field-programmable gate array) or ASIC, and 'part' performs certain roles. However, 'part' is not meant to be limited to software or hardware. &Quot; to " may be configured to reside on an addressable storage medium and may be configured to play one or more processors. Thus, by way of example, 'parts' may refer to components such as software components, object-oriented software components, class components and task components, and processes, functions, , Subroutines, segments of program code, drivers, firmware, microcode, circuitry, data, databases, data structures, tables, arrays, and variables. The functions provided in the components and components may be further combined with a smaller number of components and components or further components and components. In addition, the components and components may be implemented to play back one or more CPUs in a device or a secure multimedia card.

200: Distribution intelligent terminal device
210:
220: Sampling unit
230:
240:
250: Database
260:

Claims (9)

A measuring unit disposed in the distribution line and measuring current and voltage;
A sampling unit for sampling the current and the voltage measured by the measuring unit; And
And a determination unit for comparing the sampled current and voltage with a predetermined reference range to determine whether an abnormal waveform has occurred,
The judging unit calculates the harmonic content rate of each cycle using the measured current and voltage and judges that an abnormal waveform occurs when the case where the harmonic content rate per cycle deviates from the third reference range occurs n ₄ or more times within a designated time Distribution intelligent terminal device.
A measuring unit disposed in the distribution line and measuring current and voltage;
A sampling unit for sampling the current and the voltage measured by the measuring unit; And
And a determination unit for comparing the sampled current and voltage with a predetermined reference range to determine whether an abnormal waveform has occurred,
Wherein the determination unit calculates a third harmonic value by using the measured current and voltage and determines that an abnormal waveform has occurred when the third harmonic value is out of the fourth reference range n5 times or more within a specified time, Device.
3. The method according to claim 1 or 2,
And a control unit for extracting the waveform and a waveform for a certain period of time and storing the extracted waveform in a database when the determination unit determines that an abnormal waveform has occurred.
The method of claim 3,
And a communication unit for transmitting the waveform and the past waveform to the main server.
The method of claim 3,
Wherein the control unit receives the control command from the main server and controls equipment installed in the distribution line. delete delete delete delete

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