Accurate evaluation of indoor triplex cable capacitances taking conductor proximity effects into account

Low-voltage indoor triplex cables aimed primarily for residential power circuits are currently being used also for high-frequency applications. The propagation properties of such cables can only be established once cable natural parameters have been determined. However, due to the fact that cable conductors are very closely spaced, such parameters must necessarily be determined by numerical modeling. In this work, cable capacitances are evaluated by taking conductor proximity effects into account. Accurate results, obtained using a harmonic expansion method, are compared with approximations currently in use. Theoretical results are validated experimentally.