On-line monitoring method and system for gas content in transformer oil

Abstract

The invention relates to a method for online monitoring the content of gas in transformer oil and a system thereof. A gas optoacoustic spectroscopy is adopted to measure the gas dissolved in the transformer oil, namely, after the gas is sent into an opto-acoustic pond, a gas circuit valve is closed, laser sent by a laser is used for radiating sample gas in the opto-acoustic pond, sound wave is generated by the gas which passes through light-absorbing pulse, and the intensity of the sound wave is detected by a rheomicrophone; then, a signal is amplified by preposing and phase locking, and the data of the signal is collected by a high-accuracy digital-analog converter and a DSP data transmitter and stored; at the same time, opto-acoustic phase drift analysis is carried out by a lock-in amplifier, and the running quality or fault category and fault severity of an electrical power unit is exactly judged according to the sorts and the concentration of the gas, thus judging the running state or the property and degree of fault of the electrical power unit with high accuracy. The invention has simple structure and stable running, and can realize online monitoring for a long time.

Description

technical field [0001] The invention relates to an online monitoring method and system for gas content in transformer oil, belonging to the field of online monitoring of high-voltage electrical equipment. Background technique [0002] Since the current regular maintenance system commonly implemented in the power system is no longer suitable for the needs of the reform and development of the power system and the requirements of power users for the reliability of power supply, power companies have urgently needed to implement more advanced state-of-the-art maintenance in the world, that is, according to the equipment The operating status determines whether and how to maintain, and on-line monitoring is a necessary and effective means to implement condition-based maintenance of high-voltage electrical equipment. [0003] Since power transformers, reactors, bushings and other electrical equipment are made of oil or oil paper and cardboard to form an insulating structure, when th...

AI Technical Summary

Problems solved by technology

Among them, the "Transformer Partial Discharge Online Monitoring Device" of Patent Publication No. 02277287 detects the partial discharge of the transformer in the operating state through the sensor, and then monitors the partial discharge in time after being amplified and received. Difficult to extract

[0004] The effective method for transformer fault judgment is still the gas content monitoring method in insulating oil, which can be divided into two types: off-line and on-line monitoring. The off-line gas chromatograph has good selectivity, high separation performance, fast separation time, high sensitivity and It has the advantages of a wide range of applications, but there are also a series of shortcomings. There are human errors in the degassing operation, and the manual correction of the detection curve will also increase the error; from oil sampling to oil and gas separation to laboratory analysis, the operating procedures are complicated. , takes a long time; in addition, the development of insulation deterioration is fast or slow, and preventive tests cannot detect faults in real time. It has become an urgent need to implement on-line monitoring of gas content in power transformer oil

The online monitoring gas chromatographic monitoring system well solves the shortcomings of the off-line chromatograph, such as long detection cycle and long analysis time.

However, most of the current online monitoring systems, such as the method mentioned in the "on-line monitoring device for dissolved gas in transformer oil" with the patent number of 02277289, only use smart sensors for gas in oil for measurement, which has low measurement accuracy, less gas to be measured, and long-term work. Unstable and heavy maintenance

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