Analisa Penggunaan Thyristor pada Penyearah Terkontrol Setengah Gelombang terhadap Kecepatan Putar Motor DC

Analysis of Thyristor Usage in a Half-Wave Controlled Rectifier on the Rotational Speed of a DC Motor

Abstract

The speed of a DC motor can be controlled by varying the armature voltage (V_t) supplied to the motor. A DC motor requires a rectifier circuit to convert an AC signal into DC. A controlled half-wave rectifier is the simplest type of rectifier because it requires relatively few components, and its output voltage can be adjusted by varying the thyristor firing angle. Therefore, this circuit can be used to control the rotational speed of a DC motor during both starting and running conditions. This study aims to analyze the effect of the thyristor firing angle in a controlled half-wave rectifier on the rotational speed of a series-wound DC motor. The method employed is simulation using PSIM software. The thyristor firing angle was varied at 0°, 15°, 30°, 45°, 60°, 90°, 120°, and 150°, with torque loads of 0 Nm, 0.5 Nm, and 1 Nm. The simulation results were used to obtain the armature voltage (V_a), armature current (I_a), and motor speed (N). The results show that as the thyristor firing angle increases, the armature voltage decreases, resulting in a reduction in motor speed. Thus, the motor's rotational speed is inversely related to the thyristor firing angle. An increase in torque load also causes the motor speed to decrease. Furthermore, the use of a full-wave rectifier results in a higher rotational speed under the same source voltage and firing angle conditions because its output voltage is greater than that of a half-wave rectifier. Therefore, it can be concluded that the thyristor firing angle significantly affects the rotational speed of a series-wound DC motor, demonstrating that a controlled rectifier can be used as a motor speed controller.