Are MPP Tracking systems are features built-in in the Grid-Tied inverters? In Off-Grid systems are these features (MPPT's) in the charge controllers or in the inverters?
MPPT is only built into equipment that is connected to PV.
All interactive (grid-tied) inverters have MPPT.
Many charge controllers have MPPT
All power optimizers have MPPT
What MPPT or MPP (same thing) does is control the parameters (voltage and current on the IV curve) so that the PV is working at the optimal voltage for maximum power production. If we had a system that was always going to work at the same temperature and irradiance, then they would not need MPPT, since they would always have the same optimal voltage. On earth, we never have a situation where the irradiance and temperature is constant. When it gets colder, the array will work better at a higher voltage. The MPPT will sample different voltage scenarios and work at the best scenario for maximum power.
There would be no reason for a battery to have an MPPT, since there is available voltage and current and we take as much as we need. We are not trying to get maximum power out of a battery, since the battery is made to store energy. There would be too much current and the battery would catch fire if we tried to take as much current as we could for maximum battery power.
I have always wondered if space systems have MPPT, since the conditions should be close to constant out there 93 million miles from the sun with no shade.