What is the hazard of "Over excited"?

The hazards of over excitation:
Equipment overheating and damage: It causes the internal temperature of equipment such as generators and transformers to be too high, accelerates insulation aging, and even burns the equipment. For example, over excitation of a transformer may damage the winding insulation and shorten its service life.
Increased reactive power loss: It causes excessive reactive power, reduces the power factor of the power grid, increases reactive power loss, and affects the economy of the power grid.
Abnormally elevated system voltage: It may cause the system voltage to exceed the normal range, affecting the normal operation of electrical equipment and even damaging sensitive electronic equipment.