Experimental research on ampacity of extruded power cable under complex operating condition

Ampacity under nonuniform operating conditions is difficult to be exactly determined by theoretic calculation because of the limitation for the theoretic model. The experimental research of ampacity for 110 kV extruded power cable was conducted. In order to simulate the actual operating conditions, four full-size cable trenches were constructed, and different loads were also applied to the power cables. The main affecting factors of the ampacity for the power cables under uniform conditions are discussed in detail according to test results. The reference values of thermal resistance for soil and different backfills in the experimental research as well as a whole year temperature chart of the soil for test site were presented. The test data were used to determine the ampacity of the power cables in practical engineering, the measured values of thermal resistance and temperature will be used to adjust the reference operating conditions for theoretic calculation in practical.