Extruded solid dielectric high voltage cable resistant to electro-chemical trees

An electrical high voltage power cable for use underground including in combination a stranded conductor, a stress control layer forming a shield around and enclosing the conductor, a strand sealant that fills all spaces between the strands and any space between the strands and said stress control layer for preventing presence of moisture and water vapor within the stranded conductor and entrance of air and moisture through an end of the cable, and the strand sealant being semi-conducting, and an insulation system constructed so as to prevent the formation of electrochemical trees in the insulation, including an extruded solid polyethylene insulation layer tightly enclosing the stress control layer so that no moisture can enter at the ends of the cable at the interface between the insulation and the stress control layer, an extruded solid semi-conducting insulation shield tightly enclosing the insulation to prevent ingress of moisture between the insulation and the insulation shield, a metallic shield enclosing the semi-conducting insulation shield, and additional sealant comprising a semi-conducting compound between the insulation shield and the metallic shield and filling any clearances between the insulation shield and the metallic shield for preventing moisture that passes inward beyond the metallic shield from reaching the insulation shield, the sealant being chemically and physically compatible with the stress control layer and with the insulation shield and being a compound, and that maintains its physical and electrical characteristics in spite of the temperature caused by the load cycling of the power cable.