Power range: The power of induction heating furnaces varies from a few kilowatts to several hundred kilowatts; selecting the appropriate power level is crucial for ensuring heating efficiency and energy conservation. Operating frequency directly affects heating depth and efficiency; medium-frequency induction heating furnaces typically operate in the range of hundreds of hertz to tens of kilohertz (e.g., common frequencies of 800–20,000 Hz), while the broader operating frequency range for induction heating furnaces spans from 1 kHz to 400 kHz. Low frequencies are suitable for large workpieces or deep heating, whereas high frequencies are appropriate for small components or surface heating.
Efficiency is a key parameter for evaluating equipment performance; the energy efficiency ratio of induction heating furnaces often exceeds 90%, with advanced equipment achieving conversion rates of over 95%. Additionally, power factor and harmonic content are critical indicators of power quality. While traditional equipment may have a lower power factor (e.g., 0.84)-which can be improved to 0.98 through optimization [18]-modern advanced equipment can achieve a power factor of 0.95 and keep harmonic interference below 3%.
Modern medium-frequency induction heating furnaces are frequently equipped with advanced control systems, such as PLC (Programmable Logic Controller) technology, which enhance the precision of the heating process and ease of operation [13–14]. To further improve temperature control accuracy and responsiveness, intelligent control algorithms-such as fuzzy PID-are incorporated into system designs to achieve superior control performance.