T. Aika

This project addresses critical operational limitations in locally manufactured yam pounders by designing and implementing an adaptive Variable Frequency Drive (VFD)-based speed controller for a 1 HP single-phase yam pounder motor. Traditional yam pounding machines operate at fixed speeds, resulting in inconsistent pounding results, food quality degradation, limited user control, energy inefficiency, and accelerated machine wear. These shortcomings arise from the inability to accommodate variations in yam texture, moisture content, quantity, and regional preferences for different pounded yam consistencies. The primary objective of this work was to design, implement, and evaluate a speed control system that enables variable-speed operation while maintaining torque stability and energy efficiency. The system employs a microcontroller-based VFD architecture utilizing Arduino Due for Sinusoidal Pulse Width Modulation (SPWM) generation, IR2110 gate drivers for power stage control, and a full H-bridge inverter configuration with IGBTs. The control strategy implements Voltage-to-Frequency (V/f) control to maintain constant magnetic flux across varying operational frequencies, ensuring consistent torque output from 0 to 50 Hz. Comprehensive testing was conducted in progressive stages, beginning with low-voltage functional verification, followed by full-voltage no-load testing, and culminating in motor load testing with the 1 HP yam pounder motor. The system successfully demonstrated linear speed control from 0 to 2850 RPM with smooth torque response and minimal vibration. Key performance metrics included stable DC bus voltage at 325 V, accurate PWM carrier frequency of 10 kHz, maximum motor current draw of 4.2 A (within the 4.5 A rating), IGBT temperature of 42°C after 30 minutes of operation, and Total Harmonic Distortion (THD) of approximately 8.5% in the output voltage waveform.