Defect detection method, apparatus, and device for semi-conducting bedding layer of power cable

A defect detection apparatus for a semi-conducting bedding layer of a power cable, comprising:

• a parameter obtaining module, configured to obtain a length parameter, a corrugation pitch parameter, radius parameters, and a thickness parameter of a power cable;
• a first resistance value obtaining module, configured to obtain a first resistance value between a shield and a corrugated sheath;
• a second resistance value calculation module, configured to calculate a second resistance value of the shield based on the length parameter and the corrugation pitch parameter;
• a radial resistance value calculation module, configured to calculate a radial resistance value of a semi-conducting bedding layer based on the first resistance value and the second resistance value;
• a contact angle determining module, configured to determine a contact angle of a critical point of contact between the corrugated sheath and the semi-conducting bedding layer based on the radius parameters and the thickness parameter;
• an interpolation function obtaining module, configured to:
• take a plurality of points on a contact surface between the semi-conducting bedding layer and the corrugated sheath as base interpolation points;
• take an average value of the base interpolation points to obtain an interpolation data point;
• and obtain coordinates of the interpolation data point, and construct an interpolation function based on coordinates of a plurality of interpolation data points;
• a volume resistivity calculation module, configured to calculate first volume resistivity of the semi-conducting bedding layer in a resistance approximation mode based on the interpolation function, the radial resistance value, and the contact angle, and calculate second volume resistivity of the semi-conducting bedding layer in a conductance approximation mode based on the interpolation function, the radial resistance value, and the contact angle;
• and
• a defect detection module, configured to determine total volume resistivity of the semi-conducting bedding layer based on the first volume resistivity and the second volume resistivity, and compare the total volume resistivity with a preset evaluation parameter to obtain a defect detection result of the semi-conducting bedding layer.