Reliability of Transmission Links Consisting of Overhead Lines and Underground Cables

Underground cables will be applied more often within new connections of the extra-high-voltage (EHV) transmission network. Since EHV underground cables are a relatively new technology, not much is known about their behavior in large transmission networks. Underground cable connections (consisting of cables, joints, and terminations) are, in general, less reliable than traditional overhead lines, mainly because of their much longer repair time. This can negatively influence the reliability of the transmission network as well. It is therefore of interest to study the reliability of underground cable connections in detail. This paper concentrates on the reliability of EHV underground cable and overhead line connections. Based on actual failure statistics of individual components, the reliability of a connection is analyzed, and which factors are of influence and what measures can be taken to improve the reliability are studied. An optimized cable repair process and a configuration with additional disconnectors are two solutions.

[1]  Wenyuan Li,et al.  Risk Assessment Of Power Systems: Models, Methods, and Applications , 2004 .

[2]  Chanan Singh,et al.  Reliability Analysis of HTS Cable Systems , 2015, IEEE Transactions on Power Delivery.

[3]  G. Mazzanti,et al.  The combination of electro-thermal stress, load cycling and thermal transients and its effects on the life of high voltage ac cables , 2009, IEEE Transactions on Dielectrics and Electrical Insulation.

[4]  W. H. Wellssow,et al.  Reliability calculation of MV-distribution networks with regard to ageing in XLPE-insulated cables , 2001 .

[5]  JJ Smit,et al.  Return of experience of 380 KV XLPE landcable failures , 2011 .

[6]  Surya Santoso,et al.  Incipient Fault Location Algorithm for Underground Cables , 2014, IEEE Transactions on Smart Grid.

[7]  R. Benato,et al.  Overall Cost Comparison Between Cable and Overhead Lines Including the Costs for Repair After Random Failures , 2012, IEEE Transactions on Power Delivery.

[8]  Tae Sung Yoon,et al.  Cable Fault Localization Using Instantaneous Frequency Estimation in Gaussian-Enveloped Linear Chirp Reflectometry , 2013, IEEE Transactions on Instrumentation and Measurement.

[9]  Roberto Benato,et al.  State-space model for availability assessment of EHV OHL–UGC mixed power transmission link , 2013 .

[10]  Roy Billinton,et al.  Reliability evaluation of power systems , 1984 .

[11]  G. Hartshorn,et al.  Assuring cable reliability , 2009, IEEE Industry Applications Magazine.

[12]  S. Boggs,et al.  Cable life and the cost of risk , 2009, IEEE Electrical Insulation Magazine.

[13]  A. Bulinski,et al.  On-site diagnostics of medium-voltage underground cross-linked polyethylene cables , 2011, IEEE Electrical Insulation Magazine.

[14]  E. Gulski,et al.  Advanced solution for on-site diagnosis of distribution power cables , 2008, IEEE Transactions on Dielectrics and Electrical Insulation.

[15]  Athula D. Rajapakse,et al.  Online fault location on AC cables in underground transmission systems using sheath currents , 2014 .

[16]  Lei L Wu,et al.  Impact of EHV/HV underground power cables on resonant grid behavior , 2014 .

[17]  G. Svejda,et al.  Availability and Risk Assessment of 380 kV Cable Systems in Transmission Grids , 2012 .