Consistency Test of Ion-Flow Density Measurement System Using an Improved Gray Relational Analysis Method

It is known that the high-voltage direct-current (HVdc) transmission projects are increasingly used in actual electrical power transmission and the ion-flow field at ground level has been systematically studied. However, few studies focused on the research of the consistency among ion-flow density measurement systems (IDMS). IDMS should keep good concordance to discover the distribution law of ion-flow density in HVdc research. This study proposes an improved gray relational analysis (IGRA) method for consistency test of IDMS by introducing an entropy weight method and interval estimation method. Using this method, the consistency among IDMS is analyzed. The calibration assessment experiment was conducted and the results can be used for calibration assessment. The fault diagnosis experiment with +120 kV was also performed and findings show that the IGRA method is effective in finding potential fault for IDMS compared to the GRA method. Overall, results demonstrate that the IGRA method presented in this paper is useful for discovering distribution law of ion-flow density in HVdc research.