Performance Comparison of PD Data Acquisition Techniques for Condition Monitoring of Medium Voltage Cables

Abstract

Already installed cables are aging and the cable network is growing rapidly. Improved condition monitoring methods are required for greater visibility of insulation defects in the cable networks. One of the critical challenges for continuous monitoring is the large amount of partial discharge (PD) data that poses constraints on the diagnostic capabilities. This paper presents the performance comparison of two data acquisition techniques based on phase resolved partial discharge (PRPD) and pulse acquisition (PA). The major contribution of this work is to provide an in-depth understanding of these techniques considering the perspective of randomness of the PD mechanism and improvements in the reliability of diagnostics. Experimental study is performed on the medium voltage (MV) cables in the laboratory environment. It has been observed that PRPD based acquisition not only requires a significantly larger amount of data but is also susceptible to losing the important information especially when multiple PD sources are being investigated. On the other hand, the PA technique presents improved performance for PD diagnosis. Furthermore, the use of the PA technique enables the efficient practical implementation of the continuous PD monitoring by reducing the amount of data that is acquired by extracting useful signals and discarding the silent data intervals.

A Review on the Classification of Partial Discharges in Medium-Voltage Cables: Detection, Feature Extraction, Artificial Intelligence-Based Classification, and Optimization Techniques

“…According to the tests, RC-based sensors performed better than HFCTs because of their higher SNR. The design and performance characteristics of the RC and HFCT sensors were compared in [26] in order to measure the PD signals that are released from PD defects. These sensors were chosen for their operational behavior, installation potential around the cable shielding, and non-intrusive sensing ability.…”

A Review of Aging Models for Electrical Insulation in Power Cables

“…The clarity in the interpretation of the measured quantities and their relationship with the aging mechanism or type of deterioration is vital for reliable diagnostics. Identification of the changing pattern as a reflection of progressing deterioration can provide a traceable behavior of insulation aging and prediction of its expected condition [16]. Due to stochastic characteristics of interest observed from the analyzed measurements, it is challenging to identify the degradation patterns.…”

“…PD measurements provide a direct illustration of the insulation conditions. Initial studies conducted by the authors demonstrate the characteristics of PD signals such as PD magnitude and pulse-repetition rate analyzed from the PDIV up to the breakdown of the insulation due to the gradual increase in electrical stress [16]. The variation in these characteristics provides a cognizable pattern during various stages of degradation.…”

Cable fault and assessment using multiple frequency autoencoder regression-based reflectometry

“…Moreover, obstacles exist in gaining access to or diagnosing cable conditions once the cable has been installed and is under operation. Various cable diagnosis methods have been developed including the DC withstand, VLF tan delta, and partial discharge diagnosis [1,2,3]. The DC withstand voltage test may be adequate for identifying insulation deterioration and detecting leakage currents.…”