High Reliable Partial Discharge Online Monitoring System of Hydro-generator

Partial discharge (PD) online monitoring is considered as one of the most effective means to prevent sudden accidents of hydro-generator. In this paper, a set of high reliable hydro-generator PD online monitoring system was developed, which made use of PDA technique to obtain PD signal and adopted PD integrated monitoring method to make sure the credibility of PD analysis results. Three aspects of investigation were carried out to ensure the high reliability of the system: (a) to effectively eliminate the on-site interferences and ensure the reliability of PD pulses acquisition, the PDA method is adopted and pulse time-delay technique is studied;(b) to overcome the isolation properties of the traditional PD online monitoring and ensure the high reliability of PD analysis results, on the base of the PD influence factors analysis, the PD integrated monitoring and association analysis model was set up, (c) to verify the reliability of the installation of PD sensors, the security performance of PD sensor body during hydro-generator in short circuit fault was studied. At present, the system has been applied to several hydro-generators in a huge-size hydropower plant.