大型发电机定子绕组局部放电在线监测方法的研究

Study on online PD monitoring of large generator stator winding

考虑放电脉冲在定子绕组中的传播规律,通过安装在定子绕组线圈上的感应传感器监测发电机定子绕组局部放电,确保局部放电信号在变形和衰减前被分离,同时对局部放电信号进行处理。分析了其监测原理,以高压电缆接头或定子绕组线圈发生局部放电为例,将2个传感器分别置于试件两侧,分析这2个传感器上电压的关系,可判断局部放电是发生在试件的内部还是外部,并计算内部局部放电时的脉冲灵敏度或外部局部放电时的噪声干扰灵敏度。

Considering the propagation law of discharge pulse in stator winding,inductive sensors are installed on the stator coils to monitor its PD(Partial Discharge). The PD pulses are separated before attenuation and distortion,and then processed. The monitoring principle is analyzed with an example of the PD in high-voltage cable connector or stator coil. Two inductive sensors are installed at both sides of test object. By analyzing the voltages of sensors,whether the PD source is inside or outside the test object can be determined. Furthermore,the pulse sensitivity of inside PD or the interference sensitivity of outside PD is calculated.