JP2005269759A - Sampling synchronization system and time management system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To facilitate the effective utilization and the central time management of a plurality of management/control signals and sampling synchronization between a plurality of protective relays. <P>SOLUTION: A single management/control apparatus having a GPS receiver is a master station 11. Other management/control apparatuses are slave stations 12<SB>1</SB>-12<SB>N</SB>connected to the master station by a communication means having bus connections or star connections. Time management between the apparatuses is implemented and utilizes absolute time information received from a GPS. The absolute time information is corrected by violation. Since the master station utilizes fundamental wave frequencies 50 Hz, 60 Hz of a system synchronized with the GPS as a synchronization timing signal, sampling synchronization between the master station and the slave stations is enabled by multiplying the signals and the absolute time information is corrected by multiplying the synchronization timing signal by the violation. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention provides sampling for synchronously acquiring a plurality of measurement signals, such as a digital protective relay system and a fault location system that simultaneously sample the voltage / current of a power system and power equipment to protect the system and equipment. The present invention relates to a time management system for managing a plurality of monitoring control signals in absolute time, such as a synchronization system and a digital monitoring control system for monitoring and controlling a power system and a power device.

  As the digital type protective relay device, there are a distance relay device, a line selection device, a bus protection relay device, a transformer protection relay device, and the like as a single function type. Such a device is provided for each system or device to be protected, such as a transformer, a power transmission line, or a bus line installed in a facility to be protected at a substation.

  In addition, as a multi-function digital protection relay system that protects the entire power system lines and substations in a lump, a comprehensive protection relay system or distributed type with a wide variety of protective relay devices distributed over a wide area There is a protective relay system.

  In these digital protection relay devices or protection relay systems, current and voltage measurement signals at multiple remote locations such as transmission and distribution lines are acquired by sampling, and these sampling data are transmitted to the protection relay device at the other end. There are some that perform protection computation. For example, there is an optical PCM current differential relay shown in FIG.

  In the digital protective relay device or system as described above, sampling must be synchronized for measurement. In this sampling synchronization, sampling synchronization in units of devices within the protective relay device can be easily obtained for measurement of the same location or nearby locations such as current measurement and voltage measurement at one location of the line. However, there is a transmission delay between the measurement signal at its own end and the measurement signal from a remote place such as the above-mentioned optical PCM current differential relay. For this reason, various sampling synchronization methods capable of compensating for transmission delay have been proposed.

  For example, in the case of the optical PCM differential relay configured as shown in FIG. 12, as shown in FIG. 13, the protective relay devices A, B, and C are connected by a loop type optical fiber transmission line, and from device A to device B → device C → device. As in the case of B → device A, the synchronization signal is transmitted through the loop transmission path looped back by the device C. And, for the transmission and reception of the synchronization signal, each device A to C matches the sampling timing of each device by setting the intermediate time between the transmission timing and the reception timing as the sampling synchronization point because of the transmission delay time in the transmission line. Let

  As another synchronization method, as shown in FIG. 14, the protection relay devices A and B at remote locations receive absolute times transmitted from satellites of GPS (Global Positioning System), respectively. There is a method of establishing sampling synchronization by sampling a measurement signal based on time (see, for example, Patent Document 1).

  FIG. 15 shows an example of sampling circuits of the devices A and B. The GPS system receiver 1 receives a fixed period pulse, and the sampling synchronization circuit 2 multiplies it to obtain a 50 Hz / 60 Hz synchronization signal. Obtains 600 Hz / 720 Hz synchronization signals, uses these synchronization signals as sampling synchronization signals of the analog input processing unit 3, and samples voltage and current signals.

  The absolute time information from the GPS is transmitted at a cycle of 1 second, and the protective relay device generates a sampling synchronization signal synchronized with the received absolute time pulse as shown in FIG.

Next, in order to monitor the status and response status of each device, a digital monitoring and control system such as a power device requires a log managed in absolute time, and time management at that time is required. As a method of adding absolute time to various state change information (state change information) for this purpose, each device has a clock function, and the time is periodically corrected by a correction command from the center. There is something. As for the correction method, there are a method of adjusting the hour with a pulse every hour, and a method of transmitting an absolute time for correction and adjusting it.
Japanese Patent Laid-Open No. 11-191919

  (1) Since the conventional sampling synchronization method in units of protection relay devices constitutes a sampling synchronization circuit in units of devices, sampling synchronization with other protection relay devices is asynchronous. Therefore, since sampling synchronization cannot be established between the devices, a plurality of devices cannot effectively use one instantaneous data. In addition to this, an integrated protection system or the like that protects the entire substation is provided with a measuring device for each protection relay device or for each function, so that the hardware scale becomes large.

  In addition, the optical PCM current differential relay uses an optical transmission line between multiple terminals to synchronize and uses the data sampled at the same time. However, these data are sampled in units of the optical transmission line. This is a synchronous system, and the same problems as those described above remain. Similarly, there are a fault location system (locator), a system stabilization system, and the like that share and use data across substations, but these systems also have similar problems.

  An object of the present invention is to secure and centrally manage sampling synchronization of the entire system in a multi-function type digital protection relay system, fault location system, etc., and the same system or substation without impairing the performance of the sampling signal The object is to provide a sampling synchronization method in which the entire data or data of another system or substation can be used effectively.

  (2) As described above, the digital supervisory control system requires a time log managed in absolute time. However, when trying to manage individually in units of systems, a plurality of systems effectively use one data. Therefore, there is a problem that the response of each power device in the power system over a wide range cannot be evaluated correctly.

  Another object of the present invention is to provide a time management system that facilitates effective use of a plurality of supervisory control signals and collective time management, such as a digital supervisory control system.

  The present invention provides a time management method using absolute time information received from GPS for time management between devices in a digital supervisory control system, and sampling synchronization between devices in a digital protective relay system using GPS. This is a sampling synchronization method using a periodic signal of unit time received from, and has the following configuration.

(1) In order to have a plurality of protection relay devices or means, each protection relay device or means acquires a plurality of measurement signals in sampling synchronization, and performs a protection operation based on the plurality of sampling data, respectively. Sampling synchronization method,
Among the protection relay devices or means, one protection relay device or means having a GPS receiver is a master station, and the other protection relay device or means is a bus connection or star connection communication with the master station. A slave station connected by means,
The master station is provided with means for multiplying a periodic signal of unit time received by a GPS receiver to a necessary frequency to obtain a sampling pulse in the own station, and transmitting the periodic signal to the slave station,
The slave station generates a multiplied timing signal by synchronizing with the master station by resetting a counter that counts with a pulse of an internal oscillator with a periodic signal of the unit time transmitted from the master station. Is provided with means for making a sampling synchronization signal in the own station.

(2) A time management method for having a plurality of monitoring control devices or means, wherein each of the monitoring control devices or means manages the monitoring control signal in absolute time,
Among the monitoring control devices or means, one monitoring control device or means having a GPS receiver is a master station, and the other monitoring control devices or means are connected to the master station by bus connection or star connection communication means. As a slave station
The master station captures the absolute time information received by the GPS receiver as a message serial signal, and manages the time of the message serial signal as absolute time information in the own station according to the timing of the unit time signal received by the GPS receiver. And providing means for distributing the absolute time information to other slave stations by broadcast communication,
Each of the slave stations is provided with means for managing time by using time information distributed from the master station by simultaneous broadcast communication as an absolute time.

(3) The master station acquires a periodic signal of unit time and absolute time information with the GPS receiver, divides the periodic signal to obtain a timing signal for every predetermined time, and adds the timing signal to the periodic signal. In order to generate a timing pulse with a unit time period by applying a violation, the CPU processing unit in the own station is interrupted, and a timer that times up by a predetermined time is started by this interrupt, and the CPU processing unit In addition, the slave station broadcasts to the slave station by adding a certain time to the absolute time information received in the above, and has means for writing the absolute time information to the real-time clock by adding the certain time when the timer expires,
The slave station interrupts the CPU processing unit in its own station at the timing of the violation, starts a timer that times up after a certain time, and obtains the absolute time information that the CPU processing unit previously received when the timer expires. Means is provided for writing in a real-time clock and acquiring the absolute time information by simultaneous broadcast communication from the master station.

  (4) The management of the absolute time is characterized in that the management up to year / month / day / hour / minute / second is the message serial signal by simultaneous broadcasting, and the second or less is recorded by the counter circuit from the periodic signal of the unit time.

  As described above, the present invention has the following effects.

  (1) By using the absolute time based on the GPS time data, it becomes possible to handle the absolute time data in an entire substation or a device distributed in a wide area. Since the absolute time is the same, the events that occur can be managed in the same time series.

  (2) By using a synchronization method based on GPS hardware signals, sampling data can be handled by an entire substation or a device distributed in a wide area. Since the sampling times are the same, each phase calculation is possible. For example, like the bus protection relay device, it is possible to calculate the current sum of all feeders.

  When synchronization is performed with a 1-second cycle, the hardware timing signal sent from the master station to each slave station is only a synchronization timing signal with a 1-second cycle, so that only one hardware signal line is required. Further, when transmitting 50 Hz or the like from the master station, the multiplication frequency generation circuit of each slave station is simplified. Further, since this signal is a signal from GPS and is the signal with the smallest synchronization deviation as a reference for synchronization, the synchronization deviation can be minimized.

  (3) By associating the sampling synchronization with the absolute time with GPS, it becomes possible to handle the absolute time and the sampling data in a device such as a substation as a whole or distributed in a wide area. Since sampling and absolute time are the same, each phase calculation is possible. For example, like the bus protection relay device, it is possible to calculate the current sum of all feeders.

  Moreover, since the absolute time is the same, the events that have occurred can be managed in the same time series. For absolute time management, management up to year / month / day / hour / minute / second and subseconds are 600 Hz or 720 Hz, 12 times the synchronized fundamental wave (50 Hz or 60 Hz), 4.8 kHz, 96 times 4.8 kHz, 5. If the sampling synchronization signal of 76 kHz is counted, time measurement can be performed with an accuracy less than that.

  According to the method of Embodiment 2, the synchronization shift can be minimized. In addition, since the software processing is based on timing signals that can be recognized simultaneously by the master station and the slave station, synchronization deviation is reduced.

  (4) Detailed absolute time is managed up to year, month, day, hour, minute, and second, and hardware time is used to count less than a second with a counter, and more than a second is recorded with an RTC. Is possible.

  FIG. 1 is a system configuration diagram for time management and sampling synchronization in the present invention. For example, it is installed in a substation from time information and a 1-second periodic signal received by a GPS receiver provided in one place in the substation. Collective time management and sampling synchronization for all measurement data processing devices (or all functions in the same device).

In Figure 1, a measurement information processing apparatus 11 having a GPS receiver and a master station, a measurement information processing apparatus 12 ₁ to 12 _N which receives the absolute time information and sampling synchronization signal in the communication between the master station and the slave station .

  In FIG. 1A, a master station and a slave station are connected by a bus using a transmission medium such as Ethernet (registered trademark), and time information is simultaneously transmitted from the master station to the slave station using UDP (User Datafram Protocol) or the like. This is a case of a communication system configuration for performing broadcast communication. FIG. 1B shows a communication system configuration in which a star connection is made between a master station and a slave station using a transmission medium.

  The master station includes, for example, the GPS receiver 1 and the sampling synchronization circuit 2 shown in FIG. 15, inputs a synchronization pulse having a fixed period received by the GPS receiver 1 to the sampling synchronization circuit 2, and multiplies it to a necessary frequency. For example, signals of 50 Hz and 600 Hz, or 60 Hz and 720 Hz are obtained. These are based on pulses received from GPS artificial satellites and are synchronized between different points.

  As shown in FIG. 16, the timing of the sampling synchronization circuit is a timing signal having a fixed period synchronized with GPS, and in the same figure, it is described with a period of 1 second. A sampling synchronization signal of 50 Hz / 60 Hz or 600 Hz / 720 Hz is obtained by a self-running timing circuit employing a circuit DPLL.

  Hereinafter, embodiments of the sampling synchronization method and the time management method will be described.

(Embodiment 1) Absolute time synchronization method using GPS time data This embodiment is a correction method for absolute time between devices by absolute time management using GPS.

  The master station equipped with the GPS receiver itself manages absolute time and hardware timing. For example, the master station acquires year, month, day, hour, minute and second as absolute time information by serial communication (for example, asynchronous transmission) between the GPS receiver and the CPU. This is sufficient if the absolute time management of the master station and the slave station is in units of seconds. However, in power monitoring and control systems, absolute time management is required with a resolution of up to ms (milliseconds). There is a case.

  FIG. 2 shows a block configuration of the master station for this purpose. The GPS receiver 21 acquires absolute time information, takes this absolute time information as a message serial signal f by the signal converter 22, converts the message into, for example, an RS232C level signal, and obtains an output g. On the other hand, the interrupt processing unit 23 generates an interrupt signal b to the CPU 24 at the timing of a 1 Hz pulse a generated from the GPS receiver 21 in units of one second, for example, and the CPU 24 performs serial communication from the signal converter 22 at that time. Absolute time information is acquired on the line, and is distributed to the slave stations connected to the communication system for exchanging information such as Ethernet, for example, by simultaneous broadcast communication using the UDP protocol or the like. Thereby, the slave station in the communication system in the wide-area substation can acquire the absolute time information.

  Since the RS232C level is generally used for the asynchronous communication and the signal level in the serial communication, the signal converter 22 can be configured by, for example, a TTL / RS232C conversion circuit.

(Embodiment 2) Sampling synchronization method using GPS and H / W signal Although absolute time information can be acquired as a message by serial communication as in Embodiment 1, hardware sampling synchronization timing such as sampling synchronization cannot be obtained. . In this embodiment, sampling synchronization is achieved in hardware using a GPS system.

  From the GPS receiver, for example, there is a timing (signal a in FIG. 2) generated in units of 1 second, and a method of synchronizing using a 1 second timing signal will be described. This signal is a direct signal from the GPS receiver, and since this signal is a signal synchronized with the absolute time, it is synchronized with the absolute time by making this signal a signal that synchronizes between the master and slave. An effect that can prevent the shift to a minimum can be expected.

  For this purpose, the master station has a GPS receiver, and transmits a 1-second periodic signal of the hardware timing signal to the slave station via the transmission driver. The slave station performs DPLL from the received 1-second periodic signal, and the fundamental frequency is 50 Hz and 60 Hz, and the sampling synchronization signal is 12 times 600 Hz or 720 Hz of the fundamental wave, or 96 times 4.8 kHz or 5.76 kHz. obtain.

  FIG. 3 is a block diagram of the main part of the sampling synchronization method based on the timing generated every second.

  In FIG. 3, the master station 11 takes out a 1-second period pulse a taken out from the GPS receiver 21 as a synchronization timing signal d by the buffer circuit 25, and this signal is outputted as an optical signal by an electro-optical converter (E / O) 26. The data is converted to h and transmitted to the slave station 12. Alternatively, a drive signal i is obtained by a driver 27 such as RS422A or RS485 and transmitted to the slave station 12 in a metal system.

  The slave station 12 converts the optical signal h transmitted from the master station 11 into an electrical signal j by the opto-electric converter 28. Alternatively, the metal drive signal i transmitted from the master station 11 is received by the receiver 29 to obtain the signal k. Whether the master station and the slave station are optical signals or metal signals may be determined by application. For example, an optical signal is applied when straddling between devices in a substation, and a metal signal is applied within the same device. One of these signals is selected by the selection circuit 30, and the basic synchronization signal n and the sampling synchronization signal o synchronized with the selected synchronization timing signal 1 are generated by the DPLL circuit 31.

  The DPLL circuit 31 is provided with, for example, a 50 Hz or 60 Hz counter that counts pulses from an oscillator (not shown) provided in the slave station, and the counter is synchronized by resetting the counter with a synchronization timing signal of 1 second period from the GPS. I take the. Further, based on the basic synchronization signal n (50 Hz, 60 Hz), a signal necessary for sampling synchronization such as the sampling synchronization signal o (600 Hz, 720 Hz) is generated in synchronization with the 1 second periodic signal. Thus, the hard timing signal from the master to the slave only needs to transmit a synchronization timing signal with a period of 1 second.

  In the case of FIG. 3, a method is shown in which a signal having a 1-second period is transmitted from the master station 11 to the slave station 12 and synchronized. However, the master station 11 generates a 50 Hz or 60 Hz signal and transmits it to the slave station 12. Thus, generation of 50 Hz or 60 Hz signals in the DPLL 31 of many slave stations can be eliminated. In place of the buffer 25 in FIG. 3, a 50 Hz or 60 Hz counter for multiplying the pulses of the 1 second periodic signal a is provided, and this counter is reset by a synchronization timing signal of 1 second period from the GPS receiver 21. This is realized by using a multiplier circuit.

  In addition to the 1 second periodic signal, a GPS receiver 21 obtains, for example, a 10 kHz signal having a high frequency equal to or higher than the 1 second periodic signal. 50 Hz synchronized with the signal can be obtained.

(Embodiment 3) Association of sampling synchronization by GPS and absolute time thereof In Embodiment 1, a synchronization method between master slaves of time data in Embodiment 1, and in Embodiment 2, a one-second signal from GPS or 50 Hz or 60 Hz in the master station The timing signal is distributed, and the slave station synchronizes with the received fundamental wave 50 Hz, 60 Hz, or received 50 Hz, 60 Hz, 12 times 600 Hz or 720 Hz of the basic synchronization signal, or 96 times 4.8 kHz, 5 A sampling synchronization method for obtaining a sampling signal of .76 kHz was adopted.

  In the second embodiment, it is sufficient for sampling synchronization even if the relationship with the absolute time information is not particularly required.

  In the third embodiment, the sampling synchronization required for protection is associated with the absolute time required for monitoring control and the like. Thus, by using information in seconds that can be managed by a message in association with a timing signal by hardware, it is possible to manage even in units of microseconds or less.

In the present embodiment, the hardware timing circuit of the second embodiment is combined with the first and second embodiments. The absolute timing correction timing is a violation of the synchronous timing signal (deliberately deviates from the signal conversion rule). By doing so, the deviating timing is detected on the receiving side, and the synchronization timing is transmitted. In this way, the absolute time correction timing is shared between the master station and the slave station, and since the hardware can synchronize to the timing of less than a second, the master station and the slave station also have an absolute time of less than a second. Acquisition is possible. This example will be described in detail with reference to FIG. 4. In FIG. 4, a 1/600 synchronization signal is obtained by the frequency division counter circuit 32 for the synchronization timing signal generated in the 1 second period from the GPS receiver 21. For example, when the time correction timing is set to a period of 10 minutes, a timing signal c every 10 minutes is obtained as an output of the frequency division counter circuit 32.

  The timing superimposing circuit 33 multiplies the 1-second periodic signal a with the timing signal c every 10 minutes and superimposes the timing every 10 minutes. The violation method performs processing that does not generate a positive pulse of a square wave of 1 second.

  For example, in 10 minutes, there are 60 × 10 = 600 times of 1-second pulses, but up to 595 times are normal, and the last four times are paused. This violation is an example in which a positive pulse of a rectangular wave signal with a 50% duty ratio is originally missing n times, in this example, four times. FIG. 5 shows one violation synchronization timing signal in which a timing every 10 minutes is superimposed on a rectangular wave signal of 1 second.

  At this timing, the master station 11 interrupts the CPU processing unit 24. Next, the CPU processing unit 24 reads the absolute time information of the GPS receiver 21 from the signal converter 22, adds 10 minutes thereto, and sends time correction data to the slave station 12 via the Ethernet. The slave station side and the master station side interrupt the CPU processing units 35 and 24 at the timing of the violation, and each station side has the synchronization time data obtained in the previous time, which is not shown in FIG. 4 in an RTC (real time clock). Write.

  A synchronization timing signal e obtained by superimposing a timing of every 10 minutes on a rectangular wave signal of 1 second is transmitted to the slave station 12 by 26 or 27 as in the second embodiment. On the slave station 12 side, the timing extraction circuit 34 detects the violation signal (no four four-second pulses) via 28 to 30, and interrupts the CPU processing unit 35 in synchronization with the next one-second pulse signal. The CPU processing unit 35 sets the previous time correction data in the RTC.

  The slave station in the substation may be applied to the optical transmission system, or to the metal transmission if it is in the same device. Through the selection circuit 30 determined by the optical or metal transmission method determined by application, the timing extraction circuit 34 detects the positive pulse timing multiplied by the square wave of 1 second, and the superimposed 10 minutes. Get every timing. Further, when the rising state of the rectangular wave signal for 1 second changes, 50 Hz / 60 Hz required in the slave station via the DPLL circuit 31 for phase comparison, 600 Hz or 720 Hz which is 12 times the fundamental wave, and 96 if necessary. Double sampling signal of 4.8 kHz and 5.76 kHz is obtained.

  A processing flow of the CPU processing unit of the master station and the slave station is shown in FIG. The master station sets the time correction data sent last time at the interrupt timing of FIG. 5 in the RTC. Every 10 minutes of synchronization time is sufficient time for the master station and the slave station to confirm the delivery of absolute time. Within 10 minutes of the example, the master station acquires the absolute time (year / month / day / hour / minute / second) from the GPS receiver, adds a correction value (in this example, 10 minutes), and performs broadcast communication to the slave station.

  The slave station writes the time correction data received last time in the RTC at the same time as the master station at the interrupt timing of FIG. By the next synchronization interrupt, the master distributes the synchronization time to the slave, and the slave performs a receiving process.

  As a result, the same absolute time is set in the RTC for the master station and the slave station.

  FIG. 7 shows another time correction method. In the configuration shown in FIG. 4, the timing superimposing circuit 33 shows a case where the 1 second period signal a is multiplied by the timing signal c every 10 minutes, and the time is corrected by superimposing the timing every 10 minutes. In FIG. 7, a 50 Hz (or 60 Hz) synchronous timing signal synchronized with the 1 kHz signal a is applied with a violation at an hourly timing by dividing the 1 Hz signal a.

  FIG. 7 differs from FIG. 4 in that a timing signal c is obtained every hour by dividing the synchronization timing signal a generated by the GPS receiver 21 in a 1-second cycle into 1/3600 by the frequency dividing circuit 42, and in parallel with this. Then, a 1-second periodic signal a generated at a frequency of 1 Hz from the GPS receiver 21 is obtained by the synchronizing circuit 37 as a rectangular wave signal d of 50 Hz (or 60 Hz). In this case, the synchronization timing signal a generated from the GPS receiver 21 in units of one second and this oscillation circuit need to be synchronized by DPLL.

  As a result, the timing superimposing circuit 33 applies a violation to the 50 Hz (or 60 Hz) rectangular wave signal d with the timing signal c every hour, and superimposes the timing every hour. As a method of violation, processing that does not generate a positive pulse of a square wave of 50 Hz (or 60 Hz) is performed.

  The signal e from the timing superimposing circuit 33 is transmitted to the slave station 12, and the slave station 12 detects the positive pulse timing applied with the 50 Hz (or 60 Hz) rectangular wave violation by the timing extracting circuit 34. The obtained hourly timing is obtained. FIG. 8 shows a synchronous timing signal obtained by superimposing an hourly timing on a 50 Hz (or 60 Hz) rectangular wave signal.

  In the subsequent processing, unlike the case of FIGS. 4, 5, and 6, the RTC is set by using a software timer interrupt after a predetermined time without being set in the RTC at an interrupt timing generated by hardware. FIG. 9 shows a processing flow of the CPU processing unit of the master station and the slave station. The master station interrupts the software timer, for example, after one minute at the interrupt timing shown in FIG. 8, and the master station acquires the absolute time (year / month / day / hour / minute / second) from the GPS receiver 21 within one minute. Then, broadcast communication is performed to the slave station as time correction data with one minute added. This one minute may be sufficient time for the master station and the slave station to confirm the delivery of the absolute time.

  The slave station sets the same software timer interrupt, for example, 1 minute, as the master station at the same time as the master station at the interrupt timing of FIG. The master station sets the time correction data sent within one minute in the software timer interrupt processing after one minute to the RTC. Also, the slave station acquires time correction data from the master station within 1 minute by simultaneous broadcast communication, and sets the time correction data (absolute time plus 1 minute) to the RTC at the same timing as the master station. .

  Thus, the same absolute time is set for the master station and the slave station.

(Embodiment 4) Detailed absolute time message transfer method As described above, by using GPS, it is possible to handle absolute time data in the entire substation, etc., or in devices distributed over a wide area. However, in the case of the first embodiment, the year, month, day, hour, minute, and second can be acquired from the GPS receiver of the master station, but it cannot be made into a message by management in units of seconds.

  In the fourth embodiment, the hardware timing of the GPS receiver used in the second embodiment is used to enable subsecond management.

  For example, if there is a 10 kHz hardware signal from the GPS receiver 21, a 16-bit counter is prepared, and 10 kHz is counted 10,000 times (2710H, H indicates a hexadecimal number), so that the time with an accuracy of 0.1 ms is obtained. Enable management.

  This example will be described with reference to FIG. The counter circuit 36 is reset at a timing “a” generated from the GPS receiver 21 at a period of 1 Hz, and counts at a timing “b” generated in units of 10 kHz. The counter latch circuit 39 temporarily stores the count value of the counter circuit 36.

  When the absolute time is required for the state change detection or the like, the CPU processing unit 24 reads the time information q below the second by the read signal r from the counter latch circuit 39, and the year, Get the date, hour, minute, and second. By this method, the master station acquires absolute time information from 0.1 ms to the year.

  After that, the master station 11 uses a transmission medium such as Ethernet and performs broadcast communication of time information to the slave station 12 using the UDP protocol or the like.

  The slave station 12 obtains the 1 Hz timing a and the 10 kHz timing b from the DPLL circuit 31 that oscillates in synchronization with the timing signal from the master station, and the counter latch circuit 41 counts and resets the count value of the counter circuit 40 by counting and resetting. Is temporarily saved. The counter circuit 40 in this case is a period counter and is a counter that counts up from 0 again after counting up 10,000 (2710H) times.

  The CPU processing unit 35 acquires the year, month, day, hour, minute, and second of the absolute time by receiving the simultaneous broadcast of the absolute time information from the master station, and reads the second by the read signal r from the counter latch circuit 41. The following time information q is read, and absolute time information from 0.1 ms to the year synchronized with the master station is acquired.

  FIG. 11 shows the CPU processing flow of the master station and the slave station. The master station reads the absolute time from the counter circuit 36 and the GPS receiver every predetermined time, for example, every hour, and broadcasts it to each slave station. The slave station resets the RTC.

  As a result, the master station and the slave station set the same absolute time and the counter value counting up to 0.1 ms. When the state change occurs, the 0.1 ms counter value and the time are read from the RTC, and the state change message is edited.

  Until now, the master station broadcasts the slave station by sending the absolute year, month, day, hour, minute, and second to the slave station. It was something to take. If the master station 36 in the example of FIG. 10 is the DPLL 38 in the second embodiment, that is, FIG. 3, FIG. 4, and FIG. 7, and the slave station 40 is the DPLL 31, the master station and the slave station perform hardware sampling. The counter is synchronized with the accuracy of synchronization, and the time can be managed up to μs.

1 is a system configuration diagram showing an embodiment of the present invention. FIG. 2 is a block configuration diagram of a master station in the first embodiment. FIG. 6 is a configuration diagram of the main part of a sampling synchronization method in Embodiment 2. The principal part block diagram of the correction method (example every 10 minutes) of the absolute time in Embodiment 3. The wave form diagram which superimposed the synchronous timing signal (example for every 10 minutes) in Embodiment 3. FIG. The processing flow of the CPU process part in Embodiment 3 (example every 10 minutes). FIG. 10 is a configuration diagram of main parts of an absolute time correction method (an example of one hour) according to a third embodiment. The wave form diagram which superimposed the synchronous timing signal (example of 1 hour) in Embodiment 3. FIG. The processing flow of the CPU processing part in Embodiment 3 (example of 1 hour). The block block diagram of the master station in embodiment 4, and a slave station. 10 is a processing flow of a CPU processing unit according to the fourth embodiment. PCM relay and transmission line connection form. Explanatory drawing of a synchronization timing. Explanatory drawing of the sampling synchronization by GPS. Sampling circuit example. Sampling pulse generation time chart.

Explanation of symbols

11 ... master station 12 ₁ to 12 _N ... slave station 21 ... GPS receiver 22 ... signal converter 23 ... interrupt circuit 24 ... CPU processing unit 25 ... buffer 26 ... electro - optical converter (E / O)
27 ... Driver 28 ... Optical-electrical converter (O / E)
DESCRIPTION OF SYMBOLS 29 ... Receiver 30 ... Selection circuit 31 ... DPLL circuit 32 ... Frequency division counter circuit 33 ... Timing superimposition circuit 34 ... Timing extraction circuit 35 ... CPU processing part 36, 40 ... Counter circuit 37 ... Synchronization circuit 38 ... DPLL circuit 39, 41 ... Counter latch circuit 42. Frequency dividing circuit 43 ... Timing extraction circuit

Claims (4)

A plurality of protection relay devices or means, each of the protection relay devices or means obtains a plurality of measurement signals in sampling synchronization, and performs a protection operation or orientation calculation based on the plurality of sampling data, respectively. Sampling synchronization method for
Among the protection relay devices or means, one protection relay device or means having a GPS receiver is a master station, and the other protection relay device or means is a bus connection or star connection communication with the master station. A slave station connected by means,
The master station is provided with means for multiplying a periodic signal of unit time received by a GPS receiver to a necessary frequency to obtain a sampling synchronization signal in the own station, and transmitting the periodic signal to the slave station,
The slave station synchronizes with the master station by resetting a counter that counts with an internal oscillator signal with the periodic signal of the unit time transmitted from the master station, and generates a multiplied timing signal. A sampling synchronization method characterized by providing means for making a sampling synchronization signal in the own station. A plurality of supervisory control devices or means, each supervisory control device or means is a time management method for managing supervisory control signals in absolute time,
Among the monitoring control devices or means, one monitoring control device or means having a GPS receiver is a master station, and the other monitoring control devices or means are connected to the master station by bus connection or star connection communication means. As a slave station
The master station captures the absolute time information received by the GPS receiver as a message serial signal, and manages the time of the message serial signal as absolute time information in the own station according to the timing of the unit time signal received by the GPS receiver. And providing means for distributing the absolute time information to other slave stations by broadcast communication,
Each of the slave stations is provided with means for managing time by using time information distributed from the master station by simultaneous broadcast as an absolute time. The master station acquires a periodic signal of unit time and absolute time information with the GPS receiver, divides the periodic signal to obtain a timing signal for every predetermined time, and violates the periodic signal with the timing signal. To generate a timing pulse of unit time period, interrupt the CPU processing unit in its own station, start a timer that times up by a certain time by this interrupt, the CPU processing unit received by the GPS receiver Broadcasting to the slave station by adding a certain time to the absolute time information and providing means for writing the absolute time information to the real time clock by adding the certain time when the timer is up,
The slave station interrupts the CPU processing unit in its own station at the timing of the violation, starts a timer that times up after a certain time, and obtains the absolute time information that the CPU processing unit previously received when the timer expires. 3. A time management system according to claim 2, further comprising means for writing in a real time clock and acquiring the absolute time information by simultaneous broadcast communication from the master station.   4. The absolute time is managed by year message, month, day, hour, minute, second, and the message serial signal by simultaneous broadcast, and the second or less is recorded by a counter circuit from a periodic signal of the unit time. The time management method described in.

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