Insulating dielectric loss angle tendency online monitoring method of high-voltage cables under cross interconnection

The invention discloses an insulating dielectric loss angle tendency online monitoring method of high-voltage cables under cross interconnection. The method includes the steps of firstly, sleeving a pincer-shaped current sensor on the inlet wire of each of a cross interconnection grounding box and a direct grounding box during electrified operation of a cable to collect a current signal flowing in a cable insulator, and using a voltage collecting device to obtain a CVT (constant-voltage transformer) secondary voltage signal at the head end; secondly, by a GPS (global positioning system) clock, synchronously collecting a current signal and a voltage signal and transmitting the same to a collecting device; thirdly, extracting and calculating the current, flowing a main insulator, of each cross interconnection cable section; fourthly, obtaining the dielectric loss angle tendency of each insulating section of the cross interconnection cable under electrified operation through comparison analysis of constant duration measured voltage and current signals. By the method, effective reference can be provided for judging and evaluating the health status of each insulating section of the cross interconnection cable and predicting the service life of the cable.