A small probe, using active electronics inside, that can
measure DC electric fields has been developed and successfully tested. The requirement specification for the probe system
developed has been shown to be fulfilled. A working probe
system exists and has been used for measurements on high
voltage apparatus. As can be seen from the examples of
measurement results, the probe measurements showed reliable
results. However, the probe system is still to be considered as a
prototype, in the sense that further improvements are needed
before it can be regarded as a robust, easily operated system.
Further development of the probe system is ongoing, by
building new probe heads with improved electronics and by
including data acquisition and position control in the probe
system. An ion-drift model is also under development, which
will be used as a complementary tool for the increased
understanding of the external DC field distribution around high
voltage apparatus. Comparisons between measurement results
and simulations will thus be an important part of the work.
With the newly developed probe, it will be possible to
perform measurements that give valuable contributions to the
understanding of the external field distribution around high
voltage apparatus, for existing and future generations of
HVDC.