An induction heating device is composed of two parts, one is to provide energy ac power supply, also known as frequency conversion power supply, and the other is to complete the electromagnetic induction energy conversion induction coil and mechanical structure, known as induction furnace. Frequency conversion power has power frequency, intermediate frequency, and high frequency.
(1) High-frequency heating equipment
It has a set of devices to convert power from 50Hz alternating current to high frequency (70, 000 ~ 1000, 000Hz), usually using a vacuum tube high-frequency generator.
(2) Intermediate frequency heating equipment
There is also a device for converting 50Hz power to intermediate (500 ~ 10 000Hz) power, usually if generators (with a low power factor) and thyristor converters.
(3) Power frequency induction heating equipment
The power frequency of the inductor is the same as that of the power grid, namely 50Hz, so it can draw energy directly from the power grid. The fly in the ointment is that the power factor is too low.
With the development of market demand, the development of induction heating devices shows that the power supply becomes high-frequency with the large capacity of power electronic power devices, and the control simulation of electronic technology devices develops into digital and automatic control to intelligent development. The development trend of induction heating devices presents the following characteristics:
(1) The power supply tends to have high frequency and large capacity
Thyristors are mainly used in the middle frequency of induction heating power supply. The super audio segment mainly USES IGBT; The high frequency band used to be SIT, and now it mainly develops MOSFET power supply. Power sources using IGCT are also beginning to appear. The need for high frequency power supply gives birth to new power devices, which in turn promote the development of high frequency power supply. The large capacity of induction heating power supply, such as tens of megawatts, and hundreds of megawatts, can be achieved.
(2) Induction heating device tends to mechanization and automation
In recent years, with the rapid development of mechatronics, computer, information, and control, equipment automation, new materials, and new processes, casting, forging and heat treatment process tend to digitalization and precision. The demand trends reflected in heating are as follows: the integration of digital manufacturing into the casting and forging process, including heating and smelting equipment; Casting and forging short process production requirements to reduce resource waste; The production of large castings and forgings requires industrial energy saving; Clean production under automatic control.
Therefore, induction heating equipment, with its energy-saving and environmental protection characteristics, has the tendency to develop in the direction of large scale, automation, and intelligent control according to the market demand.
