风电双分裂变压器半穿越状态下的绕组热点研究与优化

Research and Optimization of Winding Hot Spots of Wind Power Dual Split Transformer under Semi-traversing Condition

通过运用Magnet和ANSYS Fluent仿真软件对SCSFB11-7400/35风电干式双分裂变压器在半穿越状态下的漏磁场分布、绕组负载损耗和温度场进行仿真和优化,同时通过温升试验验证仿真结果的准确性,最终确定绕组最热点的位置和大小。研究的前提条件主要包括变压器的型号和参数、运行模式、最热点限制、换热器功率、冷却液温和冷却风量要求等方面。研究发现,双分裂变压器在半穿越状态下的最热点温度在低压下绕组的上部、辐向绕组厚度约2/3 (由内往外)处,以及可以适当调整低压导电箔材厚度或/和低压绕组的匝数分布来解决半穿越状态下低压绕组电流分配不均所造成的损耗集中问题,从而改善低压绕组内部最热点温度,满足变压器可靠和安全运行的要求。为风电干式双分裂变压器的最热点确定提供了研究方法和途径,也可以为风电干式双分裂变压器的深入研究应用和现场运行维护提供了依据和指导。

Magnet and ANSYS Fluent simulation software were used to simulate and optimize the distribution of magnetic leakage field,winding load loss and temperature field of SCSFB11-7400/35 dry type dualsplit transformer for wind powerunder semi-penetrating working condition. Meanwhile, temperature rise test was used to verify the accuracy of simulation results and finally determine the position and value of hottest point of winding. The preconditions of the research mainly include transformer type and parameters, operation mode, maximum temperature limit, heat exchanger power, cooling water temperature and cooling air volume requirements, etc. The hottest point in the windings of double split transformer under semi-penetration working condition was positioned at around 2/3 thickness(from inside to outside in radial direction) of the upper low voltage winding according to the research, and adjusting conductive foil thickness and/or turns distribution of low voltage winding was verified to solve the uneven distribution of the loss of half through the condition of low voltage winding current uneven distribution of the loss concentration problem, thus the hot spot temperature inside the low-voltage windings could be improved to meet the design requirements. The research results provide a research method and approach for determining the hot spot of dualsplit transformers for wind power, and provide a basis and guidance for in-depth research, application and field operation and maintenance of dualsplit transformers for wind power.