According to the info on powerpal specsheet, the mgh200 uses a pmg , not a pure induction generator. To get 220v/50hz your generator needs to be kept at 1000rpm. The controller is like an automatic light dimmer: it has a "dump load" which is usually a heating element and the controller ramps up or down depending on the load. So for example: your mhg is running at full whack, putting out 200w, you have a couple of light bulbs running using 120w, the controller allows 80w to go to the dump load. If you switch off one of the bulbs, dropping your usage to 60w then the controller ramps up the dump load to 120w so the power used is always balanced with the power generated. If you try to run 4 lights at 60w then your generator will be overstressed and it will slow down.
Is there a problem with getting a controller from powerpal? This must be by far the simplest solution.