JPS6098819A - Reclosing 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 is directed to 'a re-closing method for automatically re-closing a line breaker which has been opened due to an accident on a power transmission line in an electric power system based on various conditions. The present invention relates to a device, and particularly to a monitoring system for a voltage detection circuit that detects bus voltage and line voltage for reclosing.

[Technical background of the invention]

When an accident occurs on a power transmission line, the accident is usually detected by a line protection relay device, and the detection signal is used to issue a control command to the circuit breaker control device to open the circuit breaker. In order to improve the stability of the power system, the circuit breaker that has been opened in this manner must be subsequently closed to restore the system to its original state. A reclosing device performs this restoration operation quickly, accurately, and automatically. The reclosing device is activated by the output signal of the relay element that operates when the protective relay device detects an accident, checks the conditions for disconnecting and reclosing for a certain period of time, and issues a closing command to the circuit breaker.

The conditions for closing a line breaker using a reclosing device include, for example, checking the presence or absence of voltage on the transmission line side and the bus side and the synchronization state, respectively, by checking the line voltage taken out via the voltage transformer and the bus voltage inside the device. It is guided to a detection circuit for judgment.

However, problems with the background art] Since the reclosing device operates only during a system fault, in order to check whether the voltage detector is operating normally, it is necessary to apply a simulated input during periodic inspection to the voltage detector. Either a mock test was conducted, or if constant monitoring was required, the detection units were duplicated and the status was monitored by comparing the outputs of each unit. However, with the former method, constant monitoring is not possible, so it is discovered due to malfunction during short-term inspections or system failures, which reduces the reliability of the equipment.
There is also a problem. In addition, the latter method requires duplication, which means that two sets of the same voltage detector are required, which leads to a rise in price, and also has disadvantages in terms of improving the reliability of the device as a whole because the number of parts increases. It became.

[Purpose of the invention]

The present invention has been made in view of the above-mentioned circumstances, and it enables easy constant monitoring using a digital voltage detector, and also reduces the number of circuit components. The purpose is to provide a circuit closing device.

[Summary of the Invention] The reclosing device of the present invention constantly monitors that the difference in the amount of electricity output from the bus voltage detection section and the line voltage detection section is within a certain range under the condition that the circuit breaker is closed. It is something to do.

[Embodiments of the invention]

FIG. 1 is a block diagram showing an application example of the reclosing device of the present invention. 1 is the bus bar, and this bus voltage is the bus bar PT2
It is now detected by Reference numeral 3 denotes a circuit breaker that connects the power transmission line 5 to the bus bar 1, and is turned on or cut off by a control circuit 7, which will be described later. Reference numeral 4 denotes a line CT, which is installed closer to the line 5 than the breaker 3. Reference numeral 6 denotes a line PT, which is also installed so as to detect the voltage on the line 5 side rather than the breaker 3. 8 is a protective relay device which determines whether or not an accident has occurred in the power transmission line 5 based on the voltage and current from the PT 5 and CT 4, and when it is determined that an accident has occurred, provides the output signal to the control circuit 7. breaker 3. 9 is a reclosing device, which includes an external input receiving circuit 10, a digital bus voltage detection circuit 11, a digital line voltage detection circuit 12, a synchronization detection circuit 13 that detects the synchronization state of line voltage and bus voltage, It is composed of a sequence processing section 14 and an output circuit 15, each of which is composed of a microprocessor. When the external human input receiving circuit 1o receives the output signal of the protective relay device 8, it takes this in as a starting command. As a result, the sequence processing unit 14 is activated, and after a predetermined time period, the bus P
Bus voltage detection circuit 11 that detects the voltage of T2 and line F
Line voltage detection circuit 12 and p'r2 that detect the voltage of T5
.

Synchronous detection circuit 13 that detects phase difference based on the conditions of PT5
The re-closing condition is confirmed by the detection output of , and the output circuit 14 gives a closing command to the circuit breaker 3 via the control circuit 7 to perform quick and accurate system maintenance. Here, a busbar width pressure detection circuit 11, a line voltage detection circuit 12, and a synchronization detection circuit 13 detect the resumption conditions for safe grid restoration.
The importance of this goes without saying.

Next, the entire heavy pressure monitoring procedure of the sequence control section 14 will be explained with reference to the flowchart of FIG.

The conditions of circuit breaker 3 are determined by the control circuit and external input receiving circuit 1.
0 is input and it is determined whether the circuit is open or closed in the circuit condition judgment step 21. If YES, the detected value VIll+ of the bus voltage detection circuit 12 and line voltage detection section 13 is input.
Read the VL in step 22. If no, proceed to the end. The voltage difference 1 va-VLl between the detected values crystallized in the 'iii press-fitting step 22 is determined in the differential voltage determination step. Fl! Jjs12 Differential voltage determination step 24 determines whether the value determined in step 23 is within a predetermined value (reference value; X), and the difference determined in step 24 is determined. If the value is greater than the reference value,
(If the unconformity f1' formula does not hold) Detection failure processing step 2
5 outputs the C-axis to the outside.

[Effects of the Invention] As described above, according to the present invention, when the breaker is in the closed circuit state, the bus voltage and line voltage connected by the breaker can be detected within the range of the reference value. Therefore, it is possible to provide a reclosing device that can immediately detect a defect in the detection unit no matter how the system pressure changes.

[Brief explanation of the drawing]

FIG. 1 is a power diagram to which a recirculating device is applied, and FIG. 2 is a flowchart showing a method for detecting a differential voltage failure between a bus voltage and a line voltage of the recirculating device. 1... Bus bar 2... Bus bar FT 3... Breaker 4... Line CT 5... Line 6... Line PT 7... Control circuit 8... Protection M electric device 9. ... Reclosing device 10 ... External input receiving circuit 1] ... Bus voltage detection circuit 12 ... Line voltage detection circuit 13 ... Synchronization detection circuit 14 ... Sequence processing unit 15 ... Output circuit 21... Breaker condition judgment Kf "Step 22
... Voltage input step 23 ... Differential voltage calculation step 24 ... Differential voltage judgment step 25 ... Detection failure processing step (7317) Representative patent attorney rule close breath right (one person) Figure 1/ Figure 2

Claims (1)

[Claims] In a reclosing device that issues a closing command to a circuit breaker using a system voltage status detection signal obtained from a voltage detector that detects the status of the line voltage and bus voltage of the circuit breaker that is activated and opened at the time of a power system fault, When the circuit breaker provided at each terminal of the system is turned on, the output values of the line voltage detector and the bus voltage detector are compared, and on the condition that the voltages at both ends are approximately equal, the line voltage detector and the bus voltage detector are switched on. A reclosing device characterized by constant monitoring of voltage detectors.