In my case, a power regenerator was the solution to wild voltage changes, though in my situation power surges were more likely than brownouts! My voltage moves between 223 and 238 volts and occasionally surges higher! My fridge with gave in and could not be repaired, though it had a DC inverter system!
Methinks, if your brownouts are within the tolerance PS Audio regenerators, then it’s one solution to consider! As opposed to old mechanical stabilizers regenerators store energy in capacitors.