JP6327866B2 - Protection relay device and protection system - Google Patents

Description

  Embodiments described herein relate generally to a protection relay device that performs time synchronization in units of applications and a protection system using the protection relay device.

  Protection systems such as an accident removal system and a system stabilization control system are applied to the power system. An accident removal system is a system that detects an accident on a power transmission line or bus and separates an accident section. A system stabilization control system is a system that detects a system fault in a power generation substation, predicts system instability events such as frequency step-out, and disconnects the generator and the like from the system.

  In these protection systems, a protection relay device is installed at each terminal of the transmission line section or the substation. Each protection relay device measures or generates electric quantity data such as current value, voltage value, contact information, etc., and exchanges this electric quantity data with other protective relay devices for communication to determine accident detection. Calculation, current differential calculation or stability calculation is performed. These calculations are executed by an application (hereinafter abbreviated as an application) installed in the protection relay device. For example, an application that performs current differential calculation is referred to as a current differential application, and an application that performs stability calculation is referred to as a stabilization application.

  By the way, when the protection relay device performs an operation for accident detection determination, it is necessary to acquire electrical quantity data at the same time (same phase). Therefore, the protection relay device generates an arbitrary measurement cycle such as an electrical angle of 15 ° or 30 ° with the divided value, and synchronizes the rising edge of the sampling pulse signal obtained by dividing the hardware clock to synchronize the measurement timing. I am letting.

  At this time, among the protection relay device groups that are connected to each other, one unit is set as a synchronization main end, the remaining n units are set as synchronization slave ends, and synchronization is established between the master end and the slave ends. We are communicating. In synchronous communication, communication is performed by adding a transmission time and a reception time to a synchronization frame used for communication, and an error (synchronization error) of a sampling pulse signal edge at the main end is calculated on the slave end side.

  The frequency division value is finely adjusted to (reference value + 1) or (reference value-1) so that the synchronization error calculated by synchronous communication approaches 0 value, and the sampling interval is expanded or contracted. Such a synchronization method is called sampling synchronization. Such synchronous communication is equivalent to standard time synchronous communication such as NTP (Network Time Protocol) synchronous communication and PTP (Precision Time Protocol) synchronous communication.

  In a protection system to which sampling synchronization is applied, normally, one protection relay device is set as a synchronization main end, and the remaining n protection relay devices are set as synchronization slave ends. This form is called system-wide synchronization. That is, in all-system synchronization, the measurement timings of all the protection relay devices can be matched by sampling-synchronizing all the slave ends with one main end.

  Here, the system synchronization will be specifically described with reference to FIG. FIG. 14 shows a transmission line accident elimination system to which the entire system synchronization is applied. As shown in FIG. 14, IEDs 11 to 13 are connected to the power transmission line 10. IED is an abbreviation for Intelligent Electronic Device, which is a protective relay device that bears the functions of measurement, calculation, and control and that can operate independently.

  The applications implemented by the respective IEDs 11 to 13 are current differential applications 11 a to 13 a of the power transmission line 10. Each of the IEDs 11 to 13 includes serial transmission units 11 b to 13 b connected to the communication line 14. In the transmission line accident elimination system of FIG. 14, among the three IEDs 11 to 13, the left IED 11 in the figure is set as the synchronization main end, and the center IED 12 and the right IED 13 are set as the synchronization slave ends. . Since such all-system synchronization is basically an extension of the synchronization master-slave 1: 1 configuration, the configuration is relatively simple.

  Generally, a protection system is provided with a plurality of protection relay devices, but the protection relay devices often have the same application installed. For example, all three IEDs shown in FIG. 14 are equipped with current differential applications 11a to 13a. In the accident removal system provided with such an IED, the application processing can be shared by a plurality of IEDs according to the calculation performance of each IED, and the processing load and communication load in the system can be distributed.

  Further, even if a specific IED falls into an unusable state due to a maintenance check, a failure of a local communication line or communication device, or failure, the IEDs on the network can cooperate with each other by communication. Therefore, other healthy IEDs can back up unusable IEDs and maintain the availability and stability of the accident removal system.

  Further, in recent years, the number of IEDs included in the protection system is increasing, and the scale of the system is on an expanding trend. In view of such a situation, a protection system has been proposed in which a plurality of IEDs that are mounted with different types of applications are provided to perform parallel operation of the applications.

  However, in a protection system in which a plurality of types of applications are operated in parallel, the scale of synchronous communication between IEDs is dramatically increased by connecting a plurality of applications. Therefore, it is difficult to operate a plurality of types of applications in parallel on a conventional standard communication line such as 54 Kbps or 1.5 Mbps. This is because even if instantaneous value data is to be transferred through a standard communication line, only a very small capacity such as one information frame length of 90 bits or 119 bits can be handled.

  Today, however, the speed of network lines has been increasing, and it has become possible to construct a communication environment in which the amount of information that can be handled between IEDs has increased dramatically. For example, as in the protection system shown in FIG. 15, the information amount can be expanded by applying a high-speed wide area network line 2 such as a gigabit level (for example, Patent Document 1).

  In this protection system, IEDs # 4 to 6 serving as current differential relays are added to the system stabilization control system including IEDs # 1 to # 4, and two types of applications are operated in parallel. As shown in FIG. 15, IEDs # 1 to # 4 have jurisdiction over generators G1 to G4 that are to be disconnected from or connected to the system. Further, IED # 4 and 5 have transmission lines L1 and L2 as protection jurisdiction, and IED # 5 and 6 have transmission lines L3 and L4 as protection jurisdiction.

  Accordingly, a stabilization application that controls the generators G1 to G4 is mounted on the IEDs # 1 to # 4, and a current differential application that controls the power transmission lines L1 and L2 is mounted on the IEDs # 4 and I5. In # 5 and 6, a current differential application having the power transmission lines L3 and L4 as a jurisdiction is mounted. The wide area network line 2 is connected with IEDs # 1 to # 6, a time distribution server 22 and a computer server 23 via SW.

  In the above protection system, a system stabilization control system and a transmission line accident elimination system are combined. For this reason, the protection system has a system stabilization control system range and a transmission line accident elimination system range, and performs synchronous communication between different types of applications, that is, a stabilization application and a current differential application. In addition, since the IED # 4 has both a stabilization application and a current differential application, it is possible to reduce the number of IEDs arranged and communication facilities. Thereby, it can contribute to improvement of maintainability and cost reduction.

  The synchronous communication in such a protection system that operates a plurality of types of applications in parallel will be specifically described with reference to FIGS. 17 to 19 are block diagrams for explaining the synchronous communication in the protection system of FIG. 15, and FIG. 20 is a block diagram of a synchronous communication driver provided in each IED.

  As shown in FIGS. 17 to 19, each IED # 1 to # 6 and the computer server 23 are provided with a network IF 8 and a synchronous communication driver 9. The range including IED # 1 to # 4, time distribution server 22 and computer server 23 shown in FIG. 17 is the range of the system stabilization control system. In this range, the time distribution server 22 is the main end of synchronization, and each IED # 1 to # 4 is the subordinate end of synchronization.

  Therefore, the IEDs # 1 to # 4 and the computer server 23 communicate with the time distribution server 22 and synchronize time with a certain period, and acquire the time when each IED # 1 to # 4 is synchronized. If any one of the IEDs # 1 to # 4 is set as the synchronization main end and the IEDs # 1 to # 4 are time-synchronized with the local time of the IED, the time distribution server 22 becomes unnecessary.

  The IEDs # 1 to # 4 receive VI information from the generators G1 to G4 shown in FIG. 15, generate a communication frame from data converted from the VI information to phasor information, and calculate the computer in one cycle period. The frame is distributed to the server 23 and other IEDs via the wide area network line 2. The computer server 23 makes a stabilization calculation determination based on the phasor information received from each of the IEDs # 1 to # 4 in one cycle period.

  The computer server 23 performs trip control according to the calculation result. In this case, the computer server 23 generates a trip command transmission frame for the IEDs # 1 to # 4 having jurisdiction over the generators G1 to G4, and transmits this to the IEDs # 1 to # 4 via the wide area network line 2. . The IEDs # 1 to # 4 that have received the trip command output trip signals to the generators G1 to G4, and control the generators G1 to G4 to be disconnected from the system or connected to the system. Such control can stabilize the system.

  The configuration including IED # 4, 5 shown in FIG. 18 is the range of the accident elimination system for power transmission lines L1, L2. IEDs # 4 and 5 connect an input signal line that takes in the passing current at the ends of the transmission lines L1 and L2, and connect an output signal line to a switch for disconnecting from the system when a section fault is detected. The IED # 4 communicates with the IED # 5 via the wide area network line 2 via the switch SW.

  For example, the IED # 4 captures a passing current at an electrical angle of 30 °, and transmits the electrical quantity data such as the passing current value to the counterpart IED # 5 with a time on the frame (the same applies to the IED # 5). is there). Each of the IEDs # 4 and 5 receives a frame from the other end, and each time, IED # 4 and 5 perform an accident determination by performing a differential operation using the passing current values at both ends as elements.

  When an accident is detected, a trip signal is output to the switch to disconnect the accident section of the transmission lines L1 and L2, thereby preventing the accident from spreading and removing the accident. In the range of the accident elimination system for the transmission lines L1 and L2, the IED # 4 is a synchronization main end, and the IED # 5 is a synchronization slave end.

  That is, IED # 4 operates as a slave terminal in the synchronous communication of the stabilization application, but operates as a main terminal in the synchronous communication of the current differential application of the transmission lines L1 and L2. This IED # 4 has a plurality of protection functions integrated in one unit, and as described above, the number of IEDs arranged and communication facilities are reduced. In addition, IED # 5 becomes a synchronous slave in the synchronous communication of the current differential application of power transmission lines L1 and L2, and performs synchronous control by acquiring the synchronous time of IED # 4. As a result, the times of IED # 4 and IED # 5 are synchronized.

  The configuration including IED # 5, 6 shown in FIG. 19 is the range of the accident removal system for power transmission lines L3, L4. In this range, IED # 5 is the main end of synchronization, and IED # 6 is the subordinate end of synchronization. That is, IED # 5 operates as a slave end in the synchronous communication of the current differential application of the power transmission lines L1 and L2, but operates as the main end in the synchronous communication of the current differential application of the power transmission lines L3 and L4.

  Further, IED # 6 becomes a slave slave in the synchronous communication of the current differential application of the power transmission lines L3 and L4, and acquires the synchronization time of IED # 5 and performs synchronous control. In addition, about the operation | movement content which removes the accident of power transmission line L3, L4, since it is the same as that of power transmission line L1, L2, description is abbreviate | omitted.

  Next, the configuration of the synchronous communication driver built in each of the IEDs # 1 to # 6 will be described with reference to FIG. As shown in FIG. 20, the synchronous communication driver 9 includes an internal clock 902, a sampling timing generation circuit 903, a communication processing unit 904, and a time synchronization processing unit 905. The synchronous communication driver 9 corrects the time of the internal clock 902 based on the synchronization time acquired by the communication processing unit 904 and simultaneously corrects the frequency division value of the sampling timing generation circuit 903.

JP 2010-41899 A

  The following problems have been pointed out in the above-described prior art. In the protection system shown in FIG. 15, there is a functional correlation between the IED group (IED # 1 to # 4) in which the stabilization application is mounted and the IED group (IED # 4 to 6) in which the current differential application is mounted. There is no. Therefore, the synchronous communication between the stabilization applications IED # 1 to # 4 and the synchronous communication between the current differential applications IED # 4 to 6 can operate independently of each other.

  However, in practice, if the sampling synchronization is performed in order to synchronize the measurement timing in the protection system of FIG. 15, all IEDs # 1 to # 6 must be synchronized as a result. This is because IED # 4, which implements two types of applications, is the synchronization main end in the range of the accident elimination system of the transmission lines L1 and L2, but is the synchronization slave end in the range of the system stabilization control system. This is because the synchronization time of the time distribution server 22 which is the main end of the time is acquired.

  In other words, in a protection system that operates multiple types of apps in parallel, even if different types of apps are functionally uncorrelated with each other, if a protection device that implements multiple types of apps exists in the protection system, All systems are synchronized. As a result, the following problems occurred.

(1) In all-system synchronization, all protection relay devices adjust the measurement timing. Therefore, if a malfunction occurs at or near the synchronization main end, all slave ends sampling-synchronize will cause synchronization failure. For this reason, the apps installed in the protection relay device outside the defect range are also stopped, and all the apps in the protection system are stopped.

  As a specific example of this point, if IED # 1 is the main synchronization end in the stabilization application implementation example shown in FIG. 16, the function of the stabilization application stops due to failure of IED # 1. However, since IED # 4 is forced to stop without being alone, the function of the current differential application of power transmission lines L1 to L4 that only requires communication between IED # 4 to # 6 is also stopped. Become.

(2) In the whole system synchronization, there is a correlation in the synchronization master-slave setting, and it is difficult to manage the configuration. This point will be described with reference to FIGS. As already described, IED # 4 operates as a slave end in the synchronous communication for the stabilization application (see FIG. 17), and operates as the main end in the synchronous communication for the current differential application of the transmission lines L1 and L2. (See FIG. 18). For this reason, the IED # 4 passes the time synchronized with the time of the time distribution server 22 to the current differential application of the IED # 5.

  However, due to a setting error or the like, in the synchronous communication for the current differential application of the transmission lines L1 and L2, IED # 4 is not the main end but the slave end, and IED # 5 is not the slave end but the main end. Suppose that it was set by mistake. In this case, IED # 4 performs control to follow the two synchronization main ends, and correct synchronization pull-in cannot be performed.

(3) In addition, if system synchronization is performed in a protection system that operates multiple types of apps in parallel, if an IED or communication equipment outside the control jurisdiction breaks down, or if an app is temporarily operated by maintenance or inspection, etc. If stopped, other apps may be affected when recovering from a failure or when resuming operation. This effect will be specifically described by taking the protection system of FIG. 15 as an example.

  In the protection system of FIG. 15 that is system-synchronized, each IED # 1 to # 6 and computer server 23 synchronize with the time of the time distribution server 22, but when IED # 4 fails, IED # 5 performs synchronous communication. It becomes impossible and becomes a self-propelled state. Therefore, IED # 6 can be controlled synchronously following the free running state of IED # 5. That is, even if IED # 4 fails, it is possible to maintain synchronization between IED # 5 and IED # 5.

  However, when the failed IED # 4 is recovered while the synchronization between the IED # 5 and the IED # 6 is maintained, the synchronous communication between the IED # 4 and the IED # 5 is restored, so that the synchronization correction control of the IED # 5 is performed. Is done. Therefore, when IED # 4 is restored, IED # 5 and IED # 6 are out of synchronization, and a synchronization failure is temporarily detected, resulting in a period during which transmission lines L3 and L4 cannot be protected. .

In recent protection systems, the following problems have become apparent as the system scale increases.
(4) As the system scale increases, the number of slaves connected to the main end of synchronization increases, so communication concentration to the main end is likely to occur, communication load fluctuations increase, and high-precision synchronization can be maintained. It becomes difficult.

(5) As the number of slave ends increases, the communication distance (number of hops) between the slave ends and the master end tends to vary, and it becomes difficult to make the synchronization accuracy (synchronization error) of all slave ends uniform.
(6) If a communication failure occurs near the main end, the spread of malfunction is large.

  Embodiments of the present invention have been proposed to solve the above-mentioned problems, and the purpose is to solve the difficulty of synchronization accuracy and synchronization failure due to synchronization of the entire system, and even if some applications stop. An object of the present invention is to provide a protection relay device and a protection system that can continue to operate with respect to a sound application and can exhibit excellent reliability, stability, and operation rate.

In order to achieve the above object, an embodiment of the present invention has the following features (a) to (c) in a protection relay device in which different types of applications are mounted.
(A) A time synchronization processing unit is incorporated for each application.
(B) A logical time is set in each time synchronization processing unit.
(C) A sampling timing difference with another protection relay device is obtained based on the logical time.

A protection system having the following features (d) to (f) is also one embodiment of the present invention.
(D) Of the plurality of applications implemented in the plurality of protection relay devices , the same type of the application is configured as one synchronization group.
(E) The main end and subordinate of synchronization are set in the protection relay devices included in the synchronization group.
(F) The main end and the slave end in the same synchronization group are configured to set a logical time in units of synchronization groups, perform synchronous communication using the logical time, and synchronously correct the logical time. .
(G) The main end in the synchronization group becomes a slave end of the main end of another synchronization group, and is configured to be capable of synchronous communication with the main end of another synchronization group, and a plurality of the synchronization groups are synchronized.

1 is a block diagram of a synchronous communication driver according to a first embodiment of the present invention. The figure which shows the format of the communication frame between IEDs. The wave form diagram for demonstrating the relationship between sampling timing and logic time. The principal part block diagram of 1st Embodiment. The principal part block diagram of 1st Embodiment. The principal part block diagram of 1st Embodiment. The wave form diagram for demonstrating a sampling timing difference. The waveform diagram for demonstrating the slip of sampling timing. (A) is a wave form diagram which shows producing | generating the sampling timing in the 2nd Embodiment of this invention with a timer, (b) is a wave form diagram which shows the relationship between a sampling timing and application process operation timing. The block diagram of the 3rd Embodiment of this invention. The block diagram which shows the structure which synchronizes in an application group in 3rd Embodiment. The block diagram of the 4th Embodiment of this invention. The block diagram which shows the redundant mounting structure of an application in 4th Embodiment. The block diagram of the conventional accident removal system of a transmission line. The block diagram of the protection system which operated two types of applications in parallel. The block diagram which shows the application and communication opposing which were mounted in each IED in the protection system of FIG. The principal part block diagram of the protection system of FIG. The principal part block diagram of the protection system of FIG. The principal part block diagram of the protection system of FIG. The block diagram of the synchronous communication driver provided in each IED.

  Embodiments of the present invention will be specifically described below with reference to the drawings. The following embodiment is a protection system that operates a plurality of applications in parallel, and is a protection system in which a system stabilization control system and a transmission line protection system are integrated, as in the related art shown in FIG. For this reason, the same components as those in the prior art of FIGS. 15 to 20 are denoted by the same reference numerals and description thereof is omitted.

[1] First Embodiment A first embodiment will be described with reference to FIGS.
[Constitution]
(Time synchronization processing section by application)
As shown in FIG. 1, the synchronous communication driver 9 of IED # 4 has two types of applications, a stabilization application and a current differential application, and the time synchronization processing units 906 and 907 are separated for each application. Built in.

  The time synchronization processing units 906 and 907 are respectively set with logical times T1 and T2. T1 is the logic time for the stabilization application, T2 is the logic time for the current differential application, and when the application type increases, the logic time is managed at a different logic time from T3, T4, and Tn. The present embodiment is characterized in that synchronous communication is performed at logical times T1 and T2 set for each application, and time synchronization correction is performed for the logical times T1 and T2.

  Although not shown, only the time synchronization processing unit 906 for the stabilization application is incorporated in the synchronous communication driver 9 of the IEDs # 1 to # 3 in which only the stabilization application is mounted. Further, only the time synchronization processing unit 907 for the current differential application is incorporated in the synchronous communication driver 9 of the IED # 5, 6 in which only the current differential application is mounted.

(Composition of communication frame)
Next, the format of a communication frame between IEDs # 1 to # 6 will be described with reference to FIG. The communication frame shown in the upper part of FIG. 2 carries information such as destination address, source address, type, IP header, UDP header, measurement time, sampling timing difference, electrical quantity data, and FCS (frame check sequence code).

  In the protection system of FIG. 15, since the computer server 23 is arranged for the calculation of the stabilization determination, it is assumed that a UDP / IP frame that is easy to handle is adopted as the communication interface of the computer. The frame type to be adopted only depends on the communication interface and application of the apparatus, and the type can be selected as appropriate. However, when real-time communication is required in the protection system of FIG. 15, it cannot be applied to a protocol with timed control such as a response waiting time of several hundred millimeters, such as TCP / IP.

  In the user data area of the UDP / IP frame, the application type, electric quantity data, measurement time information, and sampling timing difference are stored and transmitted to the wide area network line 2. The frame distribution method may be either unicast distribution or multicast distribution, and an appropriate method may be selected according to the system configuration such as the network connection configuration and the number of opposing devices.

  The amount of electricity data varies depending on the type of application. In the current differential application of the transmission line, instantaneous value data with an electrical angle of 30 ° (interval of 1.67 milliseconds in the 50 Hz system), and in the stabilization application, 1 cycle (20 (Millisecond interval). The phasor data is data that handles a sine wave signal having a phase and an amplitude.

  When two types of applications such as IED # 4 are installed, the transmission frame may be transmitted by separating the frame for current differential of the transmission line and for stabilization. Further, as in the communication frame shown in the lower part of FIG. 2, two types of information, for example, instantaneous data and phasor data, may be transmitted in one frame.

  The measurement time in the frame is the time when the self-quantity data is measured / generated by the own device, acquired from the logical times T1 and T2 in the synchronization group for the same type of application, and combined with the sampling timing difference into the transmission frame Put it on. Alternatively, a method may be used in which electric quantity data obtained by interpolating the time difference at the transmitting station is placed on the frame without adding the sampling timing difference to the frame. When the sampling period is a high-speed period such as an electrical angle of 3.75 ° or 1 °, the sampling timing difference becomes extremely small, and measurement data that substantially matches the logical times T1 and T2 can be generated. No interpolation is required.

(Logical time type)
Next, the types of logical times T1 and T2 will be described. The time synchronization processing units 906 and 907 are respectively set with logical times T1 and T2. The logical times T1 and T2 may be time units of synchronous communication used by the stabilization application or the current differential application. For example, when PTP synchronization is adopted in the stabilization application, the time information may be seconds and nanoseconds, and in the current differential application, the sampling address (for example, a step with an electrical angle of 30 °) may be used as the time information. Good.

  The time synchronization processing units 906 and 907 use the internal clock 902 of the synchronous communication driver 9 between the synchronous communications, and use the logical time T1, the minimum unit time generated inside the IED, for example, 1 ms. Update T2. In addition, the time synchronization processing units 906 and 907 may specify the 1-millisecond addition position of the logical times T1 and T2 by providing time configuration information as attached information to the logical times T1 and T2 of each application. Is possible. Note that the logical times T1 and T2 may be updated in any format as long as the unit and format are determined according to the time information unique to the application.

(Time structure information)
Table 1 below is an example of time configuration information when the step by the internal clock 902 of the synchronous communication driver 9 is performed at a cycle of 1000 μsec. Here, when the increment of the internal clock 902 exceeds the “addition period” of the logical times T1 and T2, the “addition unit” is added to the logical times T1 and T2. When the logical times T1 and T2 exceed the “addition upper limit”, the 0 cycle and the upper digit time are updated based on the “carrying process”.

  When the logical times T1 and T2 are sampling addresses (50 Hz), the first step is an addition corresponding to 1000 μs and does not exceed the addition period, so this is stored as “additional surplus of the previous step” and the next step It becomes 2000 μs in advance, and when 1667 μs is exceeded, the “addition unit” is added, and the remaining 333 μs is stored as a remainder. When time information is composed of a plurality of elements such as UCT time and system local time, the upper digit update can be supported if there is similar information for each element.

(Relationship between sampling timing and logical time)
The timing at which the time synchronization processing units 906 and 907 at the slave slaves update the logical times T1 and T2 will be described with reference to FIG. As shown in FIG. 3, the slave time synchronization processing units 906 and 907 obtain the master terminal reference timing difference by synchronous communication. At this time, the synchronous communication only obtains the difference in sampling timing, and does not correct the sampling timing itself. The slave time synchronization processing units 906 and 907 start the timer based on the sampling signal, and generate the timings of the logical times T1 and T2 according to the time information for each application.

(App multiple synchronization)
The synchronous communication in the present embodiment performs time synchronization using logical times T1 and T2 set for each application, and is therefore referred to as application multiple synchronization. In the first embodiment, application multiplex synchronous communication is performed within the scope of the system stabilization control system and the power line accident elimination system.

  In the present embodiment, a group that collects the same application is a synchronization group that performs time synchronization within the group. That is, the applications installed in IEDs # 1 to # 6 are divided into a stabilization application synchronization group and a current differential application synchronization group. The configuration and units of time information in this embodiment are set so that they can be understood within the synchronization group. For example, it may be JST time, UTC time, or local time in the system.

(Primary and secondary ends of synchronization in application multiplex synchronous communication)
In IEDs # 1 to # 6, a synchronization main end and a slave end are set for each synchronization group. Hereinafter, a main end and a slave end of synchronization in the application multiplex synchronous communication of the present embodiment will be described with reference to FIGS. 4 to 6 are block diagrams showing functions of the application multiplex synchronous communication applied to the protection system of FIG.

  In the range of the system stabilization control system shown in FIG. 4, the time distribution server 22 is the main end of synchronization, and the time synchronization processing unit 906 for each stabilizing application in the IEDs # 1 to # 4 is the slave end. In the range of the accident elimination system for the transmission lines L1 and L2 shown in FIG. 5, the time synchronization processing unit 907 for the current differential application of IED # 5 becomes the main end of synchronization, and the time for the current differential application of IED # 4. The synchronization processing unit 907 is a slave slave.

  In the range of the accident elimination system for the transmission lines L3 and L4 shown in FIG. 6, the time synchronization processing unit 907 for the current differential application of IED # 6 becomes the main end of synchronization, and the time for the current differential application of IED # 5. The synchronization processing unit 907 is a slave slave. In the time synchronization processing units 906 and 907, the slave secondary ends obtain the logical times T1 and T2 of the primary ends, and based on this, the logical corrections of the secondary logical times T1 and T2 are corrected.

(Sampling timing generator and frame transmission / reception timing controller)
Here, returning to FIG. 1, the components of the synchronous communication driver 9 will be further described. As shown in FIG. 1, the synchronous communication driver 9 is provided with a sampling timing generation unit 903 and a frame transmission / reception timing control unit 909. The sampling timing generation unit 903 according to the first embodiment does not correct the division value, calculates the sampling timing difference between the IEDs based on the logical times T1 and T2, and manages this difference. Yes.

  The frame transmission / reception timing control unit 909 is provided with a counter counting circuit 919 and a crystal oscillator 929. The counter counting circuit 919 stores the transmission / reception timing of the synchronous communication frame, and calculates the transmission delay time and the synchronization error between the synchronization main end and the slave end using the stored transmission / reception timing.

  The counter counting circuit 919 grasps the position (time) of the sampling signal with respect to the synchronization time by adding the rising edge of the sampling signal as an element, and acquires the accurate transmission / reception timing of the communication frame. Based on the transmission / reception timing acquired by the counter counting circuit 919, the sampling timing difference can be obtained with high accuracy.

(Sampling timing difference)
Next, the sampling timing difference will be specifically described with reference to FIG. FIG. 7 shows the 1PPS signal of the time distribution server 22, which is the main end of synchronization, the sampling signal of IED # 1, the 1PPS signal of the logic time T1 for the stabilizing application, and the sampling signal of IED # 2.

  IED # 1 and IED # 2 communicate with the time distribution server 22 in synchronization to acquire the time of the main end, and synchronously correct the logical time T1 for the stabilizing application. At this time, since the correction target is the logical time, the output of the 1PPS signal is not actually generated, but the theoretical 1PPS timing (timing of 0 milliseconds) is synchronized.

  In contrast, the sampling signals of IED # 1 and IED # 2 are not subject to synchronization correction. Therefore, if the sampling signal is deviated, the deviation remains. Also, the deviation width of the two sampling signals changes sequentially due to slippage due to the clock deviation of the crystal oscillator 929 of each IED. The time synchronization processing units 906 and 907 obtain the difference between the edge of the sampling signal and the 1PPS edge at the logical time T1 as the sampling timing difference.

  By the way, each of the IEDs # 1 to # 6 is input with the sampling signal as a reference, and therefore, the input values are shifted in time by the sampling timing difference. However, when an input value is transmitted to the IED at the other end, the sampling timing difference is added and transmitted, and the time width of the sampling timing difference is interpolated by the IED at the receiving end. In this way, the IEDs # 1 to # 6 can eliminate the time lag due to the sampling timing difference.

  For example, when IED # 1 and IED # 2 are synchronously communicated at a logical time T1 by the stabilization application time synchronization processing unit 906 and a sine wave signal is input in parallel to IED # 1 and IED # 2, normally, the main terminal The input value is shifted between the input value and the slave input value according to the shift of the sampling signal. Therefore, in the present embodiment, the input data can be interpolated from the sampling timing difference so that it can be handled as a substantially synchronized signal.

(Frequency deviation of crystal oscillator between IEDs)
By the way, in the conventional synchronous control, the frequency division value of the crystal oscillator 929 is adjusted when the sampling timing is corrected. Therefore, conventionally, simultaneously with the correction of the sampling timing, the frequency deviation of the crystal oscillator 929 between each IED is also corrected at the same time.

  On the other hand, sampling timing correction is not performed in this embodiment which implements application multiple synchronization. For this reason, the deviation of the frequency individual of the crystal oscillator 929 is not eliminated. Therefore, as shown in FIG. 8, the synchronous slave end sampling timing slips at a constant speed relative to the reference main end sampling timing. For example, the slave end shown in FIG. 8 indicates that Nppm slips in 1 second with reference to the sampling timing of the main end.

  Therefore, in this embodiment, the time synchronization processing units 906 and 907 obtain the sampling timing difference immediately after the synchronous communication. Then, the time synchronization processing units 906 and 907 calculate the frequency deviation of the crystal oscillator 929 from another IED based on the sampling timing difference.

  In general, when the interval of synchronous communication is widened, the slip width is accumulated as a synchronization error. In this embodiment, the slip width can be obtained from the sampling timing difference measured for each synchronous communication. Therefore, when the logical time is updated during a period when there is no synchronous communication, the time synchronization processing units 906 and 907 perform time addition considering the slip width. As a result, in the first embodiment, even if the interval of the synchronous communication is widened and the slip width is increased, it is possible to treat the logical times T1 and T2 as accurate.

[Action and effect]
The operation and effect of the first embodiment are as follows.
(1) In the first embodiment, application multiplex synchronization is performed in which synchronization ranges are grouped by application, and time synchronization control closed in the group is multiplexed. For this reason, it is not necessary for all the IEDs # 1 to # 6 to match the measurement timing as in the conventional system synchronization. Therefore, in a protection system including IED # 4 in which different types of applications are installed, even if any one of IED # 1 to # 6 fails, the application installed in a healthy IED that does not relate to the failure site has a function. It is possible to maintain. This greatly improves the stability and availability of the protection system.

(2) In the application multiplex synchronization in the first embodiment, the time synchronization is performed using the logical times T1 and T2 for each application, so that the synchronization master-slave setting is easier than the system synchronization. As a result, a setting error at the time of setting the synchronization master-slave can be prevented, the management configuration of the protection system becomes easy, and the reliability of the system is improved.

(3) In the first embodiment, even when the IED that stopped the function of the application is restored or when the operation is resumed, there is no fear of affecting other applications. For example, even if IED # 4 breaks down, IED # 5, 6 whose application is a different group from IED # 4 continues the synchronous communication independently. Therefore, even if the failed IED # 4 is recovered, the synchronization correction control is not performed at the IED # 5. Therefore, there is no concern that a synchronization failure will occur in which IED # 5 and IED # 6 are not synchronized with the recovery of IED # 4.

(4) Since the time synchronization processing units 906 and 907 calculate the frequency deviation of the crystal oscillator frequency with another IED based on the sampling timing difference, and update the logical times T1 and T2 by taking the frequency deviation into account. Even if the interval for performing synchronous communication becomes wide, excellent synchronization accuracy can be maintained.

(5) The time synchronization processing units 906 and 907 update the logical times T1 and T2 using different time configurations for each synchronization group, but have time configuration information as additional information of the logical times T1 and T2. Therefore, it is possible to update the logical times T1 and T2 of all the applications in the minimum unit time generated in the IED, and the accuracy of the logical times T1 and T2 can be improved by accurate updating.

(6) In this embodiment, the phase difference corresponding to the sampling timing difference is subjected to data interpolation calculation, and the interpolation value of the electric quantity data is used. By improving the synchronization accuracy of the logical time, the accuracy of the data interpolation calculation is also improved, and an application process having the same performance as the entire system synchronization method for correcting the sampling signal can be realized.

Further, in the present embodiment, by adopting application multiplex synchronization instead of system synchronization, a plurality of main ends can be distributed in the system. For this reason, the following operations and effects can be obtained.
(7) Even if the number of apps that are operated in parallel in the protection system increases, the main end is set for each type of app, so the number of main ends also increases in proportion to the number of apps. For this reason, even if the system scale is increased, the number of slaves connected to the main synchronization terminal can be suppressed. Therefore, communication concentration at the main end is difficult to occur, communication load fluctuations are reduced, and high-precision synchronization can be maintained.

(8) By suppressing the number of slave ends, the communication distance (hop count) between the slave end and the master end can be made uniform as much as possible, and uniform synchronization accuracy (synchronization error) can be realized.
(9) Even if a communication failure occurs near the main end, the main end is distributed, so the spread of malfunctions does not spread throughout the protection system, limiting the range of influence of the communication failure Is possible.

  According to the first embodiment as described above, even if a part of the apps are stopped, the operation can be continued with respect to the healthy apps that can be operated. In addition, application multiple synchronization can eliminate the difficulty of synchronization accuracy and synchronization failure due to system synchronization, greatly improving the reliability, stability, and availability of the protection system.

[2] Second Embodiment A second embodiment will be described with reference to FIG. The second embodiment basically has the same constituent elements as those of the first embodiment shown in FIG. 1, and the same constituent elements are denoted by the same reference numerals and description thereof is omitted.
[Constitution]
The second embodiment is characterized by an activation configuration of an application implemented in each IED. As shown in FIG. 9, in the time synchronization processing units 906 and 907 of the second embodiment, a sampling timing difference between IEDs is obtained by synchronous communication, a timer is started from this sampling timing difference, and processing is started by a timer event. I am letting. The timer value is a value obtained by subtracting the time corresponding to the sampling timing difference from the phase angle equivalent time.

(Relationship between sampling timing and application processing operation timing)
As shown in FIG. 9A, in an IED that operates in a predetermined phase angle cycle, the IED is activated using an event such as an interrupt for the purpose of activating the process at an accurate timing. For example, the rising edge of the sampling signal is sequentially used as an interrupt. App processing can be started.

  In the conventional all-system synchronization that synchronizes the sampling signal, the process start timing of the application can also be synchronized, but the sampling signal is not synchronized in the application multiple synchronization of the present embodiment. For this reason, as shown in FIG. 9B, there is a shift in process activation corresponding to the difference in sampling timing. The sampling timing difference is a deviation of the crystal oscillator 929 between the IEDs and changes sequentially, so the processing timing also changes in the same manner.

  Therefore, in the time synchronization processing units 906 and 907 of the second embodiment, the activation timing of the application process is generated as a timer value to absorb the process activation deviation according to the sampling timing difference and to synchronize the application process. Can do. At this time, if the application is a current differential application for a transmission line implemented in the time synchronization processing unit 907, the execution of IED current differential calculation processing at both ends of the transmission line is synchronized, so the trip signal output timing is tuned. be able to. Therefore, it is possible to achieve more appropriate transmission line accident removal.

  Also, in general, regarding the operation timing of the process of transmitting the electrical quantity input value as a frame, if this varies, the timing of arrival at the IED at the other end also varies, so the processing load of the received frame varies, There is a possibility that the default processing cannot be completed within the phase angle period and the IED function cannot be maintained.

  Even for such a problem, in the second embodiment, the start timing of the frame transmission process is generated by a timer, so that the process can be tuned, and the received frame processing load can be stabilized.

[Action and effect]
According to the second embodiment as described above, the application operation timing of each IED can be tuned even in the application multiplex synchronization in which the sampling signal is not synchronously corrected, and the processing operation can be stabilized by load distribution. it can.

[Modification of Second Embodiment]
Further, as a modification of the second embodiment, it is possible to make the load uniform by using a timer value in consideration of a random number so that the activation timing varies. In such a modified example, when frame transmission processing of a plurality of IEDs is started at the same timing, frame reception is concentrated in a short period of time and the processing load fluctuates, or there is a concern that the consumption bandwidth of the communication line may be exceeded. This is particularly effective for system configurations.

[3] Third Embodiment A third embodiment will be described with reference to FIGS.
[Constitution]
3rd Embodiment is a protection system for implement | achieving accident spread prevention at the time of a circuit breaker non-operation. As shown in FIG. 10, the protection system according to the third embodiment is configured such that the transmission lines L1 and L2 are determined to have an accident by IED # 4 and 5, and the transmission lines L3 and L4 are determined to have an accident by IED # 6 and 7. It is. The transmission lines L1, L2 and the transmission lines L3, L4 can be assembled as independent protection configurations, but the current differential application of the transmission lines L1, L2 by IED # 4, 5 and the transmission by IED # 6, 7 are used. The current differential application of the electric wires L3 and L4 is synchronized.

  In the third embodiment, for example, it is assumed that an accident is detected in the power transmission line L1, and the circuit breaker performs a breaking operation to remove the accident in the power transmission line L1. At this time, a case is assumed in which the circuit breaker becomes inoperative due to a circuit breaker failure, contact failure, or IED # 5 failure, and failure removal fails. In such a case, the circuit breaker in the vicinity of the circuit breaker of IED # 5, that is, the circuit breaker of IED # 7 or the circuit breaker of IED # 6 performs the circuit breaking operation, thereby preventing the spread of the accident. is there.

  In a state where all the IEDs are connected to the same network, not only the current differential between IED # 4 and IED # 5 and the current differential between IED # 6 and IED # 7, but also IED # 4 and IED # 6, IED # 4 and IED # 7, IED # 5 and IED # 6, and IED # 5 and IED # 7 current differentials can be taken. These addable current differentials can also be defined as separate current differential apps. However, in that case, it is necessary to configure synchronous master-slave between the IEDs # 4 to # 7 and perform synchronous communication, raising a concern that the communication load increases and the setting complexity increases.

  Therefore, in this embodiment, only the current differential app of IED # 4 and IED # 6 and the current differential app of IED # 6 and 7 can be synchronized, and each differential operation can be performed, and as a backup for circuit breaker non-operation The accident determination calculation can be performed with a minimum configuration. That is, as shown in FIG. 11, a time synchronization processing unit 907 serving as a slave slave is added to IED # 6 so that IED # 6 communicates with IED # 5 synchronously.

[Action and effect]
In the third embodiment as described above, IED # 6 is synchronized with IED # 5, and IED # 7 is synchronized with the logical time, so that IED # 4-7 are synchronized. That is, the time synchronization processing unit to be added is only one slave slave for IED # 6.

  Further, even if the synchronous communication between the added IED # 5 and IED # 6 is disabled, the whole system is not synchronized. Therefore, the IED # 4 and IED # 5 and the IED # 6 and IED # 7 each have a current difference. It is possible to maintain synchronization within the mobile app and continue healthy operation. That is, it becomes possible to synchronize only between the application groups, and it is possible to prevent the accident from spreading even when the circuit breaker is not operating while expanding the section for determining the accident. In addition, it is possible to reliably avoid problems caused by system synchronization.

[4] Fourth Embodiment A fourth embodiment will be described with reference to FIGS.
[Constitution]
The fourth embodiment is a protection system that employs a redundant application configuration. As shown in FIG. 12, the protection system according to the fourth embodiment is characterized in that a current differential app of power transmission lines L1 and L2 is additionally mounted on IED # 7.

[Action and effect]
In the fourth embodiment as described above, the IED # 7 is responsible for removing the accident of the transmission lines L3 and L4, and at the same time as a backup of the IED # 5 when the IED # 5 fails or when the CB of the IED # 5 is not operating. Can work. Therefore, it is possible to easily build a redundant application configuration without adding an IED.

[5] Other Embodiments The above-described embodiment is presented as an example in the present specification, and is not intended to limit the scope of the invention. In other words, the present invention can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the invention described in the claims and equivalents thereof in the same manner as included in the scope and gist of the invention.

2 Wide-area network line 22 Time distribution server 23 Computer server 9 Synchronous communication driver 902 Internal clock 903 Sampling timing generation circuit 904 Communication processing units 905, 906, 907 Time synchronization processing units 10, L1 to L4 Transmission lines 11a to 13a Current differential application 11b-13b Serial transmission unit 14 Communication lines T1, T2 Logical times # 1- # 6, 11-13 IED

Claims (7)

In protective relay devices with multiple applications implemented,
A time synchronization processing unit is incorporated for each application,
Each time synchronization processing unit is set with a logical time,
Find the sampling timing difference with another protection relay device based on the logical time ,
The time synchronization processing unit, on the basis of the sampling timing difference to calculate the frequency deviation of the crystal oscillator frequency to another protective relay device, characterized users update the logical time by adding the frequency deviation Protection relay device. A group that collects the same application becomes a synchronization group that performs time synchronization within the group.
2. The protection relay according to claim 1, wherein the time synchronization processing unit updates the logical time by using a different time configuration for each synchronization group, and has time configuration information as attached information at the logical time. apparatus. Obtain the sampling timing difference between the protection relay devices from the synchronous communication, put the electric quantity input value and the sampling timing difference on the frame as application information, send it to the other protection relay apparatus, and input the electric quantity at the protection relay apparatus that received the frame 3. The protection relay device according to claim 1, wherein a phase difference corresponding to a sampling timing difference is subjected to a data interpolation calculation from the value, and a protection calculation is performed using an electric quantity interpolation value. Protection relay device according to any one of claim 1 3, characterized in that it comprises a timer for generating a timer value to synchronize the operation timing of the application from the sampling timing difference. The protection relay device according to claim 4 , wherein the timer generates a timer value using a random value. Among a plurality of applications implemented in a plurality of protection relay devices , the same type of application is configured as one synchronization group,
The primary and secondary ends of synchronization are set in the protection relay devices included in the synchronization group,
The main end and the slave end in the same synchronization group are configured to set a logical time in synchronization group units, perform synchronous communication using this logical time, and synchronously correct the logical time ,
The main end in the sync group is a slave end of the main end of another sync group, is configured to be capable of synchronous communication with the main end of another sync group, and a plurality of the sync groups are synchronized. system. The protection system according to claim 6 , wherein a plurality of applications forming a redundant configuration are mounted on the protection relay device.

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