What benefits can get from this integrator?

Hi,
I know that a simple delay component in a feedback accumulator can be an integrator, which is often used in PLL loop design. Today, I find a loop design in a Simulink example which used a digital filter:

Numerator coefficients: 0.02
Denominator coefficients: 1 -1

as an integrator.

Besides the integrator, it also has a proportional and derivative parts. Please see the picture:



The num(z) is 0.05 in the smoothing filter. I don't know whether the integrator design is related to derivative or not.


From the frequency response curve, it does look like an integrator. I would like to know what benefits can get from this specific digital filter design.

Thanks,

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It seems that the pole at (1, 0) increases the gain at low frequency. This kind of design is normal in PI or PID loop?

Thanks,

That's the z-domain representation of an an ideal integrator. The s-domain pole at the origin corresponds to Z-domain pole at (1,0). It's not at all different from the other integrator implemetations you mention.