Frequency and Time Domain Responses of Cross-Bonded Cables

Cross-bonded cable models are compared against their versions with normal bonding (no bonding) for propagation characteristics, frequency, and time-domain responses. Contrary to no-bonding cables, coaxial modes cannot propagate in cross-bonded cables. Instead, intercore modes propagate, being always accompanied by intersheath modes. The latter property cannot be observed if a cross-bonded cable is modeled with its homogeneous equivalent. It is shown that sheath cross-bonding induces intersheath modes circulating between grounding points and impacts on the cable response at resonant frequencies. Alternate models for cross-bonded cables, including both homogeneous and nonhomogeneous equivalents, are compared based on frequency-and time-domain responses, including a field test on a 225 kV 64 km cable with 17 major sections.