The Development Of Intelligent Respirator For Large Oil-immersed Transformers

As a safety accessory of the transformer,the respirator is installed at the end of the oil conservator's connecting pipe.It is internally equipped with color silica to dry the air and avoid moisture into the transformer.In the application process,once the respirator failure will have a serious impact on the transformer,and even spread to the entire power system.In addition,it need regular maintenance,and replace the failure of color silica.The whole process not only consumes a lot of manpower and material resources,but also has a large security risk for maintainers.Therefore,it is urgent to put forward a kind of digital and intelligent transformer respirator,which can monitor the running state of the respirator in real time,and regenerate the failure of color silica.This paper mainly introduces the design process of the intelligent transformer respirator.The starting point is based on the properties of the modified silica gel,which can be regenerated by thermal desorption,so we don't need to replace it.Consider the main function and performance requirements of the respirator,and after the deep research and analysis,we finally determine the design scheme which judges the state of the color silica by detecting the air humidity and includes two silica tanks.In this paper,the design and realization of the hardware circuit and software program of the intelligent respirator are described in detail.In the design of hardware circuit,we use single-chip and DHT11 humidity sensor to measure the air humidity.At the same time,we combine with the Pt100 temperature sensor and clock circuit to regenerate the failed color silica.In addition,we introduce the design of display module,serial communication and power module minutely.As for software program,it contains upper computer software and lower computer software.The design of the lower computer software aims to realize various functions of the intelligent respirator by C programming language.The purpose of the upper computer software is to develop software interface for the communication with the intelligent respirator.After completing the functional test,we perform EMC test for it in the third party testing and certification body.The test results show that the intelligent ventilator can dry the outside air effectively,and regenerate the failed color silica.It meets design requirements.