Combining Resistive and Capacitive Stress Grading in High Voltage Cable Joints

The commonly used pre-moulded slip-one cable joint is proposed to replace with a combination of heat-shrinkable cylindrical tubes. The working principle of effective electrical stress grading is based on combining the resistive and capacitive stress grading approaches. Both resistive and capacitive stress graders are coaxial heat-shrinkable tubes of carefully designed profile, position, and dielectric properties. Optimal sizing and material properties of each tube are found by FEA modeling of electric field taking into account the leakage current. Proposed optimal parameters confirmed by preliminary laboratory test of a 110 kV cable joint.