JPS6211155Y2 - - Google Patents

Description

[Detailed description of the invention] This invention is based on the idea that when a ground fault occurs in a power distribution system, a protective relay such as a ground fault relay is activated, and after a certain short period of time after the disconnector is tripped. The present invention relates to a re-closing relay that performs high-speed re-closing by sending out a signal to close a circuit breaker.

When there are many power distribution systems in a substation or the like, a reclosing relay is installed in each of them. When a large number of reclosing relays are installed in this way,
To prevent the relays in each system from closing at the same time, a simultaneous closing prevention signal is sent and received between each reclosing relay, and the own closing signal is sent until the closing of other relays is completed. be delayed. However, in the case of high-speed reclosing, it is necessary to reclose the circuit within a short period of time after the tripping operation of the circuit breaker is completed until the sectional switch in one system opens. If the reclosing relays cooperate to delay the sending of the closing signal, there is a risk that the closing signal will be sent out after a time period during which high-speed reclosing is possible has elapsed.

An object of the present invention is to provide an improved reclosing relay that does not cause the above-mentioned disadvantages.

An embodiment of the present invention will be described below with reference to the drawings. In the figure, 1 is a terminal to which a simultaneous closing prevention signal from another reclosing relay is input, and 2 is a terminal where a protective relay (not shown) such as a ground fault relay or an overcurrent relay detects an accident and shuts off. When issuing a trip signal for a device (not shown), a fault signal obtained by detecting the signal current with a current transformer (not shown) or obtaining a signal from another contact of the protective relay is input. It is a terminal. This fault signal is held by flip-flop 3. When the flip-flop 3 is set by the fault signal, its Q output becomes "H" and the timer 4 is about to be started. This timer 4 is the high-speed reclosing time T
_s , and if the simultaneous injection prevention signal is not input, the time T from the time the accident signal is input.
After _s , the timer is turned on and a signal is output, causing the fast reclosing closing signal sending circuit 5 to send out a fast reclosing closing signal. This input signal passes through an AND gate 6 and an OR gate 10, appears at an output terminal 11, and is sent to a circuit breaker (not shown).

When the simultaneous closing prevention signal is input, the timer 4 is inhibited and cannot be started, and when the input of the simultaneous closing prevention signal ends, this inhibition state is released and the timer 4 is started. Therefore, the transmission of the closing signal is delayed until the input of the simultaneous closing prevention signal from the other reclose relay ends.

By the way, the Q output of the flip-flop 3 is also input to a timer 7 that sets the time T _R during which the distribution system can be quickly reclosed. When the timer 7 times up, the AND gate 6 is closed and the input signal is It becomes impossible to pass. Therefore, the closing signal is delayed by the simultaneous closing prevention signal from the other reclosing relays, and after the reclosing time T _R has elapsed, the closing signal is locked from being sent.

In addition, the circuit shown in this figure includes a sequence circuit 8 for low-speed reclosing, and a closing signal sending circuit 9 for low-speed reclosing.
is provided. This sequence circuit 8 is started by the Q output of the flip-flop 3, and when the high-speed reclosing closing signal is not sent out as described above, or even if it is sent out, an accident is detected again and the reclosing fails. Re-closing or re-closing is performed according to the sequence.

As described in the embodiments above, according to the present invention, when a simultaneous closing prevention signal is input from another source and the sending of the closing signal is delayed and the high speed reclosing enable time has elapsed, the high speed reclose is performed. Since the closing signal is locked so that it is not sent out, it is possible to eliminate the inconvenience that the closing signal for high speed reclosing is sent out after the high speed reclosing possible time has elapsed.

[Brief explanation of the drawing]

The figure is a block diagram of one embodiment of the present invention. 1... Simultaneous input prevention signal input terminal, 2... Accident signal input terminal, 3... Flip-flop, 4, 7
...Timer, 5...High-speed reclosing closing signal sending circuit, 8...Low-speed reclosing sequence circuit, 9...
Closing signal sending circuit for low-speed reclosing, 11... Closing signal output terminal.

Claims (1)

[Scope of utility model registration request] connected to a first external input terminal for a simultaneous input prevention signal from the outside, a second external input terminal for an accident signal from the outside, and the second external input terminal,
It comprises a memory circuit that holds an accident signal, an input terminal, and a prohibition input terminal, the output terminal of the memory circuit is connected to the input terminal, and the first external input terminal is connected to the prohibition input terminal. , a first timer for a high-speed reclosing time that is started by the output of the memory circuit after the inhibited state is released when the input of the simultaneous injection prevention signal is completed, and a time-up signal of this first timer is inputted. A high-speed reclosing circuit is provided with a closing signal sending circuit for transmitting a closing signal for high-speed reclosing circuit in response to a high-speed reclosing circuit, and an input terminal, the output terminal of the memory circuit is connected to the input terminal, and the output terminal of the memory circuit is connected to the output terminal of the memory circuit. a second timer that determines a time during which the high-speed reclosing circuit is possible; and a prohibition circuit that uses the time-up signal of the second timer as a prohibition input to inhibit the high-speed reclosing circuit closing signal from the high-speed reclosing closing signal sending circuit. , and an external output terminal connected to the output terminal of the inhibit circuit.