To answer all three of those questions completely wouid require a very long answer so I have tried to hit a scope that I thought made sense here.
A grid tie inverter makes sure:
- the inverter output matches the phase of the grid power
- the inverter has a voltage slightly above the grid voltage
- the power factor is unity
- is powered down when the grid goes down so line workers can safely make repairs
A non grid tied inverter just creates a voltage that's within tolerance, at the correct frequency
The major differences between the two in terms of components would be that the grid tied version would have circuitry/firmware to sense the grid voltage to sync to it and shut down when not present. It would also have a power factor correction circuit to achieve unity. Specific component differences I suspect would be dependent on the particular implementation.
To '"pull" energy from the solar cells, the inverter presents a low impedance load to the cells. It may, for example charge an inductor from the cells and then discharge it into the load repeatedly via a transformer.
The inductor is initially connected from the solar panel output to ground, causing current to build in the inductor. After a period of time the inductor is connected to the output and current then flows to the output. This is simplified but that's the concept. The average current in thr inductor csn be increased until the solar panel voltage there are various schemes for this, read more about PWM and MPPT inverters to learn more.