How to extrapolate a sinusoidal signal in simulink?

Question

Dani Tormo 2013-3-19

回答： Raef aboelsaud 2018-11-3

Hi,

I need to extrapolate a sinusoidal signal because I need to know its value before a certain step time.

My sinusoidal signal is 50Hz and the sample time is 0.5 ms. So I want the value of the signal 0.5 ms before.

In electronics we can tune a PLL to anticipate or delay a sinusoidal signal but I think it cannot be done with the existent blocks in simscape.

I've made an extrapolator but it has an error of 3% and I don't know if there is a better way to do it.

Thanks!

Answer 1

Raef aboelsaud 2018-11-3

You can use fourth-order Lagrange extrapolation, If the sinusoidal signal is i, the extrapolated value for one step will be

i[k+1] = 4i[k]−6i[k−1]+4i[k−2]−i[k−3].

Where k is discrete time instant