Method, device, and system for monitoring fault current

Abstract

The present invention relates to a method, device, and system for monitoring a fault current. A method according to an embodiment of the present invention comprises the steps in which: a fault detection device determines whether an overcurrent occurs in each line for a reference time period, on the basis of a sensing signal for each AC current flowing through a plurality of lines of a power system; and when an overcurrent occurs, the fault detection device separately stores, in a memory, data on a type of an overcurrent line and current data for the overcurrent among current data that is data on an AC current waveform according to the sensing signal.

Description

Method, device and system for monitoring fault current

[0001] The present invention relates to a monitoring technology for fault current, and more particularly, to a technology for rapidly detecting and monitoring fault current generated in a three-phase line for transmission or distribution of a power system.

[0002] In the power grid, electricity generated at power plants is delivered to its final consumers through transmission and distribution processes. However, fault currents can occur during these transmission and distribution processes. These fault currents occur when the magnitude of current flowing through transmission or distribution lines deviates from the normal range. These currents can be caused by various factors, such as lightning strikes, ground faults, and short circuits.

[0003] Conventionally, measuring instruments such as GIPAM (hereinafter referred to as "prior art") are used to measure the current (i.e., AC current) that is the target of monitoring in transmission or distribution lines. However, since these prior art techniques focus on the accuracy of the characteristics of the current, they use a method of measuring the current for at least multiple cycles. Accordingly, the prior art has a problem in that it cannot quickly determine whether a fault current has occurred. For reference, the cycle refers to the cycle of the AC current flowing in the line, and may be a cycle according to, for example, 60 Hz or 50 Hz.

[0004] In particular, the prior art is completely incapable of detecting overcurrents (hereinafter, “short-term overcurrents”) that occur over a relatively short period of time (e.g., half a cycle or one cycle). This is because the prior art measures current over a relatively long period of time over a plurality of cycles. Accordingly, when the prior art is used, not only is data on whether the short-term overcurrent has occurred (i.e., first data) not recorded, but also data on the current status before and after the occurrence of the short-term overcurrent (i.e., second data) is not recorded at all.

[0005] As a result, root cause analysis of problems that may arise from the occurrence of such short-term overcurrents in all or part of the current system is completely impossible. This is because, if such problems occur, the cause can be analyzed based on the first and second data described above, but these first and second data are not recorded at all using conventional technology.

[0006] However, the above-described content merely provides background information on the present invention and does not correspond to previously disclosed technology.

[0007] In order to solve the problems of the above-described prior art, the purpose of the present invention is to provide a technology for rapidly detecting and monitoring a fault current occurring in a three-phase line for transmission or distribution of a power system.

[0008] In particular, the purpose of the present invention is to provide a technology that can quickly detect and monitor the occurrence of fault currents such as overcurrents with only half a cycle or one cycle.

[0009] In addition, another purpose of the present invention is to provide a technology capable of providing data necessary for identifying the cause of a problem in all or part of a power system that may be caused by a fault current such as a short-term overcurrent that occurs over a relatively short period of time.

[0010] However, the problems to be solved by the present invention are not limited to the problems mentioned above, and other problems not mentioned can be clearly understood by a person having ordinary skill in the technical field to which the present invention belongs from the description below.

[0011] A method according to one embodiment of the present invention for solving the above-described problem includes: a step of determining, by a fault detection device, whether an overcurrent has occurred in each line for a reference time based on a sensing signal for each AC current flowing in a plurality of lines in a power system; and a step of storing, by the fault detection device, in a memory, current data related to the overcurrent among data on the type of the overcurrent line and current data which is data on an AC current waveform according to the sensing signal, respectively.

[0012] The current data related to the above overcurrent may include reference data which is current data for the reference time for the above overcurrent line, first data which is current data for a time before the above overcurrent occurs for the above overcurrent line, and second data which is current data for a time after the above overcurrent occurs for the above overcurrent line.

[0013] The current data related to the above overcurrent may further include current data for a time corresponding to each of the first data, the reference data, and the second data among the current data for a line where the above overcurrent did not occur.

[0014] The current data related to the above overcurrent can be utilized for cause analysis of power system problems caused by the above overcurrent.

[0015] The above reference time may be a time corresponding to 1 / 2 cycle to 1 cycle of the above alternating current.

[0016] A method according to one embodiment of the present invention may further include a step of generating a blocking signal for causing the fault detection device to turn off a circuit breaker connected to the overcurrent line.

[0017] The above-determining step can determine that the overcurrent has occurred in the corresponding line when the absolute value of the current value according to the sensing signal is greater than the first reference value.

[0018] The above generating step can generate the blocking signal when the absolute value of the current value is greater than the second reference value.

[0019] The second reference value may be greater than the first reference value.

[0020] A method according to one embodiment of the present invention may further include a step of monitoring the AC current by having the electronic device receive data on the type and current data related to the overcurrent from the fault detection device, and displaying an AC current waveform related to the overcurrent in the line where the overcurrent has occurred on a display based on the received data.

[0021] A fault detection device according to one embodiment of the present invention includes a receiving unit that receives a sensing signal for each alternating current flowing in a plurality of lines in a power system; and a processor that determines whether an overcurrent occurs in each line during a reference time based on the received sensing signal.

[0022] The above processor can store, in memory, data on the type of the overcurrent line when the overcurrent occurs and current data related to the overcurrent among current data which is data on the AC current waveform according to the sensing signal.

[0023] The processor may store reference data, which is current data for the reference time for the overcurrent line, second data, which is current data for a time before the overcurrent occurs for the overcurrent line, and third data, which is current data for a time after the overcurrent occurs for the overcurrent line, in the memory as current data related to the overcurrent.

[0024] The processor may additionally store, in the memory, current data for a time corresponding to each of the first data, the reference data, and the second data among the current data for the line where the overcurrent did not occur, as current data related to the overcurrent.

[0025] The above processor can generate a blocking signal that causes a circuit breaker connected to the overcurrent line to operate off.

[0026] The processor may determine that an overcurrent has occurred in the line when the absolute value of the current value according to the sensing signal is greater than a first reference value at the time of the determination, and may generate the blocking signal when the absolute value of the current value is greater than a second reference value, and the second reference value may be greater than the first reference value.

[0027] The processor can transmit data and current data of the type to an electronic device that monitors the alternating current.

[0028] A system according to one embodiment of the present invention includes: a sensor for sensing each alternating current flowing in a plurality of lines in a power system; a fault detection device for receiving a sensing signal from the sensor, detecting whether an overcurrent occurs in each line for a reference time based on the received sensing signal, and storing data on the type of the overcurrent line and current data on the overcurrent in a memory when the overcurrent occurs; and an electronic device for receiving the data on the type stored in the memory and current data related to the overcurrent from the fault detection device, and monitoring the alternating current by displaying an alternating current waveform related to the overcurrent in the line where the overcurrent occurs based on the received data.

[0029] The present invention, configured as described above, has the advantage of being able to rapidly detect and monitor fault currents occurring in three-phase lines for transmission or distribution of a power system.

[0030] In particular, the present invention has the advantage of being able to quickly identify and monitor the occurrence of fault currents such as overcurrents with only half a cycle or one cycle.

[0031] In addition, the present invention provides not only data on whether a fault current, such as a short-term overcurrent that occurs over a relatively short period of time, occurs, but also current data on the current state before and after the occurrence of the overcurrent, thereby enabling a more detailed analysis of the cause of a problem in all or part of a power system that may occur due to the fault current.

[0032] The effects that can be obtained from the present invention are not limited to the effects mentioned above, and other effects not mentioned can be clearly understood by a person having ordinary skill in the art to which the present invention belongs from the description below.

[0033] Figure 1 shows a block diagram of a system (10) according to one embodiment of the present invention.

[0034] Figure 2 shows a rough block diagram of a fault detection device (300).

[0035] Figure 3 shows a schematic block diagram of an electronic device (400).

[0036] Figure 4 shows a flowchart of a method according to one embodiment of the present invention.

[0037] Hereinafter, specific embodiments according to the present disclosure will be described with reference to the drawings. The following detailed description is provided to facilitate a comprehensive understanding of the methods, devices, and / or systems described herein. However, these are merely examples and the present invention is not limited thereto.

[0038] In describing embodiments of the present disclosure, if a detailed description of a known technology related to the present invention is judged to unnecessarily obscure the gist of the embodiments, the detailed description will be omitted. In addition, the terms described below are terms defined in consideration of their functions in the present invention, and these may vary depending on the intention or custom of the user or operator. Therefore, the definitions should be made based on the contents throughout this specification. The terminology used in the detailed description is only for the purpose of describing one embodiment and should not be limited in any way. Unless clearly used otherwise, the singular form includes the plural form. In this description, expressions such as "comprises" or "having" are intended to indicate certain features, numbers, steps, operations, elements, parts, or combinations thereof, and should not be construed to exclude the presence or possibility of one or more other features, numbers, steps, operations, elements, parts, or combinations thereof other than those described. Additionally, terms such as “part,” “unit,” “module,” and “block” described in the specification mean a unit that processes at least one function or operation, which may be implemented by hardware, software, or a combination of hardware and software.

[0039] Figure 1 shows a block diagram of a system (10) according to one embodiment of the present invention.

[0040] A system (10) (hereinafter referred to as “the system”) (10) according to one embodiment of the present invention is a system for managing, operating, monitoring or controlling a power system. That is, the system (10) may be a system for rapidly detecting and monitoring a fault current generated in a three-phase line (L1, L2, L3) for transmission or distribution of a power system. At this time, the fault current corresponds to a current when the magnitude of the current (i.e., AC current) flowing in the three-phase line (L1, L2, L3) deviates from the normal range. Such a fault current may be generated due to various causes, such as lightning, ground fault, short circuit, or other configuration problems of the power system.

[0041] In particular, fault current may include overcurrent having a current magnitude greater than the reference range. In particular, overcurrent can be simply divided into short-term overcurrent and long-term overcurrent.

[0042] Here, a short-term overcurrent corresponds to an overcurrent for a relatively short period. For example, the short-term overcurrent may be 1 / 2 to 2 cycles of the corresponding AC current, and more preferably 1 / 2 to 1 cycle of the corresponding AC current, but is not limited thereto.

[0043] Long-term overcurrent, on the other hand, refers to overcurrent that occurs over a relatively long period of time. For example, the long-term overcurrent may be greater than two periods of the corresponding AC current, and preferably, but not limited to, greater than one period of the corresponding AC current.

[0044] This system (10) may include a sensor unit (100), a circuit breaker (200), a fault detection device (300), and an electronic device (400), as shown in FIG. 1.

[0045] The sensor unit (100) is a component that senses various states of various components of a power system. In particular, the sensor unit (100) may include current sensors (110, 120, 130) that sense each current (i.e., alternating current) flowing in a three-phase line (L1, L2, L3) for transmission or distribution, etc. That is, the current sensors (110, 120, 130) are respectively provided in the three-phase lines (L1, L2, L3) to be monitored, and can detect the current of each line (L1, L2, L3). At this time, the alternating current flowing in each line (L1, L2, L3) may have a certain cycle. For example, each alternating current may have a cycle that changes according to a frequency such as 60 Hz or 50 Hz.

[0046] That is, the first current sensor (110) is provided on the first line (L1) and can sense the first AC current flowing in the first line (L1), the second current sensor (120) is provided on the second line (L2) and can sense the second AC current flowing in the second line (L2), and the third current sensor (130) is provided on the third line (L3) and can sense the third AC current flowing in the third line (L3). For example, it may be preferable that each of the current sensors (110, 120, 130) is a current transformer (CT).

[0047] Each current sensor (110, 120, 130) can transmit a sensing signal for an AC current flowing in the corresponding line to the fault detection device (300). At this time, according to the AC current whose current size changes over time, each current sensor (110, 120, 130) can generate a sensing signal of an analog signal for the current size that changes over time. However, the sensing signal may have an analog signal that is transformed into a current size that is a certain multiple lower than the corresponding AC current.

[0048] The circuit breaker (200) is a circuit breaker connected to a three-phase line (L1, L2, L3) to block and turn off the line where the fault current has occurred among the three-phase lines (L1, L2, L3) when a fault current occurs. It may be preferable that the circuit breaker (200) be a high-voltage circuit breaker that performs an off operation for the electrical connection of the target line according to an input blocking signal. At this time, a circuit breaker (200) may be separately provided for each of the three-phase lines (L1, L2, L3). The blocking signal for each of these circuit breakers (200) may be transmitted from a fault detection device (300) described later. At this time, the first circuit breaker (210) may be installed on the first line (L1), the second circuit breaker (220) may be installed on the second line (L2), and the third circuit breaker (230) may be installed on the third line (L3).

[0049] Figure 2 shows a rough block diagram of a fault detection device (300).

[0050] The fault detection device (300) is a device that performs the function of detecting a fault current occurring in a three-phase line (L1, L2, L3) (hereinafter referred to as the "first function"). In addition to this first function, the fault detection device (300) may additionally perform various functions.

[0051] That is, the fault detection device (300) can perform a function (hereinafter referred to as the "second function") of storing data (hereinafter referred to as "current data") related to the AC current waveform for each line (L1, L2, L3) identified during the first function. That is, the current data includes data on AC current that changes over time (i.e., data on current size, etc.). In particular, when a fault current such as an overcurrent is detected according to the first function during the second function, current data for the corresponding fault current can be stored together with current data for the before and after that.

[0052] In addition, the fault detection device (300) can perform a function of generating a blocking signal to control the off of each line (L1, L2, L3) (hereinafter referred to as the "third function"). In addition, the fault detection device (300) can perform a function of transmitting stored current data, etc. to an electronic device (400) according to the second function (hereinafter referred to as the "fourth function").

[0053] For these first to fourth functions, the fault detection device (300) may include a receiving unit (310), a memory (320), and a communication unit (330), as illustrated in FIG. 2. For example, it may be preferable that the fault detection device (300) be a dedicated embedded system implemented based on Embedded Linux, etc., rather than a general-purpose computing system, or a dedicated edge device implemented based on a dedicated program, etc.

[0054] The receiving unit (310) is configured to receive sensing signals of alternating current for each line (L1, L2, L3) required for the first function from each current sensor (110, 120, 130). At this time, since each sensing signal is an analog signal, the receiving unit (310) can convert the analog signal into a digital signal and transmit the converted digital signal to the control unit (340). For this purpose, the receiving unit (310) may include an analog-to-digital converter (ADC).

[0055] The memory (320) stores various data required for operations according to the first to fourth functions of the fault detection device (300). At this time, the data stored in the memory (320) may include, but is not limited to, data on sensing signals converted into digital signals, data transmitted and received with other devices such as electronic devices (400) via the communication unit (420), data for control operations of the control unit (330), programs related to the method described below, etc.

[0056] For example, the memory (320) may include, but is not limited to, a volatile memory device such as DRAM or SRAM, a non-volatile memory such as PRAM, MRAM, ReRAM, or NAND flash memory, a hard disk drive (HDD), or a solid state drive (SSD). In addition, the memory (320) may include, but is not limited to, a cache, a buffer, a main memory, or an auxiliary memory depending on its use / location. In particular, current data according to the second function may be stored in a non-volatile memory, a hard disk drive (HDD), or a solid state drive (SSD).

[0057] The communication unit (330) is a component that performs data communication with other devices, such as the electronic device (400). At this time, the data communication may be performed through a wired or wireless digital communication method. In particular, the communication unit (330) can transmit and receive various data with the electronic device (400), and can transmit current data stored according to the second function to the electronic device (400) according to the fourth function. In addition, the communication unit (330) can also receive a request signal for performing the third function, the fourth function, etc. from the electronic device (400).

[0058] For example, the communication unit (330) may perform wireless communication such as cellular communication, LoRa communication, SigFox communication, 5G (5th generation communication), LTE-A (long term evolution-advanced), LTE (long term evolution), WiFi communication, or Bluetooth, or may perform wired communication using RS-485, USB (Universal Serial Bus), Ethernet, optical cable, coaxial cable, UTP (Unshielded Twisted Pair cable) cable, or HFC (Hybrid Fiber Coaxtial) cable, but is not limited thereto.

[0059] The control unit (340) can perform various control operations on the fault detection device (300). That is, the control unit (340) can control the performance of the first to fourth functions of the fault detection device (300), and can control the performance of the method described below. In addition, the control unit (340) can control the operations of the remaining components of the fault detection device (300), such as the receiving unit (310), the memory (320), and the communication unit (330).

[0060] For example, the control unit (340) may include, but is not limited to, a hardware processor or a software process executed on the processor. For example, the processor may include, but is not limited to, a microprocessor, an MCU (Micro Controller Unit), a CUP (Central Processing Unit), a processor core, a multiprocessor, an ASIC (Application-Specific Integrated Circuit), or an FPGA (Field Programmable Gate Array).

[0061] Figure 3 shows a schematic block diagram of an electronic device (400).

[0062] The electronic device (400) is a device for managing, operating, monitoring, or controlling a three-phase line (L1, L2, L3) using a fault detection device (300). In particular, the electronic device (300) may perform a function (hereinafter referred to as the “fifth function”) of monitoring the current flowing through each line (L1, L2, L3) using current data for each line (L1, L2, L3) received from the fault detection device (300) according to the fourth function. Accordingly, the electronic device (400) may also be referred to differently as a “monitoring device.”

[0063] That is, the electronic device (400) is an electronic device that performs computing for the fifth function, etc., and may include an input unit (410), a communication unit (420), a display (430), a memory (440), and a control unit (450), as illustrated in FIG. 3.

[0064] For example, the electronic device may be a general-purpose computing system such as a desktop personal computer, a laptop personal computer, a tablet personal computer, a netbook computer, a workstation, a smartphone, or a smartpad, or a dedicated embedded system implemented based on Embedded Linux, but is not limited thereto.

[0065] The input unit (410) generates input data in response to various user inputs and may include various input means.

[0066] For example, the input unit (410) may include, but is not limited to, a keyboard, a keypad, a dome switch, a touch panel, a touch key, a touch pad, a mouse, a menu button, etc.

[0067] The communication unit (420) is a component that performs data communication with other devices such as the fault detection device (200). At this time, the data communication can be performed through a wired or wireless digital communication method. In particular, the communication unit (420) can transmit and receive various data with the fault detection device (200), and can receive current data from the fault detection device (200) according to the fourth function. In addition, the communication unit (330) can transmit a request signal to the fault detection device (200) to cause the fault detection device (200) to perform the third function or the fourth function. In addition, the communication unit (420) can also transmit data regarding the results of performing the method described below to other devices.

[0068] For example, the communication unit (420) may perform wireless communication such as cellular communication, LoRa communication, SigFox communication, 5G (5th generation communication), LTE-A (long term evolution-advanced), LTE (long term evolution), WiFi communication, or Bluetooth, or may perform wired communication using RS-485, USB (Universal Serial Bus), Ethernet, optical cable, coaxial cable, UTP (Unshielded Twisted Pair cable) cable, or HFC (Hybrid Fiber Coaxtial) cable, but is not limited thereto.

[0069] The display (430) displays various image data on a screen and may be configured as a non-luminous panel or a luminous panel. That is, it can display image data according to the performance of the method described below, and in particular, the display (430) can display image data regarding the waveform of current data according to the performance of monitoring according to the fifth function.

[0070] For example, the display (430) may include, but is not limited to, a liquid crystal display (LCD), a light emitting diode (LED) display, an organic light emitting diode (OLED) display, a micro electro mechanical systems (MEMS) display, or an electronic paper display. In addition, the display (430) may be implemented as a touch screen or the like by being coupled with the input unit (410).

[0071] The memory (440) stores various types of information necessary for the operation of the electronic device (400). The information stored in the memory (440) may include, but is not limited to, temperature data, information transmitted and received with other devices via the communication unit (420), information for the control operation of the control unit (450), and program information related to the method described below.

[0072] For example, the memory (440) may include, but is not limited to, a volatile memory device such as DRAM or SRAM, a non-volatile memory such as PRAM, MRAM, ReRAM, or NAND flash memory, a hard disk drive (HDD), or a solid state drive (SSD). In addition, the memory (3200) may include, but is not limited to, a cache, a buffer, a main memory, or an auxiliary memory depending on its use / location.

[0073] The control unit (450) can perform various control operations for the electronic device (400). That is, the control unit (450) can control the performance of management, operation, monitoring, or control, etc., for the three-phase line (L1, L2, L3) using the fault detection device (300). In particular, the control unit (450) can control the performance of the fifth and sixth functions, and can control the performance of the method to be described later. In addition, the control unit (450) can control the operations of the remaining components of the electronic device (400), i.e., the input unit (410), the communication unit (420), the display (430), the memory (440), etc.

[0074] For example, the control unit (450) may include, but is not limited to, a hardware processor or a software process executed on the processor. For example, the processor may include, but is not limited to, a microprocessor, an MCU (Micro Controller Unit), a CUP (Central Processing Unit), a processor core, a multiprocessor, an ASIC (Application-Specific Integrated Circuit), or an FPGA (Field Programmable Gate Array).

[0075] Hereinafter, a method according to one embodiment of the present invention will be described in more detail.

[0076] Figure 4 shows a flowchart of a method according to one embodiment of the present invention.

[0077] A method according to one embodiment of the present invention (hereinafter referred to as “the present method”) is a method performed under the control of a control unit (340) of a fault detection device (300) and a control unit (450) of an electronic device (400), and may include steps S410 to S460, as illustrated in FIG. 4. That is, steps S410 to S460 may be processed by a processor of each control unit (340, 450). However, S410 may correspond to a step that is necessarily performed, and at least one of S420 to S460 may correspond to a step that is optionally performed.

[0078] First, the control unit (340) receives sensing signals of alternating current for each line (L1, L2, L3) from each current sensor (110, 120, 130) through the receiving unit (310), and detects (judges) whether a fault current occurs in each line (L1, L2, L3) based on the received sensing signals (S410). In other words, S410 is a step for performing the first function.

[0079] At this time, each sensing signal in the form of an analog signal received by the receiving unit (310) can be converted into a digital signal form through an analog-to-digital converter (ADC) and then transmitted to the control unit (340). Accordingly, the control unit (340) can analyze the sensing signal (i.e., sensing data) in the form of a corresponding digital signal to detect (determine) whether a fault current has occurred for each line (L1, L2, L3).

[0080] To this end, the control unit (340) can determine whether a fault current has occurred in each line (L1, L2, L3) by determining the current value (i.e., a value related to the current size) of the alternating current flowing in each line (L1, L2, L3) over time from the sensing data. For example, the control unit (340) can determine that an overcurrent fault current has occurred in the line that generated the alternating current when the absolute value of the current value determined according to the sensor data is greater than the first reference value. At this time, the first reference value has a value greater than the range of current values ​​that the alternating current should originally have.

[0081] In particular, in order to minimize misjudgment due to temporary errors in sensing signals, etc., the control unit (340) can use sensor data to determine data (hereinafter referred to as “current data”) of AC current waveforms for each line (L1, L2, L3) for a recent period of time (i.e., a reference time). Accordingly, if the absolute value of the current value according to the current data for the recent reference time is greater than the first reference value, the control unit (340) can determine that an overcurrent has occurred in the corresponding line for the corresponding reference time.

[0082] At this time, the current value may be a maximum value, a peak value, an RMS value, an average value, etc. Accordingly, through the current data for the latest reference time, the current value for the maximum value, peak value, RMS value, or average value of the corresponding AC current for the latest reference time is identified, and if the absolute value of the identified current value is greater than the first reference value, it can be determined that an overcurrent has occurred in the corresponding line.

[0083] In particular, the reference time may be a time corresponding to 2 cycles or less of the corresponding AC current, preferably a time corresponding to 1 / 2 cycle to 2 cycles, and more preferably a time corresponding to 1 / 2 cycle to 1 cycle. If it is shorter than the range of the reference time, the time for sampling the current value according to the sensor data is not sufficient, so that the judgment of the occurrence of overcurrent may become inaccurate. In addition, if it is longer than the certain time, it takes too long to detect overcurrent, and in particular, it may become impossible to detect short-term overcurrent. In other words, the range of the reference time may be an optimal range for detecting short-term overcurrent that was not detected in the prior art.

[0084] For example, if the absolute value of the current value (e.g., maximum value) according to the current data of the first line (L1) during the latest 1 / 2 cycle reference time is greater than the first reference value, it can be determined that an overcurrent occurred in the first line (L1) during the reference time.

[0085] That is, based on the current data for the latest reference time, the fault detection device (300) can quickly detect and monitor the fault current of the overcurrent occurring in the three-phase line (L1, L2, L3) for transmission or distribution of the power system. In particular, the fault detection device (300) can quickly determine and monitor whether the fault current of the overcurrent occurs with only the current data for the latest reference time, such as 1 / 2 cycle or 1 cycle.

[0086] Next, the control unit (340) stores data such as current data identified in S410 in the memory (320) (S420). That is, S420 is a step for performing a second function. In particular, the control unit (340) can store current data for each line (L1, L2, L3) for the latest reference time identified in S410. At this time, the control unit (340) can store the current data in a non-volatile memory, a hard disk drive (HDD), a solid state drive (SSD), or the like.

[0087] In particular, if it is determined that an overcurrent has occurred in S410, the control unit (340) can store current data for the overcurrent. At this time, the control unit (340) can store not only current data for a reference time period in which the overcurrent occurred (hereinafter referred to as “reference data”), but also current data for a time period before the overcurrent occurred (hereinafter referred to as “first data”) and current data for a time period after the overcurrent occurred (hereinafter referred to as “second data”).

[0088] That is, based on the reference data, the first data before and the second data after can be stored together. In particular, not only the reference data for short-term overcurrent, but also the first and second data before and after it can be stored together.

[0089] At this time, it may be desirable to store the first data, reference data, and second data for the line where the overcurrent occurred together. However, in order to analyze the cause of a problem in all or part of the power system that may occur due to the overcurrent, current data for lines where the overcurrent did not occur may also be needed in addition to the line where the overcurrent occurred, and thus such data may also be stored together. That is, among the current data for lines where the overcurrent did not occur, current data for the time corresponding to the first data, reference data, and second data for the line where the overcurrent occurred may also be stored together.

[0090] Of course, if it is determined that an overcurrent has occurred in S410, the control unit (340) may also store data on the line where the overcurrent has occurred (hereinafter referred to as “overcurrent status data”) together with the current data. At this time, the overcurrent status data may further include, in addition to the type of line where the overcurrent has occurred, an index for accessing the current data for the overcurrent or data on the time when the overcurrent has occurred.

[0091] Accordingly, the fault detection device (300) can store not only overcurrent data for short-term overcurrents that occur over a relatively short period of time, but also first data, reference data, and second data regarding the current status before and after the occurrence of the overcurrent. Accordingly, the cause of an unexpected problem in all or part of the power system that may occur due to the overcurrent can be analyzed more closely based on the stored data.

[0092] At this time, it may be desirable for the first data to include current data from the reference time at which the overcurrent occurred to a previous time corresponding to multiple cycles. For example, the first data may include current data from the reference time at which the overcurrent occurred to a previous time corresponding to 1 to 10 cycles, but is not limited thereto.

[0093] Likewise, it may be desirable for the second data to include current data from a reference time at which the overcurrent occurred to a time corresponding to multiple cycles thereafter. For example, the second data may include current data from a reference time at which the overcurrent occurred to a time corresponding to one to ten cycles thereafter, but is not limited thereto.

[0094] Next, the control unit (340) generates a blocking signal, which is a control signal for controlling the off of each line (L1, L2, L3) (S430). At this time, the blocking signal is a signal for controlling the circuit breaker (200) connected to the corresponding line to operate off. In other words, S430 is a step for performing the third function. Of course, this S430 may be performed after or before S420, or may be performed together with S420.

[0095] To this end, the control unit (340) can transmit a blocking signal to each circuit breaker (200) as needed. In particular, the control unit (340) can transmit a blocking signal to the corresponding circuit breaker (200) to turn off a line in which an overcurrent fault current is determined to have occurred according to S410.

[0096] For example, in S410, if it is determined that an overcurrent has occurred in the AC current of the first line (L1), the control unit (340) can transmit a blocking signal to turn off the first line (L1) to the first circuit breaker (210) connected to the first line (L1). In addition, in S410, if it is determined that an overcurrent has occurred in the AC current of the second line (L2), the control unit (340) can transmit a blocking signal to turn off the second line (L2) to the second circuit breaker (220) connected to the second line (L2). Similarly, in S410, if it is determined that an overcurrent has occurred in the AC current of the third line (L3), the control unit (340) can transmit a blocking signal to turn off the third line (L3) to the third circuit breaker (230) connected to the third line (L3).

[0097] However, it may be desirable to generate a blocking signal only when the absolute value of the current value for the overcurrent detected in S410 is greater than the second reference value. This is because even if it is an overcurrent, if the absolute value of the current value is below a certain level, the impact on the power system may be minimal or very small. Accordingly, it may be desirable for the second reference value to have a value greater than the first reference value.

[0098] That is, if the first reference value is a standard for determining whether the AC current is an overcurrent that exceeds the reference range even when considering only the margin of error, the second reference value can be a standard for determining whether the AC current determined to be an overcurrent is a dangerously high overcurrent that can cause a major problem (failure, fire, etc.) in the power system. For example, the second reference value can be a standard for determining whether it is an overcurrent with a very high current value, such as in the case of lightning, ground fault, or short circuit.

[0099] Accordingly, if the absolute value of the overcurrent determined according to S410 is greater than the first reference value but less than the second reference value, the control unit (340) may not generate a blocking signal. On the other hand, if the absolute value of the overcurrent determined according to S410 is greater than both the first and second reference values, the control unit (340) may transmit a blocking signal to the circuit breaker (200) connected to the corresponding line.

[0100] Next, the control unit (340) transmits the current data for each line (L1, L2, L3) stored according to S420 to the electronic device (400) (S440). That is, S440 is a step for performing the fourth function. Accordingly, the current data stored according to S420 can be transmitted from the communication unit (330) of the fault detection device (300) to the communication unit (420) of the electronic device (400). Of course, for the current data determined to have occurred as an overcurrent in S410, data on whether an overcurrent has occurred can be transmitted to the electronic device (400) together with the corresponding current data. At this time, the corresponding current data may include not only the reference data but also the first and second data before and after it.

[0101] Next, the control unit (450) monitors the AC current flowing through each line (L1, L2, L3) using current data for each line (L1, L2, L3) received from the fault detection device (300) according to S440 (S450). In other words, S450 is a step for performing the fifth function.

[0102] At this time, during the monitoring, the control unit (450) can display a graph of the AC current waveform for each line (L1, L2, L3) according to the received current data through the display (430). In particular, when an overcurrent occurs, not only the reference data for it but also a graph according to the first and second data before and after it can be displayed on the display (430). Accordingly, by performing monitoring based on the graph, the cause of an unexpected problem in all or part of the power system that may occur due to the overcurrent can be analyzed more closely. That is, the current data received from the fault detection device (300) according to S440 can be utilized for cause analysis of a problem in the power system that occurs due to the overcurrent.

[0103] Meanwhile, S430 or S440 may be performed by the fault detection device (300) itself as needed, but is not limited thereto, and may be performed even when the electronic device (400) sends a request signal to the fault detection device (300), or may be performed only when the electronic device (400) sends a request signal to the fault detection device (300).

[0104] For example, the control unit (450) of the electronic device (400) may transmit a request signal for performing S440 to the communication unit (330) of the fault detection device (300) periodically or according to a user's selection, etc., through the communication unit (420). In this case, the control unit (340) of the fault detection device (300) that receives the request signal may perform S440 in response thereto.

[0105] In addition, in case at least one of the three-phase lines (L1, L2, L3) must be arbitrarily turned off for reasons such as maintenance, the control unit (450) of the electronic device (400) may transmit a request signal for performing S440 to generate a blocking signal to cause the circuit breaker (200) connected to the corresponding line to turn off, to the communication unit (330) of the fault detection device (300) through the communication unit (420) according to the user's selection, etc. In this case, the control unit (340) of the fault detection device (300) that has received the request signal may transmit the blocking signal to the corresponding circuit breaker (200) in response thereto.

[0106] In addition, in the present method, when overcurrent data indicating that an overcurrent has occurred in a certain line is received from the fault detection device (300) according to S440, the control unit (450) can control the notification information regarding the occurrence of the overcurrent to be displayed through the display (430) or transmitted to another device (e.g., a user's mobile terminal or a central server, etc.) through the communication unit (420).

[0107] While the present invention has been described in detail above through representative examples, those skilled in the art will appreciate that various modifications and equivalent embodiments are possible. Therefore, the true scope of technical protection of the present invention should be determined by the technical spirit of the appended claims.

[0108] This relates to a monitoring technology for fault current, and more specifically, to a technology for rapidly detecting and monitoring fault current occurring in a three-phase line for transmission or distribution of a power system.

Claims

1. A step in which a fault detection device determines whether an overcurrent occurs in each line for a reference time based on a sensing signal for each AC current flowing in multiple lines in a power system; and When an overcurrent occurs, a step of the fault detection device storing in memory the current data related to the overcurrent among the data on the type of the overcurrent line and the current data which is data on the AC current waveform according to the sensing signal; How to include.

2. In paragraph 1, A method in which the current data related to the overcurrent includes reference data, which is current data for the reference time for the overcurrent line, first data, which is current data for a time before the overcurrent occurs for the overcurrent line, and second data, which is current data for a time after the overcurrent occurs for the overcurrent line.

3. In paragraph 2, A method in which the current data related to the overcurrent further includes current data for a time corresponding to each of the first data, the reference data, and the second data among the current data for a line in which the overcurrent did not occur.

4. In paragraph 2 or paragraph 4, A method in which current data related to the above overcurrent is utilized to analyze the cause of a problem in a power system caused by the above overcurrent.

5. In paragraph 1, A method in which the above reference time is a time corresponding to 1 / 2 cycle to 1 cycle of the above alternating current.

6. In paragraph 1, A method further comprising the step of generating a blocking signal for causing the circuit breaker connected to the overcurrent line to operate off.

7. In paragraph 6, The above judgment step determines that the overcurrent has occurred in the corresponding line when the absolute value of the current value according to the sensing signal is greater than the first reference value, The above generating step generates the blocking signal when the absolute value of the current value is greater than the second reference value, The above second reference value is greater than the above first reference value.

8. In paragraph 1, A step of monitoring the AC current by having the electronic device receive data on the type and current data related to the overcurrent from the fault detection device and displaying an AC current waveform related to the overcurrent in the line where the overcurrent occurred on a display based on the received data; How to include more.

9. A receiving unit that receives a sensing signal for each AC current flowing in multiple lines in a power system; and A processor that determines whether an overcurrent occurs in each line for a reference time based on a received sensing signal; The above processor is a fault detection device that stores, in memory, data on the type of the overcurrent line and current data related to the overcurrent among current data, which is data on the AC current waveform according to the sensing signal, when the overcurrent occurs.

10. In paragraph 9, The above processor is a fault detection device that stores, in the memory, reference data which is current data for the reference time for the overcurrent line, first data which is current data for a time before the overcurrent occurs for the overcurrent line, and second data which is current data for a time after the overcurrent occurs for the overcurrent line, as current data related to the overcurrent.

11. In paragraph 10, The above processor is a fault detection device that additionally stores, in the memory, current data for a time corresponding to the first data, the reference data, and the second data, among the current data for the line where the overcurrent did not occur, as current data related to the overcurrent.

12. In paragraph 9, The above processor is a fault detection device that generates a blocking signal to cause a circuit breaker connected to the overcurrent line to turn off.

13. In paragraph 12, The above processor, In the above judgment, if the absolute value of the current value according to the sensing signal is greater than the first reference value, it is determined that the overcurrent has occurred in the corresponding line. When the absolute value of the current value is greater than the second reference value, the blocking signal is generated, A fault detection device in which the second reference value is greater than the first reference value.

14. In paragraph 9, The above processor is a fault detection device that transmits data and current data for the above type to an electronic device that monitors the alternating current.

15. A sensor that senses each alternating current flowing in multiple lines in a power system; A fault detection device that receives a sensing signal from the above sensor, detects whether an overcurrent occurs in each line for a reference time based on the received sensing signal, and stores data on the type of the overcurrent line and current data on the overcurrent in a memory when the overcurrent occurs; and An electronic device that receives data on the type stored in the memory and current data related to the overcurrent from the fault detection device, and monitors the alternating current by displaying an alternating current waveform related to the overcurrent in the line where the overcurrent occurred on the basis of the received data; A system that includes.

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