Abstract
According to field interference characteristics of power transformer, the directional coupling method with software aided is used to suppress pulse shaped interferences. Pulse signals are coupled by two magnetic core current sensors respectively installed near the flange of the HV bushing and near the capacitance tap to earth per phase, then sent to a computer after amplification. A software program is used to identify the polarity of the head wave for every pulse signal from each sensor, and then distinguish noise from true partial discharge signal by their different pulse polarities. Different anti-interference techniques, such as dynamic threshold, digital filter and phase windows, are used in the monitoring system to remove background noise, fixed band interferences and periodic pulses to make the monitored data real and reliable. The effectiveness and reliability of the monitoring system is validated by its practice in a 220 kV substation.
| Original language | English |
|---|---|
| Pages (from-to) | 104-107 |
| Number of pages | 4 |
| Journal | Dianli Zidonghua Shebei/Electric Power Automation Equipment |
| Volume | 27 |
| Issue number | 2 |
| State | Published - Feb 2007 |
Keywords
- Anti-interference
- Partial discharge
- Power transformer
- Pulse polarity discrimination