Analysis The Effect of Additional Load on Stator Resistance on Three-Phase Induction Motor Rotation

Abstract

This study aims to analyze the effect of additional load on the rotation of a three-phase induction motor by considering the conditions of balanced and unbalanced stator resistance. The study was conducted using an experimental method using loading variations of 25%, 50%, 75%, and 100% on balanced and unbalanced stator resistance (1.1 ohm, 2.1 ohm, 3.1 ohm, and 4.1 ohm). The parameters observed include motor rotation (rpm), slip, current in each phase (Ia, Ib, Ic), and torque. The results showed that the addition of load significantly reduced the motor speed in both stator resistance conditions. In the balanced stator resistance condition, the highest speed was recorded at 1470 rpm at 25% load and the lowest speed was 1425 rpm at 100% load. In the unbalanced stator resistance condition, the highest speed of 1430 rpm occurred at 25% load, while the lowest speed of 1390 rpm occurred at 100% load. The unbalanced stator resistance resulted in uneven current distribution between phases, increased slip, and decreased motor speed. Motor torque also increases with the unbalance of stator resistance. The largest torque was recorded at 2.03 Nm at an unbalanced resistance of 4.1 ohms with a load of 100%, while the smallest torque of 0.70 Nm occurred at a balanced resistance of 1.1 ohms with a load of 25%. These results indicate that unbalanced resistance can increase torque but has a negative impact on motor efficiency and stability. The addition of load and unbalanced stator resistance affect the performance of a three-phase induction motor, especially in terms of rotation and torque. Therefore, it is important to maintain the balance of stator resistance in order to maintain optimal motor performance.