A voltage is excited in a winding wire when lines of magnetic flux cross it. It only rises to a peak potential, if there is nothing draining it.
If a load is present, the peak voltage is diminished, as it is draining at the same time as it is trying to build up. If the load is excessive, the voltage excitement is drained off before it can build.
Think of the stator windings as a bucket receptacle for excited electrons, the outlet wires as variable size hole in the bucket. Big hole; the bucket, can't fill as electrons are siphoned off. Small hole; the bucket can reach a nearly full state of max excited electrons.
Excited electrons = voltage potential.
Please don't confuse the terms regulator, with rectifier. "Regulator" is a control mechanism. "Rectifier" converts and connects a load.
There can be a configuration that includes both, but are separate functions within.
Cheers,