JPH0216094B2 - - Google Patents

Description

TECHNICAL FIELD OF THE INVENTION The present invention relates to a reclosing device, and particularly to a reclosing device configured to prevent erroneous outputs for each command output.

Technical Background of the Invention Generally, an accident on a power transmission line is detected by a protective relay device, and the detection signal is used to issue a control command to a circuit breaker control device to open the circuit breaker. Moreover, it is necessary to close the circuit breaker once opened and restore the system to its original state, and a re-closing device is a device that quickly, accurately, and automatically performs this restoration operation.

Regarding these reclosing devices, the conventional devices will be explained with reference to the functional block diagram shown in FIG.

The devices shown in FIG. 1 include a bus 1 of the power system, a circuit breaker 3 that turns power on and off to the transmission line 2, a line PT4 that detects the line voltage of the transmission line 2, and a line PT4 that detects the line voltage of the transmission line 2. A line CT5 that detects current, a bus PT6 that detects bus voltage, a protective relay device 7 that receives the outputs from these PT4 and CT5 and detects a fault on the transmission line 2, and a reclosing device that recloses the circuit breaker 3. 8, a control device 9 that actually turns on and off the circuit breaker 3, and an automatic PT switching device 10 that switches the PT voltage for the busbar.

As is clear from the above configuration, line voltage and bus voltage are introduced to the protective relay device 7 and the reclosing device 8 via PT4 and PT6, respectively.

A fault current flowing in the event of a fault in the power transmission line 2 is detected via the line CT5 and introduced into the protective relay device 7. Therefore, the protective relay device 7 detects each of the above-mentioned inputs and provides a relay cutoff signal to the re-closing device 8. Also, before the accident, the reclosing device 8 inputs the on/off state of the circuit breaker 3 via the control device 9, and if the circuit breaker 3 is in the "on" state, it counts a certain period of time as the preparation time. After the above-mentioned time has elapsed, it becomes ready and waits for a relay cutoff signal from the protective relay device 7. However, unless there is an accident, it will remain in this state indefinitely.

FIG. 2 is an internal block diagram of the reclosing device.
And each block is connected to the circuit breaker 3 from the control device 9.
a preparation time circuit 11 that counts the preparation time based on the "on" state signal of the relay cutoff receiving circuit 12 that receives the relay cutoff signal from the protective relay device 7;
A starting circuit 13 that starts up upon completion of the preparation time count and a relay cutoff signal, and a reclosing condition confirmation circuit 1 that checks the conditions for reclosing operation after starting.
4. A reclosing output unit 15 that confirms the establishment of reclosing conditions for a certain period of time and outputs a reclosing command; a voltage and synchronization detection circuit 18 for the power transmission line 2 and the bus 1; and a circuit breaker 3 according to the conditions of the detection circuit 18. It is composed of a cutoff command output section 17 that issues a cutoff command to the machine, and a return circuit 16 that returns startup and preparation completion.

The operation of the reclosing device having the above configuration is as follows.

That is, the preparation time circuit 11 starts counting upon receiving the circuit breaker status signal from the control device 9, and waits for a relay cutoff signal after the counting ends. When the relay cutoff receiving circuit receives a signal from the protective relay device 7 due to the occurrence of an accident, the next stage starting circuit 13 is started. After counting a certain voltage-free time, the re-closing condition confirmation circuit 14 is driven. When the above-mentioned conditions are stably established, the re-closing output circuit 15 is driven to output a re-closing command, and further after a certain period of time,
The reset circuit 16 is driven to restore the output and return to the initial state. Further, a cutoff command is outputted via the cutoff command output circuit 17 depending on the condition of the synchronization detection circuit 18.

As explained in detail above, the reclosing device provides a control signal (“on”, “off”) to the circuit breaker 3. Therefore, the re-closing output unit 15 and the cut-off command output unit 17 for giving the closing command must be highly reliable devices.

FIG. 3 is a basic circuit diagram of a reclosing output section (the same applies to the cutoff command output section) of a conventional digital reclosing device.

Problems with the Background Art As shown in the figure, the logic signal from the control circuit a1 energizes the relay X1 via the converter b1, and becomes a closing signal to the circuit breaker 3 through the contact g1. . However, in the configuration shown in FIG. 3, if a single block circuit (single element) of the control circuit a1 and the converter b1 is defective, an erroneous output may occur.

OBJECTS OF THE INVENTION The present invention has been made to solve the above-mentioned drawbacks, and it is an object of the present invention to provide a reclosing device that does not generate erroneous outputs.

Summary of the Invention The present invention divides one signal that controls a controlled object into two different logic signals, and only when each of the control signals is output as a different logic value,
The control signal is made valid, and the outputs from these AND circuits are used as the respective outputs of the reclosing device.

Embodiments of the invention Examples will be described below with reference to the drawings. Fourth
The figure is a circuit configuration diagram of one embodiment of the recloser according to the present invention, which uses a microprocessor.

In FIG. 4, a2 is a control circuit, b2, b
2' is a converter, and l ₁ and l ₂ are converters, for example, photocouplers are used. and said converter l ₁ ,
The secondary sides of _l2 are each connected in series to form a logical AND condition. X2 is a relay, g2 is a contact, R1,
R2 is a resistor, and P, N and P1, N1 are power supplies. Here, the control signal A1, 1 from the control circuit a2
are contradictory signals; for example, if A1 is "1", 1 becomes "0", and if A1 is "0", 1 becomes "1". However, in this embodiment, A1 is "1" and 1 is "0" as valid signals.

Note that output 1 and A1 are converted from one signal to two signals by software processing by a microprocessor. The two signals thus converted are then output from the microprocessor to the control circuit via the data bus using one bit each, a total of two bits.

Now, considering the case where the control signal is not output,
A1 is "0", 1 is "1", and converter b2,
b2' outputs "0" and "1", respectively. And since the output of converter b2 is "0", converter l ₁
No excitation current can flow through the primary side of the motor, so the secondary side is in an off state. On the other hand, since the output of the converter b2' is "1", no excitation current can flow to the primary side of the converter _l2 , and therefore the secondary side is in an off state. Therefore, the logic condition on the secondary side of each converter l ₁ and l ₂ is not satisfied, and the relay X2 is in an inoperable state.

Next, considering the case where a control signal is output, A1
is “1” and 1 is “0”, so converter b2,
The outputs of b2' are "1" and "0", respectively.

Since the output of converter b2 is "1", the converter
An excitation current flows to the primary side of _l1 , so the secondary side is turned on. On the other hand, since the output of the converter 62' is "0", the excitation current flows to the primary side of the converter _l2 , so that the secondary side of the converter _l2 is turned on. Here, the secondary sides of both converters l ₁ and l ₂ are turned on, and the logical product condition is established, and the relay
operates, and a closing command is output through contact g2.

Therefore, even if the microprocessor goes out of control and the control signals are at the same level, for example, A1 will be "1", 1 will be "1", A1 will be "0", and 1 will be "0".
Even so, if different logic value signals are used as valid signals, the probability of malfunction will be lower than in the past. In other words, the output circuit of 1 and A1 is 2
Since it is valid only when both bits are normal,
There is no erroneous output unless both bits become defective. On the other hand, if the output circuit is 1 bit, a defective 1 bit will result in an erroneous output. Furthermore, even if the converters b2 and b2' are destroyed in the same mode due to the intrusion of an external surge, only one of the converters l ₁ and l ₂ will be conductive, and the relay X2 will not operate.

Although the above embodiment describes a combination of two drive circuits that operate with one signal of positive logic and negative logic, the present invention is not limited to the above embodiment.
Of course, two or more drive circuits may be combined in series and the drive circuits may be configured to operate only when the signals for driving the drive circuits are in a certain pattern.

Effects of the Invention As explained above, according to the present invention, one control signal is made into two mutually different logical value signals, and the logical product output of these is made into an effective signal. Even if a malfunction occurs, erroneous output can be prevented and a highly reliable reclosing device can be provided.

[Brief explanation of drawings]

Fig. 1 is a system block diagram of the reclosing device, Fig. 2 is an internal block diagram of the reclosing device, Fig. 3 is a basic circuit configuration diagram of the reclosing output section of a conventional digital reclosing device, and Fig. 4 is a FIG. 1 is a circuit configuration diagram of an embodiment of a reclosing device according to the present invention. 1... Bus bar, 2... Transmission line, 3... Circuit breaker, 4
...PT for track, 5...CT for track, 6...For bus bar
PT, 7...Protective relay device, 8...Reclosing device,
9...Control device, 10...PT automatic switching device, 1
DESCRIPTION OF SYMBOLS 1...Preparation time circuit, 12...Relay cutoff receiving circuit, 13...Starting circuit, 14...Reclosing condition starting circuit, 15...Reclosing output section, 16...Return circuit, 17...Blocking command output Part, 18...Synchronization detection circuit, a1, a2...Control circuit, b1, b2, b
2'...Converter, l ₁ , l ₂ ...Converter, X1, X2...
...Relay, g1, g2... Contact, R1, R2...
resistance.

Claims (1)

[Claims] 1. In a reclosing device that provides a control signal to a circuit breaker installed in a power transmission line, means for dividing the control signal into two logical values having mutually contradictory logic, and a means for dividing the control signal into two logical values having mutually contradictory logical values. 1. A reclosing device comprising: a logical product means for detecting a logical value, and a means for taking in an output from the logical product means as a closing signal.