Prediction of the Temperatures in a Three-Core Distribution Cable and Splice with Load Changes

Real-Time Temperature Estimation of Three-Core Medium-Voltage Cable Joint Based on Support Vector Regression

“…As seen in the literatures [16,17], the temperature inside joints was calculated cooler than that of cable. The reason given by those papers was that the ferrule diameter was considerably larger than that of the conductor (27.2 mm compared with 19.1 mm) without consideration of contact resistance.…”

“…Thus, "G-factors" can not be used to calculate this part of thermal resistance. What's more, a very important assumption made in [16,17] was that the cable and joint outer surfaces are isothermal. Nevertheless, according to the FEM thermal analysis as illustrated in Figure 15, the temperature difference in outer surface of the joint can reach over 10 • C due to its triangular shape, which demonstrates the joint outer surface is not isothermal.…”

“…According to the literature search mentioned above, there are totally three kinds of methods to calculate the temperature of three-core cable joint, including FEM, finite difference method [16,17] and analytical method [5]. But the analytical method can only solve steady-state problem so that it is hard to realize temperature monitoring.…”

“…Determination of thermal resistances with irregular shapes is the key point. In literature [16,17], the irregular thermal resistances, as seen in Figure 13, were calculated using the so-called "G-factors", which can be obtained by 2-D dimensional field plots in IEC 60287 [23]. …”

Power Cable Rating Calculations - A Historical Perspective [History]

“…In this approach, the differential equation governing the axial and radial heat flows in an infinitely long conductor is applied to three longitudinal sections along the cable length exposed to different external conditions. Also in 1986, the effect of axial heat conduction in electric cables was further i n v e s t i g a t e d b y Weedy, who developed steady-state and transient thermal models for the determination of the axial temperature in threecore cables of infinite length jointed with splices and buried in the ground [51], [52] ( Figure 8). The transient thermal model considers several longitudinal subsections in which the multicore cable and splice are simplified into equivalent single-core conductors using a geometric factor of the IEC Standard, Publication 287.…”