MTS Series 793 Controller - Manual (Page 62)

MTS Series 793 Controller Overview
About Compensators
Operation Concepts 62
ALC is typically used in matrix depletion fatigue tests where only one or two
cycles of a particular amplitude are executed before new amplitudes are
introduced.
Adaptive Harmonic
Cencellation (AHC)
Adaptive Harmonic Cancellation (AHC) works with Amplitude Phase Control
(APC) to minimize spurious harmonic distortion.
Note The adaptive harmonic canceller function can only be enabled if
Amplitude Phase Control (APC) is on.
Adaptive Harmonic Cancellation allows you to set up adaptive harmonic
cancellers to reduce or cancel spurious harmonics in the feedback when
programming sine waves. This approach injects input harmonics into the
controller command waveform with just the right phase and amplitude to cancel
the feedback harmonics.
Example of
feedback dropping
off in a test
waveform without
ALC compensation.
The same waveform
with ALC
compensation