Digital Controller for Industrial Induction Heating System

Abstract

This experiment demonstrates the design and im- plementation of a smart control system for an induction casting machine using the dsPIC33CK256MC506-E microcontroller. The system integrates a PFU-400 TAIE PID Temperature Con- troller** to regulate the machine’s heating process. The tem- perature inside the heating coil is measured using a sensor and displayed on the PID controller, which also allows manual adjustment of temperature settings. The PID controller outputs a control signal to the microcontroller, which dynamically ad- justs the phase shift of the voltage supplied to the induction coil. This phase-shift regulation ensures precise power delivery, maintaining the desired temperature for the casting process. The closed-loop system effectively combines real-time feedback and advanced phase-shift control to achieve stable and efficient heating. The experiment highlights the synergy between embedded systems and control algorithms in industrial applications.

Introduction

The study focuses on designing a smart temperature control system for an induction casting machine using the dsPIC33CK256MC506-E microcontroller and a PFU-400 TAIE PID Temperature Controller. Induction casting machines rely on electromagnetic induction to heat metals, making accurate temperature control critical for product quality, energy efficiency, and process stability.

Key Features of the System:

1. PID-Based Feedback Control:

   • A temperature sensor (thermocouple) monitors the crucible’s temperature in real time.

   • The PID controller compares actual vs. setpoint temperatures and outputs a control signal.

   • The microcontroller receives this signal and dynamically adjusts the phase shift of voltage supplied to the induction coil, precisely regulating heating power.

2. Microcontroller Integration:

   • The dsPIC33CK256MC506-E handles PID outputs, generates PWM signals, and coordinates real-time control.

   • It enables energy-efficient operation and rapid response to temperature deviations.

3. Power Electronics:

   • Three-phase AC input is converted to DC via Power Factor Correction (PFC) circuits.

   • High-frequency inverters and a transformer deliver energy to the induction coil, inducing eddy currents in the metal.

   • A capacitor bank stabilizes energy transfer and enhances efficiency.

4. Safety and Monitoring:

   • Real-time display of temperature, voltage, and current on an HMI interface.

   • Overcurrent and overvoltage protection prevent damage.

   • Cooling mechanisms (air or water) maintain safe operating temperatures.

System Architecture and Workflow:

• The three-phase supply is processed through PFC and inverter stacks to the induction coil via a high-frequency transformer.

• Temperature feedback is continuously sent to the PID controller and microcontroller.

• The system adjusts the coil’s phase shift to maintain stable temperature and optimize energy use.

• Once the target temperature is reached, the casting process proceeds under controlled conditions.

Advantages:

• Precise and stable temperature control ensures consistent metal quality.

• Energy efficiency is improved through phase-shift modulation and PFC circuits.

• Real-time monitoring and feedback enhance reliability and safety.

• User-friendly interface allows easy operation and manual adjustment of setpoints.

Conclusion

The proposed induction casting machine demonstrates a robust and efficient system for precise metal heating, lever- aging advanced microcontroller technology, PID tempera- ture control, and user-friendly interfaces. By integrating the DSPIC33CK256MC506 microcontroller with the PFU-400 TAIE PID Temperature Controller, the system achieves real- time phase-shift regulation, ensuring accurate temperature control and energy efficiency. The inclusion of an HMI provides operators with seamless interaction and monitoring capabilities, while safety mechanisms enhance operational reliability. This design not only improves process accuracy and productivity but also reduces manual intervention, making it a significant advancement in industrial casting applications. Although the system’s complexity and initial costs present challenges, its long-term benefits in terms of precision, ef- ficiency, and traceability outweigh these limitations. Future developments could include remote monitoring via IoT in- tegration and enhanced fault-tolerant mechanisms to further optimize its industrial application potential.

References

[1] Ang Huaguang. Electronic Technology Foundation (Volume 1) [M]. Beijing: People’s Education Press, 1979. [2] A Jixun. Key Difficulties and Typical Solutions of Analog Electronic Technology [M]. Xi’an: Xi’an Jiaotong University Press, 2000 [3] Ingshi Mo, Lili Li. Phase-shifting three-phase sinusoidal oscillator [J]. Electrical measurement and instrumentation,1982(08):30-33. [4] Ohan, Undeland, Robbins “Power electronics converters, Applications, and Design” Third edition, Wiley publications. [4] Akshmi S. P. “Power tracking of Resonant Inverter with Softswitching over Full Load range for induction heating applications” IEEE 2015. [5] Uxi Wang, Juan Sabate “Phase-shift Soft-switching power amplifier with lower EMI Noise” IEEE 2014.

Copyright

Copyright © 2026 Siddharth Mhaskar, Ratanraj Narayankar, Jatan Nipurte, Dr. Rajendra Sawant. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.