直流偏磁引起的500kV电力变压器振动和噪声的现场测量与分析

Field Monitoring and Analysis on Vibration and Noise of 500 kV Electrical Transformer under DC Current Biasing

设计了500 kV单相电力变压器振动与噪声在线同步监测方案,并通过振动与噪声传感器及相应的数据采集和分析系统实现了对广东惠州500 kV变电站单相电力变压器直流偏磁条件下的振动与噪声的实时监测。监测得到了500 kV电力变压器外壳上典型位置在直流偏磁前后的振动与噪声的时域波形数据,分析得到了500 kV单相变压器振动与噪声信号在直流偏磁前后的频率范围。试验结果表明:直流偏磁条件下电力变压器的振动与噪声幅值增加明显且频谱中出现了大量高次谐波,对于变压器的运行有着不利的影响。

In order to observe the influence caused by the DC biasing current through the neutral point of the power transformer, a new on-line vibration and sound monitoring program was designed with use of both qualified vibration and sound sensors at the same time. The experiment was operated in Huizhou 500 kV substation and a 500 kV single phase electrical transformer was chosen as experimental object. Based on the experiment platform, steady and clear vibration and sound waveform before and after the DC biasing condition was recorded and spectrum analysis was also achieved based on the data monitored. In conclusion, DC biasing is harmful for power transformers and the result of this research provides valuable reference to the on-line vibration and sound monitoring system of transformers.