轨道交通冲击直流对电网变压器偏磁影响

Impacts of Rail Transit Impulse DC on the Magnetic Bias of Power Grid Transformers

针对城市地铁过站时冲击泄漏电流引起的临近电网变压器偏磁问题,研究了冲击直流对变压器振动噪声的传播干扰。基于电磁-机械-声耦合原理,建立三相变压器仿真模型,分析不同场景下冲击直流对变压器构件的振动加速度及噪声的影响情况,总结了冲击直流与漏磁、振动加速度及噪声的关联规律。搭建了动模试验平台,测量不同程度的冲击直流下变压器振动、噪声数据,并与仿真结果进行对比,分析结果表明:变压器构件的振动加速度、声压均随直流水平上升而增大;与绕组相比,铁芯受直流干扰影响更大,并且铁芯主柱振动噪声强于旁柱。

In addressing the issue of the magnetic bias generated by the impulse leakage current on the power grid transformer close to the subway when a subway train passes a metro station,this paper investigates the propagation interference of the impulse DC on the transformer vibration noise.The simulation model of the transformer is built based on electromagnetic mechanical sound coupling principle.The impulse DC impact on vibration acceleration and noise of transformer components is studied under different scenarios,and the correlation rules between impulse DC and magnetic flux leakage,vibration acceleration and noise is summarized.A dynamic experimental platform is built to measure the vibration and noise data of transformers under different levels of impulse DC.The results are compared with simulation results to verify the correctness and effectiveness of the model and conclusions proposed in this paper.The analysis results show that the vibration acceleration and sound pressure of transformer components increase with increase of DC level;and compared with the winding,the iron core is more affected by DC interference,and the vibration noise of the main column of the iron core is stronger than that of the side column.