Building a fully digital controller with Altera Cyclone FPGA and Nios Processor for Induction Heating application

This paper presents the development of a fully digital controller designed for induction heating machines capable of delivering up to 50 kW across a frequency range up to 500 kHz. A critical feature of the controller is its ability to prevent operation within capacitive region, thereby safeguarding the integrity of the inverter. The control strategy employs a proportional-integral algorithm based on phase shift between voltage and current to regulate power by adjusting frequency. The phase shift calculation is achieved through successive subtractions performed at high speed. Performance evaluation was conducted by comparing the obtained phase shift with the setpoint. The implementation utilizes Intel Altera devices, ensuring robust performance and adaptability. Experimental results demonstrate the controller’s efficacy, achieving low errors within specified safety margins of operation. The proposed architecture can be adapted to implement control systems for different modulation techniques. This research contributes to advancing digital control solutions in high-frequency power electronics, offering scalability and versatility for industrial applications.