JP2006221483A - Digital protection relay device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce writing of data and the like from a nonvolatile memory to a storage medium in occurrence of a momentary power failure and the like for preventing generation of an undefined value even when a device power supply is turned on during storage of the data from the storage medium to the nonvolatile memory. <P>SOLUTION: By interruption in a power failure of the device power supply or in power supply turn-off operation, data of the storage medium such as a RAM 1<SB>2</SB>are stored in a backup RAM 1<SB>4</SB>equipped with a short-time specification backup power supply and an EEPROM 1<SB>3</SB>. When a normal keyword is not written in the backup RAM in recovery of the device power supply or in power supply turn-off operation, the data and keyword stored in the EEPROM are written in the backup RAM. In the case of a power failure of the device power supply or in turn-off operation, the data in the backup RAM are stored in the nonvolatile memory only when the normal keyword is written in the backup RAM. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a digital type protective relay device, and more particularly to a data protection system at the time of a power failure of a device power supply.

  The digital protection relay device captures the voltage and current of the power system to be protected as digital data by sampling, and uses these data to perform various protection calculations to detect system short circuits, ground faults, etc. Protective output such as tripping the circuit breaker when required.

  As shown in FIG. 3, the digital type protective relay device having such a function has a computer 1 as a central part and includes various input / output devices 2 to 5 to realize various protective functions, and is also normal. A protection function for maintaining a proper protection processing function is provided in a hardware or software configuration.

As one of the protection functions, a function for protecting current data at the time of a power failure of the apparatus power supply 6 is prepared. This data protection function interrupts the CPU ₁₁ of the computer 1 when a power failure is detected, and the EEPROM 1 that converts the data (measurement data, arithmetic processing data, trip state data, etc.) requiring protection from the RAM ₁₂ or register to a nonvolatile memory. ₃ is saved, and the contents of the non-volatile memory are read out to the RAM or register when power is restored, and the protection operation is resumed.

  In such a data protection method, when an off operation or a power failure occurs immediately after the device power is turned on, that is, while data to be stored in the nonvolatile memory is being read to another storage medium such as the RAM 12 by turning on the device power. If a power failure occurs or the power is turned off again, indefinite value data is re-saved from the other storage medium to the non-volatile memory. Indefinite value data is read out, resulting in an erroneous protection operation.

  In order to solve this problem, there is a data storage method shown in FIG. 4 (see, for example, Patent Document 1). In this method, the apparatus power supply is restored, and data stored in a nonvolatile memory such as an EEPROM is written in a storage medium such as a RAM (S1), and a specific keyword is written in the storage medium when the writing is completed (S2). . Thereafter, when the apparatus power is turned off (S3) and the data of the storage medium is stored in the non-volatile memory, it is stored only when the keyword matches a preset value, and is left as it is when the keyword does not match ( S4, S5).

With this save method, if the power is turned off before the keyword is written, the indeterminate value is prevented from being written to the nonvolatile memory, the normal value is retained in the nonvolatile memory, and the next power Can be written to storage media when on.
Japanese Patent Laid-Open No. 10-191547

  In the conventional data protection method having the processing flow shown in FIG. 4, it is necessary to write the data saved in the nonvolatile memory such as the EEPROM to the storage medium such as the RAM and the save completion keyword every time the apparatus power is restored. The return process is delayed.

  Also, when the device power is turned off (S3) and the device power is turned on or restored again (S1) while data is being saved from another storage medium to the EEPROM, the undefined value is stored in the EEPROM. Is written to the storage medium (S2). In this case, there is a problem that an erroneous protection operation is caused.

  An object of the present invention is to reduce the writing of data from a nonvolatile memory to a storage medium when an instantaneous power failure occurs, and when the apparatus power is turned on while saving data from the storage medium to the nonvolatile memory. Another object of the present invention is to provide a digital protective relay device that can prevent the occurrence of indefinite values.

  In order to solve the above-mentioned problems, the present invention provides a backup RAM with a short-time specification backup power supply, writes and holds data in a storage medium such as a RAM, and data from a nonvolatile memory for the power supply holding time. It is possible to write and hold keywords and has the following method.

(1) means for interrupting the CPU at the time of a power failure or power-off operation of the apparatus power supply and storing data in the storage medium in a backup RAM and a nonvolatile memory with a short-time specification backup power supply;
Means for writing data and keywords stored in the nonvolatile memory to the backup RAM when a normal keyword is not written to the backup RAM at the time of power recovery of the apparatus power supply or power-on operation;
Means for storing data in the backup RAM in the non-volatile memory only when the regular keyword is written in the backup RAM at the time of power failure or off operation of the apparatus power supply.

  As described above, according to the present invention, a backup RAM with a short-time specification backup power supply is provided, and writing and holding of data in a storage medium such as a RAM, and data and keywords from a nonvolatile memory for the power holding time. Because it is possible to write and hold data, it is possible to reduce the writing of data, etc. from the nonvolatile memory to the storage medium when an instantaneous power failure occurs, and the device power is turned on while data is being saved from the storage medium to the nonvolatile memory. In this case, an indefinite value can be prevented from occurring.

FIG. 1 is a configuration diagram of a main part for data protection in a digital type protective relay device showing an embodiment of the present invention. Portions figure differs from FIG. 4, the computer 1 is in that to add a backup RAM 1 _4. Backup RAM 1 ₄ is included backup power for a short time specifications, such as capacitors, enabling holding the power supply holding time just holding the write data in the storage medium such as a RAM, and the writing of data and keywords from the nonvolatile memory To.

The data storage method according to this embodiment is a processing flow shown in FIG. First, the interrupt processing to CPU 1 ₁ for when power failure or the like of the device power supply, protection required data (measurement data and processing data, trip state data, etc.) from RAM 1 ₂ and registers the backup RAM 1 ₄ and EEPROM, Save to both the non-volatile memory 1 _3.

Thereafter, when the device power supply is restored, because the backup RAM 1 ₄ to determine whether healthy, (and 1234H) specific keywords backup RAM 1 ₄ checks whether written (S11). In this case, since the time of power failure of the device power not written keyword is written into the backup RAM 1 ₄ the EEPROM 1 ₃ stored data (S12), it is written the keyword further backup RAM1 ₄ (S13).

When again power-off occurs in this state (S14), and executes the interrupt processing to the CPU 1 _1, keywords backup RAM 1 ₄ checks whether or not the normal (S15), legitimate storing data from the backup RAM 1 ₄ to EEPROM 1 ₃ if (S16). Furthermore, if the keyword backup RAM 1 ₄ is not legitimate it may keep the processing ends without anything.

In this state, when the device power is restored or turned on, in the process S11, as long as the keyword of the backup RAM 1 ₄ is a regular, without executing the process S12, S13, CPU 1 ₁ returns to the normal processing. Therefore, if the backup RAM 1 ₄ is healthy, you are possible to omit the execution of the processing S12, S13.

Further, in the middle of processing S16, when the power is restored, since the keyword backup RAM 1 ₄ is normally held, without EEPROM 1 ₃ data are made to the backup RAM 1 ₄ writes (S12) or the like, is undefined It can be prevented from occurring.

The principal part block diagram for the data protection which shows embodiment of this invention. The data protection processing procedure figure in embodiment. The block diagram of a digital type protective relay device. The conventional data protection processing procedure figure.

Explanation of symbols

1 Computer 1 ₁ CPU
1 ₂ RAM
1 ₃ EEPROM
1 ₄ backup RAM

Claims (1)

Means for interrupting the CPU at the time of a power failure or power-off operation of the apparatus power supply and storing the data in the storage medium in a backup RAM and a nonvolatile memory with a short-time specification backup power supply;
Means for writing data and keywords stored in the nonvolatile memory to the backup RAM when a normal keyword is not written to the backup RAM at the time of power recovery of the apparatus power supply or power-on operation;
Means for storing data in the backup RAM in the non-volatile memory only when the regular keyword is written in the backup RAM at the time of power failure or off operation of the apparatus power supply Relay device.

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