This document discusses high voltage transformers and the various types of tests performed on transformers. It describes partial discharge testing, insulation resistance testing, and routine testing. Partial discharge testing detects localized breakdowns in insulation under high voltage stress. Insulation resistance testing measures insulation quality. Routine testing confirms operational performance and checks for manufacturing defects. The document outlines advantages like safety, efficiency, and failure detection, and disadvantages like insufficient oil level and overloading.

1. Presented by
K.PRAVEEN

2.  Introduction of high voltage transformers.
 Types of testing of transformers .
 Explanation of each type .
 Advantages of HV testing of transformer.
 Disadvantages of HV testing of transformer.
 Conclusion.

3.  High voltage transformers convert voltages
from one level or phase configuration to
another ,usually from higher to lower.
 They can include features for electrical isolation
power distribution ,and control and
instrumentation application.
 These transformers usually depend on the
principle of magnetic induction between coils
to convert voltage and current levels.

4.  Partial discharge test.
 Insulation resistance test.
 Routine test.

5.  Partial discharge is a small localised dielectric
breakdown of an electrical insulation system
under high voltage stress.
 Each discrete partial discharge is the result of
an electrical breakdown of an air pocket within
the insulation.
 These discharges erode insulation and
eventually result in insulation failure.

7.  Insulation ages and deteriorates because of
moisture, dust and electrostatic stress .
Insulation should be monitored continually to
avoid sudden failure of equipment.
 An insulation resistance test detects insulation
quality within the transformer.

9.  It is mainly for confirming operational
performance of individual unit .
 All transformers are subjected to following routine
tests:
1. Insulation resistance test.
2. Winding resistance test.
3. Turns/voltage ratio test.
4. Open and short circuit test.
5. Continuity test.
6. Partial discharge test.
7. High voltage test.

10.  Pure conductivity by IR value test.
 Removing of discrete waveform by PDT.
 Terminals connected correctly by transformers
turns ratio test.
 Units measured correctly and manufacturing
defect check by routine test.

11.  Insufficient oil level .
 Faulty operation of tap changer switch.
 Lack of installation checks.
 Prolonged over loading.

12.  By conducting this HV test gives the solution of
the most adjustment transformer in respect of
parameters and prices.
 These are main advantages of safety, higher
efficiency , lower cost , savings of energy,
avoiding of failures , failure detection , quality
assurance.