Self-adaptive monitoring method for gas dissolved in oil of traction transformer, and the device thereof

Abstract

The invention discloses a self-adaptive detect method of the gas dissolved in the oil of a drawing transformer, and a relative device, wherein the invention uses a high-density gas sensor array to check the object gas to obtain a first check value, when the first check value is higher than a preset threshold value, using the first check value as the check result, or else, uses a low-density gas sensor array to check the object gas again, using the second check value as the check result. And the invention judges if the ratio between the average value and mean square difference of the check values of all sensors in the array is over a preset value to check the condition of the array. The invention has high measuring accuracy, better repeatability, long service life, and low check cost.

Description

technical field [0001] The invention relates to a detection technology of dissolved gas in insulating oil of electric equipment, in particular to an online monitoring method and device thereof for dissolved gas in insulating oil of traction transformers. Background technique [0002] At present, large-scale transformers use oil to insulate and dissipate heat. When overheating faults, discharge faults, or internal insulation in the transformer occur, the oil and solid insulating materials will age and deteriorate, and crack to produce low-molecular gas (H 2 、CH 4 、C 2 h 6 、C 2 h 4 、C 2 h 2 and CO, etc.), and dissolved in transformer oil. For the same type of fault, the amount of gas produced varies with the severity of the fault and has nothing to do with the type of insulating oil. Therefore, the dissolved gas and content in the oil reflect the degree of transformer insulation aging or fault to a certain extent. Dissolved gas can be monitored and analyzed as a charac...

AI Technical Summary

Problems solved by technology

[0005] At present, the on-line detection device that uses semiconductor sensors to detect gas in oil uses air as the carrier gas, and does not consider the influence of the former gas on the latter gas test when detecting gas. This method is not suitable for the monitoring of traction transformers: because traction transformers The concentration difference between the various gases dissolved in the oil is larger than that in the power transformer, especially the concentration of CO is large. When the gas separation column first separates the gas with a higher concentration (such as CO), the recovery time of the sensor is not enough. , will bring bias to the detection of the separated gas

At the same time, air is usually used as the carrier gas in existing detection devices, and changes in the oxygen content in the air will affect the response of the semiconductor sensor, thereby affecting the measurement accuracy; and the oxygen content of the air directly affects the sensitivity of the sensor response

In addition, high-precision sensors are exposed to high concentrations of combustible gases for a long time, and their service life, measurement accuracy and repeatability are greatly affected

[0006] The monitoring of traction transformers in foreign countries mainly uses sensing technologies such as high-precision thermal conductivity detectors and photoacoustic spectroscopy detection, but the monitoring costs are too high

Images