This paper analyses the starting performance of two-leg AC voltage controller-fed three-phase induction motor drive and establishes that optimum value of firing angle combination for the voltage controller depends on the motor parameters. Identically rated machines with different motor parameters are used for the work. Optimum firing angle combination is obtained from the simulation, which gives zero negative torque pulsations with minimum acceleration time and other electrical characteristics like peak positive electrodynamic torque pulsations, peak starting current are having satisfactory values. Results show that cost effective two-leg controller is giving an improved performance with the optimum firing angle combination and is found to depend on motor parameters.
Keywords: AC voltage controller, induction motor starting, optimum firing angle, parameter dependence, two-leg control