There are three main experiment settings in the Experiment tab:- Plant Type: Specifies whether the plant is asymptotically stable or integrating. It this
example, the boost converter plant is stable. - Plant Sign: Specifies whether the plant has a positive or negative sign. The plant sign
is positive if a positive change in the plant input at the nominal operating point results
in a positive change in the plant output when the plant reaches a new steady state.
Otherwise, the plant sign is negative. If a plant is stable, plant sign is equivalent to the
sign of its dc gain. If a plant is integrating, the plant sign is positive (or negative) if the
plant output keeps increasing (or decreasing). It this example, the boost converter
plant has a positive plant sign. - Sine Amplitudes: Specifies amplitudes of the injected sine waves. In this example,
choose 0.03 for all the five frequencies of the perturbation signal to ensure the plant
is properly excited within the saturation limit. If the excitation amplitude is too large,
the boost converter will operate in discontinuous-current mode. If the input amplitude
is too small, the sinusoidal signals will be indistinguishable from ripples in the power
electronics circuits. Both situations produce inaccurate frequency response estimation
results.
8 PID Autotuning