Natural Commutation (Line Commutation)
Generally, whenever we start thinking about AC supply, the will that is current through the zero crossing line while going from good top to top that is negative. Hence, a reverse voltage will probably be through the device simultaneously, that will turn the thyristor down immediately. This process is known as as normal commutation as thyristor is turned off demonstrably without the need for almost any elements which are outside supply or circuit for commutation function. Normal commutation are found in AC voltage controllers, period controlled rectifiers and cycloconverters.