How to avoid Quartus to merge MegaWizard function after Fitter?

I have three instances, A, B, and C. All of them use the same IP module which contain PLL MegaWizard function file.

It means that A=B=C.

After Fitter, Quartus only implements a PLL for those three instances using.

Then SDC file can't find the PLL port to create the clock.

The question is that how to keep the PLL MegaWizard function after Fitter?

In other words, how to avoid Quartus to merge PLLs?

Quartus can implements three PLL MegaWizard function for those three instances.

Thank you very much.