牵引变压器绕组温升与油流的关联性

为明确牵引负荷下绕组温升与油流速度动态变化的相互跟随性,构建了牵引变压器温升试验平台,模拟各种负荷下绕组和铁心的生热及油流循环过程,并同步测量油温、绕组热点温度以及散热器油流速度.在此基础上,建立了对应的数值计算模型,仿真求解其温度场与油流场.研究结果表明:稳态时油流速度与绕组热点温度基本呈线性关系;阶跃负荷时油流速度有一个冲击回落的过程,油流速度冲击峰值受负荷作用时间和负载系数大小影响,达到峰值时间比绕组热点温度达到峰值迟10 min;连续冲击负荷下,冲击负荷之前的温度与流速只影响绕组热点温度的绝对值,对铜油温差基本无影响. 

Correlation between Winding Temperature Rise and Oil Flow in Traction Transformer

To clarify the dynamic relationship between winding temperature rise and flow velocity under traction loads, a special temperature rise test platform for traction transformer was set up. By the test platform the temperature of oil, the winding hot spot as well as oil flow velocity in radiator can be measured at the same time, when the test platform worked under various simulated traction loads. Then a numerical model was established, which was validated by experiment. The results show that flow velocity is proportional to the winding temperature under steady state; oil flow velocity has a shock-down process under step load, the peak of oil flow velocity is affected by load acting time and load factor, the peak time is later 10 minutes than the winding hot spot temperature; under continuous impulsive load, the temperature and velocity before impulsive load affect the absolute value of the hot spot temperature only, while have little effect on the temperature difference between copper and oil.