The advantages of Duolin medium frequency heater

At present, the majority of forging manufacturers in China use medium frequency induction heating furnaces for forging, which are mainly developed in the early 1980s using controllable silicon as frequency conversion medium frequency induction equipment. In the early 1990s, a new power device IGBT was born internationally, which has high power, low switching loss, and high operating frequency (up to 100Khz). The manufacturing technology of IGBT has been quite mature after 20 years of development, especially the fourth generation IGBT produced by INFINEON company, whose saturation voltage drop is ≤ 1.7 and hard switching frequency has reached 20KHZ. IGBT has become an absolute protagonist in the fields of frequency converters, switching power supplies, and induction heating.

The main characteristics of IGBT circuit:

*Uncontrolled rectifier circuit (using rectifier diodes, voltage cannot be adjusted), IGBT frequency conversion, series resonance.

*Under the same power and the same induction coil, the power loss of the series resonant induction coil is much lower than that of the parallel resonant induction coil, and the overall efficiency is 80% -90%.

*The turn-on and turn off of IGBT are directly controlled by its gate, independent of the power factor of the oscillation circuit and the Q value of the oscillation circuit. Therefore, regardless of the weight of the load, it can be successfully started. Therefore, as long as the appropriate Q value is selected in the design, the reliability of the equipment can be guaranteed and the equipment can have high efficiency, thus achieving the goal of power saving.

*The series resonant intermediate frequency induction heating furnace with IGBT frequency conversion has a high power factor of ≥ 0.95. If 12 pulse rectification is used, the power factor can be ≥ 0.97; The advantages of significant energy saving (saving 10% -30% compared to traditional thyristor intermediate frequency furnaces) and successful start-up under any load make it the best choice for forging manufacturers to replace traditional thyristor intermediate frequency furnaces with energy-saving renovations.

Patent Announcement:

Name: Energy saving high-power IGBT series resonant intermediate frequency induction heating power supply

Application (Patent) No.: CN200920078558.6

Application date: January 8, 2009

Public Announcement Number: CN201345751

Publication (Announcement) Date: November 11, 2009

Main classification number: H05B6/04 (2006.01) I

Classification number: H05B6/04 (2006.01) I; H02M5/458(2006.01)I

Applicant (patent holder): Chengdu Duolin Electric  Co., Ltd

Address: No. 6 Hancheng Road, Xindu Industrial Zone, Chengdu City, Sichuan Province 610500

Country and province code: Sichuan; fifty-one

Inventor (designer): Zeng Xiaolin