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Brief description of the problem:
The dielectric testing of materials and high voltage equipment (e.g. transformers) is accomplished by applying a short but very high amlitude test signal to the insulation (so called lightning impulse tests). The level of test signal is increased in consecutive measurements and the waveform change on the test object is observed.
Parameters of a typical front chopped lightning impulse test signal:
Duration:
1-2 microsec.
Amplitude:
1 MV
Performance limitation:
Such a signal can be measured only trough a special high voltage divider.
The required bandwidth usually cannot be achieved by the large voltage
ratio. The performance of the system is limited by the divider.
Compensation of the high voltage divider:
Test setup:
Measurements were made at the Swiss Federal Institute of Technology
(ETH),
High Voltage Laboratory
Zürich, Switzerland