Cable Partial Discharge Detection and Monitoring
Cable partial discharge detection is a crucial measure for ensuring the safe operation of the power system. By regularly inspecting cables for partial discharges, potential faults can be identified and addressed promptly, extending equipment life and enhancing the reliability of the power grid.
Partial Discharge in Cables
Definition & causes of cable partial discharge
Cable partial discharge is an electrical discharge or spark phenomenon that occurs in electrical cables. This is often due to imperfections in the cable’s construction, such as poor workmanship, water treeing, manufacturing defects, or excessive bending. While these defects may not completely bridge the insulation, they can lead to partial discharges, which can potentially cause a short circuit. Moreover, partial discharge (PD) in cables can have several detrimental effects on the cable’s performance such as cable insulation degradation.
Where does cable partial discharge occur?
Cable partial discharge typically occurs at inner or near cable joints and terminations. They can develop between the conductor and insulation, within voids in the insulation, between insulation layers, or between the insulation surface and the cable’s shield.
Types of PD in cables
As for partial discharge in cable, there are three types, including void PD discharges, surface PD discharges, and corona PD discharges.
Void partial discharges in cables occur when air pockets or voids exist within or on the surface of the insulating material. These voids significantly weaken the insulation’s dielectric strength. Under the influence of a high-voltage electric field, the gas within the void ionizes, leading to a partial discharge in cables.
Cable Surface partial discharge is a type of electrical discharge that occurs on the outer surface of a cable’s insulation. It’s often caused by physical damage like scratches, abrasions, or punctures on the cable sheath, the aging of the cable’s insulation, or the accumulation of dirt, moisture, or other contaminants on the cable’s surface.
Corona PD discharge in cables may be caused by high voltage, conductor geometry, Humidity, temperature, and air pressure environment, etc. For example, if the cable has air within the void or the wrong installation of termination or splice, the corona PD discharge will occur in the cables.
Cable Partial Discharge Detection and Monitoring Solution
A partial discharge detection and monitoring solution is required to monitor cable partial discharge for the cable conductor, bus bar or near-ground point, cable joint, and cable termination shields.
Here are some common solutions for partial discharge in cables.
| PD types in cables | Cable Partial Discharge Detection Solution by Sensor | Cable Partial Discharge Detection Solution By PD3000 |
| Void partial discharge | UHF PD Sensor HFCT PD Sensor AE Contact Probe sensor TEV Sensor | The PD300 can monitor cable PD activity in short and long cable systems. No matter what type of cable partial discharge, PD3000 is your best and cost-effective solution. |
| Suface partial discharge | Airborne Acoustic Sensor Acoustic Contact Sensor UHF PD Sensor TEV PD Sensor | |
| Corona partial discharge | AE PD Sensor Ultrasonic PD Sensor HFCT PD Sensor |
PD3000 partial discharge monitoring system for cables
Compatible with various sensors
Monitoring a wide range of partial discharge activities
Strong anti-interference ability
