From what you said, burnt out electrical appliances are caused by poor grounding. The grounding points of the generator and power grid are shallow or the grounding area is small, causing zero point offset;
Three-phase electrical appliances should be connected to three phases, not two lights and one zero;
It is better not to connect line 0 to ground and connect it directly when using 220V, connect it directly. one fire and one zero;
Single-phase power cannot be used for too long, otherwise one phase of the generator will overheat and burn;
It is best to keep the frequency at 50 Hz, but there will be no problem if the frequency is between 45 and 55 Hz, and it will not damage electrical appliances.