integrity is essential for all high voltage
apparatus. Standard AC test systems have
been able to provide a solution for some
applications, but when certain apparatus
have much higher voltage and current
requirements a straight AC test system may
not be sufficient. In order to limit input
power requirements a resonant test system
requires a capacitive test object and a
variable core (variable reactor).
A resonant test system is designed with
means to adjust the inductance to precisely
compensate for the capacitance in the high
voltage circuit thereby tuning the system to
resonance. The main advantage to this is
that very low (real) input power is required
for large output (reactive) power.
Another solution which
also has low input power requirements and
high output power is a variable frequency
series resonant test system. These systems
are typically used for testing GIS or cable
in the field since they are smaller in size
than a variable core resonant system.
The variable frequency systems are tuned by
frequency variation instead of changing the
inductance of the test system.