智能变电站就地智能设备电磁兼容抗扰度试验分析

Experimental Analysis of EMC Immunity for Field Installed Intelligent Equipment of Intelligent Substation

随着智能变电站建设的全面推进,二次智能设备就地布置成为趋势,但就地布置后,开关场的电磁环境比保护小室更为严酷,为了研究开关场的电磁骚扰对就地智能设备的影响并定量分析电磁骚扰强度,在某110 k V智能变电站就地合并单元发生异常情况之后,运用排除法确定了刀闸操作产生的电磁骚扰是合并单元产生异常情况的重要原因,随后对该变电站就地合并单元进行电磁兼容相关实验并对其结构进行改进,测录了该110 k V和某500 k V智能变电站的电磁骚扰信号,分析了电磁骚扰信号的幅频和时频特性。结果表明:110 k V变电站的合并单元地线骚扰信号峰峰值为4.6 k V,500 k V变电站TV二次侧电压通道骚扰信号的峰峰值甚至达到了6 k V,此骚扰信号峰峰值大于IEC 61000-4-4标准规定的IV级电快速瞬变脉冲峰值,IEC61000-4-5标准规定的IV级浪涌(冲击)信号峰值和IEC61000-4-10标准规定的IV级阻尼振荡波幅值,此外,实测的骚扰信号主频都在兆赫兹级,目前最新的IEC61000-4-10阻尼振荡波抗扰度标准已经新增了3 MHz、10 MHz和30 MHz的振荡频率,因此综合来看,当前国内的电磁兼容抗扰度试验标准已不足以考核就地安装的二次智能设备。

Along with the construction of intelligent substation, the field installation of secondary intelligent devices becomes a trend. The distance from field installation intelligent secondary devices to the disturbance source is nearer, so the intelligent devices suffer greater electromagnetic disturbance. To study the influence of electromagnetic disturbance of switchyard on the field installed intelligent device and to quantitatively analyze the intensity of electromagnetic disturbance to merge units, after the occurrence of the abnormal phenomenon of the 110 k V intelligent substation merging unit, we have determined that the electromagnetic disturbance generated by switch operation is an important reason for the abnormal phenomenon. The electromagnetic compatibility experiments are carried out and the structure of the merging unit is improved. The electromagnetic transient disturbance signal of the 110 k V substation and 500 k V substation which is caused by switching operation is measured and recorded. The characteristics of amplitude and time-frequency of the recorded electromagnetic transient disturbance signal are analyzed. The results show that： the peak values of the transient disturbance signal in 110 k V and 500 k V substation are more than the highest grade standard of electrical fast transient pulse packet immunity, surge immunity and the peak of damp immunity. Besides, the measured main frequency of disturbance signal are megahertz grade. The newest IEC6100-4-10 standard add frequency at 3 MHz, 10 MHz, and 30 MHz. So, it is pointed out that the current standard is not adequate to examine the field installed intelligent equipment.