Method for monitoring opening and closing time of circuit breaker based on relay protection device

Abstract

The invention relates to a method for monitoring the opening and closing time of a circuit breaker based on a relay protection device, and the method comprises the steps: monitoring the change of an auxiliary contact in the closing and reclosing processes of the circuit breaker, recording related moments, calculating the closing and reclosing time, and carrying out the early warning of the time exceeding a preset value; and monitoring the change of the auxiliary contact in the protection tripping process, recording the output moment of the protection tripping contact and the tripping confirmation moment, calculating the tripping time, and carrying out early warning on the tripping time exceeding a preset value. In addition, the method further comprises the steps of obtaining a no-current moment and a circuit breaker tripping moment, and determining a tripping confirmation moment after comparing the two moments. According to the method, the action time of the circuit breaker can be monitored in real time, the safety and reliability of a power system are effectively improved, and an important basis is provided for fault analysis and system maintenance.

Description

Technical Field

[0001] The present invention relates to the technical field of substations, and in particular to a method for monitoring the opening and closing time of a circuit breaker based on a relay protection device. Background Art

[0002] As an important component of the power system, the circuit breaker is one of the key devices for power grid power supply. The stability and reliability of its performance are of great significance to ensuring the safe operation of the power system. The mechanical characteristics of the circuit breaker, such as the opening and closing speed and operation time, are important indicators for evaluating its performance. The operation time of the circuit breaker directly affects the magnitude and distribution of the fault current. If the circuit breaker's operation time is too long, the fault current in the circuit will continue to flow, which may cause damage to other equipment in the circuit and easily cause the circuit breaker contacts to burn. The opening and closing speed of the circuit breaker directly affects the voltage quality and frequency stability of the power system. If the opening and closing speed of the circuit breaker is too slow, it may cause problems such as voltage fluctuations and frequency deviations, affecting the stable operation of the power system.

[0003] Currently, the mechanical performance monitoring of high-voltage circuit breakers mostly relies on dedicated condition monitoring equipment. This requires installing multiple sensors on the breaker body to collect and analyze data such as the opening and closing coil current, operating mechanism vibration signals, and contact displacement. While this solution is suitable for critical high-voltage circuit breakers, it is difficult to scale for the vast number of medium- and low-voltage circuit breakers due to cost and maintenance workload. These breakers far outnumber high-voltage breakers, and their quality varies widely. Summary of the Invention

[0004] The purpose of the present invention is to propose a method for monitoring the opening and closing time of circuit breakers based on relay protection devices, which can monitor the circuit breakers in real time, detect potential faults in time and deal with problems, greatly improve the safety of the power system and ensure the stability of the power system.

[0005] To achieve the above object, the present invention provides a method for monitoring the opening and closing time of a circuit breaker based on a relay protection device, comprising the following steps:

[0006] Monitor the changes of auxiliary contacts during the closing process of the circuit breaker and record the output time t of the remote closing contact 合输出 And closing confirmation time t 合 ;

[0007] Calculate the remote closing time, T 合 =t 合 -t 合闸输出 ;

[0008] When T 合 >When the preset value is reached, a remote closing time warning will be issued.

[0009] Preferably, the method further comprises the following steps:

[0010] Monitor the changes of auxiliary contacts during the circuit breaker reclosing process and record the reclosing contact output time t 重合输出 And closing confirmation time t 重合 ;

[0011] Calculate the reclosing time, T 重合 =t 重合 -t 重合输出 ;

[0012] When T 重合 >When the preset value is reached, a reclosing time warning will be issued.

[0013] Preferably, the method further comprises the following steps:

[0014] Monitor the changes of auxiliary contacts during the circuit breaker opening process and record the output time t of remote control opening contacts 分输出 and trip confirmation time t 分 ;

[0015] Calculation of tripping time, T 分 =t 分 -t 分输出 ;

[0016] When T 分 >When the preset value is reached, a trip time warning will be issued.

[0017] Preferably, the method further comprises the following steps:

[0018] Get the no-flow time t 无流 and the circuit breaker tripping time t 跳位 ;

[0019] Compare 无流 and t 跳位 , take t 无流 and t 跳位 The latter moment is t 分 ;

[0020] Preferably, the method further comprises the following steps:

[0021] If at least two of the three phase currents are greater than the preset value before remote tripping, the time when all three phase currents are less than the preset value after remote tripping is recorded as t 无流 If there is no remote tripping before at least two of the three phase currents are greater than the preset value, then t 无流 is an invalid value, then take t 跳位 As t 分 .

[0022] Preferably, the method further comprises the following steps:

[0023] Monitor the changes of auxiliary contacts during the circuit breaker protection tripping process and record the protection tripping contact output time t 跳输出 and trip confirmation time t 跳闸 ;

[0024] Trip time calculation, T 跳闸 =t 跳闸 -t 跳闸输出 ;

[0025] When T 跳闸 >When the preset value is reached, a trip time warning will be issued.

[0026] Preferably, the method further comprises the following steps:

[0027] Get the no-flow time t 无流 and the circuit breaker tripping time t 跳位 ;

[0028] Compare 无流 and t 跳位 , take t 无流 and t 跳位 The latter moment is t 跳闸 ;

[0029] Preferably, the method further comprises the following steps:

[0030] If at least two of the three phase currents are greater than the preset value before the protection trips, the time when the three phase currents are all less than the preset value after the protection trips is recorded as t 无流 If there is no protection trip before at least two of the three phase currents are greater than the preset value, then t 无流 is an invalid value, then take t 跳位 As t 跳闸 .

[0031] The method proposed by the present invention has the following beneficial effects:

[0032] By monitoring the opening and closing time of the circuit breaker through the relay protection device, the operating status of the circuit breaker can be grasped in real time, and potential faults can be discovered in time; by monitoring the opening and closing time of the circuit breaker, once an abnormality is found, an early warning can be immediately issued, so that measures can be taken to prevent the accident from expanding and improve the safety of the power system; the method of the present invention does not need to install a variety of sensors on the circuit breaker body, simplifies the monitoring equipment, reduces costs, and is easy to promote in medium and low voltage circuit breakers; due to the simplification of the monitoring equipment, the corresponding maintenance workload is also greatly reduced, which is convenient for the management of operation and maintenance personnel; by monitoring the opening and closing time of the circuit breaker, voltage fluctuations and frequency deviations can be effectively controlled to ensure the stable operation of the power system. In summary, the present invention provides a simple, efficient and economical method for monitoring the opening and closing time of the circuit breaker, which is of great significance for ensuring the safe and stable operation of the power system. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0034] Figure 1 The present invention is a flowchart of a method for monitoring the opening and closing time of a circuit breaker based on a relay protection device. DETAILED DESCRIPTION

[0035] The detailed description of the accompanying drawings is intended as an illustration of the current embodiment of the present invention and is not intended to represent the only form in which the present invention can be implemented. It should be understood that the same or equivalent functions can be accomplished by different embodiments that are intended to be included in the spirit and scope of the present invention.

[0036] See Figure 1 An embodiment of the present invention provides a method for monitoring the opening and closing time of a circuit breaker based on a relay protection device. The relay protection device collects the normally open auxiliary contacts and normally closed auxiliary contacts of the circuit breaker: "normally open auxiliary contact closed + normally closed auxiliary contact open" - corresponding to the circuit breaker closing state; "normally open auxiliary contact open + normally closed auxiliary contact closed" - corresponding to the circuit breaker opening state; the change sequence of the auxiliary contacts during the circuit breaker closing process is: 1) normally closed auxiliary contact closed - open; 2) normally open auxiliary contact open - closed; the change sequence of the auxiliary contacts during the circuit breaker opening process is: 1) normally open auxiliary contact closed - open; 2) normally closed auxiliary contact open - closed; Based on this, the method of this embodiment includes the following steps:

[0037] Step S10, monitoring the changes of the auxiliary contacts during the closing process of the circuit breaker, and recording the remote control closing contact output time tClose output and the closing confirmation time tClose;

[0038] Specifically, the relay protection device continuously monitors the state changes of the normally open auxiliary contacts and normally closed auxiliary contacts of the circuit breaker. When receiving the remote closing command, it records the moment when the normally closed auxiliary contacts change from closed position to open position, i.e., t 合输出 . The normally open auxiliary contact is detected to change from open position to closed position, confirming that the circuit breaker has completed the closing action, and the time is recorded as t 合 .

[0039] Step S20, calculate the remote control closing time, Tclose = tclose - tclose output;

[0040] Specifically, T 合 Indicates the time required from the issuance of the remote closing command to the actual completion of the circuit breaker closing action.

[0041] Step S30: When Tclose>preset value, remote closing time warning is issued.

[0042] Specifically, the calculated T 合 Compared with the preset value, if T 合 If it is greater than the preset value, it means that the closing time is too long, there may be a fault or abnormality. 合 >When the preset value is reached, the relay protection device triggers a closing time warning, notifying the operation and maintenance personnel to check the circuit breaker and its control system to ensure the safe and stable operation of the power system.

[0043] Furthermore, the method further comprises the following steps:

[0044] Step S40: monitor the changes of the auxiliary contacts during the reclosing process of the circuit breaker and record the output time of the reclosing contacts t 重合输出 And closing confirmation time t 重合 ;

[0045] Specifically, the relay protection device monitors the state changes of the normally open auxiliary contacts and the normally closed auxiliary contacts of the circuit breaker during the reclosing process. When the reclosing operation is performed, the moment when the normally closed auxiliary contacts change from closed position to open position is recorded, that is, t 重合输出 , the normally open auxiliary contact is detected to change from open position to closed position, confirming that the circuit breaker has completed the reclosing action, and the time is recorded as t 重合 .

[0046] Step S50, calculate the reclosing time, T 重合 =t 重合 -t 重合输出 ;

[0047] Specifically, T 重合 Indicates the time required from the issuance of the reclosing command to the actual completion of the circuit breaker reclosing action.

[0048] Step S60, when T 重合 >When the preset value is reached, a reclosing time warning will be issued.

[0049] Specifically, the calculated T 重合 Compare with the preset value; if T 重合 If it is greater than the preset value, it means that the reclosing time is too long, and there may be a fault or abnormality. 重合 >When the preset value is reached, the relay protection device triggers the reclosing time warning, notifying the operation and maintenance personnel to check the circuit breaker and its control system and take corresponding measures to prevent possible power system instability or equipment damage.

[0050] Furthermore, the method further comprises the following steps:

[0051] Step S70: monitor the changes of the auxiliary contacts during the circuit breaker opening process and record the remote opening contact output time t 分输出 and trip confirmation time t 分 ;

[0052] Specifically, the relay protection device monitors the state changes of the normally open auxiliary contacts and the normally closed auxiliary contacts of the circuit breaker during the opening process. When receiving the remote opening command, it records the moment when the normally open auxiliary contacts change from closed position to open position, that is, t 分输出 . The normally closed auxiliary contact is detected to change from open position to closed position, confirming that the circuit breaker has completed the opening action, and the time is recorded as t 分 .

[0053] Step S80, calculation of the tripping time, T 分 =t 分 -t 分输出 ;

[0054] Specifically, T 分 Indicates the time required from the issuance of the opening command to the actual completion of the circuit breaker opening action;

[0055] Step S90, when T 分 >When the preset value is reached, a trip time warning will be issued.

[0056] Specifically, the calculated T 分 Compared with the preset value, if T 分 If it is greater than the preset value, it means that the tripping time is too long, and there may be a fault or abnormality. 分 >When the preset value is reached, the relay protection device triggers the trip time warning, notifying the operation and maintenance personnel to check the circuit breaker and its control system and take appropriate measures to prevent possible power system instability or equipment damage.

[0057] Furthermore, step S70 further includes:

[0058] Get the no-flow time t 无流 and the circuit breaker tripping time t 跳位 ;

[0059] Compare 无流 and t 跳位 , take t 无流 and t 跳位 The latter moment is t 分 ;

[0060] Specifically, in step S70, in order to more accurately determine the opening confirmation time t 分 When the current drops to the no-current state, record the time t 无流 When the tripping mechanism of the circuit breaker is detected to be complete, the time t is recorded. 跳位Monitor and record the moment when the current in the circuit drops to zero or below a predetermined threshold after the circuit breaker is opened, i.e. t 无流 , which means that the fault current has been successfully cut off, and the time when the mechanical tripping mechanism of the circuit breaker is completed is monitored and recorded, that is, t 跳位 , this moment marks the complete separation of the moving contact and the static contact of the circuit breaker. 无流 and t 跳位 Compare to determine which moment is later, starting from t 无流 and t 跳位 The latter moment is selected as the trip confirmation moment t 分 The reason for this is that t 分 The timer should represent the final moment when the circuit breaker fully opens and cuts off the current. This more accurately reflects the actual opening time of the circuit breaker, thereby improving the accuracy and reliability of the monitoring system. This is invaluable for analyzing circuit breaker performance and diagnosing potential problems.

[0061] Furthermore, step S70 further includes:

[0062] If at least two of the three phase currents are greater than the preset value before remote tripping, the time when all three phase currents are less than the preset value after remote tripping is recorded as t 无流 If there is no remote tripping before at least two of the three phase currents are greater than the preset value, then t 无流 is an invalid value, then take t 跳位 As t 分 .

[0063] Specifically, in step S70, in order to more accurately determine the no-flow moment tno-flow and thereby determine the gate opening confirmation moment t 分 Before executing the remote trip command, monitor the current values ​​of the three phases of the circuit breaker and check whether the current of at least two phases is greater than the preset value before tripping. This step is to confirm whether there is a fault current, so as to ensure t 无流 If at least two of the three phase currents are greater than the preset value before the trip, then after the trip, monitor the moment when all three phase currents drop below the preset value and record this moment as t 无流 If there is no situation where at least two phase currents are greater than the preset value before the trip, it is considered that t 无流 is an invalid value, which means that no effective fault current is cut off. 无流 Invalid, then use t 跳位 As the opening confirmation time t 分 , this is because in this case, t 无流It cannot accurately reflect the moment when the current is cut off. This method can more accurately determine the moment when the opening action is completed, especially in the presence of fault current, ensuring the accuracy of monitoring data and the effectiveness of circuit breaker operation. This is of great significance for the safe operation of power systems and fault analysis.

[0064] Furthermore, the method further comprises the following steps:

[0065] Step S110: monitor the changes of the auxiliary contacts during the protection tripping process of the circuit breaker and record the output time t of the protection tripping contact. 跳输出 and trip confirmation time t 跳闸 ;

[0066] Specifically, the relay protection device monitors the state changes of the normally open auxiliary contacts and normally closed auxiliary contacts of the circuit breaker during the protection tripping process. When the protection device detects a fault and issues a tripping command, it records the moment when the normally closed auxiliary contacts change from closed to open, that is, t 跳输出 , the moment when the normally open auxiliary contact changes from closed position to open position, confirming that the circuit breaker has completed the tripping action, that is, t 跳闸 .

[0067] Step S120, trip time calculation, T 跳闸 =t 跳闸 -t 跳闸输出 ;

[0068] Specifically, by calculating t 跳闸 With t 跳输出 The time difference is used to obtain the protection tripping time of the circuit breaker, which reflects the time required for the circuit breaker to actually complete the tripping action from receiving the tripping command.

[0069] Step S130, when T 跳闸 >When the preset value is reached, a trip time warning will be issued.

[0070] Specifically, a tripping time threshold is set in advance. If the calculated tripping time Ttrip is greater than the preset value, it means that the tripping time of the circuit breaker is too long, and there may be a fault or abnormality. 跳闸 >When the preset value is reached, the relay protection device triggers a trip time warning, notifying the operation and maintenance personnel to check the circuit breaker and its protection system and take corresponding measures to prevent possible power system instability or equipment damage. Further, step S110 also includes:

[0071] Get the no-flow time t 无流 and the circuit breaker tripping time t 跳位 ;

[0072] Compare 无流 and t 跳位 , take t无流 and t 跳位 The latter moment is t 跳闸 .

[0073] Specifically, in step S110, in order to more accurately determine the confirmation time t of the circuit breaker protection tripping 跳闸 , monitor and record the moment when the current in the circuit drops to zero or below a predetermined threshold after the circuit breaker trips, i.e. t 无流 , which means that the fault current has been successfully cut off, and the time when the mechanical tripping mechanism of the circuit breaker is completed is monitored and recorded, that is, t 跳位 This moment marks the complete separation of the moving contact and the static contact of the circuit breaker; in the protection tripping process, it is necessary to compare t 无流 and t 跳位 Two moments to determine which moment is later, so as to more accurately reflect the actual tripping time of the circuit breaker. If t 无流 later than or equal to t 跳位 , then t 跳闸 =t 无流 This indicates that the current drops to the no-current state after or at the same time as the circuit breaker trips. 跳位 later than t 无流 , then t 跳闸 =t 跳位 , indicating that the mechanical tripping of the circuit breaker is completed after the current drops to the zero-current state. In this way, the trip confirmation time ttrip of the circuit breaker can be determined more accurately, thereby improving the accuracy and reliability of the monitoring system, which is very important for analyzing circuit breaker performance and diagnosing potential problems.

[0074] Furthermore, step S110 further includes:

[0075] If at least two of the three phase currents are greater than the preset value before the protection trips, the time when the three phase currents are all less than the preset value after the protection trips is recorded as t 无流 If there is no protection trip before at least two of the three phase currents are greater than the preset value, then t 无流 is an invalid value, then take t 跳位 As t 跳闸 .

[0076] Specifically, in step S110, in order to more accurately determine the confirmation time ttrip of the protection trip, before the protection device triggers the trip command, the current values ​​of the three phases of the circuit breaker are monitored to check whether the current of at least two phases is greater than the preset value before tripping. This step is to confirm whether there is a fault current, so as to ensure t 无流If at least two of the three phase currents are greater than the preset value before the protection trips, the current situation after the trip is continuously monitored. After the protection trips, the moment when the three phase currents are all less than the preset value is recorded as t 无流 , which indicates that the fault current has been successfully cut off. If there is no situation where at least two of the three phase currents are greater than the preset value before the protection trips, it is considered that t 无流 Is an invalid value. 无流 When it is an invalid value, directly take t 跳位 As t 跳闸 If t 无流 is the effective value, compare t 无流 and t 跳位 , take the later moment as t 跳闸 If t 无流 If it is an invalid value, use t directly. 跳位 As t 跳闸 In this way, the actual action time of the circuit breaker during the protection tripping process can be reflected more accurately, thereby improving the accuracy and reliability of the monitoring system, which is of great significance for the safe operation and fault analysis of the power system.

[0077] In summary, the method of the embodiment of the present invention monitors the opening and closing time of the circuit breaker through the relay protection device, can grasp the operating status of the circuit breaker in real time, and detect potential faults in time; by monitoring the opening and closing time of the circuit breaker, once an abnormality is found, an early warning can be immediately issued, so that measures can be taken to prevent the accident from expanding and improve the safety of the power system; the method of the present invention does not require the installation of multiple sensors on the circuit breaker body, simplifies the monitoring equipment, reduces costs, and is easy to promote in medium and low voltage circuit breakers; due to the simplification of the monitoring equipment, the corresponding maintenance workload is also greatly reduced, which is convenient for the management of operation and maintenance personnel; by monitoring the opening and closing time of the circuit breaker, voltage fluctuations and frequency deviations can be effectively controlled to ensure the stable operation of the power system.

[0078] While various embodiments of the present invention have been described above, the above descriptions are intended to be illustrative, non-exhaustive, and not limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments. The terminology used herein is selected to best explain the principles of the embodiments, their practical applications, or technological improvements in the marketplace, or to enable others skilled in the art to understand the embodiments disclosed herein.

Claims

1. A method for monitoring the opening and closing time of a circuit breaker based on a relay protection device, characterized in that: The following steps are involved: Monitor the changes of auxiliary contacts during the closing process of the circuit breaker and record the output time t of the remote control closing contact 合输出 And closing confirmation time t 合 ; Calculate the remote control closing time, T 合 =t 合 -t 合闸输出 ; When T 合 >When the preset value is reached, a remote control closing time warning is issued.

2. The method according to claim 1, characterized in that The following steps are also included: Monitor the changes of auxiliary contacts during the circuit breaker reclosing process and record the reclosing contact output time t 重合输出 And closing confirmation time t 重合 ; Calculate the reclosing time, T 重合 =t 重合 -t 重合输出 ; When T 重合 >When the preset value is reached, a reclosing time warning is given.

3. The method according to claim 1, characterized in that The following steps are also included: Monitor the changes of auxiliary contacts during the circuit breaker opening process and record the output time t of the remote control opening contact 分输出 and the opening confirmation time t 分 ; Calculation of opening time, T 分 =t 分 -t 分输出 ; When T 分 >When the preset value is reached, a trip time warning will be issued.

4. The method according to claim 3, characterized in that The following steps are also included: Get the no-flow time t 无流 and the circuit breaker tripping time t 跳位 ; Compare 无流 and t 跳位 , take t 无流 and t 跳位 The latter moment is t 分 .

5. The method according to claim 4, characterized in that The following steps are also included: If at least two of the three phase currents are greater than the preset value before the remote control trip, the time when the three phase currents are less than the preset value after the remote control trip is recorded as t 无流 ; If there is no remote control before the tripping, at least two of the three phase currents are greater than the preset value, then t 无流 is an invalid value, then take t 跳位 As t 分 .

6. The method according to claim 1, characterized in that The following steps are also included: Monitor the changes of auxiliary contacts during the circuit breaker protection tripping process and record the output time t of the protection tripping contact 跳输出 and trip confirmation time t 跳闸 ; Trip time calculation, T 跳闸 =t 跳闸 -t 跳闸输出 ; When T 跳闸 >When the preset value is reached, a trip time warning is given.

7. The method according to claim 6, characterized in that The following steps are also included: Get the no-flow time t 无流 and the circuit breaker tripping time t 跳位 ; Compare 无流 and t 跳位 , take t 无流 and t 跳位 The latter moment is t 跳闸 .

8. The method according to claim 7, characterized in that The following steps are also included: If at least two of the three phase currents are greater than the preset value before the protection trips, the time when the three phase currents are all less than the preset value after the protection trips is recorded as t 无流 ; If there is no protection trip before at least two of the three phase currents are greater than the preset value, then t 无流 is an invalid value, then take t 跳位 As t 跳闸 .

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