A random forest based communication-less approach for protection scheme of six-phase transmission line against shunt, series, evolving and cross-country faults

To meet the rising power demand, it has become mandatory to consider alternative solutions to the existing transmission line framework. Six phase transmission line can be a potential solution due to its ability to transfer 73% more power relative to classical three phase double circuit system. However, due to the increased number of series and shunt faults in the six-phase transmission line, the development of an accurate protection scheme is quite challenging in a six-phase system. Also, because of the larger number of phases, the possibility of non-typical shunt faults, viz. evolving and cross-country faults, are quite high in a six-phase system. Hence, the significance of developing a protection scheme with increased sensitivity against all types of faults (series, shunts, evolving, and cross-country) has become vital for the acceptance of six-phase transmission lines by power utilities. In this regard, a random forest (RF)-based classifier and regression approach have been respectively proposed for the detection/classification and location estimation of all possible faults in a six-phase transmission line. Separate RF classifier modules have been developed for shunt and series faults for detection and classification, followed by further categorization of shunt faults into evolving and cross-country faults. For location estimation, the high dimensional nonlinear mapping characteristics of the Regression Tree (RT) have been utilized. The use of single-end data, avoids the issue of latency and data loss associated with communication assisted protection schemes. The proposed RF-based scheme's efficacy has been tested for various types of typical and non-typical shunt and series faults, with a wide range of fault and power system parameters. The test findings of the RF-based protection illustrate that the protection scheme is resistant to a wide variation in the fault types, fault conditions, extent of nonlinear loading, and noise intrusion.