摘要详情

ID / 提交时间

78 / 2023-10-11 16:25:22

标题

Dynamic behavior characteristics of bubbles in oil under coupling of multiple physical fields

关键字

Converter transformers,Multi-field coupling,gas bubbles,dynamic characteristics

主题及专题

4.High voltage and insulation technology > (3)、High Voltage insulation technologies

状态

终稿

作者

Luyao Liu / Shandong University；Shandong Provincial Key Laboratory of UHV Transmission Technology and Equipment

Hongbin Wu / Shandong University；Shandong Provincial Key Laboratory of UHV Transmission Technology and Equipment

Pengfei Lu / Shandong University；Shandong Provincial Key Laboratory of UHV Transmission Technology and Equipment

Hongzheng Liu / Shandong University；State Grid Shandong Electric Power Company Electric Power Science Research Institute

Mingming Han / State Grid Shandong Electric Power Research Institute

Hongshun Liu / Shandong University；Shandong Provincial Key Laboratory of UHV Transmission Technology and Equipment

Qingquan Li / Shandong University；Shandong Provincial Key Laboratory of UHV Transmission Technology and Equipment

摘要

As a “new infrastructure” investment support economic project, ultra-high voltage direct current transmission has ushered in a new round of development and acceleration period. The demands of today’s times, such as larger transmission capacity, higher voltage level, and better transmission quality, have put forward higher requirements for the insulation reliability of converter transformers. The oil-pressboard insulation system is the main insulation structure of its casing valve side winding, outlet device, and other core parts. Due to the complexity and variability of the withstand voltage and working environment, it is prone to produce bubble defects under the combined action of various electrical and thermal factors. The migration, deformation, accumulation or other behaviors of bubbles with the oil flow will further distort the extremely uneven field of the insulation gap, leading to partial discharge and insulation degradation. For the purpose of clarifying the dynamic behavioral characteristics of air bubbles in oil prior to air gap breakdown under AC and DC compound voltages, this paper establishes a multi-field coupled bubble dynamics simulation model, investigates the influence laws and mechanisms of different factors such as the effective value of applied voltage, voltage polarity, and transformer oil temperature on the migration and deformation of bubbles, to provide theoretical guidance for the design, manufacturing, and fault warning of converter transformers.