This article summarizes the hardware organization and working principles of the thyristor zeropassage trigger capacity control circuit which have a singlechip as its main body.

The paper surveyed the thyristor models which are usually applied to computer simulation of thyristor circuits and discussed in detail the principles, features, advantages and shortages of the models.

Thereby the work principle of this commutating circuit is understood clearly, and an overall and correct foundation for engineering design of the inverter is found.