TransformerCare Unit
TCU Features
HYDAC FILTER SYSTEMS GMBH
en
Page 14 / 64
BeWa TCU 3472805b en 2011-07-05.doc
2011-07-05
TCU Features
The Transformer Care Unit TCU is a maintenance system for extending the service
life of transformers and reactors filled with oil.
Continuous degassing, draining and filtration of the insulating oil keeps the oxygen
content, water content and particle contamination in the transformer at a constantly
low level, increases the breakdown voltage of the insulating oil and thus improves
the operational safety and extends the service life of the insulation.
The residual service life of the transformer (open expansion vessel) can typically be
tripled.
The throughput is only ~ 15 m³ / week, preventing harmful turbulence in the
transformer.
The TCU is used during the service life, while the transformer is operational and
connected to the grid.
Effective degasification and dewatering is achieved at high oil temperatures in the
degasification and dewatering unit and at low ambient temperatures.
Increased safety:
Facilitated by the monitoring function in the TCU. The operating
pressure of the degasification and dewatering unit (vacuum) is monitored. It can be
used to calculate the gas content in the oil and changes proportionally to the total
gas content in the oil.
An increase in the pressure therefore indicates increasing gas content in the oil. The
pressure switch is connected to two separate floating monitoring circuits.
Connection to a central alarm means that a warning signal is sent whenever
anything occurs in the transformer which requires a more thorough investigation.
Precise status control:
After a period of continuous degasification, a stable
condition occurs in which the gas content of the oil is stabilized at a constant low
level. In this status, the error gases removed with the TCU correspond to the gas
formation rate in the transformer, which makes a clearer interpretation possible than
with a standard DGA (dissolved gas analysis).
Optimized service life:
. The TCU reduces the chemical deterioration of the oil and
the solid insulation (cellulose). Permanent degasification keeps the oxygen content
at a constantly low level. As oxygen is the transformer's worst enemy, degasification
has a key influence on reducing the aging rate.
Why are water and air/oxygen dissolved in the oil?
At a natural balance, insulating oil dissolves approximately 10 percent volume of the
air on contact with atmospheric air. One third of this is oxygen. The atmospheric air
has the effect that the oil also absorbs water until it reaches the same relative
moisture as the air. In the same way, the cellulose insulation reaches the same
saturation level as the surrounding oil by diffusion.
Optimized :
The TCU is equipped with a particle filter which also removes very
small particles (from 3
μ
m). This not only increases the dielectric strength, but also
increases the service life of the insulating oil.
Summary of Contents for TCU Series
Page 63: ...Notes ...
