You said "the hydroelectric generator generates 220 volts at its output". In fact, it can have tens of thousands of volts, like the one in the Three Gorges.
Since the wind force is generally at level 7 or 8, such as the wind at level 4 or 5, its driving force is not large, the motor speed will not be high and the voltage emitted is proportional to the speed, so the voltage is generally not very high. The designs of different generators have different characteristics due to their different driving forces.