JPS60223416A - 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 realized by software (hereinafter abbreviated as S/W) using a microcomputer.

[Prior art]

A conventional device of this type is shown in FIG. 1
is a transformer installed in a power system (not shown).

an input section that inputs voltage and current from a current transformer or the like and converts the input level; 2 is an analog/digital conversion section that converts the analog value supplied from the input section 1 into a digital value; 3 is the analog; A central control unit that performs calculations, timers, sequences, and system fault judgment according to a program read from the memory unit 4 based on the digital value output from the digital conversion unit 3; 5 connects the central control unit 3 with an external circuit; This is an input/output section that performs input/output signal interoperation. The combination K of the above-mentioned parts 1 to 5 constitutes a part of the digital relay.

The conventional digital protective relay device has the above-mentioned configuration, and its operation will be explained below with reference to the processing flow shown in FIG. 2. The input section 1 uses a built-in filter circuit to extract the fundamental frequency component in the input data, removes unnecessary harmonic components, and converts the output data of the analog value into a digital value using the analog/digital conversion section 2. Then, using the digital value output from the analog/digital converter 2, the central controller 3 executes calculations and judgments in accordance with the program stored in the memory 44C, and outputs the data to the external device via the input/output unit 5. Outputs the output signal to. The procedure for executing calculations, discrimination, etc. in this central control unit 3 is as follows.
As shown in the processing flow of FIG. 2, a series of processes 1. Process 2 is executed sequentially and time-divisionally within a predetermined time.

Conventional devices are configured as described above, so if many relays are configured with one digital relay, the relay performance must be degraded or the number of digital relays must be increased. There were disadvantages such as a decrease in the performance of the protective relay device, an increase in the size of the device, and an increase in cost.

[Summary of the invention]

This invention was made in order to eliminate the drawbacks of the conventional methods as described above, and it separates the processing methods into those that require high speed and those that require low speed. The purpose of the present invention is to provide a high-performance, low-cost, compact digital protective relay device by performing 1/n times of processing.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to FIG.

FIG. 3 shows a processing flow executed by the central control section of the digital relay unit shown in FIG. 1.

The operating principle of the digital relay is as described above. The functional processing that constitutes the characteristics of the digital relay consists of a first processing 1 that performs calculations using input data and performs accident determination, and a second processing 2 that controls the timer and sequence functions. In addition, the principle of fault discrimination for digital relays is as shown in example (3). For example, by using input data every 30' electrical angle,
The difference input data are squared, the magnitude is determined, and accident determination is performed. All relay processing must be executed within such a short fixed period of time. In this way, in order to process all the processes within a certain period of time, it is necessary to increase the number of digital relay units.

Therefore, the present invention divides the relay processing in the central control unit into the first process 1, which is a process that determines the detection performance of the relay and must be executed at high speed, and the relay process that does not become a factor that determines the detection performance of the relay. The first process 1 is distinguished from the second process 2 that executes a timer and lee sequence.
For the second process 2, the process is divided into n equal parts and the time-sharing process is executed every n times. In this way, the relay processing section is divided into a high-speed processing section and a low-speed processing section that directly determine the relay performance, and the relay processing section is configured to perform time-sharing processing.

In the above embodiment, a digital relay was described, but the same effect (4) can be obtained with an analog relay.

〔Effect of the invention〕

As described above, according to the present invention, the relay processing is divided into the first processing for determining a system fault and the second processing for processing the timer and sequence, and the first processing is executed every time. The second process is configured to be executed every n times, which eliminates the need for hardware (H/W) and allows a highly accurate digital protective relay device to be made compact and inexpensive without deteriorating performance. It has the effect of

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of a digital relay, FIG. 2 is a conventional processing flow diagram, and FIG. 3 is a processing flow diagram according to an embodiment of the present invention. DESCRIPTION OF SYMBOLS 1... Input section, 2... Analog/digital conversion section, 3... Central control section, 4... Memory section, 5... Input/output section, 6... Part of digital relay. In the figures, the same reference numerals indicate the same or equivalent parts. Figure 1 6 - Figure 2 71-

Claims (1)

[Scope of Claims] An input section that converts an input level, an analog/digital conversion section that converts an analog value supplied from the input section into a digital value, and the analogue. A central control unit that performs calculations, timers, sequences, and judgments on grid failures according to the program read from the memory unit based on the digital values output from the digital conversion unit, and input/output by connecting the central control unit and external circuits. In a gagetal relay that is composed of an input/output section that performs a signal interface, the relay processing performed by the central control section is divided into a first processing that calculates input values and determines a system fault, and a second processing that processes a timer and sequence. A digital protective relay device characterized in that it is divided into two processes, the first process is executed every time, and the second Asahi burial is executed every n times.