大型发电机主变压器感应过电压计算方法分析

Analysis on Calculation Method of Main Transformer Induction Over Voltage of Large Generator

当冲击电压波侵入到变压器高压绕组时,除在本绕组内产生暂态振荡外,也会通过静电感应和电磁感应传递到低压绕组中,使低压绕组侧产生过电压。根据主变压器的等值模型,可以得到电磁感应过电压的计算方法,从而可以定量地计算出主变压器低压侧和发电机可能的过电压,以及发电机的过电压上升速度。计算结果可以作为选择过电压保护设备的依据。

While the impulse voltage wave is intruded into the HV winding of the transformer, except it produces the transient oscillation within the winding itself, it also transfers to the LV winding through the electrostatic and electromagnetic inductions, which causes the over voltage at the LV winding side. According to the equivalent model of the main transformer the calculation method for electromagnetic induction can be obtained to calculate quantitatively the over voltages at the transformer LV side and generator side possibly, as well as rising speed of over voltage at the generator side. The calculation results can be the criteria for selection of over voltage protection.