Sinac’s high-frequency systems offer parallel- and serial-compensated converters. The parallel-compensatedhigh-frequency systems are based on the same fast IGBT technology as the medium-frequency systems, making it possible to run up to 200 kHz. Sinac’s serial-compensated high-frequency systems feature IGBT transistors and three-phase diode rectifiers. The IGBT inverters are based on EFDInduction-patented switching pattern technology that utilizes the IGBT transistors at high frequencies without any extra stress. Solid-state technology helps ensure maximum uptime and throughput. Multi-frequency systems Sinac multi-frequency systems use patented EFD Induction technology to deliver two different frequencies—one high and one low—to one coil at the same time. This gives you the flexibility to treat a wide range of components. The systems are serialcompensated and feature rugged IGBT transistors in full bridge circuits. The custom-designed coils are connected directly to the inverter matching cabinets.
All the system uses the same generator and heating unit (coil) perfectly adapted to our purpose. The induction coil is powered by a HF-generator operating at a frequency high enough to give the induced current a penetration depth smaller than 1/10 of a mm. The HF power is adjusted and continuously measured and automatically adjusted to provide equal heating independent of product size, coil size and steel grade. The coil with a flexible cable is mounted on a hydraulic servo unit. The servo centers the coil and moves with the billet for safety, equal heating of all faces and positions the coil automatically when changing billet size. The coil is released when hit to prevent serious damage.
