JPS6118311A - Digital protective relaying device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to a digital protective relay device for a power system, and in particular monitors abnormalities in the device itself, outputs an alarm when an abnormality is detected, and displays an abnormality display. This invention relates to a digital protective relay device that performs

[Prior art]

Conventionally, there have been devices of this type as shown in FIGS. 1 to 4. In these figures, 1 is a circuit breaker, 2 is a transformer, 3a to 3d are protection relays, and 4a to 4d are contacts of the protection relays 38 to 3d. In FIG. 3, 3 is a digital relay.

Next, the operation will be explained. System input is introduced to protection relays 38 to 3d via transformer 2 to detect system faults. Protection relays 3a to 3d each have contacts 4a to 4d individually.
When an accident is detected in the system, the circuit breaker 1 is operated to close them, and the circuit breaker 1 is shut off by K, thereby disconnecting the accident from the system.

On the other hand, in the case of the digital relay 3 shown in FIG. 3, each digital relay 3 houses many relay elements, introduces system information to each one via the transformer 2, and executes each relay calculation process. When an accident is detected in the system, the corresponding output relay is activated to shut off the circuit breaker 1, thereby disconnecting the accident from the system. These relay elements are composed of multiple parts, and if any of the parts becomes defective, the protection function must stop. That is, if even one of the parts constituting the digital relay 3 is defective, all the functions contained therein will be stopped, so it is necessary to stop the protective function over a wide maintenance range.

Conventional digital protective relay devices are configured as described above, so even if a single component malfunctions, the protection function must be stopped over a wide range of areas, and in order to obtain such protection function, The disadvantages were that multiple digital relays were required and the equipment was bulky (and expensive).

[Summary of the invention]

This invention was made in order to eliminate the drawbacks of the conventional ones as described above, and by diagnosing the defective part in a part of the digital relay and stopping only the relay element related to the defective partial pressure, The purpose is to provide a low-cost, highly reliable digital protective relay device.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to the drawings. Fifth
In the figure, 58-5d are input quadrature lance parts, 6a-6d
is a filter section, 7 is an input switching section, 8 is an analog/digital (A/D) conversion section, and 9 is a central processing unit (CPU)
10 is a memory section, 11 is an output section, and 4a to 4d are contacts. FIG. 6 shows a flowchart of the processing of the apparatus of this invention.

128 to 12C are respective processing blocks. Next, the operation will be explained.

The system input is detected by the transformer 2, and the input quadrature transformer 53-5
After insulation and level conversion are performed on the signal detected in step d, the signal is led out to the next filter sections 63 to 6d. The filter sections 63 to 6d remove unnecessary harmonic components from the input signals and extract fundamental wave components. The input switching section 7 sequentially selects and outputs the inputs from the filter sections 6a to 6d, and inputs the selected signal to the next A/D conversion section 8, where it is converted from an analog value to a digital value. The CPU section 9 uses this digital value as data and executes calculations and processing for detecting the presence or absence of a system fault using the program stored in the memory section 10 and KJ. When the CPU section 9 detects a fault in the system, it operates the contacts 4a to 4d corresponding to the fault via the output section 11 to disconnect the circuit breaker and remove the fault from the system. As mentioned above, this digital relay 31C has many functions as relay elements, executes all the processes of these functions, and also appropriately executes automatic monitoring processes for detecting abnormalities in each part. When viewed from a hardware and software perspective, this digital relay 3 is composed of individual parts of each relay element and common parts. For example, the input quadrant 5a
5d, filters 6a to 6d, output relay part 11, etc. are individually provided for each relay. The functions of these hardware are automatically monitored on an individual basis as described above, and the operation and termination of each relay element is determined according to the resulting diagnosis results. That is, in order to detect the defective part, the processing block 128 of the relay element shown in FIG.
- 12C, etc. to minimize the range of malfunctions caused by malfunctions, improve the operability of the equipment, and maintain reliability.

In addition, in the above embodiment, the input/output section was explained, but
The same applies to the memory section and the like.

Further, although it has been explained that the abnormality processing is bypassed, the final output may be locked, and the same effect can be achieved.

〔Effect of the invention〕

As described above, according to the present invention, since the system is configured to limit the range of outage when an abnormality occurs, the system can be manufactured at low cost and with high accuracy.

[Brief explanation of drawings]

Figure 1 is a block diagram of a conventional digital protective relay, Figure 2 is a trip circuit diagram using the contacts of the protective relay shown in Figure 1, and Figure 3 is a block diagram of a conventional digital protective relay. Block diagram, FIG. 4 is a trip circuit diagram using the contacts of the digital relay shown in FIG. 3, FIG. 5 is a block diagram of a digital protective relay device according to an embodiment of the present invention, and FIG. 6 is shown in FIG. FIG. 3 is a processing block diagram of the device. 1... Breaker, 2... Transformer, 3... Digital relay, 3a to 3d... Protection relay, 48 to 4d...
・Contacts, 5a to 5d... Input quadrature lance part, 6a to 6d
...Filter section, 7.Input switching section, 8.Human/D conversion section, 9.CPU section, 10.Memory section,
11... Output section. In addition, in the figures, the same reference numerals indicate the same or equivalent parts. Patent Applicant: Mitsubishi Electric Corporation Figure 1 Figure 2 Figure 3 Figure 4 Figure 6 - EXT Procedural amendment (voluntary)

Claims (1)

[Claims] A plurality of filter sections that extract fundamental wave components from each signal detected from the system to be protected, an input switching section that sequentially selects and outputs the output signals of these filter sections, and an output signal of the input switching section that converts the output signal into a digital signal. An analog/digital converter converts it into a signal, reads the output signal of this analog/digital converter, performs arithmetic processing to detect an accident occurring in the above system, and issues a shutdown command when an accident is detected. The central processing unit includes a central processing unit that outputs an output, and an output relay that causes a circuit breaker connected to the system to shut off so as to eliminate the accident based on the shutoff command output from the central processing unit, and the central processing unit is a digital protection system that executes monitoring processing to determine whether the function of each part including the above analog-to-digital converter is good or bad, and when a fault is detected in the above function, it outputs an output to notify the fault. Relay device.