Department of Electrical Engineering, Energy and Automation, University of Ngaoundere, National School of Agro-Industrial Sciences, Ngaoundere, Cameroon
This paper deals with the influence of parameters of an asynchronous motor on its starting phase. Five electrical parameters of the asynchronous motor are concerned by the present study. These are the stator resistance (Rs), the rotor resistance (Rr), the stator inductance (Ls), the rotor inductance (Lr) and the mutual inductance (M). Two mechanical parameters are also studied. These are the moment of inertia (J) and the number of pole pairs (P). The simulation results show that the starting current decreases with increasing values of each of the parameters such as stator resistance, rotor resistance, stator inductance, rotor inductance and the number of pole pairs. On the other hand, the starting current increases with the increase in the mutual inductance and the moment of inertia. The torque decreases with increasing parameters such as stator resistance, stator inductance, rotor inductance and mutual inductance. On the other hand, the torque increases with the increase in rotor resistance, number of pole pairs and moment of inertia. The variation in the values of the different parameters influences the behavior of the rotor speed differently. Increasing the values of parameters such as stator resistance, stator inductance, rotor inductance and moment of inertia influence the rotational speed of the rotor such that the motor takes more time to reach steady state. Increasing the values of rotor resistance, mutual inductance influences the rotor speed such that not only does the motor take longer to reach steady state, but the speed drops in steady state when the motor is loaded. Increasing the values of the number of pole pairs lowers the rotor speed and the motor takes less time to reach steady state. On the basis of the various results obtained from the simulations, we proceeded to optimize the parameters studied in order to reduce the current and obtain a smooth start but with a minimized start-up time. For this purpose the values obtained are as follows: Rr=5.85Ω; Rs=13.805 Ω; Ls=0.300 H; Lr=0.299 H; J=0.031 Kg.m2; f=0.001136 N.m/rad/s; P=2; M=0.255 H.