| With the social progress, that the clean and green energy construction must be built to meet the needs of the community’s electricity is in imminent situation. At present, the concept of building global energy internet has been proposed. In general it can be divided into three stages: domestic interconnection, intra-continental interconnection, and intercontinental interconnection. Power transmission between countries or regions on all continents of the interconnection in power network requires the large single-phase three winding converter transformer which discussed in this paper, and the valve-side outlet device is one of the most important parts of the converter transformer. Under the background of the rapid development of power grid interconnection and DC power transmission, the development and realization of the valve-side outlet device with high reliability is a problem which must be solved at present.In this paper, a model of ZZDFPSZ-230 MVA/400 k V single-phase three winding converter transformer is taken for example to develop the valve-side outlet device. The main research work of this paper is demonstrated as follows:(1)Actual product structure of converter transformer was simplified reasonably. Then a valve-side of converter transformer outlet device model was built based on the Maxwell equations. Focus on the electric field strength of AC withstand-voltage, DC withstand-voltage, and long field polarity reversal test, the electric strength in these three cases was calculated, analyzed and checked. The distribution of the electric field strength under different working conditions and the corresponding allowable values were acquired.(2) The valve-side outlet device of the converter transformer was designed. The key points of processing, manufacturing and assembling process of the outlet device in the design and production process were described. Reasonable and appropriate measures were taken to ensure that the outlet device met the design requirements and can be smoothly installed on the converter transformer.(3) The outlet device was tested with being installed on the converter transformer. The detailed test items were listed. The test circuit, the main test equipment, the criteria, and the results of the test were introduced. The outlet device was tested with the converter transformer according to the technical agreement, GB standards, and IEC standards. And the strict electrical test was passed smoothly in one trail.With the finite element analysis and the factory test of the valve-side outlet device, the conclusion further proves that the research methods and solutions which was proposed in this paper and have solved the problem are feasible, and can be provided as references and instructions for future development and research in this field. |
