DYNAMIC BRAKING OF INDUCTION MOTORS

Abstract

The scope of this dissertation extends only to the dynamic braking of induction motors by d.c. injection. The various methods of analysis of the problem have been critically reviewed. A simpli-fied method along with the associated set of equations, based on Cochran's method for the calculation of the d.c. braking performance of an induction motor is presented. This method is shown to give reasonable accuracy comparable with the existing methods of analysis. The most accurate existing method of analysis has been discussed first. The other methods are presented later with a discussion of their relative merits and drawbacks in the subsequent chapters. All the methods of analysis have been reduced to a standard form of equations for effective analytical comparison. Practical utility of the methods has been analysed and comparison with actual test results have been made by calculating the d.c. braking character-istics of two induction motors (one slip-ring and the other a squirrel-cage) by using all the methods. The test details of the motors concerned have been compiled from published works.