Research On Automatic Control System Of Power Transformer Test

Power transformer test is an important means of checking the transformers'quality. And it is the base of quality management and improvement of quality.However, the domestic transformer test is still in the level of the manual operation,and it falls behind the modernization of production. To enhance the productionefficiency, it is very necessary to develop a transformer automatic testing andcontrolling system that has a high precision and automation. There is the importantmeaning to improve production efficiency and product quality, to reduce laborintensity.This paper does researches to the temperature rise test, no-load and load test, andtemperature rise test is the most important part of the system. Based on the research,an automatic testing and controlling system is developed. It takes the PC as the centerof the system, meanwhile, power analyzer device, DC resistance testing device,temperature sampling module, temperature sensor and relay module are used as thesubordinate equipment of system. With serial communications, PC controls the worksof subordinate equipment. Developed software is based on VC6.0 of Microsoft. UsingCOM technique and the applications software of Microsoft Word and Accessdatabase on the platform ofvc6.0, later management of the test are programmed.The paper expatiate the transformer test's purpose, methods, process and datacalculation of test result. Then the choice of testing and controlling equipment isintroduced, and the technical parameters and the communication protocol have beendescribed.-After that, the hardware of the system has been designed. The software isdeveloped which it bases on the platform of VC6.0. And, the system are composed ofsix parts, such as the main program, data calculation of winding temperature riseprogram, data management program, test report automatic writing and communicationprogram. The program flow chart is also displayed. Meanwhile, it describes thedesign idea of these programs. Focusing on the complex communication protocolsand instruction set of Power Analyzer Device (NORMA4000), the program of serialcommunication between PC and Power Analyzer Device are programmed, and theprogram flow chart is also displayed. At last, in order to meet the needs of calculationof winding temperature rise, least square method are used to fit the hot resistance graph, and the program of calculation of winding temperature rise are also furtherdeveloped. Then, the program flow chart is given in the paper.When the system is applied in the transformer manufacture, the level ofautomatic control will be greatly enhanced, and the later data management is alsomore convenient. In that case, it achieves intelligent and automatic control oftransformer test.