KR101566270B1 - Differential current protective relay and method for driving thereof - Google Patents
Differential current protective relay and method for driving thereof Download PDFInfo
- Publication number
- KR101566270B1 KR101566270B1 KR1020150078611A KR20150078611A KR101566270B1 KR 101566270 B1 KR101566270 B1 KR 101566270B1 KR 1020150078611 A KR1020150078611 A KR 1020150078611A KR 20150078611 A KR20150078611 A KR 20150078611A KR 101566270 B1 KR101566270 B1 KR 101566270B1
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- South Korea
- Prior art keywords
- phase angle
- reference signal
- synchronization
- relay
- sampling time
- Prior art date
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
- H01H47/00—Circuit arrangements not adapted to a particular application of the relay and designed to obtain desired operating characteristics or to provide energising current
- H01H47/002—Monitoring or fail-safe circuits
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
- G01R31/327—Testing of circuit interrupters, switches or circuit-breakers
- G01R31/3277—Testing of circuit interrupters, switches or circuit-breakers of low voltage devices, e.g. domestic or industrial devices, such as motor protections, relays, rotation switches
- G01R31/3278—Testing of circuit interrupters, switches or circuit-breakers of low voltage devices, e.g. domestic or industrial devices, such as motor protections, relays, rotation switches of relays, solenoids or reed switches
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- G—PHYSICS
- G08—SIGNALLING
- G08C—TRANSMISSION SYSTEMS FOR MEASURED VALUES, CONTROL OR SIMILAR SIGNALS
- G08C19/00—Electric signal transmission systems
- G08C19/02—Electric signal transmission systems in which the signal transmitted is magnitude of current or voltage
Abstract
Description
Current differential protection relays and their driving methods.
The current differential protection relay is installed at both ends of the transmission line, and it is a device which judges whether or not a fault occurs in the transmission line by using the current difference measured at both ends. The relays installed at both ends can be connected to each other by communication. If the current value measured by the other relay is received, the current value measured by the relay is compared with the current value measured by the other relay.
Today, the current differential protection relay operates digitally and does not process the whole signal, but it periodically adjusts to the reference clock inside the relay and reads the voltage and current signal values at that point to perform the measurement function . However, when the sampling points of different relays installed at both ends of the transmission line are different, the voltage value or current value of the signal measured at both ends will be different. In such a case, there is no difference in the actual signal, but there is a possibility that the relay at both ends of the transmission line may erroneously judge that there is a difference in the signal and malfunction.
In order to solve such a problem, there is a conventional sampling synchronization algorithm. However, since it operates under the assumption that the transmission and reception delay times between the relays of both stages are the same, when the transmission and reception delay times are different according to the actual communication environment, There is still a problem that there is no.
According to one aspect, a differential current protective relay is provided. Wherein the current differential protection relay includes a processor for calculating a first phase angle corresponding to a first sampling time of a reference signal transmitted along a transmission line and for measuring the reference signal at a second sampling time following the first sampling time, Transmitting a correction request message associated with synchronization to a master relay connected to the transmission line and receiving a correction response message corresponding to the first sampling time of the reference signal and including a second phase angle calculated at the master relay And a communication unit. In addition, the processor may perform the synchronization with the master relay at the second sampling time using the first phase angle and the second phase angle. Also, the processor may measure the reference signal on the transmission line, and calculate the first phase angle when the measured value of the reference signal is equal to or greater than a predetermined threshold value.
According to one embodiment, the processor may calculate the reference phase angle difference by removing the second phase angle at the first phase angle, and calculate the synchronization difference with the master relay using the reference phase angle difference . In addition, if the synchronization difference is positive, the processor increases the second sampling time by the synchronization difference, and if the synchronization difference is negative, slows down the second sampling time by the synchronization difference, Synchronization can be performed.
According to another aspect, a method of synchronizing with the master relay at the sampling time is provided. The method includes the steps of determining whether a reference signal is present on a transmission line, calculating a first phase angle corresponding to a first sampling time of the reference signal according to a result of the determination, Receiving a correction response message that includes a second phase angle corresponding to the first sampling time of the reference signal and computed at the master relay, And performing a synchronization of the second sampling point along the first sampling point with the master relay using the second phase angle and the second phase angle. In addition, the reference signal may be a voltage signal, and the step of determining whether the reference signal exists may determine that the reference signal exists when the reference signal exists at a predetermined ratio or more of the rated voltage.
According to one embodiment, performing synchronization at the sampling time with the master relay includes calculating the reference phase angle difference by removing the second phase angle at the first phase angle, And calculating the synchronization difference using the frequency. In addition, the step of performing synchronization with the master relay at the sampling time may perform synchronization by controlling the sampling time so that the synchronization difference becomes zero.
According to another aspect, a current differential protection relay is provided. Wherein the current differential protection relay includes a meter for measuring a reference signal transmitted along a transmission line based on a sampling period, a first phase angle corresponding to a first sampling time of the reference signal from a slave relay connected to the transmission line, A communication unit for receiving a correction request message and a second phase angle corresponding to the first sampling time of the reference signal in accordance with the correction request message and transmitting a correction response message including the second phase angle through the communication unit Lt; / RTI > In addition, the measuring device may determine whether the measured reference signal is greater than or equal to a predetermined threshold value and determine the validity of the measured reference signal.
According to an embodiment, the processor may divide the phase angle measured in the reference signal by the phase angle variation per predetermined sampling period, and calculate the remaining value as the second phase angle. Meanwhile, the processor may calculate a phase angle that is greater than zero and smallest among the phase angles measured in the reference signal, as the second phase angle.
1 is an exemplary diagram showing different sampling timings between a master relay and a slave relay.
2 shows a block diagram of a slave relay according to one embodiment.
3 shows a waveform diagram of a reference signal flowing through a transmission line according to an embodiment.
4 shows a block diagram of a master relay according to one embodiment.
5 illustrates a flow diagram of a method for performing sampling point-in-time synchronization of relays on both ends of a transmission line according to one embodiment.
6 shows a flow diagram of a method for calculating a phase angle in a reference signal according to an embodiment.
In the following, some embodiments will be described in detail with reference to the accompanying drawings. However, the scope of the rights is not limited or limited by these embodiments. Like reference symbols in the drawings denote like elements.
The terms used in the following description are chosen to be generic and universal in the art to which they are related, but other terms may exist depending on the development and / or change in technology, customs, preferences of the technician, and the like. Accordingly, the terminology used in the following description should not be construed as limiting the technical thought, but should be understood in the exemplary language used to describe the embodiments.
Also, in certain cases, there may be a term chosen arbitrarily by the applicant, in which case the meaning of the detailed description in the corresponding description section. Therefore, the term used in the following description should be understood based on the meaning of the term, not the name of a simple term, and the contents throughout the specification.
1 is an exemplary diagram showing different sampling timings between a master relay and a slave relay. The relay described in the following description may be a device installed at both ends of an electric circuit to open or close an electric circuit according to an electric signal such as voltage, current, power and frequency. More specifically, it may be a current differential protection relay installed at both ends of a transmission line and judging whether or not a fault has occurred on the line by using a current difference measured at both ends. Today, the International Electrotechnical Commission (IEC) standardizes and establishes communication protocols such as IEC 61850 as communication protocols between substations. Accordingly, the current differential protection relay according to this embodiment may include an Intelligent Electronic Device (IED) operable using a communication protocol such as IEC 61850. The current differential protection relay is a device that detects and controls the relevant part when a short circuit or ground fault occurs on the transmission line or when an abnormal operation occurs, and it is an essential function in safety of today's large capacity electric power facility .
According to one embodiment, the
There is a need to match the sampling points between the
The
The
First, the slave relays 120 receive the first synchronization information transmitted from the master relay 110 (160)
2 shows a block diagram of a slave relay according to one embodiment. The
The
In addition, the
More specifically, the
The
In addition, the
As shown in Equation 2, the reference phase angle difference is equal to the second phase angle calculated by the master relay at the first phase angle calculated by the
Illustratively, if 60 Hz of power is being transmitted through the transmission line provided with the
In addition, the
3 shows a waveform diagram of a reference signal flowing through a transmission line according to an embodiment. The first waveform diagram 310 shows the
In general, it is possible to detect whether or not a fault occurs on a transmission line connecting the master relay and the slave relays by comparing the reference signals 311 and 321 measured in the master relay and the slave relay. When a ground fault occurs in a line of a direct grounding type and the line touches the ground, or when the line touches a high resistance object such as a tree, the resistance of the transmission line is changed when the distribution line is broken, Since the signals of the reference signals 311 and 321 measured at both ends of the
Referring to FIG. 3, the
In addition, when there is a difference in the transmission and reception delay times of the master relay and the slave relays, it is as described above that complete synchronization can not be performed using only the conventional sampling synchronization algorithm. In such a case, there is a need to perform sampling time synchronization according to the present embodiment.
Illustratively, assume that the second phase angle of the slave relays in FIG. 3 is 30 degrees. The slave relays can be calculated to have a reference phase angle difference of 30 degrees. In addition, the slave relays use the reference phase angle difference of 30 degrees,
4 shows a block diagram of a master relay according to one embodiment. The
In addition, the
In another embodiment, when the phasor phase angle value of the reference signal varies with a constant difference in the range between 0 and 360 degrees, the
5 illustrates a flow diagram of a method for performing sampling point-in-time synchronization of relays on both ends of a transmission line according to one embodiment. A
Step 510 is a step of determining whether a reference signal exists on the transmission line. It is judged whether there is a valid reference signal enough to perform the sampling point-in-time synchronization of the present invention. Master and slave relays installed at both ends of the transmission line may be physically separated from several kilometers to several tens of kilometers. Therefore, a signal of a type that can be stably transmitted without being deformed or distorted while flowing along the distance of the two relays can be selected. Illustratively, the reference signal can be a voltage signal. The voltage signal can be transmitted to both relays even when there is a disconnection in a part of the transmission line, so that the voltage signal can be detected more stably than when the current signal is used. A detailed description of
Step 520 is a step of calculating a first phase angle corresponding to a first sampling time of the reference signal according to a result of the determination performed in
Step 530 is the step of sending a correction request message associated with synchronization to the master relay connected to the transmission line. Each of the master relay and the slave relay can measure the reference signal with its own sampling period according to the internal clock signal. In
Step 540 is a step in which the slave relay receives the correction response message from the master relay. The correction response message may include information for performing the synchronization. More specifically, the correction response message may include a second phase angle corresponding to the first sampling time of the reference signal and calculated at the master relay. In addition, the transmission and reception of the correction request message and the correction response message described in
Step 550 is a step of performing synchronization between the master relay and the second sampling point following the first sampling point using the first phase angle and the second phase angle. Illustratively, the second sampling time represents a time point corresponding to any one of the sampling performed by the slave relays after the first sampling time, and is not limited to a specific sequence or is not limited. In
In addition, the method of performing sampling point-in-time synchronization of the relay may further include a plurality of additional steps. The method may further include transmitting an initialization message for confirming the presence of the master relay. Illustratively, the step of transmitting the initialization message may be performed by the
In addition, the method may further include transmitting a synchronization request message at a sampling time. In addition, the method may further comprise receiving a synchronization response message corresponding to the synchronization request message from the master relay. More specifically, the synchronization response message is generated from the first sampling time of the master relay to the first synchronization information
In addition, the method may further comprise calculating a synchronization difference between the master relay and a sampling point. In this step, the slave relays use the difference between the second sampling time performed after the first sampling time and the reception timing of the synchronization response message,
As another embodiment, a method of performing sampling point-in-time synchronization of relays at both ends to a transmission line performed by a master relay can be provided. The method may include receiving an initialization message from the slave relays. When the initialization message is received, the master relay can recognize that a slave relay is present within a communicable distance range. In addition, the method may further include transmitting the response message corresponding to the initialization message to the slave relay. In the step of transmitting the response message, the master relay can inform the slave relays to perform synchronization. In addition, the method may further include receiving a synchronization request message at the sampling time. The method may further include, when the synchronization request message is received, transmitting a synchronization response message at a sampling time corresponding to the synchronization request message to the slave relays. The synchronization response message is generated from the first sampling time of the master relay to the first synchronization information
6 shows a flow diagram of a method for calculating a phase angle in a reference signal according to an embodiment. A method 600 for calculating a phase angle in a reference signal includes comparing 610 a measured reference signal to a predetermined threshold and calculating 620 a phase angle corresponding to a first sampling time.
Step 610 is a step of measuring the reference signal and comparing the measured reference signal with a predetermined threshold value. As described above, the reference signal can be input to the transmission line in the form of various signals. In one embodiment, when the reference signal is current, the measurement of the reference signal in
In addition,
Step 610 may determine whether the size of the reference signal measured is greater than or equal to the previously set threshold. The determination may be performed by the
Step 620 is performed when it is determined that the reference signal measured in
The embodiments described above may be implemented in hardware components, software components, and / or a combination of hardware components and software components. For example, the devices, methods, and components described in the embodiments may be implemented within a processor, a controller, an arithmetic logic unit (ALU), a digital signal processor, a microcomputer, a field programmable gate array such as an array, a programmable logic unit (PLU), a microprocessor, or any other device capable of executing and responding to instructions. The processing device may execute an operating system (OS) and one or more software applications running on the operating system. The processing device may also access, store, manipulate, process, and generate data in response to execution of the software. For ease of understanding, the processing apparatus may be described as being used singly, but those skilled in the art will recognize that the processing apparatus may have a plurality of processing elements and / As shown in FIG. For example, the processing apparatus may comprise a plurality of processors or one processor and one controller. Other processing configurations are also possible, such as a parallel processor.
The software may include a computer program, code, instructions, or a combination of one or more of the foregoing, and may be configured to configure the processing device to operate as desired or to process it collectively or collectively Device can be commanded. The software and / or data may be in the form of any type of machine, component, physical device, virtual equipment, computer storage media, or device , Or may be permanently or temporarily embodied in a transmitted signal wave. The software may be distributed over a networked computer system and stored or executed in a distributed manner. The software and data may be stored on one or more computer readable recording media.
The method according to an embodiment may be implemented in the form of a program command that can be executed through various computer means and recorded in a computer-readable medium. The computer-readable medium may include program instructions, data files, data structures, and the like, alone or in combination. The program instructions to be recorded on the medium may be those specially designed and configured for the embodiments or may be available to those skilled in the art of computer software. Examples of computer-readable media include magnetic media such as hard disks, floppy disks and magnetic tape; optical media such as CD-ROMs and DVDs; magnetic media such as floppy disks; Magneto-optical media, and hardware devices specifically configured to store and execute program instructions such as ROM, RAM, flash memory, and the like. Examples of program instructions include machine language code such as those produced by a compiler, as well as high-level language code that can be executed by a computer using an interpreter or the like. The hardware devices described above may be configured to operate as one or more software modules to perform the operations of the embodiments, and vice versa.
While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. For example, it is to be understood that the techniques described may be performed in a different order than the described methods, and / or that components of the described systems, structures, devices, circuits, Lt; / RTI > or equivalents, even if it is replaced or replaced. Therefore, other implementations, other embodiments, and equivalents to the claims are also within the scope of the following claims.
Claims (14)
Transmitting a correction request message associated with synchronization to a master relay connected to the transmission line and receiving a correction response message corresponding to the first sampling time of the reference signal and including a second phase angle calculated at the master relay Communication section
Lt; / RTI >
Wherein the processor divides the phase angle measured in the reference signal by the phase angle variation per predetermined sampling period and calculates the remaining value as the first phase angle and calculates the first phase angle using the first phase angle and the second phase angle And performs synchronization with the master relay at the second sampling time.
Wherein the processor calculates the reference phase angle difference by subtracting the second phase angle at the first phase angle and calculates a synchronization difference with the master relay using the reference phase angle difference.
Wherein the processor increases the second sampling time by the synchronization difference when the synchronization difference is positive and makes the second sampling time by the synchronization difference when the synchronization difference is negative so as to synchronize the master relay and the sampling point Current differential protection relay performing.
Wherein the processor measures the reference signal on the transmission line and calculates the first phase angle when the measured value of the reference signal is greater than or equal to a predetermined threshold.
Wherein the processor calculates a phase angle greater than zero and a smallest phase angle among the phase angles measured in the reference signal as the first phase angle.
Calculating a first phase angle corresponding to a first sampling time of the reference signal according to a result of the determination;
Transmitting a correction request message associated with synchronization to a master relay connected to the transmission line;
Receiving a correction response message corresponding to the first sampling time of the reference signal and including a second phase angle calculated at the master relay; And
Performing synchronization at a second sampling time following the first sampling time with the master relay using the first phase angle and the second phase angle
Lt; / RTI >
Calculating the first phase angle includes dividing the phase angle measured in the reference signal by a phase angle variation per predetermined sampling period and calculating the remaining value as the first phase angle
Synchronization method at sampling point with master relay.
Wherein the reference signal is a voltage signal and the step of determining whether the reference signal is present includes a step of synchronizing a sampling point with a master relay that determines that the reference signal exists if the reference signal exists at a predetermined ratio or more of the rated voltage .
Wherein the step of performing synchronization with the master relay at the sampling time comprises: calculating a reference phase angle difference by removing the second phase angle at the first phase angle; And a step of calculating a time difference between the master relay and the master relay.
Wherein the step of performing synchronization with the master relay at the sampling time synchronizes the sampling time with the master relay so that the synchronization difference becomes zero.
And a communication unit for receiving a correction request message including a first phase angle corresponding to a first sampling time of the reference signal from a slave relay connected to the transmission line,
Lt; / RTI >
The processor divides the phase angle measured in the reference signal by the phase angle variation per sampling period in accordance with the correction request message and calculates the remaining value as a second phase angle corresponding to the first sampling time, And transmits a correction response message including the second phase angle through the second phase angle.
Wherein the processor determines whether the measured reference signal is greater than or equal to a predetermined threshold value and determines the validity of the measured reference signal.
Wherein the processor calculates a phase angle greater than zero and a smallest phase angle among the phase angles measured in the reference signal as the second phase angle.
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| KR1020150078611A KR101566270B1 (en) | 2015-06-03 | 2015-06-03 | Differential current protective relay and method for driving thereof |
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| KR1020150078611A KR101566270B1 (en) | 2015-06-03 | 2015-06-03 | Differential current protective relay and method for driving thereof |
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Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR20190115764A (en) * | 2018-04-03 | 2019-10-14 | 한국전력공사 | System and method for measuring live insulation resistance |
| KR102322283B1 (en) * | 2021-05-21 | 2021-11-05 | 주식회사 부림테크 | Digital protective relay equipment for a pole transformer |
| KR20230151599A (en) | 2022-04-25 | 2023-11-02 | 코츠테크놀로지주식회사 | Current ratio differential relay and operating method thereof |
| CN116995625A (en) * | 2023-08-08 | 2023-11-03 | 国网重庆市电力公司 | Power distribution network differential protection method and system based on regional ad hoc network communication |
-
2015
- 2015-06-03 KR KR1020150078611A patent/KR101566270B1/en active IP Right Grant
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR20190115764A (en) * | 2018-04-03 | 2019-10-14 | 한국전력공사 | System and method for measuring live insulation resistance |
| KR102424070B1 (en) | 2018-04-03 | 2022-07-25 | 한국전력공사 | System and method for measuring live insulation resistance |
| KR102322283B1 (en) * | 2021-05-21 | 2021-11-05 | 주식회사 부림테크 | Digital protective relay equipment for a pole transformer |
| KR20230151599A (en) | 2022-04-25 | 2023-11-02 | 코츠테크놀로지주식회사 | Current ratio differential relay and operating method thereof |
| CN116995625A (en) * | 2023-08-08 | 2023-11-03 | 国网重庆市电力公司 | Power distribution network differential protection method and system based on regional ad hoc network communication |
| CN116995625B (en) * | 2023-08-08 | 2024-01-30 | 国网重庆市电力公司 | Power distribution network differential protection method and system based on regional ad hoc network communication |
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