Techimp On‑line Spot Testing provides an assessment of the insulation of MV/HV assets in the real TEAM (Thermal, Electrical, Ambient and Mechanical) stress condition. It is performed using the the Portable PDcheck unit with a sensors kit suitable for a wide range of different assets: Rotating machine, Variable speed drive, Gas insulated switchgear, High voltage cable, Medium voltage cable, Transformer, High voltage CT/VT, Medium voltage switchgear.
In online conditions de-noising tools patented by Techimp play a key role in the effectiveness of the recorded data.
As an output of the measurement, an accurate Technical Report is release by Service dept. containing diagnosis and suggested actions.
Sensors installation activities, PD measurement procedures and worksite organization plan are customized on customer needs.
Online PD tests are measurements carried out during the normal operating condition of the rotating machine. In order to being able to detect PD signals permanent or temporary capacitive couplers must be installed. This methodology can be considered the most sensitive approach since all the aging factors are simultaneously combined.
The measuring principle in Variable speed drives and windmills is the same of the rotating machines, a capacitive couplers are utilized as Partial Discharge sensors, the biggest difference is in the construction of the phase resolved PD Pattern, for this task an Impulsive Test Synchronization Module can be utilized.
Online PD tests are considered measurements carried out during the normal operating condition of the GIS system. Fast and effective screening of the GIS system can be provided depending on the typology of the GIS and presence/absence of detection point.
In order to provide an assessment of the cable system a PD test can be performed on the energized cable. Typical detection points are the accessories of the cable system (joins and terminations) where sensors can be positioned in order to acquire High Frequency signals. In online conditions, de-noising tools patented by Techimp play a key role in the effectiveness of the recorded data. Several solution can be provided knowing to the cable system layout.
In distribution network and in industrial grids without redundancy to provide an outage of the assets can be very uncomfortable and costly. Indeed, a periodic on line screening of the network health is the only possible action to prevent unexpected failures. Facing with several network layouts and MV cables typology, Techimp Service dept. has developed a wide portfolio of sensors and techniques to meet the customer expectations and get the most effective diagnosis from on line PD measurement with the on going conditions.
Partial discharge is one of the possible problems originating failures in transformers. Depending on the transformer size and voltage levels, PD test can be done in on-line conditions, with no outage. This approach results in a fast and cheap diagnostic test able to spotlight the partial discharge source
Different detection points and different sensors will be used due to the equipment under test characteristics. It is possible to perform a PD measurement directly on the switch panels by the mean of TEV sensors or by HFCT sensor on the ground lead of the feeder or directly on the cable.