Voltage channel sampling anomaly detection method of transformer substation relay protection device

Abstract

The invention discloses a voltage channel sampling anomaly detection method of a transformer substation relay protection device. The method comprises steps of S1-S8. The scheme is used for detecting arelay protection device in a transformer substation. Whether the voltage collected by a feeder device is normal or not is detected by comparing the voltage collected by the feeder device with the voltage collected by a PT measurement and control device, and therefore whether the feeder device works normally is judged. The process of detecting whether the voltage acquired by the PT measurement andcontrol device is normal is set in the scheme, so that the detection accuracy is improved. According to the scheme, comparison is carried out according to line voltage, and two typical wiring modes of PT star wiring and delta wiring are considered.

Description

technical field [0001] The invention relates to the technical field of substation relay protection, in particular to a voltage channel sampling abnormal detection method of a substation relay protection device. Background technique [0002] After the substation relay protection device has been in operation for a long time, the sampling circuit may be abnormal. In particular, the collection of voltage channels is directly related to the operation of the standby automatic switching device and the operation of the compound voltage blocking current protection logic. The voltage sampling circuit generally includes: voltage transformers, filter resistors, operational amplifiers, A / D chips, etc. Any abnormality of any device will cause abnormal sampling data, which is characterized by the following characteristics: [0003] (1) The sampling raw data is all 0 or very small, which will cause the voltage vector calculation to be too small, or 0 or zero drift; [0004] (2) The sample...

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Problems solved by technology

[0003] (1) The sampling raw data is all 0 or very small, which will cause the voltage vector calculation to be too small, or 0 or zero drift;

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

[0005] (3) The sampling raw data fluctuates up and down, which cannot correctly reflect the real analog quantity, resulting in continuous and rapid mutation of the calculation results

[0007] 1. The external situation is actually normal, but the voltage vector is misjudged as a voltage loss, which will cause the wrong operation of the standby automatic switching device, and then cause the load shedding action to cause a large-scale power outage; or misjudge the PT disconnection, causing direction locking or compound voltage protection Exit, and then lead to over-current protection misoperation, resulting in unexpected power outages

[0008] 2. If there is a voltage loss due to an external actual fault, but the device cannot detect it, the automatic switch will refuse to operate, which will cause a large-scale power outage

[0009] 3. The protection device cannot normally respond to the actual load situation, causing frequent protection start and protection return of the protection device, causing panic among the operation and maintenance personnel

When the abnormal data lasts longer than the fixed value, it may cause more serious malfunctions

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