Diagnosis and treatment for frequency hopping of PMU within an intelligent substation

Abstract

In the wide area measurement system （WAMS） of a province， occasional frequency hopping has been observed in digital phasor measurement unit （PMU） within an intelligent substation. Firstly， dynamic data records and waveform files are retrieved during instances of frequency hopping. Analysis is conducted in conjunction with on-site operational mode， and the causes behind two instances of frequency hopping are figured out. Subsequently， adjustments are made to the analog threshold values of the smart terminal， improvements are implemented in the sampling value （SV） network mode， virtual local area network （VLAN） switches are partitioned， and bandwidth thresholds of the device are fine-tuned to address frequency fluctuations caused by SV packet loss. Moreover， SV data recovery is conducted to enhance the fault tolerance of the PMU， ensuring that a loss of fewer than 3 frames will not lead to frequency fluctuation limit. Furthermore， efforts are made to identify on-site disturbance sources and analyze the causes of disturbances leading to frequency fluctuations in the PMU. A rapid disturbance identification method based on triggering waveform files is proposed. Finally， the effectiveness of the proposed method is validated through experimentation.

Keywords

• intelligent substation
• pmu
• frequency hopping
• sv packet loss
• disturbance
• networking