It's a bit difficult in another way: Obviously 50/60hz is not such a high speed that it's difficult to synchronize.
The harder part is this: To pump power into the grid you lead the cycle ever so slightly, as if you were trying to push the cycle to go faster. If instead you lag the phase the grid would be pumping power into you.
That lead is very very small, and probably difficult to measure and synchronize on. I would imagine that when the two grids connect everything jumps just a little as power level equalize, it probably generates a lot of torque and some heat, I would assume it's hard on the generator.
From a physics point of view, by leading the cycle you introduce a tiny voltage difference (squared), divided by the tiny resistance of the entire grid. And that's how many watts (power) you are putting into the grid.
The harder part is this: To pump power into the grid you lead the cycle ever so slightly, as if you were trying to push the cycle to go faster. If instead you lag the phase the grid would be pumping power into you.
That lead is very very small, and probably difficult to measure and synchronize on. I would imagine that when the two grids connect everything jumps just a little as power level equalize, it probably generates a lot of torque and some heat, I would assume it's hard on the generator.
From a physics point of view, by leading the cycle you introduce a tiny voltage difference (squared), divided by the tiny resistance of the entire grid. And that's how many watts (power) you are putting into the grid.