The several types of strongly intensive correlation variables are studied in nuclear collisions at LHC energy. These quantities are expected not to depend on centrality class width. They have been calculated in the dipole-based parton-string Monte Carlo model with string fusion. The centrality dependence of the mean transverse momentum correlation coefficient and strongly intensive quantity $\Sigma$ between multiplicity and $P_T$ have been obtained. Dynamical charge fluctuation $\nu_{dyn}$ has been also calculated and compared with experimental data. It is shown that string fusion improves agreement with the experiment.