JPH10191547A - Digital type protection relay device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a digital type protection device capable of definitely pro tecting data even though the equipment power supply becomes OFF state immedi ately after the equipment power supply turns ON in a data protection method in which an interrupt is applied to a computer during power interruption of equipment power supply or power supply OFF operation, data in a memory medium is stored in a non-volatile memory, and stored data of non-volatile memory are read to the memory medium during power recovery or power supply ON operation. SOLUTION: Data to be stored in EEPROM, which becomes a non-volatile memory after power supply ON, are read to other memory medium (S1), when this reading is completed, a keyword meaning read completion is written to other memory medium (S2). Thereafter, when the equipment power supply is turned off (S3), it is checked whether a keyword coincides with a preset value (S4), and data in the memory medium are stored in EEPROM only when the keyword is the same (S5). By doing this, the storage of an indeterminate value in a non-volatile memory can be avoided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a digital protection relay device, and more particularly to a data protection method in the event of a power failure of a device power supply.

[0002]

2. Description of the Related Art Digital protection relays take in various types of protection by detecting the voltage and current of a power system to be protected as digital data by sampling, and using these data to detect a short circuit or a ground fault. Operation is performed to obtain a protection output such as tripping a circuit breaker when protection is required.

As shown in FIG. 2, a digital protection relay device having such a function includes a computer 1 as a central unit, and various input / output devices 2 to 5 to realize various protection functions. In addition, a protection function for maintaining a normal protection processing function is provided with a hardware or software configuration.

[0004] As one of the protection functions, a function is provided for protecting the current data at the time of a power failure of the apparatus power supply 6. This data protection function enables the computer 1
CPU 1 ₁ to interrupts, protection data (measurement data and processing data, trip state data) that needs to save the RAM 1 ₂ or become non-volatile memory from the register EEPROM 1 _3, nonvolatile memory when power returns of Is read into the RAM or the register and the protection operation is restarted.

[0005]

In the conventional data protection system, data is stored in a non-volatile memory by interrupt processing when a power failure or off operation of the device power supply, and is stored in the non-volatile memory when power is restored or the power is turned on. The data is read out to a storage medium such as a RAM.

In this data protection method, when a power-off operation or power failure occurs immediately after the power supply of the device is turned on, that is, when a power failure occurs while data stored in the non-volatile memory is being read to another storage device due to the power-on. When the power is turned off or the power is turned off, the undefined data is re-saved from another storage device to the non-volatile memory, and is restored from the non-volatile memory to the other storage medium when the power is restored or at the next power-on. Data is read, resulting in an incorrect protection operation.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a digital protection relay capable of reliably protecting data even when the power of the device is turned off immediately after being turned on.

[0008]

SUMMARY OF THE INVENTION The present invention checks whether or not the process of reading data from a non-volatile memory to another storage medium is completed when the power of the device is turned on. It is designed to prevent the value from being stored, and is characterized by the following method.

When a power failure or power off operation of the apparatus power supply is performed, the computer is interrupted, data in a storage medium is stored in a non-volatile memory, and when power is restored or a power on operation is performed, the data stored in the non-volatile memory is stored in the storage medium. In a digital protection relay device for performing a protection operation by reading, a keyword is written into the storage medium when the data stored in the nonvolatile memory is completely read into the storage medium, and the data in the storage medium is stored in the nonvolatile memory. Means for saving only when the keyword matches a value set in advance.

[0010]

FIG. 1 shows a processing procedure of a data protection processing function according to an embodiment of the present invention. In the configuration of FIG. 2, in the power recovery or on operation of the device power supply, read in RAM1 of ₂ or CPU registers comprising the data to be stored in EEPROM 1 ₃ comprising the non-volatile memory to another storage medium (S1), this reading is completed Then, a keyword (for example, 1234H) indicating completion of reading is written into the RAM ₁₂ or the like serving as another storage medium (S2).

In this state, the computer 1 starts the protection operation, and when a power failure occurs or is turned off during the protection operation, the computer 1 starts an interruption process to the CPU due to the power off (S3). It is checked whether the written keyword matches a preset value (S4).

If the check shows that the keywords are the same,
The data to be stored in another storage medium is stored in the EEPROM (S5). If the keywords are not the same, the interrupt processing ends without performing the processing S5.

According to the above processing, whether or not data writing from the EEPROM to another storage medium, which is executed when the apparatus power is turned on, is completed is stored as a keyword, so that it can be used during a subsequent power failure or power off operation. When the predetermined keyword is stored, it is determined that the regular data is stored in another storage medium, and the data is stored in the non-volatile memory to prepare for the next power-on.

Therefore, when the power is turned off immediately after the power is turned on, it is possible to prevent an indefinite value from being written to the nonvolatile memory.

[0015]

As described above, according to the present invention, by checking whether or not the process of reading data from the nonvolatile memory to another storage medium has been completed when the power of the device is turned on, the nonvolatile memory is turned off when the power is turned off. In the case that the power is turned off immediately after the power is turned on, it is possible to prevent the writing of the indefinite value to the nonvolatile memory even when the power is turned off. This has the effect of reliably preventing the protection operation.

[Brief description of the drawings]

FIG. 1 is a data protection processing procedure diagram showing an embodiment of the present invention.

FIG. 2 is a configuration diagram of a digital protection relay device.

[Explanation of symbols]

1 ... computer _{1 1 ... CPU 1 2 ... RAM} 1 3 ... EEPROM ( nonvolatile memory) 2-5 ... output device 6 ... unit power

Claims (1)

[Claims] An interrupt is issued to a computer at the time of a power failure or power-off operation of a device power supply, and data in a storage medium is stored in a non-volatile memory, and the stored data of the non-volatile memory is stored at the time of power recovery or power-on operation. In a digital protection relay device for performing a protection operation by reading out to a medium, when the data stored in the nonvolatile memory is completely read out to the storage medium, a keyword is written to the storage medium,
A digital protection relay device, comprising: means for storing data of the storage medium only when the keyword matches a preset value when storing the data in the nonvolatile memory.