Improvement of measurement techniques in PD pulse detection in large HV equipment

Partial discharge (PD) measurement has been used as a tool to assess insulation integrity for many years. In terms of detection of PD pulses, a proper assessment of insulation integrity relies on accurate acquisition of the PD pulse signal. However, measurement errors may arise due to the measurement facilities involved. This paper discusses one aspect of the measurement system, the role of connecting cables. It is shown that the connecting cables used in PD measurement may distort PD waveforms recorded. Attenuation, reflection, resonance, and coupling occur in coaxial cables for transmission of RF/UHF signals