The insulation medium of high-voltage switchgear and its internal high-voltage equipment will deteriorate with the operation time, and its performance will be reduced until the insulation breakdown. In order to avoid electric fire and other serious accidents, partial discharge and temperature online monitoring methods can be used to grasp the insulation status of equipment in real time.

When the high-voltage switchgear and its internal high-voltage equipment (such as PT, CT, busbar, cable connector, etc.) generate partial discharge (partial) due to insulation fault, it is often accompanied by pulse current, electromagnetic wave, ultrasonic, light, ozone, heat and other physical or chemical phenomena and corresponding processes. LY-DM500 adopts ultra-high frequency detection technology. Based on the principle of "field", it receives ultra-high frequency electromagnetic wave radiated during partial discharge through antenna sensor to detect partial discharge. In order to make the test data true and reliable, LY-DM500 adopts comprehensive anti-interference measures such as analog filtering, pulse grouping, periodic pulse elimination, and setting dynamic threshold.

Features

◇ The extraction of the specific frequency band of the discharge signal can effectively suppress the common interference signals in the substation. Then, it can effectively determine whether it is the discharge at the high-voltage equipment or the external interference signal. 

◇ Alarm function: alarm status can be given according to the severity of partial discharge. 

◇ The partial discharge monitoring subsystem adopts the special statistical method of "abnormal cycles" of our company, which can eliminate the instantaneous pulse impact interference caused by the operation of the interference switch. Generally, the shock electromagnetic wave generated by switching operation only occurs 1-5 times in individual power frequency cycles, and such abnormal cycles are relatively simple. By counting the number of such abnormal cycles, it can be determined whether it is switching operation or partial discharge signal.

◇ All sensors of the partial discharge monitoring subsystem are connected with a single digital bus bar and power supply integrated multi-core cables, with the minimum wiring quantity, greatly reducing the number and complexity of wiring on the switchgear, and minimizing the impact of the monitoring equipment on the original equipment. 

◇ Touch screen displays amplitude, frequency, alarm status and other information in real time.