Design of a Three-Phase Inverter Using PWM Technique for Induction Motor Applications
Wanapri Pangaribuan (a), Bakti Dwi Waluyo (a*), Selly Annisa Binti Zulkarnain (a), Muhammad Aulia Rahman Sembiring. (a)

a) Department of Electrical Engineering Education, Universitas Negeri Medan, Medan, Indonesia.

*bakti_dw[at]unimed.ac.id

Abstract

The rapid expansion of variable-speed drive systems in industrial automation has intensified the need for compact, high-efficiency three-phase inverters capable of delivering precise control to induction motors. This study presents the design, implementation, and experimental validation of a 2 kVA three-phase voltage-source inverter employing sinusoidal pulse-width modulation (SPWM) for induction-motor applications. The hardware architecture integrates a high-frequency gate-drive circuit, discrete IGBT power modules, and a DSP-based control platform that executes real-time PWM generation at 10 kHz. A closed-loop speed-control algorithm, driven by incremental encoder feedback, is implemented to enhance dynamic response under load transients. Prototype evaluation was conducted on a 1.5 kW squirrel-cage induction motor across a speed range of 0-1500 rpm. Measured results show a total harmonic distortion in line-to-line output voltage below 4.7 %, inverter efficiency peaking at 95.2 %, and settling time under 80 ms for a 50 % step-load change. Thermal profiling confirms junction temperatures remain within safe limits (< 85 C) after one hour of continuous full-load operation, validating the inverter^s thermal reliability. Comparative analysis with a conventional six-step inverter highlights a 36 % reduction in current THD and a 12 % improvement in motor torque ripple. The findings demonstrate that the proposed SPWM-controlled three-phase inverter offers a cost-effective, high-performance solution for medium-power induction-motor drives, making it suitable for retrofitting existing industrial equipment and supporting emerging smart-factory initiatives.

Keywords: Three-phase inverter- Sinusoidal PWM- Induction motor drive- Voltage-source inverter- Harmonic distortion

Topic: Sciences, Engineering and Material Science