How can I change the phase of a triangular waveform while simulation is running?

I use a number of triangular generators in my Simulink model with very close but still different frequencies. They start from 0 (or specified) phase angle. During the simulation, their small frequency differences cause the triangular waves to have a phase difference between each other. Now, I would like to "synchronize" them periodically, by updating all their phases as 0 in each, let's say, 1 second during the simulation. For this part, it is not important to assign a "master triangular" and assign the others' phases 0 compared to master's phase; they can all be set as 0 as long as I can do it periodically during the simulation.

Then, my next attempt would be to synchronize them according to a "master triangular", where I would like to zero the phase differences between the master triangular and the others.

Would you please help me for those?

Thanks in advance.