UHF sensors for Transformer
An UHF sensor plays a significant role in UHF PD measurement because the initial step of PD measurement is to acquire electromagnetic signals using these devices for further signal processing. To this end, the performance of the sensors will dramatically influence the accuracy and sensitivity of the PD detection system.
UHF sensor, PDU-T consists of a broadband antenna optimized for the UHF frequency range radiated by PD and of its mechanical adaption for the installation at power transformers. Two different mechanical adaptions for internal PD measurement mainly are used for practical applications.
A. UHF Drain Valve Sensor，PDU-T1
An UHF drain valve sensor is designed for transformers which are equipped with standard of gate valves. It is recommended to use only straight opening valves at new transformers in order to provide sensor compatibility.
B. UHF Plate Sensor，PDU-T2
UHF plate sensors can be mounted directly to the tank wall which is suitable e.g. for newly built transformers or for transformers in repair. A dielectric window is integrated into the tank wall.
Why UHF technology?
- UHF technology is industry proven technology for online monitoring of partial discharge in insulations of HV apparatus
- The sensitivity is higher than any other kind of PD measurement e.g. DGA, Acoustic, or conventional measurement
- immediate detection of partial discharge makes it ideal for online monitoring and detects PD earlier than DGA (Dissolved Gas Analysis)
- Excellent interference immunity compared to acoustic and conventional measurements