JPS60183936A - Dispersive digital bus protecting relay unit - 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 distributed digital busbar protection relay device in a central location.

[Prior art]

FIG. 1 is a circuit configuration diagram showing a conventional busbar maintenance system. It is installed in 4 is a circuit breaker 5 installed on each power transmission line B above.
are current transformers (CT) installed on each of the above power transmission lines 6, 6 is a potential transformer (PT or PD), 7 is a back-up protection relay for the power transmission line, 8 is a back-up protection relay for the transformer, 9 is the busbar protection relay.

The conventional busbar protection system is configured as described above, and the transmission line back-up protection relay 7 and the transformer back-up protection relay 8 input current and voltage information from the current transformer 5 and the voltage transformer 6, respectively. , a fault in the power transmission line 6 or the transformer 2 is detected by calculating the distance relay, and in the event that the main protection relay, which is omitted in Fig. 1, becomes inoperable, the corresponding main protection relay is Trip circuit breaker 4.

On the other hand, the busbar protection relay 9 inputs current information from the current transformer 5 of each power transmission line 6 independently from the relays indicated by the transmission line backup protection relay 7, the transformer backup protection relay 8, etc., and inputs the current information from the current transformer 5 of each power transmission line 6 to Unless there is a fault, the circuit breaker 4 of all terminals connected to the bus is tripped by detecting a failure of the bus by utilizing the fact that the current inflow and outflow to the bus are equal. It has become.

However, as described above, in the conventional device configuration, the power transmission line back-up protection relay 7, the transformer back-up protection relay 8, and the bus bar protection relay 9 must be installed separately for each terminal. However, considering that all of the protection relays operate very infrequently, they have the drawback of extremely poor cost/performance. Furthermore, in the busbar protection relay 9, input information is concentrated and trip commands must also be distributed to each terminal, and cables or command information transmission paths must also be installed for this purpose, which is uneconomical.

[Summary of the Invention] This invention was made to eliminate the drawbacks of the conventional ones as described above, and by distributing backup protection digital relays for each terminal with the function of busbar protection, By configuring the back-up protection digital relay to only trip its own terminal or tEfi device,
The objective is to obtain a distributed digital busbar protection relay device that improves the efficiency and reliability of power system protection.

[Embodiments of the invention]

FIG. 2 is a circuit configuration diagram showing an embodiment of the present invention,
1 to 6 are the same as the conventional device shown in FIG. 10 is a digital relay that has both a transmission line backup protection function and a busbar accident detection function; 11 is a digital relay that has a transformer backup protection function and a busbar accident detection function; 12
is an optical transmission line in which digital relays 10 and 11 are coupled in a ring shape.

The digital relays 10 and 11 are composed of a filter, a sample holder, a multiplexer, an analog-to-digital converter, a microcomputer, an oscillator that generates sampling and clock pulses, and so on. Explanation will be omitted.

The embodiment of the present invention is configured as described above, and the following:
The operation of the digital relay 10 installed at the power transmission line terminal will be explained. Note that the operation of the digital relay 11 at the transformer terminal may be considered to be completely similar.

The digital relay 10 receives current and voltage information from the current transformer 5 and the voltage transformer 6, digitizes it, and performs distance relay calculation processing, etc., thereby detecting an accident on the power transmission line. Furthermore, the digital relay -10 uses a ring-shaped optical transmission path to transmit current information measured at its own end to a plurality of digital relays 10 and 11 installed at other terminals. Similarly, current information measured at the other terminal is sent from the digital relay at the other terminal.

In this way, information measured at all the power transmission line terminals and transformer terminals is collected in the digital relay 10, so that an accident on the bus can be detected by applying Kirchhoff's law. In the case of a busbar fault, the digital relays 10.11 of each terminal simultaneously detect the fault, so all the circuit breakers 4 of the busbar are tripped, and the busbar protection function is satisfied.

The above-mentioned digital relay 10 performs a back-up protection function on the transmission line B as well as detecting a bus fault, but since the back-up function is generally a timed trip, the calculation process can be relatively slow, and current microcomputers, which are the components of the digital relay, can perform the backup function. Multiplexing of both functions is possible.

Although the above embodiment shows an 8-terminal bus bar configuration,
The number of terminals may be arbitrary. Further, even if there are bus ties, bus sections, etc., there is usually a bus separation relay, etc., so it is sufficient to have such a relay share the bus protection function.

[Effects of the Invention] As described above, according to the present invention, the busbar protection function is distributed to the backup protection digital relay functions of the power transmission line terminals and transformer terminals connected to the busbar, so that the backup protection relay and the busbar protection There is no need to provide separate relays, the device can be made inexpensive, and there is no need to route trip command information transmission lines as in the past, resulting in a highly reliable distributed digital busbar protection relay device. In addition, since multiple back-up protection digital relays are connected in a ring shape through optical transmission lines, consideration must be given to avoiding information collisions and synchronizing data sampling points when transmitting and receiving information between each back-up protection digital relay. It's something you don't need.

[Brief explanation of the drawing]

Figure 1 is a circuit diagram of a conventional busbar protection relay device;
The figure is a circuit configuration diagram of a bus bar maintenance dφ relay device according to an embodiment of the present invention. In the figure, 1...Bus bar, 2...Transformer, 6...
Transmission line, 4... Breaker, 5... Current transformer, 6...
Instrument transformer, 7, 8...backup protection relay, 9...
Bus line protection IJ relay 10.11...Digital relay, 12...Optical transmission line. In addition, in the figures, the same reference numerals indicate the same or equivalent parts. Figure 1

Claims (1)

[Claims] Sampling and digitizing measured amounts of current and voltage in the power system, processing these digital data to detect a failure in the power system, and tripping the breaker at each terminal of the protected bus of the power system. It is equipped with a plurality of backup protection digital relays and an optical transmission line that connects each of the backup protection digital relays in a ring shape, and transmits current information measured at each of the terminals to each of the backup protection digital relays through the optical transmission path. By configuring a program so that each back-up protection digital relay can detect an accident on the protected bus, the bus protection function is decentralized to each of the back-up protection digital relays. Distributed digital busbar protection relay device that is tentatively based on this.