This paper analyses the starting performance of AC voltage controller fed-induction motor drive to find out an optimum firing angle for the AC voltage controller using particle swarm optimisation(PSO). Investigations on dependence of optimum firing angle on motor parameters and the effect of variation of motor parameters on the starting performance of motor are also made in this work. About nine machines grouped into four, with each group consisting of equally rated machine with different motor parameters are used for the study. Optimum firing angle is first obtained through graphical method and then through the PSO algorithm. Experimental evaluation is done using DSP TMS320F2812 as the controller. All the results show that optimum firing angle obtained through graphical method and PSO is matching and there is a good agreement with the simulation and hardware results. Results also show that, though the machines have same rating, their optimum firing angles are different due to the difference in motor parameters.