Live-line oil refill unit may avoid substation outages

2026-08-13 20:20:16

A Chinese equipment maker has launched an on-line vacuum oil-refilling machine that the maker says tops up current and voltage transformers (CT/PT) without de-energizing them, aiming to address air-ingress and false oil-level problems of manual methods.

Model MDB-BY2 refills at 0.5–2.0 L/min under a working vacuum of −0.075 MPa. A vacuum pump and fine filtration keep the system evacuated, while a heating unit removes trace moisture.

Used after oil sampling on CT/PT units across substations, the maker says the device counters false readings caused by residual air in traditional plunger-and-nitrogen filling.

The maker says the 35 kg unit runs manually or automatically. Power-maintenance experts caution that live work requires electrical testing and qualified procedures before deployment.

The company says it also handles quantitative filling and evacuation of other equipment. Demand for compact on-line tools rises with unmanned, outage-free maintenance. This story will be updated on pilot use and procurement.