基于高次电流谐波对主变运行异响研究

Research on abnormal noise of main transformer operation based on high-order current harmonic

变压器运行噪声和电气性能是设备状态评价的重要依据,厂站内噪声源众多,难以判断引起主变异响的根源,为主变健康度判断带来不确定因素。为此,针对部分用户向电网注入高次谐波污染问题,分析谐波电流导致主变异响机理,推导出谐波电流与主变振动异响的关系:高次谐波电流促使主磁通及磁屏蔽回路饱和,产生磁致伸缩噪声;磁屏蔽边缘的电磁吸力引起磁屏蔽边缘的振动产生噪声。在实际运行案例中,通过对电能质量、主变声响的监测及负荷调换,验证结论的正确性。

Transformer operation noise and electrical performance are the important basis of equipment status evaluation.There are many noise sources in the plant,so it is difficult to determine the source of the main variation noise,which brings uncertain factors to the health degree judgment of the main transformer.Therefore,in view of the problem that some customers inject high-order harmonic pollution into the power grid,the mechanism of main variation noise caused by harmonic current is analyzed,and the relationship between harmonic current and the abnormal noise of the main transformer vibration is derived.The high-order harmonic current causes saturation of the main magnetic flux and magnetic shielding circuit,resulting in magnetostrictive noise.The electromagnetic attraction at the edge of magnetic shielding causes vibration and noise at the edge of magnetic shielding.In the actual operation case,the correctness of the conclusion is verified through the monitoring of power quality,main transformer sound and load exchange.