In this paper approximate analytical expressions from which the extinction angles , in the analysis of the 3-phase thyristor regulators feeding inductive loads , can be obtained directly are presented . To check the validity of these expressions they were used to obtain the values of the extinction angles , and consequently several results for the characteristics of the 3-phase thyristor regulators. These results were compared with those obtained when the values of the extinction angles are obtained numerically . Close agreement was observed between the two sets of results .