DIAGNOSTICS AND MAINTENANCE
Base of the expert activity:
- Assessment of the equipment good condition;
- Determination of the defect type, cause and danger;
- Determination of the repair necessity and scope, drafting
the defects and failures card;
- Technical following up of the equipment operation in presence
of the defect symp-toms;
- Determination of the equipment wearing level and technical
condition for the pur-pose of its life extension;
- Working out the recommendations in respect to improvement
of the operational conditions.
Methods used in ZTZ-Service Co. allow:
- Accumulated during more than 35 years and continuously expanding
database on operation, technical condition, failure types, etc.
including information about more than 5000 power transformers.
- High-skilled specialists having a great practical experience
in the field of research, design, system investigation of the
failures, tests and repair.
- Updated diagnostic instruments and special laboratory equipment
with wide use of the computer technique.
- Multi-step diagnostics and functional test methods developed
by ZTZ-Service Co. specialists, definition of the probable defects
image via diagnostic characteristics.
- Continuous research in the field of development and implementation
of new test and diagnostics methods.
- Standards and methodical materials MEI, CIGRE, IEEE, ASTM,
Doble, extensive foreign information concerning methods of the
early diagnostics and their practical application.
- To determine the probable defects in the certain operational
conditions, to assess the margin of safety and weak points in
- To detect the insulation moisture level basing on the results
of Water Heat Run Test and temperature dependence of the insulation
- To evaluate the insulation and oil spaces contamination level
basing on the data of the insulation features temperature dependence
and oil special analysis includ-ing the particles disperse analysis.
- To determine overheating of the current-conducting joints
on the base of measur-ing the contact transient resistances,
dissolved gases and degradation products analysis.
- To determine value and level of the windings deformation basing
on the calcula-tion of the possible deformation, change of the
short-circuit and capacitance pa-rameters.
- To detect the presence of overheating and discharges in electromagnetic
system basing on the special analysis of the dissolved gases,
electromagnetic character-istics and vibroacoustic measurements
taking into account the design particular features.
- To evaluate the insulation overheating presence and its aging
level basing on the analysis of the dissolved gases, furanic
components and insulation polymerization degree in the specially
- To determine presence and type of the local defect in the
bushing core, oil con-tamination and aging level in the bushing
and sediment presence on the porcelain internal surface through
insulation characteristics temperature changes and im-balance
current on the adjusted transformer in operation.
- To determine the oil aging level and its residual resource.