JP2014064396A - Protection controller, and current differential protective relay device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a protection controller and a current differential protective relay device in combination of a dedicated power communication network with a LAN communication.SOLUTION: A protection controller 100 includes AI (Analog Input) means 1, A/D conversion means 2, TIM (Timing) control means 3, calculation means 4, output means 5, synchronization correction controller 6, LAN communication means 7, and transmission controller 10. The transmission controller 10 cyclically exchanges data through a dedicated line communication network to synchronize sampling synchronous timing with an opposite end. The LAN communication means 7 exchanges data by cyclically transferring packets through an internet protocol communication network to synchronize sampling synchronous timing with the opposite end. The synchronization correction controller 6 corrects sampling synchronization to synchronize the sampling synchronous timing of the transmission controller 10 with the sampling synchronous timing of the LAN communication means 7.

Description

  The present invention relates to a protection control device and a current differential protection relay device, and more particularly, to a protection control device and a current differential protection relay device that detect a system fault in a protection section and remove an accident.

  There is a current differential protection control device that measures terminal current at each terminal, sends / receives digital data to / from each other via a transmission line, detects a system fault in the protection section from the difference current, and eliminates the accident.

  In this case, the transmission path or communication method is a method of cyclically transmitting data at a predetermined cycle at a transmission rate of 54 kbps or 1.5 Mbps, as described in Patent Document 1 and Non-Patent Document 1, for example. However, it has been adopted uniformly on a nationwide scale. This transmission method is based on the premise that it is configured by power-dedicated communication.

  The above power-dedicated communications are special specifications, and technical and cost gaps compared to the Internet Protocol (IP) communication network or LAN (Local Area Network) communication, which has increased in speed and capacity and reduced in cost. It is expected to spread.

  For this reason, as described in Patent Document 2, a technique has been proposed in which general LAN communication is applied as a communication medium to the transmission path of the protection control device.

  In addition, as described in Patent Document 3, when general LAN communication is applied to a transmission line, it is necessary to synchronize sampling of the current value of each terminal. Therefore, IEEE (Institute of Electrical and Electronics Engineers) A protection control device synchronized with 1588 technology has been proposed.

JP 2007-068325 A JP2011-188572A JP 2011-200100 A

Second Generation Digital Relay Technical Committee, “Second Generation Digital Relay”, Electric Joint Research Group, Vol. 50, No. 1, 1994

  In the case of adding a terminal to the system protection by the conventional protection control device that communicates exclusively with electric power, it is conceivable to add a protection control device using general LAN communication due to cost requirements.

  In this case, power dedicated communication and general LAN communication having different communication speeds and sampling synchronization methods are used in combination, but synchronization of sampling of current values for each terminal is a problem.

  The present invention has been made in view of such circumstances, and an object thereof is to provide a protection control device and a current differential protection relay device that combine a dedicated power communication network and LAN communication.

  In order to solve the above-described problems, a protection control device according to the present invention includes an input unit that inputs a current of a transmission line and converts it into a digital quantity, a timing control unit that determines a sampling timing in the input unit, and the input unit A calculation unit that performs a protection calculation using a digital amount from the output unit, an output unit that provides a control signal for a circuit breaker provided in the power transmission line according to a calculation result of the calculation unit, and a cyclic circuit using a dedicated line communication network A first communication unit that performs data transmission / reception and performs sampling synchronization timing adjustment with the other end, and a first communication unit that performs cyclic packet transfer over the Internet protocol communication network to perform data transmission / reception and perform sampling synchronization timing adjustment with the other end. A second communication unit including at least one communication unit of the two communication units, the first communication unit, and the second communication unit. And a synchronization correction controller for performing ring synchronization correction.

  A current differential protection relay device according to the present invention includes an input unit that inputs a current of a transmission line and converts it into a digital quantity, a timing control unit that determines a sampling timing in the input unit, and a digital quantity from the input unit. A calculation unit that performs a protection calculation using an output unit, an output unit that provides a control signal of a circuit breaker provided in the power transmission line according to a calculation result of the calculation unit, and cyclic data transmission / reception via a dedicated line communication network, A first communication unit that performs sampling synchronization timing adjustment with the other end, and a second communication unit that performs data transmission / reception by cyclic packet transfer in the Internet protocol communication network and performs sampling synchronization timing adjustment with the other end. Sampling synchronization correction between different types of communication units when including at least one communication unit, the first communication unit, and the second communication unit It includes cormorants and synchronization correction controller, the protection and control device provided to each terminal of the transmission line, in the arithmetic unit obtains a difference between the current detected by the respective terminals.

  According to the present invention, a protection control device and a current differential protection relay device are constructed by combining a protection control device using power-dedicated communication and general LAN communication with high speed, large capacity and cost reduction. be able to. As a result, existing power-only communication equipment can be used, and communication equipment costs can be saved.

It is a figure which shows the structure of the current differential protection relay apparatus which employ | adopts the protection control apparatus which concerns on embodiment of this invention. It is a figure which shows the structure of the synchronous correction control part and timing control means of the protection control apparatus which concerns on the said embodiment. It is a figure which shows the example of a communication format only for the electric power of the transmission control part of the protection control apparatus which concerns on the said embodiment. It is a figure which shows the example of a format transmitted / received by the packet communication of the LAN communication means of the protection control apparatus which concerns on the said embodiment. It is a figure explaining the operation | movement outline | summary of the system which takes the sampling synchronization between each terminal using the communication only for the electric power of the protection control apparatus which concerns on the said embodiment. It is a figure explaining the sampling synchronization of the structure of 2 terminals of the master station of the protection control apparatus which concerns on the said embodiment, and a slave station. It is a figure explaining the signal processing example of the synchronous correction control part in case the protection control apparatus which concerns on the said embodiment becomes a main station. It is a figure explaining the signal processing example of the synchronous correction control part in case the protection control apparatus which concerns on the said embodiment becomes a slave station. It is a figure which shows the structure of the SP synchronous time correction | amendment part of the protection control apparatus which concerns on the said embodiment. It is a figure which shows an example of the time chart of SP synchronous time correction | amendment of the SP synchronous time correction | amendment part of the protection control apparatus which concerns on the said embodiment.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a diagram illustrating a configuration of a current differential protection relay device that employs a protection control device according to an embodiment of the present invention.
As shown in FIG. 1, the current differential protection relay device includes three terminals A, B, and C (A terminal, B terminal, and C terminal), and a transmission line L <b> 1 between the terminals A, B, and C. L2, and each of the terminals A, B, and C includes protection control devices 100A, 100B, and 100C, and a circuit breaker CB200 that protects the transmission lines L1 and L2 by being interrupted by a given trip command 100k, A current transformer CT300 that detects currents of the terminals A, B, and C is provided.

  In the current differential protection relay device, protection control devices 100A, 100B, and 100C, a circuit breaker CB200, and a current transformer CT300 are arranged at electric stations on both ends of the transmission lines L1 and L2, respectively, and current is transmitted and received using a communication device. To achieve protection based on the principle of current operation. In the following description, the protection control devices 100A, 100B, and 100C are referred to as the protection control device 100 unless they are particularly distinguished.

  The protection control device 100 transmits and receives current data via a dedicated power line (hereinafter referred to as a dedicated line) or a general LAN communication (hereinafter referred to as LAN communication), which is a dedicated power transmission path, to prevent system failures in the protected section. Detect and eliminate accidents.

  The current differential protection relay device is a system that combines a protection control device 100A using a power line, a protection control device 100B using a power line and LAN communication, and a protection control device 100C using LAN communication. Built. Here, the protection control device 100A and the protection control device 100B send and receive current data via a power-dedicated transmission path, and the protection control device 100B and the protection control device 100C are in a packet communication transmission mode via LAN communication. Send and receive current data. That is, the protection control device 100A and the protection control device 100B perform transmission control using a conventional dedicated line, and the protection control device 100B and the protection control device 100C perform transmission using LAN communication. The protection control device 100B sends and receives current data using a combination of transmission using only a conventional dedicated line and transmission using LAN communication. If the power communication between the protection control device 100A and the protection control device 100B is the first generation (parent-child) and the power communication between the protection control device 100B and the protection control device 100C is the second generation (child-grandchild), all Sampling synchronization must match between generations (parent-child-grandchild), that is, the protection control device 100A, the protection control device 100B, and the protection control device 100C. In the present embodiment, synchronization correction control for matching sampling synchronization on the LAN communication side with sampling synchronization on the communication side dedicated to power will be described.

  The transmission lines 100A and 100B between the protection control devices of the A terminal and the B terminal are connected by a conventional dedicated line, and the current value of the B terminal is sampled in synchronization with the sampling timing of the current value of the terminal A.

[Protection control device 100A]
The protection control device 100A detects an internal accident occurring in the protection section of the transmission line L1 between the A terminal and the B terminal at high speed, issues a trip command 100k to the circuit breaker CB200, and protects the transmission line L1. To do.

  The protection control device 100A includes an analog input means (AI means) 1, an analog / digital conversion means (A / D conversion means) 2, a timing control means (TIM control means) 3, an arithmetic means 4, an output means 5, and synchronization correction control. Unit 6 and a transmission control unit 10. The AI unit 1 and the A / D conversion unit 2 constitute an input unit that inputs the current of the transmission line L1 and converts it into a digital quantity.

  The transmission control unit 10 includes a receiving unit 10a that receives a dedicated line signal from the other end, a transmitting unit 10b that transmits a dedicated line signal to the other end, and a sampling synchronization control that controls a sampling (SP) synchronization signal. Means (SP synchronization control means) 8, transmission means 10c for overall control of reception means 10a, transmission means 10b, sampling synchronization control means 8, and bi-directional access for data transmission / reception, transmission and reception A memory means 10d for storing data and information necessary for transmission control and a parallel bus 10e in which these are tightly coupled are configured.

  Current transformer CT300 detects the current of power transmission line L1.

  The AI means 1 takes in the current signal 100i of the power system detected by the current transformer CT300 and performs analog signal processing. Although not shown, a transformer for detecting the voltage signal of the power system is connected to the A terminal, and the AI means 1 takes in the voltage signal of the power system detected by the transformer.

  The A / D conversion means 2 converts the input current value of the transmission line L1 into a digital quantity. The A / D conversion start timing (sampling timing) is started by a conversion command signal from the TIM control means 3.

  The TIM control unit 3 determines the sampling timing in the analog input unit 1. The TIM control unit 3 is synchronously corrected by the synchronous correction control unit 6.

  The calculation means 4 performs a protection calculation using the digital quantity from the A / D conversion means 2. Specifically, the calculation means 4 takes in the input signal digitally converted by the A / D conversion means 2 and performs various protection calculations, in particular, a differential calculation for obtaining a difference between the current signals to determine an internal accident. Do. The arithmetic means 4 outputs a circuit breaker trip command signal to the output means 5 when an internal accident is determined.

  The output means 5 outputs a trip command 100k to the circuit breaker CB200 based on the calculation result of the calculation means 4. A series of these operations in the current differential protection relay device is generally repeated every 30 electrical angles.

  The synchronization correction control unit 6 performs synchronization correction that matches the synchronization reference with the SP synchronization signal by LAN communication. Details of the synchronization correction control unit 6 will be described later with reference to FIG.

  The SP synchronization control means 8 extracts a reference signal for sampling synchronization at the terminal B through a dedicated line and outputs the SP synchronization signal to the TIM control means 3 and the synchronization correction control unit 6.

  The transmission control unit 10 is a first communication unit that cyclically transmits and receives data on a dedicated line communication network and adjusts the sampling synchronization timing with the other end. The transmission control unit 10 uses a conventional dedicated line that communicates voltage / current system information with the other end, and performs transmission control using a 1.5 Mbps cyclic transmission method, for example. Here, the transmission control unit 10 cyclically transmits / receives data to / from the transmission control unit 10 of the protection control device 100B through a dedicated line, and performs sampling synchronization timing adjustment with the partner end.

[Protection control device 100B]
The protection control device 100B detects an internal accident occurring in the protection section of the transmission line L1 between the A terminal and the B terminal at a high speed, issues a trip command 100k to the circuit breaker CB200, and protects the transmission line L1. To do.

The protection control device 100B includes an AI unit 1, an A / D conversion unit 2, a TIM control unit 3, a calculation unit 4, an output unit 5, a synchronization correction control unit 6, a LAN communication unit 7, and a transmission control unit 10. Is done.
That is, the protection control device 100B has a configuration in which the LAN communication unit 7 is further added to the configuration of the protection control device 100A.

  The synchronization correction control unit 6 performs synchronization correction that matches the synchronization reference with the SP synchronization signal by LAN communication. That is, the synchronization correction controller 6 performs sampling synchronization correction that matches the sampling synchronization timing of the LAN communication means 7 with the sampling synchronization timing of the transmission controller 10.

  The LAN communication unit 7 is a second communication unit that performs data transmission / reception by cyclically transferring packets over the IP network, and matches the sampling synchronization timing with the other end. The LAN communication means 7 transmits data by cyclically transferring the digital quantity of the AI means 1, receives data cyclically transferred by the packet, and gives it to the arithmetic means 4.

  The LAN communication means 7 is a general LAN communication that transmits transmission data in a packet communication transmission form. The LAN communication means 7 uses an IP network compatible network instead of a power dedicated communication network, and transmits transmission data in a packet communication transmission form.

The LAN communication means 7 is also synchronously corrected by the synchronous correction control unit 6.
Data obtained via the LAN communication means 7 is connected to the arithmetic means 4 via the bus and transmitted in parallel.

  The protection control device 100B has both a route via the transmission control unit 10 using a conventional dedicated line and a route via the LAN communication means 7 as transmission control routes. The transmission control unit 10 is cyclic control, whereas the LAN communication unit 7 is different in that the packet transmission is activated by cyclic transmission. In the present embodiment, either one of the transmission routes is selectively used. However, the transmission routes may be used in parallel or in accordance with the execution status.

[Protection control device 100C]
The protection control device 100C detects an internal accident occurring in the protection section of the transmission line L2 between the B terminal and the C terminal at high speed, issues a trip command 100k to the circuit breaker CB200, and protects the transmission line L2. To do.

  The protection control device 100C has a configuration in which the transmission control unit 10 is omitted from the configuration of the protection control device 100B, that is, the AI unit 1, the A / D conversion unit 2, the TIM control unit 3, the calculation unit 4, the output unit 5, and the synchronization correction. It comprises a control unit 6 and LAN communication means 7.

  Note that the protection control device 100A and the protection control device 100C may have the same configuration as the protection control device 100B. The protection control device 100A may include the LAN communication unit 7, and the protection control device 100C may include the transmission control unit 10. In this case, the protection control device 100A can be operated so as not to use the LAN communication unit 7, and the protection control device 100C may not use the transmission control unit 10. Alternatively, the LAN communication unit 7 or the transmission control unit 10 may be selected and used. If comprised in this way, general-purpose operation will be attained only by preparing one protection control apparatus 100B.

  FIG. 2 is a diagram showing the configuration of the synchronization correction control unit 6 and the TIM control means 3. The same components as those in FIG. 1 are denoted by the same reference numerals.

  As shown in FIG. 2, the synchronization correction control unit 6 includes an SP synchronization time correction unit 61, a LAN communication time correction unit 62, a time correction unit switching unit (selector) 63, a LAN communication oscillator (CLK1) 64, a LAN A communication time counter 65, a synchronization pulse generator 66, and a LAN synchronization controller 67 are provided.

  The TIM control means 3 includes an A / D conversion oscillator (CLK2) 31, an A / D conversion timing counter 32, and an A / D conversion control signal generation unit 33.

  The synchronization correction control unit 6 and the TIM control unit 3 are configured according to whether the protection control device 100 is a master station that transmits data through a conventional dedicated line or LAN communication, or a slave station that receives data from the master station. Combination and function are different. When the protection control device 100 is a main station, the synchronization correction control unit 6 mainly includes an SP synchronization time correction unit 61, a switching means (selector) 63, an oscillator (CLK1) 64, a time counter 65, and a LAN synchronization control unit. A combination of 67 and the TIM control means 3 is used. When the protection control device 100 is a slave station, the LAN communication time correction unit 62, the switching means (selector) 63, the oscillator (CLK1) 64, the time counter 65, the synchronization pulse generation unit 66, and the LAN synchronization control unit 67 A combination is used.

  The SP synchronization time correction unit 61 of the synchronization correction control unit 6 obtains a difference from the value of the time counter 65 at the rise of the SP synchronization signal passed from the SP synchronization control means 8 for every electrical angle of 30 °, for example, and the difference value Only the value of the time counter 65 is adjusted. By adjusting the value of the time counter 65, it is possible to match the reference for sampling synchronization between power-dedicated communication and LAN communication.

  The LAN communication time correction unit 62 corrects the time by subtracting an offset time Toff from the LAN synchronization control unit 67 described later from the value of the time counter 65.

  The selector 63 selects whether the correction of the time counter 65 is performed by the SP synchronization time correction by the SP synchronization time correction unit 61 or the LAN communication time correction by the LAN communication time correction unit 62.

  The LAN communication oscillator (CLK1) 64 outputs a LAN communication clock signal.

  The time counter 65 for LAN communication counts the clock signal of the oscillator (CLK1) 64 and outputs time data to the SP synchronization time correction unit 61, and corrects the count value adjusted by the SP synchronization time correction unit 61. The data is output to the synchronization pulse generator 66 and the LAN synchronization controller 67 as later time data.

  The synchronization pulse generation unit 66 generates a synchronization pulse using the corrected value of the time counter 65 and outputs it to the TIM control means 3.

  The LAN synchronization control unit 67 calculates the offset time Toff and outputs it to the LAN communication time correction unit 62 and the LAN communication means 7. Here, since the LAN synchronization control unit 67 performs the LAN synchronization control based on the corrected time data of the time counter 65, prior to the LAN synchronization control by the LAN synchronization control unit 67, the communication dedicated to power is already performed. And the reference synchronization of LAN communication sampling synchronization have been completed.

  The LAN synchronization control unit 67 synchronizes the sampling of the current value in the protection control device 100 of the corresponding terminal and the sampling in the protection control device 100 of the other corresponding terminals by LAN communication with the LAN communication means 7. be able to.

  On the other hand, the A / D conversion oscillator (CLK2) 31 of the TIM control means 3 outputs an A / D conversion signal.

  The A / D conversion timing counter 32 counts the signal of the CLK2 (oscillator) 31 and resets the counter value to 0 at the rising edge of the pulse signal of the synchronization pulse generator 66.

  The A / D conversion control signal generator 33 outputs a control signal such as an A / D conversion start timing signal to the A / D conversion means 2 according to the value of the A / D conversion timing counter 32.

  Details of operations of the synchronization correction control unit 6 and the TIM control unit 3 will be described later with reference to FIGS. Details of the configuration and operation of the SP synchronization time correction unit 61 will be described later with reference to FIGS.

Hereinafter, the operation of the current differential protection relay device configured as described above will be described.
As shown in FIG. 1, the current differential protection relay device includes a power transmission line L1, L2 between terminals A, B, C, a circuit breaker CB200 and a current transformer installed at each terminal A, B, C. CT300 and protection control apparatus 100A, 100B, 100C are provided.

  The current at each terminal A, B, C is detected by the current transformer CT300, and the current value is converted into digital data by the A / D conversion means 2 via the AI means 1 in the protection control device 100. The current value converted into digital data is transmitted and received by the communication means (reception means 10a and transmission means 10b) of the transmission control unit 10 or the LAN communication means 7, and protection is realized by the current differential principle. At that time, the current value is calculated by the calculation means 4 and a trip command 100k is issued to the circuit breaker CB200 via the output means 5 according to the calculation result.

[A terminal and B terminal protection control devices 100A and 100B]
The transmission line between the protection control devices 100A and 100B of the A terminal and the B terminal is connected by a conventional dedicated line, and the current value of the B terminal is sampled in synchronization with the sampling timing of the current value of the A terminal.

  The SP synchronization control means 8 of the transmission control unit 10 of the protection control apparatus 100B for the B terminal extracts the sampling synchronization reference signal of the terminal A through the dedicated line and outputs the SP synchronization signal. The SP synchronization signal is passed to the TIM control 3 that controls the start timing of the A / D conversion unit 2 and the synchronization correction control unit 6 that corrects the synchronization by the LAN communication unit 7. Here, the synchronization correction control unit 6 uses the LAN communication unit 7 to adjust the synchronization reference to the SP synchronization signal.

[Protection control devices 100B and 100C for B terminal and C terminal]
Transmission paths between the B terminal and C terminal protection control devices 100B and 100C are connected by the LAN communication means 7, and the current value at the C terminal is sampled in synchronization with the sampling timing of the current value at the B terminal.

[Protection control device 100C for C terminal]
The C terminal protection control device 100C uses the LAN communication means 7 to extract the sampling synchronization reference signal at the B terminal by the synchronization correction control section 6, and to the TIM control means 3 that controls the start timing of the A / D conversion means 2. Output sync signal.

  As described above, the synchronization of sampling of the current value from the A terminal to the B terminal is synchronized with the dedicated line, and the B terminal to the C terminal is synchronized with general LAN communication. The B terminal protection control device 100B performs synchronization correction to match the sampling synchronization of general LAN communication with the sampling synchronization of the dedicated line. Thereby, sampling synchronization of the current values of the terminals A, B, and C can be adjusted.

FIG. 3 is a diagram illustrating an example of a communication format dedicated to power of the transmission control unit 10.
The transmission control unit 10 using a dedicated line performs information transmission every period T (generally an electrical angle of 30 °).

In the example of FIG. 3, the period T is divided into 12 frames (12 frames from # 0 to # 11), and one of these frames (for example, # 1) has the frame header FH at the head, and the line Current data (1a, 1b, 1c), I / O information I / O, subcome data (transmitting a plurality of data at a rate of once every several times) and CRC (Cyclic Redundancy Check: (Cyclic Redundancy Check) Information is sequentially inserted and transmitted and received as a unit.
This frame describes a general configuration. For example, the direct grounding system is configured at a transmission rate of 54 kbps, the 50 Hz system is configured with 75 bits per frame, and the 60 Hz system is configured with 90 bits per frame.

  FIG. 4 is a diagram showing a format example of transmission / reception by packet communication of the LAN communication means 7.

  As shown in FIG. 4, the beginning of the packet starts with a preamble (not shown), destination MAC address, source MAC address, header, data (Ia, Ib, Ic current data, I / O data, status, etc.) It consists of a frame check sequence (FCS). This packet is configured so that real-time property can be ensured by repeating from the preamble to the next preamble every period T.

  FIG. 5 is a diagram for explaining the outline of the operation of the method for obtaining sampling synchronization between the terminals using the power-dedicated communication in FIG. FIG. 5 shows a synchronization signal 41 from the slave station to the master station in the transmission control, and a synchronization signal 42 from the master station to the slave station in the transmission control. In the present embodiment, this power-dedicated communication is mainly performed by the SP synchronization control means 8 (see FIG. 2) of the transmission control unit 10.

  In this system, one of the protection control device 100A for the A terminal and the protection control device 100B for the B terminal is the master station, and the others are slave stations. The slave station first transmits a synchronization signal 41 to the master station. The master station obtains a time difference TM from the timing at which the synchronization signal transmitted from the slave station is received from the sampling timing of the own station. The master station transmits the time difference TM obtained above to the slave station.

  The slave station obtains the time difference TS from the timing at which the synchronization signal transmitted from the master station is received from the sampling timing of the own station, and simultaneously reads the sampling time difference TM received from the master station. If the delay time Tdu of data transmitted from the slave station to the master station is equal to the delay time Tdd of data transmitted from the master station to the slave station, the timing difference ΔT between them can be expressed by the following equation (1).

ΔT = (TS−TM) / 2 (1)
The slave station controls the sampling timing so that ΔT in equation (1) becomes 0, and the master station does not control the sampling timing. By repeating the above sampling synchronization control, the sampling of the master station and the slave station can be made substantially the same.

  Next, a sampling synchronization method when transmitting and receiving using packet communication of LAN communication will be described.

  FIG. 6 is a diagram for explaining sampling synchronization of the two-terminal configuration of the master station and the slave station. This synchronization method is a method defined in IEEE1588. In FIG. 6, a transmission packet Sync 51 that is a synchronization start signal from the master station to the slave station in the LAN communication means 7, a transmission packet Follow Up 52 that is a follow-up signal from the master station to the slave station in the LAN communication means 7, and a slave station in the LAN communication means 7. A transmission packet Delay Request 53 that is a delay information transmission request signal to the master station and a transmission packet Delay Response 54 that is a delay information response signal from the master station to the slave station in the LAN communication means 7 are shown. In the present embodiment, this LAN communication is performed between the LAN synchronization control unit 67 (see FIG. 2) of the synchronization correction control unit 6 and the LAN communication means 7.

  First, the master station transmits a transmission packet Sync51 for synchronous control to the slave station. Subsequently, the master station transmits to the slave station the time data t1 at which the transmission packet Sync51 was transmitted included in the next transmission packet Follow Up 52. On the other hand, the slave station confirms the time t0 when the first transmission packet Sync51 is received, and extracts the transmission time data t1 in the next transmission packet Follow Up 52.

  Next, the slave station transmits a transmission packet Delay Request 53 for synchronous control with respect to the master station. At this time, the slave station acquires the transmission time t2. Next, the master station transmits the time t3 at which the transmission packet Delay Request 53 is received on the next transmission packet Delay Response 54 to the slave station.

  Through these series of operations, the slave station can acquire time data at times t0 to t3. From this time data, the sampling timing between the master station and the slave station is calculated by the following equations (2) and (3). It is possible to obtain a delay time Tdx and an offset time Toff for correcting the deviation.

Tdx = ((t1-t0) + (t3-t2)) / 2 (2)
Toff = (t2-t1) -Tdx (3)

  By controlling the offset time Toff to be close to 0 by the above equations (2) and (3), the slave station can control the sampling time to be the same as that of the master station. In this way, sampling synchronization is possible by periodically sending and receiving packets for measuring communication delay time. In addition, sampling synchronization control is possible even when packet transmission / reception is performed irregularly.

  Note that, regarding the sampling synchronization control state, it is necessary to constantly monitor the offset time Toff. For example, by monitoring that the offset time Toff is 1 μs or less, the influence on the current differential calculation is grasped, and if necessary, the device is locked.

  The transmission of current data is performed by packet transfer different from the sampling synchronization control packet.

Next, the operation of the synchronization correction control unit 6 of the protection control device 100 will be described.
7 and 8 are diagrams for explaining the operation of the synchronization correction control unit 6 of FIG. 2, and FIG. 8 shows a signal processing example of the synchronization correction control unit 6 when the protection control device 100 is a slave station. In the figure, the signal flow in the corresponding operation is indicated by thick solid arrows.

  As described above, the protection control device 100A and the protection control device 100B perform transmission control using a conventional dedicated line, and the protection control device 100B and the protection control device 100C perform transmission using LAN communication. The protection control device 100B sends and receives current data using a combination of transmission using only a conventional dedicated line and transmission using LAN communication. Here, sampling synchronization must match between all the protection control devices 100, that is, between the protection control device 100A, the protection control device 100B, and the protection control device 100C. Since the protection control device 100B best shows the characteristics of the present invention in the sampling synchronization control, the operation of the synchronization correction control unit 6 in the protection control device 100B is taken as an example. In FIG. 1, the protection control device 100B is the main station when transmission control is performed with the protection control device 100A using a conventional dedicated line. In particular, control for correcting time data is required based on a sampling synchronization signal in power-only communication. The protection control device 100B becomes a slave station when general LAN communication is performed with the protection control device 100C. In particular, it is necessary to perform time correction by subtracting the offset from the value of the time counter 65.

<Master station>
An operation of the synchronization correction control unit 6 when the protection control device 100B for the terminal B operates as a main station will be described.

  As shown in FIG. 7, the sampling synchronization processing on the dedicated line includes the SP synchronization time correction unit 61, the time correction means switching means (selector) 63, the LAN communication oscillator (CLK1) 64, and the LAN communication time counter 65. This is implemented by a combination of the LAN synchronization control unit 67.

  By the sampling synchronization processing on the dedicated line, the SP synchronization signal is transferred from the SP synchronization control means 8 to the SP synchronization time correction unit 61, for example, every 30 electrical angles. The SP synchronization time correction unit 61 takes in the value of the time counter 65 when the SP synchronization signal rises, and obtains the count value and the difference of the time counter 65 in units of electrical angles of 30 °. The SP synchronization time correction unit 61 can adjust the value of the time counter 65 by the difference value to match the reference for sampling synchronization between the power line and the LAN communication. The details of the configuration and operation of the SP synchronization time correction unit 61 will be described later with reference to FIGS.

  The selector 63 selects whether the correction of the time counter 65 is performed by the SP synchronization time correction by the SP synchronization time correction unit 61 or the LAN communication time correction by the LAN communication time correction unit 62. In this case, since it is the protection control device 100B of the B terminal, the selector 63 selects the output of the SP synchronization time correction unit 61 and corrects the time counter 65 by the SP synchronization time correction.

<Subordinate station>
An operation of the synchronization correction control unit 6 when the protection control device 100B for the terminal C operates as a slave station will be described.

  As shown in FIG. 8, the sampling synchronization processing in the LAN communication means 7 includes a LAN synchronization control unit 67, a LAN communication time correction unit 62, a LAN communication oscillator (CLK1) 64, a time counter 65, and a synchronization pulse generation unit 66. It is carried out in combination.

  The LAN synchronization control in the LAN communication means 7 calculates the offset time Toff and outputs it to the LAN communication time correction unit 62. The LAN communication time correction unit 62 corrects the time by subtracting the offset time Toff from the value of the time counter 65, and samples the current value in the protection control device 100B for the B terminal and protects the terminal C by LAN communication. Sampling in apparatus 100C can be synchronized.

  The selector 63 selects whether the time counter 65 is corrected by SP synchronization time correction by the SP synchronization time correction unit 61 or LAN communication time correction by the LAN communication time correction unit 62. Since the protection control device 100C has a C terminal, the selector 63 selects the LAN communication time correction unit 62 output and corrects the time counter 65 by the LAN communication time correction.

  The synchronization pulse generation unit 66 generates a pulse using the corrected value of the time counter 65 and outputs the pulse to the TIM control unit 3.

  The TIM control unit 3 includes a CLK 2 (oscillator) 31, an A / D conversion timing counter 32, and an A / D conversion control signal generation unit 33. A / D conversion is performed by the rising edge of the pulse signal of the synchronization pulse generation unit 66. The value of the timing counter 32 is reset to 0. The A / D conversion control signal generator 33 outputs a control signal such as an A / D conversion start timing signal to the A / D conversion means 2 according to the value of the A / D conversion timing counter 32.

  By reflecting the synchronization timing of the dedicated line and the LAN communication in the control signal for the A / D conversion means 2 described above, the sampling of the current values for the terminals A, B, and C can be synchronized.

  FIG. 9 is a diagram showing a configuration of the SP synchronization time correction unit 61. FIG. 10 is a diagram illustrating an example of a time chart of SP synchronization time correction of the SP synchronization time correction unit 61 in FIG.

  As shown in FIG. 9, the SP synchronization time correction unit 61 includes a time data fetch circuit 61a, a time data correction circuit 61b, a correction value switching timing generation unit 61c, a correction value switching selector 61d, and a time correction value register 61e during SP synchronization. And a time data switching selector 61f.

  The time data capturing circuit 61a at the time of SP synchronization captures time data at the rising edge of the SP synchronization signal waveform (see FIG. 10).

  The time data correction circuit 61b performs time data correction that adds a time corresponding to an electrical angle of 30 ° to the time data acquired by the time data acquisition circuit 61a. As a result, time data corresponding to the SP synchronization signal after 30 electrical degrees is prepared next time.

  The correction value switching timing generator 61c generates a timing signal for switching the time data prepared by the time data correction circuit 61b. The timing for switching the time data is the time when the current time data is compared with the time data captured at the rise of the SP synchronization signal waveform, and the electrical angle has advanced to 15 °, which is half the electrical angle of 30 ° from the rise of the SP synchronization signal waveform. The correction value switching timing generator 61c outputs a switching pulse signal. Thereby, the correction range can be shifted from an electrical angle of 0 to 30 ° to an electrical angle of ± 15 °.

  The correction value switching selector 61d updates the value of the time correction value register 61e with the switching pulse signal.

  The time correction value register 61e stores a time correction value when the SP synchronization signal is generated.

  The time data switching selector 61f selectively outputs the time data or the time corrected time data stored in the time correction value register 61e. The time data switching selector 61f selects time data whose time has been corrected when the SP synchronization signal is generated.

  FIG. 10A is a time chart of SP synchronization time correction in which the SP synchronization signal and time data are synchronized.

  As shown in FIG. 10A, when the SP synchronization signal and time data are synchronized, the correction value when the SP synchronization signal is at the H level and the value of the time counter 65 are the same.

FIG. 10B is a time chart during time correction.
As shown in FIG. 10B, when the SP synchronization signal and the time data are not synchronized, the correction value and the time data do not match when the SP synchronization signal is at the H level. However, it is possible to match the correction value by selecting the time data after the time correction.

  As described above, the current differential protection relay device according to the present embodiment includes the power transmission lines L1 and L2 disposed between the terminals A, B, and C, the protection control devices 100A, 100B, and 100C, It has circuit breaker CB200 which protects electric wires L1, L2, and current transformer CT300 which detects the current of each terminal A, B, C. The protection control device 100 includes an AI unit 1, an A / D conversion unit 2, a TIM control unit 3, a calculation unit 4, an output unit 5, a synchronization correction control unit 6, a LAN communication unit 7, and a transmission control unit 10. The transmission control unit 10 cyclically transmits and receives data through the dedicated line communication network, and performs sampling synchronization timing adjustment with the partner end. The LAN communication means 7 transmits / receives data by cyclically transferring packets over the Internet protocol communication network, and performs sampling synchronization timing adjustment with the other end. Further, the synchronization correction control unit 6 performs sampling synchronization correction that matches the sampling synchronization timing of the LAN communication unit 7 with the sampling synchronization timing of the transmission control unit 10.

  With this configuration, the sampling of the current values of the power transmission lines L1 and L2 for the terminals A, B, and C is synchronized among all the protection control devices of the protection control device 100A, the protection control device 100B, and the protection control device 100C. Can do. According to the protection control device of the present invention, a current obtained by combining a protection control device using general LAN communication in which high-speed and large-capacity and cost reduction have advanced with respect to a conventional protection control device using power-only communication. A differential protection relay device can be constructed. Moreover, the communication equipment for exclusive use of the existing electric power can be used, and communication equipment cost can be saved.

  Here, for example, in FIG. 1, the protection control device 100B includes different communication means, that is, a transmission control unit 10 and a LAN communication means 7 that use a conventional dedicated line. The parallel configuration of the communication means 7 is not characteristic in itself. There is no need for a control that always operates and switches both communication means. As shown in FIG. 1, the present embodiment includes a protection control device 100A using only a dedicated line, a protection control device 100B using a dedicated line and LAN communication, a protection control device 100C using only LAN communication, Is a current differential protection relay system that combines the protection control devices 100A to 100C. By matching the sampling synchronization between a series of protection control devices ranging from the protection control device 100C to the protection control device 100C, a current differential that combines the protection control devices. It is characterized by constructing a protective relay system.

  The present invention is not limited to the above-described embodiments, and includes other modifications and application examples without departing from the gist of the present invention described in the claims.

  For example, although a three-terminal configuration has been described, a two-terminal configuration may be used.

  Further, the above-described exemplary embodiments have been described in detail for easy understanding of the present invention, and are not necessarily limited to those having all the configurations described. Further, a part of the configuration of an embodiment can be replaced with the configuration of another embodiment, and the configuration of another embodiment can be added to the configuration of an embodiment. . Further, it is possible to add, delete, and replace other configurations for a part of the configuration of each exemplary embodiment.

  Each of the above-described configurations, functions, processing units, processing means, and the like may be realized by hardware by designing a part or all of them with, for example, an integrated circuit. Further, as shown in FIGS. 1 and 5, the above-described configurations, functions, and the like may be realized by software for interpreting and executing a program that realizes each function by the processor. Information such as programs, tables, and files for realizing each function is stored in a memory, a hard disk, a recording device such as an SSD (Solid State Drive), an IC (Integrated Circuit) card, an SD (Secure Digital) card, an optical disk, etc. It can be held on a recording medium. Further, in this specification, the processing steps describing time-series processing are not limited to processing performed in time series according to the described order, but are not necessarily performed in time series, either in parallel or individually. The processing (for example, parallel processing or object processing) is also included.

  In addition, the control lines and information lines are those that are considered necessary for the explanation, and not all the control lines and information lines on the product are necessarily shown. Actually, it may be considered that almost all the components are connected to each other.

1 Analog input means (AI means)
2 Analog / digital conversion means (A / D conversion means)
3 Timing control means (TIM control means)
4 arithmetic means 5 output means 6 synchronization correction control section 7 LAN communication means 8 sampling synchronization control means (SP synchronization control means)
DESCRIPTION OF SYMBOLS 10 Transmission control part 31 Oscillator for A / D conversion 32 A / D conversion timing counter 33 A / D conversion control signal generation part 61 SP synchronous time correction part 62 LAN communication time correction part 63 Switching means (selector)
64 Oscillator 65 Time counter 66 Synchronization pulse generator 67 LAN synchronization controller 100, 100A, 100B, 100C Protection controller CB200 Breaker CT300 Current transformer

Claims (7)

An input unit for inputting the current of the transmission line and converting it into a digital quantity;
A timing control unit for determining a sampling timing in the input unit;
A calculation unit that performs a protection calculation using a digital quantity from the input unit;
An output unit for supplying a control signal for a circuit breaker provided in the power transmission line according to a calculation result of the calculation unit;
A first communication unit that cyclically transmits / receives data in the dedicated line communication network and matches the sampling synchronization timing with the other end, and transmits / receives data by cyclically transferring packets in the Internet protocol communication network, At least one communication unit of the second communication unit that performs the sampling synchronization timing adjustment,
A synchronization correction control unit that performs sampling synchronization correction between different types of communication units when the first communication unit and the second communication unit are provided;
A protection control device comprising: The first communication unit and the second communication unit;
The protection control apparatus according to claim 1, wherein the synchronization correction control unit performs sampling synchronization correction that matches the sampling synchronization timing of the second communication unit with the sampling synchronization timing of the first communication unit. The first communication unit and the second communication unit;
The protection control device according to claim 1, wherein the first communication unit and the second communication unit have a serial connection configuration. The first communication unit and the second communication unit;
The protection control apparatus according to claim 1, wherein the second communication unit is LAN communication. The first communication unit and the second communication unit;
The first communication unit performs synchronous correction on the sampling timing of the communication partner end,
The protection according to any one of claims 1 to 4, wherein the second communication unit transmits the sampling timing corrected by the first communication unit to a communication partner end different from the communication partner end. Control device. The synchronization correction control unit counts a signal for LAN communication and outputs time data; and
A sampling synchronization time correction unit that adjusts the value of the time counter based on a sampling synchronization signal in the dedicated line communication;
A LAN synchronization control unit that performs LAN communication synchronization control with the second communication unit based on the time data corrected by the sampling synchronization time correction unit;
The protection control device according to claim 1, further comprising: a LAN communication time correction unit that performs time correction by subtracting an offset from a value of the time counter. An input unit for inputting the current of the transmission line and converting it into a digital quantity;
A timing control unit for determining a sampling timing in the input unit;
A calculation unit that performs a protection calculation using a digital quantity from the input unit;
An output unit for supplying a control signal for a circuit breaker provided in the power transmission line according to a calculation result of the calculation unit;
A first communication unit that cyclically transmits / receives data in the dedicated line communication network and matches the sampling synchronization timing with the other end, and transmits / receives data by cyclically transferring packets in the Internet protocol communication network At least one communication unit of the second communication unit that performs the sampling synchronization timing adjustment,
A synchronization correction control unit that performs sampling synchronization correction between different types of communication units when the first communication unit and the second communication unit are provided, and a protection control device including each of the terminals of the power transmission line, The arithmetic operation unit obtains a difference between currents detected at each terminal, and the current differential protection relay device.

Images