Non-impact reclosing detection method and system

Abstract

The invention relates to a non-impact reclosing detection method and system, and belongs to the technical field of power transmission line safety control. When a line switch in the power transmission line is detected to perform action tripping, whether the power transmission line has a continuous fault or not is judged by using a voltage value of a switch load side of the tripping line and a voltage value of a next adjacent switch power supply side, if yes, the line switch is controlled to skip reclosing operation, and if not, the power transmission line is switched on. Otherwise, the circuit switch is controlled to perform reclosing operation. According to the method, continuous fault judgment can be realized only by utilizing the voltage value of the switch load side of the tripping line and the voltage value of the next adjacent switch power supply side, a characteristic signal does not need to be injected, a detection mode is simplified, and an original line is not influenced.

Description

Technical Field

[0001] The invention relates to a detection method and system for a non-impact reclosing switch, belonging to the technical field of power transmission line safety control. Background Art

[0002] Automatic reclosing is an important automatic device in the power system. This operation is designed to improve the power supply reliability of the power system, especially after the transmission line fault is cleared, it can close the line switch in a short time to restore power supply. When the line switch trips, if the transmission line is a transient fault, the automatic reclosing operation can improve the power supply reliability and enable the line to quickly restore power supply. However, if the fault is continuous, the automatic reclosing may cause the power system to be impacted again, which may reduce the stability of the system parallel operation and worsen the working conditions of the line switch. The line switch is cut off twice in a short period of time, which has an adverse effect on the working conditions of the switch. Therefore, it is necessary to judge the fault type of the transmission line when performing reclosing control.

[0003] The Chinese patent application document with application publication number CN118739212A discloses a distribution line fault self-healing method based on active detection signals. The method uses a distribution line intelligent reclosing scheme based on injection signals to determine whether the faulty line can be reclosed. When the protection device in the line trips, the distributed power source injects a characteristic signal into the feeder after a preset delay time. By detecting whether there is a characteristic signal in this section of the line and the duration exceeds the preset time, it is determined whether the circuit is reclosed or whether the faulty circuit is isolated. Although this scheme can make a judgment before the reclosing operation, this method needs to inject a characteristic signal into the line, the judgment method is relatively complicated, and it is easy to affect the line. Summary of the invention

[0004] The purpose of the present invention is to provide a detection method and system for impact-free reclosing, so as to solve the problem that the current method of injecting characteristic signals for continuous fault judgment is complicated and easy to affect the line.

[0005] In order to solve the above technical problems, the present invention provides a method for detecting a non-impact reclosing switch, the method comprising: When a line switch in the transmission line trips, the voltage value on the load side of the line switch and the voltage value on the power supply side of the next adjacent switch of the line switch along the current direction of the transmission line are obtained; The voltage value on the load side of the line switch and the voltage value on the power supply side of the next adjacent switch are used to determine whether the transmission line is a continuous fault. If so, the line switch is controlled to skip the reclosing operation; otherwise, the line switch is controlled to perform the reclosing operation.

[0006] Furthermore, the judgment process of the continuous fault is: comparing the voltage value on the load side of the line switch and the voltage value on the power supply side of the next adjacent switch with the corresponding threshold range respectively; if both are within the threshold range of the continuous fault, it indicates that it is a continuous fault; the threshold range is obtained by analyzing the voltage values ​​on the load side of the line switch and the power supply side of the next adjacent switch under a continuous fault and the voltage values ​​on the load side of the line switch and the power supply side of the next adjacent switch under a transient fault.

[0007] Furthermore, the judgment process of the persistent fault is: inputting the voltage value on the load side of the line switch and the voltage value on the power supply side of the next adjacent switch into a trained fault detection model, and the trained fault detection model outputs a judgment result.

[0008] Furthermore, the training data used by the fault detection model includes voltage values ​​on the load side of the line switch and the next adjacent switch power side under a continuous fault and voltage values ​​on the load side of the line switch and the next adjacent switch power side under a transient fault.

[0009] Furthermore, the voltage values ​​on the load side of the line switch and the next adjacent switch power supply side under a continuous fault and the voltage values ​​on the load side of the line switch and the next adjacent switch power supply side under a transient fault are obtained as follows: A transmission line model is established, continuous faults and transient faults are simulated in the transmission line model respectively, and the voltage values ​​on the load side of the line switch and the power supply are detected.

[0010] Furthermore, the method also includes, after controlling the line switch to skip the reclosing operation, determining the type of fault causing the persistent fault, and uploading the determination result.

[0011] Furthermore, the method for determining the fault type that causes the persistent fault is as follows: The voltage value on the load side of the line switch and the voltage value on the power supply side of the next adjacent switch are input into a trained fault detection model, and the trained fault detection model outputs a judgment result; the training data used by the fault detection model includes the voltage values ​​on the load side of the line switch and the power supply side of the next adjacent switch under various fault types, and the various fault types refer to various fault types that cause persistent faults.

[0012] Furthermore, the method further comprises controlling the line switch to reset after the persistent fault is cleared.

[0013] The present invention also provides a detection system for a shockless reclosing switch, comprising a processor, wherein the processor is used to execute a computer program to implement the steps of the detection method for a shockless reclosing switch of the present invention.

[0014] The beneficial effects of the present invention are as follows: As an improved invention, when the present invention detects that a line switch in a transmission line has tripped, the voltage value on the load side of the tripped line switch and the voltage value on the power supply side of the next adjacent switch are used to determine whether the transmission line is a continuous fault. If so, the line switch is controlled to skip the reclosing operation, otherwise the line switch is controlled to perform the reclosing operation. It can be seen that the present invention only needs to use the voltage value on the load side of the tripped line switch and the voltage value on the power supply side of the next adjacent switch to realize the judgment of continuous faults, without injecting characteristic signals, simplifying the detection method, and not affecting the original line. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a flow chart of the detection method of the impact-free reclosing switch of the present invention; Figure 2 It is a schematic diagram of the principle of continuous fault judgment by the detection method of the impact-free reclosing switch of the present invention. DETAILED DESCRIPTION

[0016] The specific implementation of the present invention will be further described below in conjunction with the accompanying drawings.

[0017] When the present invention detects that a line switch in a transmission line has tripped, the voltage value on the load side of the tripped line switch and the voltage value on the power supply side of the next adjacent switch are used to determine whether the transmission line is a continuous fault. If so, the line switch is controlled to skip the reclosing operation, otherwise the line switch is controlled to perform the reclosing operation. The present invention does not need to inject characteristic signals, simplifies the detection method, and does not affect the original line.

[0018] Method Embodiment When a line switch in a power transmission line trips, the present invention first obtains the voltage value on the load side of the line switch and the voltage value on the power supply side of the next adjacent switch of the line switch along the current direction of the power transmission line; then uses the voltage value on the load side of the line switch and the voltage value on the power supply side of the next adjacent switch to determine whether the power transmission line is a continuous fault. If so, the line switch is controlled to skip the reclosing operation, otherwise, the line switch is controlled to perform the reclosing operation. The implementation process of the method is as follows: Figure 1 As shown, the detailed description is given below.

[0019] 1. Obtain the voltage values ​​on both sides of the line switch on the transmission line.

[0020] Assume that N line switches are set on the transmission line in this embodiment. Along the direction of the transmission line, these N line switches are K1, K2...Kn, K(n+1)...KN respectively. The line switches here are generally circuit breakers. The voltage values ​​on both sides of each line switch are collected by the data acquisition system of the feeder terminal. The data acquisition system collects the three-phase voltages of the voltage sensors on the power supply side and the load side of the line switch through an analog sampling circuit to obtain U n1 and U n2 , where U n1 is the voltage value collected on the power supply side of the nth line switch Kn, U n2 It is the voltage value collected on the load side of the nth line switch. The present invention can collect the voltage values ​​on both sides of each line switch in real time, and can also collect according to needs.

[0021] 2. When a line switch in a transmission line trips, the voltage value on the load side of the line switch and the voltage value on the power supply side of the next adjacent switch along the current direction of the transmission line are used to determine whether the transmission line has a continuous fault.

[0022] When a line switch in the transmission line trips, the present invention finds the voltage value on the load side of the line switch and the voltage value on the power supply side of the next adjacent switch of the line switch along the current direction of the transmission line from the voltage values ​​collected in real time. In this embodiment, if the line switch Kn in the transmission line trips, the voltage value U on the load side of the line switch Kn is obtained. n2 And the voltage value U on the power supply side of the circuit breaker K(n+1) （n+1）1 , where line switch K(n+1) is the next adjacent switch of line switch Kn. These two values ​​can be used to determine the continuous fault, such as Figure 2 The present invention provides two judgment methods.

[0023] Method 1: Compare the voltage value on the load side of the line switch and the voltage value on the power supply side of the next adjacent switch with the corresponding threshold ranges respectively. If both are within the threshold range of a continuous fault, it indicates a continuous fault; if both are within the threshold range of a transient fault, it indicates a transient fault.

[0024] The threshold range is obtained by analyzing the voltage values ​​on the load side of the line switch and the next adjacent switch power supply side under a continuous fault and the voltage values ​​on the load side of the line switch and the next adjacent switch power supply side under a transient fault, and can be determined using the ROC curve method or the PR curve method.

[0025] Method 2: Input the voltage value on the load side of the line switch and the voltage value on the power supply side of the next adjacent switch into a trained fault detection model, and the trained fault detection model outputs a judgment result.

[0026] The training data used by the fault detection model include the voltage values ​​of the load side of the line switch and the power supply side of the next adjacent switch under a continuous fault and the voltage values ​​of the load side of the line switch and the power supply side of the next adjacent switch under a transient fault. The fault detection model can be implemented using a machine learning model, for example, a classification model such as a neural network or a random forest.

[0027] Both of the above methods require the voltage values ​​on the load side of the line switch and the power supply side of the next adjacent switch under a continuous fault, and the voltage values ​​on the load side of the line switch and the power supply side of the next adjacent switch under a transient fault. These data can be obtained on the actual line or through simulation. For example, a transmission line model is established in a test field, continuous faults and transient faults are simulated in the transmission line model, and the corresponding output voltage values ​​of the sensors on both sides of the line switch are detected, which are used as training data for the fault detection model or as a basis for determining the threshold range.

[0028] 3. Control the circuit switch according to the judgment result.

[0029] When it is determined that the current fault is a continuous fault, it means that the reclosing operation cannot be performed at present. At this time, the line switch is controlled to skip the reclosing operation; when it is determined that the current fault is a transient fault, it means that the reclosing operation can be performed. At this time, the line switch is controlled to perform the reclosing operation.

[0030] 4. Determine the fault type that causes the persistent fault and send it to the upstream.

[0031] When it is determined that the current fault is a persistent fault, in order to avoid the problem of long-term inability to work normally due to the persistent fault, the fault needs to be repaired as soon as possible. In order to facilitate the repair, the specific fault type that causes the persistent fault needs to be accurately determined so that accurate repair can be carried out.

[0032] The detection of specific fault types can be achieved through the constructed fault detection model, which can directly adopt the fault detection model in step 2, and only needs to include the voltage data on both sides of the line switch under various specific fault types that cause continuous faults in the training data used during training. It can also be achieved by reconstructing a new fault detection model.

[0033] After the specific fault type is detected, the specific fault type can be sent to the upper computer, so that the upper computer can give a corresponding maintenance strategy when receiving the specific fault type. If the corresponding fault disappears after maintenance, the tripped line switch can be controlled to reset.

[0034] System Example The detection system of the impact-free reclosing switch of the present invention comprises a processor, and the processor is used to execute a computer program to implement the steps of the detection method of the impact-free reclosing switch of the present invention. The specific implementation process of the method has been described in detail in the method embodiment, and will not be repeated here.

[0035] It can be seen that the present invention can use the voltage value on the load side of the tripped line switch and the voltage value on the power supply side of the next adjacent switch to realize the judgment of a continuous fault. In this way, before the equipment automatically recloses, it is possible to efficiently, accurately and comprehensively judge whether a continuous fault has occurred in the transmission line and the fault type of the line, thereby realizing efficient and stable operation of the distribution network.

Claims

1. A method for detecting a non-impact reclosing switch, characterized in that the method comprises: When a line switch in the transmission line trips, the voltage value on the load side of the line switch and the voltage value on the power supply side of the next adjacent switch of the line switch along the current direction of the transmission line are obtained; The voltage value on the load side of the line switch and the voltage value on the power supply side of the next adjacent switch are used to determine whether the transmission line is a continuous fault. If so, the line switch is controlled to skip the reclosing operation; otherwise, the line switch is controlled to perform the reclosing operation.

2. The detection method for impact-free reclosing according to claim 1 is characterized in that the judgment process of the continuous fault is: comparing the voltage value on the load side of the line switch and the voltage value on the power supply side of the next adjacent switch with the corresponding threshold range respectively. If both are within the threshold range of the continuous fault, it indicates that it is a continuous fault; the threshold range is obtained by analyzing the voltage values ​​on the load side of the line switch and the power supply side of the next adjacent switch under a continuous fault and the voltage values ​​on the load side of the line switch and the power supply side of the next adjacent switch under a transient fault.

3. The detection method for impact-free reclosing according to claim 1 is characterized in that the judgment process of the persistent fault is: the voltage value on the load side of the line switch and the voltage value on the power supply side of the next adjacent switch are input into a trained fault detection model, and the trained fault detection model outputs a judgment result.

4. The method for detecting impact-free reclosing according to claim 3 is characterized in that the training data used by the fault detection model includes the voltage values ​​on the load side of the line switch and the power supply side of the next adjacent switch under a continuous fault and the voltage values ​​on the load side of the line switch and the power supply side of the next adjacent switch under a transient fault.

5. The method for detecting impactless reclosing according to claim 2 or 4, characterized in that the voltage value between the load side of the line switch and the power supply side of the next adjacent switch under a continuous fault and the voltage value between the load side of the line switch and the power supply side of the next adjacent switch under a transient fault are obtained in the following manner: A transmission line model is established, continuous faults and transient faults are simulated in the transmission line model respectively, and the voltage values ​​on the load side of the line switch and the power supply are detected.

6. The method for detecting impact-free reclosing according to claim 1 is characterized in that the method further comprises, after controlling the line switch to skip the reclosing operation, determining the type of fault causing the persistent fault and uploading the determination result.

7. The method for detecting impact-free reclosing according to claim 6 is characterized in that the fault type causing the persistent fault is determined by: The voltage value on the load side of the line switch and the voltage value on the power supply side of the next adjacent switch are input into a trained fault detection model, and the trained fault detection model outputs a judgment result; the training data used by the fault detection model includes the voltage values ​​on the load side of the line switch and the power supply side of the next adjacent switch under various fault types, and the various fault types refer to various fault types that cause persistent faults.

8. The method for detecting impact-free reclosing according to claim 6, characterized in that the method further comprises controlling the line switch to reset after the persistent fault is cleared.

9. A detection system for a shockless reclosing switch, comprising a processor, wherein the processor is used to execute a computer program to implement the steps of the detection method for a shockless reclosing switch according to any one of claims 1 to 8.

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