A voltage channel sampling anomaly detection method for a substation relay protection device

Abstract

The present invention discloses a method for detecting abnormal sampling of a voltage channel of a transformer substation relay protection device, which comprises steps S1-S8. The scheme is used to detect the relay protection device in the transformer substation, and by comparing the voltage collected in the feeder device with the voltage collected in the PT measurement and control device, it is detected whether the voltage collected by the feeder device is normal, thereby determining whether the feeder device is working normally; and the scheme is provided with a process for detecting whether the voltage collected by the PT measurement and control device is normal, thereby increasing the accuracy of the detection; the scheme performs the comparison according to the line voltage, taking into account two typical connection modes of PT star connection and delta connection.

Description

Technical Field

[0001] The present invention relates to the technical field of transformer substation relay protection, and in particular to a voltage channel sampling anomaly detection method of a transformer substation relay protection device. Background Art

[0002] After long-term operation of the substation relay protection device, the sampling circuit may be abnormal. In particular, the acquisition of the voltage channel is directly related to the operation of the backup automatic transfer device and the operation of the composite voltage blocking current protection logic. The voltage sampling circuit generally includes: voltage transformer, filter resistor and capacitor device, operational amplifier device, A / D chip, etc. Any abnormal device will cause abnormal sampling data, which is manifested as the following characteristics:

[0003] (1) If the sampled raw data are all 0 or very small, the voltage vector calculation will be too small, or 0 or zero drift;

[0004] (2) The original data is sampled directly with full code or is very large, and the calculated voltage vector is too large;

[0005] (3) The sampled raw data fluctuates, which cannot correctly reflect the actual analog quantity, causing continuous and rapid mutations in the calculation results.

[0006] The above situation mainly has the following characteristics:

[0007] 1. The external situation is actually normal, but the voltage vector is misjudged as loss of voltage, which will cause the backup automatic transfer device to erroneously operate, and then cause load shedding to cause a large-scale power outage; or the PT line is misjudged to be broken, causing the direction to be locked or the composite voltage protection to exit, which will cause the overcurrent protection to erroneously operate, causing an unexpected power outage.

[0008] 2. If the device cannot detect the actual external fault and pressure loss, the backup automatic switch will refuse to operate, causing a large-scale power outage.

[0009] 3. The protection device cannot normally respond to the actual load conditions, causing the protection device to frequently start and return protection, causing panic among the operation and maintenance personnel. When the duration of abnormal data is greater than the set value, it may cause more serious malfunctions. Summary of the invention

[0010] In view of the above-mentioned deficiencies in the prior art, the present invention provides a method for accurately detecting abnormalities in voltage channel sampling of a substation relay protection device.

[0011] In order to achieve the above-mentioned object of the invention, the technical solution adopted by the present invention is:

[0012] A method for detecting abnormal sampling of a voltage channel of a transformer substation relay protection device is provided, which comprises the following steps:

[0013] S1: Collect the measured voltage U1 of the feeder device and the voltage U3 of the PT measurement and control device;

[0014] S2: If the measured voltage U1 < 12V, it is determined that the feeder device is under maintenance, and the voltage anomaly detection is terminated;

[0015] S3: If the measured voltage U1 ≥ 12V, calculate the maximum error ΔU1 = |U1 - U2| between the measured voltage U1 and the set voltage reference value U2, the maximum error ΔU2 = |U1 - U3| between the measured voltage U1 and the voltage U3, and the maximum error ΔU3 = |U2 - U3| between the voltage reference value U2 and the voltage U3;

[0016] S4: Compare ΔU3 with the set voltage error threshold Uset3;

[0017] S5: If ΔU3 < Uset3, the voltage U3 measured by the PT measurement and control device is a normal value, and then determine whether ΔU2 is greater than the set voltage error threshold Uset2;

[0018] S6: If ΔU2 > Uset2, the voltage sampling of the feeder device is abnormal, otherwise the sampling is normal, and the voltage anomaly detection is terminated;

[0019] S7: If ΔU3 ≥ Uset3, the voltage U3 measured by the PT measurement and control device is an abnormal value, and then determine whether ΔU1 is greater than the set voltage error threshold Uset1;

[0020] S8: If ΔU1 > Uset1, the voltage sampling of the feeder device is abnormal, otherwise the sampling is normal, and the voltage anomaly sampling detection is terminated.

[0021] Furthermore, the following steps are also included:

[0022] S9: Mark the feeder device with abnormal voltage sampling as abnormal sampling once;

[0023] S10: After a delay of the set time, repeat steps S1 - S8, and mark the feeder device with abnormal voltage sampling as abnormal sampling once;

[0024] S11: Repeat step S10, and screen out the feeder devices with the number of abnormal sampling marks greater than or equal to two, and determine them as the feeder devices with abnormal sampling;

[0025] S13: Record and save the detection data and the address information of the feeder devices with abnormal sampling during the detection process, and send them to the remote control workstation.

[0026] Furthermore, the set delay time is 90 seconds.

[0027] Furthermore, the detection data and address information in step S13 are saved by generating a file format and sent to the telecontrol workstation.

[0028] Furthermore, the PT measurement and control device and the feeder device both collect three line voltages of the same section of the bus.

[0029] A computer-readable storage medium stores a computer program, which implements the steps of a voltage channel sampling anomaly detection method for a transformer substation relay protection device when executing the computer program.

[0030] The beneficial effects of the present invention are as follows: the present scheme is used to detect the relay protection device in the substation, by comparing the voltage collected in the feeder device with the voltage collected in the PT measurement and control device, to detect whether the voltage collected by the feeder device is normal, thereby determining whether the feeder device is working normally; and the present scheme is provided with a process for detecting whether the voltage collected by the PT measurement and control device is normal, thereby increasing the accuracy of the detection.

[0031] This solution realizes automatic inspection of the voltage sampling channel of the relay protection device without replacing or modifying the relay protection device, thereby automatically warning and notifying maintenance personnel in time to conduct targeted inspections on abnormal feeder devices to prevent accidents. By setting up three rounds of voltage acquisition abnormality detection, the feeder device is identified as sampling abnormal only when the sampling abnormality is marked more than twice, which greatly reduces the possibility of misjudgment; this solution compares the line voltage and takes into account the two typical wiring methods of PT star wiring and triangle wiring. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 The present invention is a flow chart of a voltage channel sampling anomaly detection method for a substation relay protection device. DETAILED DESCRIPTION

[0033] The specific implementation modes of the present invention are described below so that those skilled in the art can understand the present invention. However, it should be clear that the present invention is not limited to the scope of the specific implementation modes. For those of ordinary skill in the art, as long as various changes are within the spirit and scope of the present invention as defined and determined by the attached claims, these changes are obvious, and all inventions and creations utilizing the concept of the present invention are protected.

[0034] like Figure 1 As shown, the voltage channel sampling abnormality detection method of the substation relay protection device is characterized by comprising the following steps:

[0035] S1: collects the measured voltage U1 of the feeder device and the voltage U3 measured by the PT measurement and control device;

[0036] S2: If the measured voltage U1 < 12V, it is determined that the feeder device needs to be repaired, and the voltage anomaly detection is terminated;

[0037] S3: If the measured voltage U1 ≥ 12V, calculate the maximum error ΔU1 = |U1 - U2| between the measured voltage U1 and the set voltage reference value U2, the maximum error ΔU2 = |U1 - U3| between the measured voltage U1 and the voltage U3, and the maximum error ΔU3 = |U2 - U3| between the voltage reference value U2 and the voltage U3;

[0038] S4: Compare ΔU3 with the voltage error threshold Uset3;

[0039] S5: If ΔU3 < Uset, the voltage U3 measured by the PT measurement and control device is a normal value, and the PT measurement and control device can work normally. Then, determine whether ΔU2 is greater than the set voltage error threshold Uset2;

[0040] S6: If ΔU2 > Uset2, the voltage sampling of the feeder device is abnormal; otherwise, the sampling is normal, and the voltage anomaly detection is terminated;

[0041] S7: If ΔU3 ≥ Uset, the voltage U3 measured by the PT measurement and control device is an abnormal value, and the voltage measured by the PT measurement and control device is an abnormal voltage; then, determine whether ΔU1 is greater than the set voltage error threshold Uset1;

[0042] S8: If ΔU1 > Uset1, it is determined that the voltage sampling of the feeder device is abnormal; otherwise, the sampling is normal, and the voltage anomaly detection is terminated.

[0043] This solution also includes the following steps:

[0044] S10: Mark the feeder device with abnormal voltage sampling as abnormal sampling once;

[0045] S11: After a delay of the set time, preferably 90 seconds, repeat steps S1 - S9, and mark the feeder device with abnormal voltage sampling as abnormal sampling once;

[0046] S12: Repeat step S11, screen out the feeder devices with the number of abnormal sampling marks greater than or equal to two, and determine them as the feeder devices with abnormal sampling;

[0047] S13: Record and save the detection data and the address information of the feeder devices with abnormal sampling during the detection process, and send them to the remote control workstation. The detection data (U1, U3, ΔU1, ΔU2, ΔU3, and comparison results, etc.) and the address information are saved in the form of a generated file and sent to the remote control workstation. The remote power dispatching center obtains the information through the remote control workstation and dispatches a special person to the site for repair.

[0048] In this solution, the PT measurement and control device and the feeder device both collect the three line voltages of the same section of the bus.

[0049] The present solution also includes a computer-readable storage medium, which stores a computer program. When the computer program is executed, the steps of the voltage channel sampling anomaly detection method of the substation relay protection device are implemented. The computer program is built on the local monitoring background.

[0050] This scheme is used to detect the relay protection device in the substation. By comparing the voltage collected in the feeder device with the voltage collected in the PT measurement and control device, it is detected whether the voltage collected by the feeder device is normal, thereby determining whether the feeder device is working normally; and this scheme is provided with a process for detecting whether the voltage collected by the PT measurement and control device is normal, which increases the accuracy of the detection.

[0051] This solution realizes automatic inspection of the voltage sampling channel of the relay protection device without replacing or modifying the relay protection device, thereby automatically warning and sending the judgment result to the remote control workstation, so as to facilitate and promptly notify the maintenance personnel to conduct targeted inspections on abnormal feeder devices and prevent accidents before they happen. By setting up three rounds of voltage acquisition abnormality detection, the feeder device is identified as sampling abnormal only when the sampling abnormality is marked more than twice, which greatly reduces the possibility of misjudgment; this solution compares the line voltage and takes into account the two typical wiring methods of PT star wiring and triangle wiring.

Claims

1. A voltage channel sampling anomaly detection method for a substation relay protection device, characterized in that: It includes the following steps: S1: Collect the measured voltage U1 of the feeder device and the voltage U3 of the PT measurement and control device; S2: If the measured voltage U1 < 12V, it is determined that the feeder device needs to be repaired, and the voltage anomaly detection is terminated; S3: If the measured voltage U1 ≥ 12V, calculate the maximum error ΔU1 = |U1 - U2| between the measured voltage U1 and the set voltage reference value U2, the maximum error ΔU2 = |U1 - U3| between the measured voltage U1 and the voltage U3, and the maximum error ΔU3 = |U2 - U3| between the voltage reference value U2 and the voltage U3; S4: Compare ΔU3 with the set voltage error threshold Uset3; S5: If ΔU3 < Uset3, the voltage U3 measured by the PT measurement and control device is a normal value, and then determine whether ΔU2 is greater than the set voltage error threshold Uset2; S6: If ΔU2 > Uset2, the voltage sampling of the feeder device is abnormal, otherwise the sampling is normal, and the voltage anomaly detection is terminated; S7: If ΔU3 ≥ Uset3, the voltage U3 measured by the PT measurement and control device is an abnormal value, and then determine whether ΔU1 is greater than the set voltage error threshold Uset1; S8: If ΔU1 > Uset1, the voltage sampling of the feeder device is abnormal, otherwise the sampling is normal, and the voltage anomaly sampling detection is terminated.

2. The voltage channel sampling anomaly detection method of the substation relay protection device according to claim 1 is characterized in that: It also includes the following steps: S9: Mark the feeder device with abnormal voltage sampling as abnormal sampling once; S10: After delaying the set time, repeat steps S1 - S8, and mark the feeder device with abnormal voltage sampling as abnormal sampling once; S11: Repeat step S10, and screen out the feeder devices with the number of abnormal sampling marks greater than or equal to two, and determine them as the feeder devices with abnormal sampling; S13: Record and save the detection data and the address information of the feeder devices with abnormal sampling during the detection process, and send them to the remote control workstation.

3. The voltage channel sampling anomaly detection method of the substation relay protection device according to claim 2 is characterized in that: The set delay time is 90 seconds.

4. The voltage channel sampling anomaly detection method of a substation relay protection device according to claim 2, characterized in that: The detection data and address information in step S13 are saved in the form of a generated file and sent to the remote control workstation.

5. The voltage channel sampling anomaly detection method of a substation relay protection device according to claim 1, characterized in that: Both the PT measurement and control device and the feeder device collect the three line voltages of the same section of the bus.

6. A computer-readable storage medium storing a computer program, characterized in that: When the computer program is executed, it realizes the steps of the voltage channel sampling anomaly detection method of the substation relay protection device described in any one of claims 1 to 5.

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