JP5663267B2 - Protection relay system and protection relay device - Google Patents

Description

  The present invention relates to a protection relay system and a protection relay device using transmission.

  For faults that occur in the power system, so-called short-circuits, ground faults, etc., protective relay devices installed for each element such as transmission lines, transformers, buses, and generators that form the power system are within the defensive range. The fault is removed by disconnecting the section including the fault point from the remaining healthy power system by tripping the circuit breaker. In the technical field of such a power system protection relay device, it is necessary to refer to information on the amount of electricity at the same time at a plurality of points, so it is necessary to synchronize the sampling time of the amount of electricity at each point.

  As a synchronization method, for example, there is a method described in Patent Document 1. This Patent Document 1 discloses a method of transmitting and receiving a transmission frame including a transmission time in electrical quantity information between protection relay devices, calculating a deviation from the transmission time and reception time of the frame, and performing synchronization.

JP 2007-306739 A

IEEE Std 1588-2002, “IEEE Standard for a Precision Clock Synchronization Protocol for Networked Measurement and Control Systems”

  On the other hand, a time synchronization protocol defined in Non-Patent Document 1 is known as a method of exchanging time information with a reference time source via transmission and synchronizing each local clock. IEEE 1588 known from Non-Patent Document 1 is a technology that handles time in nanosecond units and enables synchronization in nanosecond units. In IEEE 1588, by exchanging time information, a transmission delay between the local clock and the reference time source and a time shift indicating a relative time difference can be obtained.

In the IEEE 1588 standard, the following items are defined.
(A) The reference time source is called the master, and the side that sets the time to the master is called the slave.
(B) Four types of synchronization frames are exchanged: Sync from master to slave, Follow Up from master to slave, Delay Req from slave to master, and Delay Resp from master to slave.
(C) Sync transmission time t1, Sync reception time t2, Delay Req transmission time t3, Delay Req reception time t4.
(D) When t1 to t4 are used, the transmission delay t can be calculated by the following formula (1), and the master time difference d seen from the slave can be calculated by the formula (2).
[Equation 1]
t = {(t4-t3) + (t2-t1)} / 2 (1)
[Equation 2]
d = {(t4-t3)-(t2-t1)} / 2 (2)
(E) The transmission time and reception time are the time points of SFD (start frame delimiter) indicating the end of the preamble and the start of data.

  Here, when it is considered to apply the communication technology of IEEE 1588 to the protection relay device in a practical form, there are some problems to be solved. For example, when applied to the method described in Patent Document 1, transmission information, for example, electric quantity information is attached with a synchronization signal in order to perform a function as a protection relay device. When a signal is required, synchronization is delayed or the timing of synchronization becomes complicated. Moreover, there is a possibility that a situation such as a collision of packets of the plurality of transmission information occurs.

  In order to solve the above-described problems, in the present invention, when using both IEEE 1588 technology and protection relay technology in combination, the timing of synchronization is controlled, and high-precision sampling synchronization is achieved without any trouble such as packet collision. It aims at providing the protection relay system and protection relay apparatus which implement | achieve.

  The above-mentioned problem is that a relay that detects a power system fault from the system current information transmitted between the units, each unit of the power system having a unit that samples system current information for each predetermined electrical angle from the power system. In the protection relay system that performs computation, the plurality of units divide the predetermined electrical angle period into a plurality of slots for each data to be transmitted, and at least the system current information is stored in the plurality of slots. The protection relay system includes a first slot transmitted between the plurality of units and a second slot in which a synchronization signal at the sampling time is transmitted.

  According to the present invention, when both of the protection relay technologies are used for connection using the IEEE 1588 technology, the synchronization timing can be controlled, and high-precision sampling synchronization can be realized without any trouble such as packet collision.

The figure which shows the whole structure at the time of applying this invention apparatus to 4 terminal power transmission system. The figure which shows the structural example of the master unit M. FIG. The figure which shows the structural example of slave unit SB. The figure which shows the time chart which shows operation | movement between the master unit M, the slave unit SB, and a transmission line. The figure which shows the time chart which shows the operation | movement between the master unit M, the slave unit SB, and the transmission line at the time of the big synchronization shift | offset | difference. The figure explaining the sampling synchronous system in the case of transmitting / receiving by packet communication. The structure of a packet containing large synchronization loss occurrence information. The figure which shows the structural example of the time synchronizer 280 which aims at time synchronization. The figure which shows the structural example of the period generation part 290. FIG. The figure which shows the time chart which shows the operation | movement of the period production | generation part 290. FIG.

  Embodiments of the present invention will be described below with reference to the drawings.

  The protection relay device of the present invention can be applied to a device or a power transmission system that protects a device to be protected by using transmission. Specifically, the protection relay device is applied to a digital differential protection relay device that performs protection based on a differential principle. Is good. In particular, the present invention is applied to the multi-terminal power transmission system of FIG. 1 because the effect of the present invention is considered to be greater when the electrical quantity measurement point is far away and the number of devices is large. The case where it does is demonstrated.

  FIG. 1 shows an overall configuration when the device of the present invention is applied to a four-terminal power transmission system. This power transmission system includes three power transmission lines L1, L2, and L3 provided between four terminals A, B, C, and D. Each terminal A, B, C, D is provided with a circuit breaker CB and a current transformer CT. Then, the current transformer CT detects the current at each terminal, and gives an on / off command signal to the circuit breaker CB.

  A master unit M is installed at the terminal A, and a slave unit S is installed at the terminals B, C, and D. Transmission paths 161, 162, and 163 are provided between the master unit M and the slave units SB, SC, and SD. This transmission path is not an expensive dedicated transmission line but uses inexpensive high-speed general-purpose transmission such as Ethernet (registered trademark) and packet transmission control by a real-time OS.

  Each terminal unit takes in the current I at that terminal and the contact point information X of the circuit breaker CB. Further, in the slave units SB, SC, SD, these information are transferred to the master unit via the transmission lines 161, 162, 163. Send to M. In the master unit M, differential calculation is performed using the current information I from each terminal, and finally a trip command X is given from each unit to the breaker of each terminal. In FIG. 1, for convenience of description, the contact information and the trip command are also represented by the symbol X.

  Thus, it becomes possible to configure a current differential protection relay device for power transmission line protection by arranging the master / slave unit corresponding to each terminal of the power transmission line and connecting between them by the transmission line. .

  Here, there are two meanings when the unit of terminal A is called a master and the unit of other terminals is called a slave. One meaning is that it represents a side (master) that transmits a time signal in conformity with the IEEE 1588 standard and a side (slave) that receives the time signal and corrects the time (slave).

  Another reason is that slot processing will be described later with reference to FIG. 4, but in order to simplify this description, only the terminal A performs a protection relay operation, and the other terminals perform transfer blocking according to the determination. This is because it is most suitable to carry out the embodiment. The relationship between the terminals at this time was suitable for calling the master / slave. Accordingly, it is possible in the present invention to exchange current information with each other and to determine an accident in each terminal. In this case, for this reason, it is called a master / slave. Is not appropriate.

  The slave unit SB is provided with a display unit 150, which outputs display information 151. The display unit 150 displays various information in a form that can be recognized by humans based on the display information 151. The display unit 150 may be realized by a substrate using a liquid crystal display (LCD) or the like, or the display information 151 may be an HTML file, and the display unit 150 may be displayed on a general-purpose web browser as a personal computer. Is possible. These display units 150 can be provided in other units as appropriate.

  Next, a sampling synchronization method when transmitting and receiving by packet communication will be described with reference to FIG. FIG. 6 describes the sampling synchronization of the two-terminal configuration of the master unit M and the slave unit S. This figure is a time chart in which time passes downward. This synchronization method is a method defined in IEEE 1588, and only an outline of the operation will be described.

  First, the master unit M transmits a transmission packet 61 (usually referred to as Sync) for synchronous control to the slave unit S. Subsequently, the master unit M transmits the time data t2t1 at which the signal 61 (Sync) is transmitted to the slave unit S in the next transmission packet 62 (usually referred to as Follow Up). On the other hand, the slave unit S confirms the time t1t2 when the first transmission packet 61 (Sync) is received, and extracts the transmission time data t2t1 in the next transmission packet 4d62 (Follow Up).

  Next, the slave unit S transmits a transmission packet 63 (usually referred to as “Delay Request”) for synchronous control with respect to the master unit M. At this time, the slave unit S acquires the transmitted time t3. Next, the master unit M transmits the time t4 at which the transmission packet 63 (Dlay Request) is received to the slave unit S on the next transmission packet 64 (usually referred to as Delay Response).

  Through these series of operations, the slave unit S can acquire the time data of t1 to t4, and the master unit can be obtained from the time data by the calculations shown in the equations (1) and (2) described above. A delay time t, an offset time, and d, which are data for correcting a sampling timing shift between M and the slave unit S, can be obtained.

  From the above formulas (1) and (2), the slave unit S can be controlled so that the sampling time is the same as that of the master unit M by controlling the delay time t to be close to zero. In this way, it is possible to send and receive packets that periodically measure communication delay times. Of course, it is necessary to constantly monitor the delay time t regarding the state of the sampling synchronization control. For example, by monitoring that the offset is 1 μs or less, the influence on the current differential calculation is grasped. If necessary, lock the device.

  FIG. 2 shows a configuration example of the master unit M. The master unit M includes a CPU 210, a contact control unit 220, an A / D conversion unit 230, a protocol control unit 240, a reception unit 251, 252, 253, a transmission unit 260, a physical layer 271, 272, 273, a time synchronization unit 280, a cycle. A generation unit 290 is provided.

  The A / D converter 230 receives the terminal current IA obtained from the current transformer CT of the terminal A, samples this, and converts it into digital electric quantity data. Further, the contact control unit 220 inputs the contact state information X of the circuit breaker CB of the terminal A. These digital electric quantity data and contact state information are exchanged with the CPU 210 through the CPU bus 211 and further passed to the protocol control unit 240.

  The protocol control unit 240 creates a data structure of various frames, outputs the transmission protocol data 241 to the transmission unit 260, and inputs the reception protocol data 254, 255, and 256 from the reception units 251, 252, and 253. Receiving units 251, 252, and 253 are receiving units for signals from slave units SB, SC, and SD, respectively.

  The transmission unit 260 outputs transmission data 261 to the slave units SB, SC, SD via the physical layers 271, 272, 273, and the reception units 251, 252, 253 receive data from the slave units SB, SC, SD. 274, 275, 276 are input. The physical layers 271, 272, and 273 perform conversion to electric signals that can be transmitted, and perform transmission through the transmission lines 161, 162, and 163.

  The time synchronizer 280 will be described later with reference to FIG. 9, but the time synchronizer 280 of the master unit M may self-oscillate and give a signal 281. In many cases, self-oscillation determined by a multiple of the frequency of the AC electric quantity is performed.

  The cycle generator 290 generates a cycle start signal 291 using the signal 281 from the time synchronizer 280 and determines the sampling timing of the A / D converter 230.

  FIG. 3 shows a configuration example of the slave unit SB of FIG. The slave unit SB is different from the master unit M of FIG. 1 in that a time synchronization unit 280 and a path for outputting the display information 151 from the CPU bus 211 are added. It is. The slave units SC and SD in FIG. 2 have the same configuration as the slave unit SB.

  In the slave unit SB of FIG. 3, the time synchronization unit 280 receives the reception timing 259 from the reception unit 251, the transmission timing 262 from the transmission unit 260, and the protocol information 242 from the protocol control unit 240. Based on these, the reception time and transmission time of the synchronization packet defined in IEEE 1588 are created / held, and from there, the transmission delay t, the master unit, and the master unit according to the calculations of Equations (1) and (2) defined in IEEE 1588 The time difference d of the slave unit is calculated. The transmission delay t and the time lag d are connected to the CPU bus 211 and can be read out by the CPU 210.

  Further, the time synchronization unit 280 creates the current time 281 and gives it to the cycle generation unit 290. As described above, the cycle generation unit 290 of the master unit shown in FIG. 2 determines the sampling timing by oscillating at a cycle determined within itself, and the cycle generation unit 290 of the slave unit shown in FIG. The sampling timing is determined according to the current time 281 given by Furthermore, since the time synchronization unit 280 creates the current time 281 reflecting the transmission delay t and the time difference d between the master unit and the slave unit, the sampling timing is synchronized as a result.

  The reception timing 259 and the transmission timing 262 indicate the timing of SFD (start frame delimiter) indicating the end of the preamble and the start of data defined by IEEE 1588.

  As described above, FIG. 1 shows an example of the protection target to which the present invention is applied and the devices included in each terminal, FIG. 2 shows a configuration example of the master unit M, and FIG. 3 shows a configuration example of the slave unit SB. . Using these devices, in the present invention, the measured amount of electricity is transmitted, the protection relay calculation is executed, and the circuit breaker is instructed to be tripped. It explains using.

  FIG. 4 is a time chart showing the overall operation of the apparatus of the present invention. In this time chart, the horizontal axis indicates a time period obtained by dividing the electrical angle of 60 degrees of the AC electricity quantity of the power system into 16 slots. These slots are referred to as slot 0 to slot 15, respectively. Since the electrical angle of 60 degrees is 3.333 milliseconds for the 50 Hz system and 2.777 milliseconds for the 60 Hz system, the unit slot length is 1/16 of the length. In the 50 Hz system, it becomes 200.8208.3 microseconds and in the 60 Hz system 173.6 microseconds.

  The vertical axis of the figure shows each part in the master unit M, each part in the transmission path 161, and the slave unit SB. As a result, according to FIG. You can understand if you are doing. In this figure, only the operation of the slave unit SB is shown on behalf of the slave unit. However, the other slave units SC and SD are operating in the same way at the same time as the slave unit SB. Not too long.

  In explaining the operation in each slot of FIG. 4, the protection relay function part as the protection relay apparatus, the information collection function part for collecting the current information necessary for the protection relay apparatus, and the like, and the transmission Since there is a synchronization function portion that performs sampling synchronization, and is shown in FIG. 4, it will be described below in the order of this function.

  First, regarding the protection relay function part, according to this figure, in the A / D conversion unit 230 of the master unit M and the slave unit SB, the period from slot 1 to slot 7 and the period from slot 9 to slot 15 are shown. , A / D conversion is performed. Although not shown in this figure, sampling of the electric power system current is performed at the beginning of this period.

  The CPU 210 of the master unit M and the slave unit SB determines that the digital electric quantity value converted in the period from slot 1 to slot 7 is the slot 8 and the digital electric quantity value converted in the period from slot 9 to slot 15 is In slot 0 of the cycle, a reading process from the A / D conversion unit 230 to the CPU 210 is performed.

  Using this digital electric quantity value, each CPU 210 performs a filter operation in the following three slots (slot 1-3 or slot 9-11). The operations of both CPUs 210 so far are the same, but in the subsequent three slots (slot 4-6 or slot 12-14), the CPU 210 of the master unit M performs a protection relay operation, whereas the slave unit SB The CPU 210 does not perform this protection relay calculation. Thereafter, both CPUs 210 execute this repetition process every 8 slots.

  The above is the protection relay function part among the function parts to be described in FIG. In this state, information such as the other terminal current required for the protection relay device to perform the differential principle calculation is not supplied to the master unit M. It is only explained that the detected current at the terminal is obtained in the unit.

  For this reason, the information collection function part for collecting current information and the like necessary for the protection relay device by transmission will be described next. In this case, the necessary information is the detected current I at each terminal and the contact information X of each terminal breaker CB, but since they are processed in different time slots, they will be described sequentially in this order.

  As will be apparent from the following description, the slave unit S collects current information and provides data to the master unit M after the filter calculation, and accepts the result of the protection relay calculation in the master unit M. Perform breaker operation.

  Hereinafter, the flow of current information in the information collection function part will be described. In FIG. 4, the flow of current information is shown as a path P1. At this stage, the current information is held as a filter-calculated value. First, the CPU 210 of the slave unit SB sends the filter calculation result to the protocol control unit 240 in the slot 5 after the filter calculation period of the slot 1-3. hand over.

  The filter calculation result shifted to the protocol control unit 240 of the slave unit SB is transmitted as an analog value on the transmission line 161 via the transmission unit 260 of the slave unit SB in the slots 9 and 10. The receiving unit 251 of the master unit M receives the filter calculation result from the slave unit SB in the slots 9 and 10 at this timing. The analog value transmission received by the receiving unit 251 of the master unit M is read by the CPU 210 of the master unit M at the slot 0 of the next cycle via the protocol control unit 240 and used for the protection relay calculation.

  Although the current transmission path P1 has been described above, again, the slave unit SB read out by the CPU 210 of the master unit M and used for the protection relay calculation in the slot 0 having an electrical angle of 60 degrees in FIG. Is obtained by the flow of the current path P1 starting from the slot 5 having the previous electrical angle of 60 degrees, and further going further, the slot 9 having the previous electrical angle of 60 degrees is obtained. The result is A / D conversion in the slave unit SB at -15. In this way, it is used for the protective relay calculation only after 90 degrees or more have elapsed from the actual sampling time.

  Here, the current transmission path P1 is shown. This is shown as a route for the A / D converted data to finally reach the CPU of the master unit via each part such as a CPU. In other words, this is a series of data in the meantime. It can be said that the plurality of work procedures are divided into several parts and assigned to work in each slot for each divided procedure. For example, the processing content of slot 5 is a work procedure for transferring data from the CPU to the protocol control unit, and slots 9 and 10 are a work procedure for transferring current information from the slave unit to the master unit.

  The idea of dividing this series of work procedures into several parts and allocating them to each slot as appropriate is based on the same idea in the processing of other paths or synchronization functions described below. Yes.

  Further, there is another current transmission path P1 (not shown) within the time range of 60 electrical angles in FIG. This is a path from the slot 12 after the slot 9-11 where the filter operation is performed to the start point to the time when the CPU 210 of the master unit M reads the data in the slot 8 of the next time slot with an electrical angle of 60 degrees.

  Specifically, the electric quantity value read in the slot 8 by the CPU 210 of the slave unit SB is filtered and passed to the protocol control unit 240 in the slot 13, and transmitted to the slave unit SB in the slots 1 and 2 in the next cycle. The analog value is transmitted by the transmission 161 via the unit 260. Further, the analog value transmission received by the receiving unit 251 of the master unit M in the slots 1 and 2 of the next cycle is read to the CPU 210 of the master unit M in the slot 8 via the protocol control unit 240.

  From this, it can be understood that the current is taken in at intervals of 30 degrees, and is only provided for the protection relay calculation after a time of about 90 degrees has passed for the A / D conversion, the filtering process, and the transmission process. In this way, the digital electricity quantity acquired by the master unit M and the slave unit S can be collected in the CPU 210 of the master unit M.

  Next, the flow of contact information in the information collection function part will be described. In FIG. 4, the flow of contact information is shown as a path P2 and a path P3. The path P2 is when the contact information is transmitted from the slave unit S to the master unit M, and the path P3 is the time when the contact information is transmitted from the master unit M to the slave unit S.

  First, in the path P2 from the slave unit S to the master unit M, the contact information fetched into the contact control unit 220 in the slot 0 of the slave unit S is obtained from the contact control unit 220 of the slave unit SB and the slave unit SB in the slot 4. The data is transferred to the transmission unit 260, the transmission 161, the reception unit 251 of the master unit M, and the contact control unit 220 of the master unit M, and read to the CPU 210 of the master unit M in slot 8. This path also exists between slot 8 and slot 0 of the next cycle, but the description thereof is omitted here.

  On the contrary, the path P3 for transmitting contact information from the master unit M to the slave unit S is, in the slot 12, the contact control unit 220 of the master unit M, the transmission unit 260 of the master unit M, the transmission 161, and the reception of the slave unit SB. 251 and the contact control unit 220 of the slave unit SB, and read by the CPU 210 of the slave unit SB at slot 0 of the next cycle. This path also exists between slot 0 and slot 8, but the description thereof is omitted here.

  In this way, contact information between the master unit M and the slave unit S is exchanged. In particular, the path P3 for transmitting contact information from the master unit M to the slave unit S may include a trip signal for the circuit breaker CB on the slave unit S side, which is a protection relay calculation of the CPU 210 in the slot 4-6. This result is transferred to the contact control unit 220 in the slot 8 and sent to the slave unit S side through the path P3 described above, and the CPU 210 recognizes it in the slot 0 of the next cycle. The shut-off operation on the master unit M side may be performed in the slot 8 prior to the shut-off operation on the slave unit S side, or may be performed in the slot 0 of the next cycle in accordance with the shut-off operation on the slave unit S side. It may be. As described above, the information collection function part that collects current information and the like necessary for the protection relay device by transmission through the paths P1, P2, and P3 has been described with reference to FIG.

  Finally, a synchronization function part that performs sampling synchronization by transmission will be described. This process is performed using slots 6 and 14 in FIG. In slot 6, the route from the protocol control unit 240 of the master unit M to the transmission unit 260 of the master unit M, the transmission 161, the reception unit 251 of the slave unit SB, and the protocol control unit 240 of the slave unit SB is first defined by IEEE 1588. SYNC packet transmitted, and then a Follow Up packet is transmitted. In this case, transmission from the master unit M to the slave units SB, SC, SD is carried out in the form of so-called broadcast communication for all.

  Further, in the slot 14, the route is a protocol control unit 240 of the slave unit SB, a transmission unit 260 of the slave unit SB, a transmission 161, a reception unit 251 of the master unit M1, and a protocol control unit 240 of the master unit M, and is defined by IEEE 1588. Transmit Delay Req packet. Transmission from the slave unit in this case is performed individually from each slave unit toward the master unit M. Therefore, individual transmission from the three slave units is performed within the slot 14 period.

  Subsequently, the response Delay Resp packet in the slot 14 is transmitted from the protocol control unit 240 of the master unit M to the transmission unit 260 of the master unit M, the transmission 161, the reception unit 251 of the slave unit SB, and the protocol control unit 240 of the slave unit SB. Is transmitted on the route. In this case, transmission from the master unit M to the slave units SB, SC, SD is performed with different contents for each slave unit. Accordingly, a total of six individual transmissions are performed within the period of the slot 14 including the Delay Req packet. In the slave units SB, SC, SD that have received the Delay Resp packet from the master unit M, the sampling timing shift is calculated, and the sampling time is corrected so as to eliminate the shift.

  Thus, in the present invention, the IEEE 1588 SYNC and Follow Up packets are transmitted in the first half period up to the slot 0-7, and the IEEE 1588 Delay Req and Delay Resp packets are transmitted in the second half period up to the slot 8-15. By distributing the functions to each other, the function as a protection relay device and the function of synchronization can be efficiently used separately.

  As described above, mainly using FIG. 4, a protection relay function part as a protection relay apparatus within this period, an information collection function part for collecting current information, contact information, etc. required by the protection relay apparatus by transmission, It has been described that the synchronization function portion that performs sampling synchronization by transmission is executed. According to the present invention, when transmission of electrical quantity data, contact information, synchronization packets, and the like is performed in this way, periodic transmission is performed between different pieces of information by assigning slots to be transmitted in advance. It is possible to transmit without causing a collision.

  In addition, FIG. 4 shows a time chart in the case of the transfer cut-off method for the purpose of simple explanation, but this is to configure the device so that each terminal transmits current to each other and makes an accident judgment for each terminal. Is also possible. In this case, if the slots shown in FIG. 4 are divided more finely (the number of slots is increased), and the flow of signal exchange between terminals and between devices in the terminals is assigned to each slot without omission. Good. In other words, the number of slots into which a predetermined electrical angle period is divided may be determined according to the number of procedures of each function.

  FIG. 8 shows a time synchronization unit 280 installed in the slave unit SB as a configuration example of the time synchronization unit 280 that performs time synchronization based on the theory of FIG. 6 in the present invention. The time synchronization unit 280 includes an adder 50, a current time register 51, a reception time register 54, a transmission time register 55, a transmission delay / time shift calculation circuit 56, a transmission delay register 57, and a time shift register 58.

  During the normal time, the adder 50 adds the operating frequency time (for example, 40 ns for 25 MHz and 0x28 in hexadecimal) to the current time 281 output from the current time register 51 via the added value 592. The current time register 51 is updated every cycle.

  On the other hand, the reception time register 54 and the transmission time register 55 receive two types of signals. One of them is a signal of reception timing 259 and transmission timing 262 coming from the reception unit 251 and the transmission unit 260. The current time which is another input signal is input and held according to the reception time of the timing signal, and the reception time 541 is received. , And stored as transmission time 551.

  The transmission delay / time shift calculation circuit 56 receives the reception time 541 and the transmission time 551 which are the outputs of the reception time register 54 and the transmission time register 55, receives the protocol information 242 from the protocol control unit 24, and based on that, the IEEE 1588. The transmission delay t and the time shift d are calculated based on the formulas (1) and (2) defined in (1) and output to the transmission delay register 57 and the time shift register 58. The transmission delay register 57 and the time shift register 58 hold / output the transmission delay t and the time shift d. Further, a time correction signal 563 is created, and the current time is corrected by adding the time shift d by the adder 50 via the added value 592.

  FIG. 8 shows the circuit configuration of the time synchronization unit 280 of the slave unit SB. However, in the circuit configuration of the time synchronization unit 280 of the other slave unit S, the reception unit and the transmission unit 260 in the own unit A circuit may be configured similarly by inputting a signal.

  In addition, the time synchronization unit 280 of the master unit M has been described above as long as self-oscillation is required. However, as a specific circuit configuration, only the adder 50 and the current time register 51 in the circuit of FIG. And the operation frequency time “0x28” may be used as the added value 592. The time synchronization unit 280 of the master unit M does not require other circuits.

  FIG. 9 shows a configuration example of the cycle generation unit 290 of the slave unit SB. The cycle generation unit 290 includes an adder 61, a cycle end time register 62, and a comparator 63. Here, the cycle end time 621 output from the cycle end time register 62 is compared with the current time 281 defined in FIG. 6. If the current time 281 exceeds the cycle end time 621, the cycle start signal 291 is asserted. At this time, the cycle end time 621 and the cycle time 601 are added, and the next cycle end time is stored in the cycle end time register 62.

  For example, if the electrical time is a value of 60 degrees, the cycle time 61 is 33333333 ns in the case of a 50 Hz system, and is converted to a hexadecimal number of 0x32DCD5. In the case of the 60 Hz system, it is 2777778 ns, and when converted to a hexadecimal number, the number is 0x2A62B2.

  FIG. 10 is a time chart showing the operation of the cycle generator 290 of the present invention. The current time 281 is incremented by 40 ns (0x28) every cycle. When the current time 281 becomes a value of 0x32DCF0 exceeding the value of 0x32DCD5 at the cycle end time 62, the cycle start signal 291 becomes 1, and in the next cycle, the cycle end time 620 is incremented by 0x32DCD5 and becomes a value of 0x65B9AA. Until the time 281 reaches this value, the time of the next cycle will pass.

  In this way, it is possible to generate the timing for starting the cycle with a very simple circuit, and by determining the A / D conversion timing based on this, it is possible to realize highly accurate sampling synchronization.

  As described above, in this embodiment, each slot used for transmission can be divided into the function as a protection relay device and the function of synchronization and can be implemented by using them efficiently. Further, in this embodiment, the protection relay device can be configured by using inexpensive general-purpose transmission such as Ethernet (registered trademark) in contrast to the protection relay device that has been configured by using expensive dedicated transmission until now. It is possible to greatly reduce the cost. Also, the accuracy of sampling synchronization can be improved from the microsecond level to the nanosecond level when a dedicated transmission line is used. Furthermore, by realizing these synchronization processes by hardware, synchronization accuracy is improved, and synchronization is possible without interfering with the processing of the CPU 210.

  In the synchronization of IEEE 1588, it is necessary to consider how to deal with a large synchronization shift. Because, when a large synchronization shift occurs, the acquired electrical quantity information is acquired at a different time and becomes an incorrect value, but the protection relay calculation using an incorrect value also results in an incorrect result and the circuit breaker malfunctions. This is because it leads to a great social impact such as a power outage. However, IEEE 1588 has a specification in which each slave is treated as a synchronization error, and there is no function for collecting and dealing with information on a large synchronization error globally. Therefore, in this embodiment, a description will be given of a response when a synchronization shift occurs.

  FIG. 5 is a diagram illustrating a time chart for explaining operations among the master unit M, the slave unit SB, and the transmission path when a large synchronization shift occurs. 4 is a time chart from slot 0 to slot 15, whereas FIG. 5 is a time chart in which slots 8 to 15 are common and subsequent slots 16 to 23 are added. Yes.

  When a large synchronization shift occurs in the slot 6 in FIG. 4, it is necessary to transmit information indicating the large shift from the slave to the master. At this time, an example of sending a new packet with large deviation occurrence information may be considered, but a new slot needs to be allocated to the new packet, so a large deviation occurs in an existing packet that has already been assigned a slot. It is best to place information on it, and it is best to place it in an analog value packet that transfers the amount of electricity that makes the data meaningless when a large shift occurs.

  In the P1 path, an analog value including an electric quantity is transferred in the slot 9 and the slot 10, so it is preferable to transfer the information indicating the occurrence of synchronization deviation in the analog value packet. The occurrence of a large synchronization shift can be detected by determining whether or not the calculated offset time d exceeds a predetermined value. Thereafter, the path of P1 is taken into the master CPU 210 in the slot 16. When the contents of the packet are scrutinized at that point and the information on the occurrence of synchronization loss is included, the relay operation from the slot 20 to the slot 22 is stopped, and the contact operation is performed when the interruption operation is performed according to the result of the relay operation. Information that does not change the state of the circuit breaker at P3 that transmits the information (locks the relay output) is sent to prevent erroneous output of the protective relay.

  In addition, when the relay calculation is stopped, another process such as a self-diagnosis process can be performed instead of the free time. Since there is a high possibility that a failure around the CPU of the master is a cause of the occurrence of a large synchronization shift, there is a possibility that the failure can be detected early by self-diagnosis processing. In this way, it is possible to avoid a situation in which the relay malfunctions using the data out of synchronization, and the reliability of the protective relay device can be improved.

  FIG. 7 shows an example of the configuration of an analog value packet including large synchronization error occurrence information. When general-purpose Ethernet (registered trademark) transmission is used, a packet starts with a destination MAC address 710 and a source MAC address 720 and ends with FCS 750. During this time, the header portion 730, the data portions 741, 742,. The number of data does not matter as long as it falls within the maximum size of Ethernet (registered trademark). At this time, if 1 bit of the header portion 730 is assigned as a synchronization bit 735 and is set to 1 when synchronized, and 0 when not synchronized, information indicating whether or not the packet is synchronized can be included. It is possible to transmit from each slave to the master whether or not each slave is synchronized with the master.

  In this way, in this embodiment, by performing appropriate processing such as locking the relay when synchronization is lost, low-cost general-purpose transmission such as Ethernet (registered trademark) and sampling synchronization on it are realized. Therefore, it is possible to greatly reduce the cost and improve the sampling synchronization accuracy.

  In addition, this invention is not limited to an above-described Example, Various modifications are included. For example, the above-described 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 one embodiment can be replaced with the configuration of another embodiment, and the configuration of another embodiment can be added to the configuration of one embodiment. Further, it is possible to add, delete, and replace other configurations for a part of the configuration of each embodiment.

  In addition, each of the above-described configurations, functions, processing units, processing means, and the like may be realized by software by causing a processor to interpret and execute a program that realizes each function. Information such as programs, tables, and files that realize each function can be stored in a memory, a recording device such as a hard disk or an SSD (Solid State Drive), or a recording medium such as an IC card, an SD card, or a DVD.

  Further, the control lines and information lines indicate what is 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.

  Since the protection relay device according to the present invention can realize high-precision sampling while using an inexpensive general-purpose high-speed transmission line, it is highly likely to be widely applied in place of an existing system using a dedicated line transmission line.

50, 61 Adder 51 Current time register 54 Reception time register 55 Transmission time register 56 Transmission delay / time shift calculation circuit 57 Transmission delay register 58 Time shift register 62 Period end time register 63 Comparator 150 Display unit 151 Display information 161, 162 , 163 Transmission path 210 CPU
220 Contact Controller 230 A / D Converter 240 Protocol Controller 251, 252, 253 Receiver 260 Transmitter 271, 272, 273 Physical Layer 280 Time Synchronizer 290 Period Generator CB Breaker CT Current Transformer I Terminal Current L Transmission line M Master unit SB, SC, SD Slave unit X Breaker contact or breaker operation command

Claims (5)

A protection relay that performs a relay operation for detecting an accident in the power system from the system current information transmitted between the units provided with a unit that samples the system current information for each predetermined electrical angle from the power system at each terminal of the power system In the system,
The plurality of units divide the predetermined electrical angle period into a plurality of slots for each data to be transmitted, and the plurality of slots include at least:
A first slot for transmitting the grid current information between the plurality of units;
A second slot in which a synchronization signal of the sampling time is transmitted ,
Of the plurality of units, the master unit serving as the reference time for sampling is the
Send the tracking signal with the transmission time of the synchronization signal to the other unit after the transmission of the synchronization signal,
The other unit transmits a delay request signal with the tracking signal reception time to the master unit.
Reply to
The master unit transmits a delay response signal indicating the reception time of the delay request signal to the other user.
Send to the knit,
The other unit that has received the delay response signal transmits the synchronization signal transmission time, the synchronization
From the reception time of the signal, the transmission time of the delay request signal, and the reception time of the delay response signal
An error of the sampling time with the master unit is calculated, and the master unit
Synchronize with the sampling time,
The other unit displays information indicating an error in the calculated sampling time as the grid current information.
Sent to the master unit,
The master unit provides information indicating the error on condition that the error is within a predetermined range.
Using the grid current information marked with for relay calculation,
If the error is out of the predetermined range, the master unit is in good health of its own unit.
Protection relay system characterized by diagnosing integrity . A protection relay device equipped with a protection relay function that detects an accident in the power system from information obtained by sampling the AC current of the power system is provided at each terminal of the power system, and signals are transmitted between the terminals. In the protective relay system that operates the circuit breaker,
The protection relay function comprises an information collection function consisting of a plurality of procedures for collecting information necessary for executing a protection relay operation, and a synchronization function consisting of a plurality of procedures for synchronizing the sampling,
A predetermined electrical angle period of the electricity amount of the power system is divided into a plurality of slots, and the protection relay function detects an accident of the power system from information obtained by sampling the AC electricity amount of the power system within this period. A protection relay system, wherein a plurality of procedures of the information collection function and the synchronization function performed within this period are determined for each slot. In claim 2 ,
In the plurality of procedures of the information collecting function, a procedure for signal transmission of the AC electricity quantity detected at each terminal of the power system and for the calculation of the protection relay function,
And a procedure for transmitting the contact point information of the circuit breaker of each terminal of the power system to be used for the calculation of the protection relay function, and the plurality of procedures are controlled to be executed in the different slots. Protection relay system characterized by that. In claim 2 or claim 3 ,
The protection relay function and the information collection function are repeatedly executed thereafter in units of processing in a series of slots, and the synchronization function uses a specific position slot in the series of slots to specify a specific power system. The signal is transmitted twice from the terminal to the other terminal, and the first position from the other terminal to the specific terminal is used by using the specific position slot in the series of subsequent slots.
In response to this, the signal is sent back from the specific terminal to the other terminal, and the synchronization function of the other terminal is used in a series of two sets of a plurality of slots. A protection relay system that corrects the sampling timing by calculating a signal transmission delay time and a time lag from a signal exchange between the synchronization functions. A protection relay device equipped with a protection relay function that detects an accident in the power system from information obtained by sampling the AC electricity amount of the power system is provided at each terminal of the power system, and signals are transmitted between the terminals. In the protective relay system that operates the circuit breaker of
The protection relay function comprises an information collection function consisting of a plurality of procedures for collecting information necessary for executing a protection relay operation, and a synchronization function consisting of a plurality of procedures for synchronizing the sampling, Information obtained by dividing a predetermined electrical angle period of the electricity amount of the power system into a plurality of slots and sampling the AC electricity amount of the power system within the half of the electrical angle period. In the period of half of the electrical angle period, the information collecting function performs a process for providing information necessary for the calculation of the protection relay function, Repetitively executed in units of half a period, and the synchronization function uses specific position slots in a series of slots in a half period of an electrical angle,
Send a signal twice from one terminal of the power system to the other terminal, and use the specific position slot in a series of multiple slots in the half of the following electrical angle period, from the other terminal The first signal is transmitted toward the specific terminal, and the signal is returned from the specific terminal toward the other terminal. The synchronization function of the other terminal is continuously 2 A protection relay system that corrects the sampling timing by calculating a signal transmission delay time and a time lag from a signal exchange between the synchronization functions in a series of a plurality of slots.

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