Humidity sensing system for monitoring insulation state of power transformer

Abstract

The invention discloses a humidity sensing system for monitoring an insulation state of a power transformer. The humidity sensing system comprises a transformer oil tank, an oil gas separating film, a permeating gas eduction chamber, a humidity sensing element, a capacitance-voltage switching circuit, an ATmega 128 microprocessor, an HC-12 wireless communication module and an audible and visual alarm, wherein the humidity sensing element is served as a humidity sensing film by modifying a graphene oxide compound film with nanometer zinc oxide and is prepared on a ceramic substrate with a dual-rectangular shaped interdigital electrode ceramic substrate. According to the humidity sensing system, the permeating gas in the transformer oil is filtered through the oil gas separating film and then is guided into the permeating gas eduction chamber, the humidity sensing element is arranged in the eduction chamber for the permeating gas in the transformer oil and the humidity detection for the transformer oil environment is realized by detecting the capacitance change of the humidity sensing film; the humidity sensing system has the functions of data collection, storage, display and audible and visual alarm; the monitoring data is sent to an upper computer and remote wireless communication. The humidity sensing system can judge the insulation state of the power transformer and make early warning according to the corresponding humidity change and has the characteristics of anti-electromagnetic interference, high sensitivity, stability, reliability, and the like.

Description

technical field [0001] The invention relates to a humidity sensing system and a manufacturing method thereof, in particular to a nano zinc oxide modified graphene oxide film capacitive humidity sensing system for monitoring the insulation state of a power transformer. Background technique [0002] As the key equipment of the power system, the safe operation of large power transformers is particularly important to ensure the safety and stability of the power system. Once the transformer fails, it will cause huge losses to the national economy. Insulation status monitoring of power transformers has received much attention in the construction of smart grids. 90% of the power transformers used in power plants and substations in my country are oil-immersed transformers. The insulation system of this type of transformer is mainly insulating oil and insulating paper. The change of its humidity during long-term operation will lead to serious deterioration of insulation performance, ...

AI Technical Summary

Problems solved by technology

The humidity sensor is the core component of the humidity sensor to detect the humidity of the external environment. At present, polymers, ceramic materials, and metal oxides are used as the humidity sensor of the capacitive humidity sensor. The polymer humidity sensor is widely used. However, due to the poor high temperature resistance of its moisture absorption layer, this type of sensor cannot be used in high temperature environments, and severe hysteresis occurs under high humidity conditions; semiconductor ceramic humidity sensor has stable performance, high temperature applicability, and wide detection range etc., but it is easily interfered by environmental smog and organic gas, and needs to be heated regularly to regenerate its humidity-sensitive characteristics; metal oxide humidity-sensitive devices have the characteristics of high temperature resistance and high sensitivity, but they can only work at high temperatures and consume a lot of power , short life and other disadvantages

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