Induction heating power supply is closely related to the development of semiconductor power devices. Therefore, the development trend of induction heating power supply shows the following characteristics due to the continuous improvement of power devices:
The capacity of power semiconductor devices has an extremely close relationship with their frequency of use. Early thyristors and transistors could not achieve the effect of obtaining both high power and high frequency due to the mutual constraint of capacity and frequency.
With the development of new types of devices, such as MOSFET, IGBT, and MCT, the future induction heating power supply will inevitably develop towards the direction of unifying high power and high frequency. There are still many basic application technologies that need further exploration in this aspect.
The on-state resistance of new power devices is very small, and the on-state voltage drop is small, so the loss is primarily reflected in the loss of gate or base drive circuits. With the development of power devices, coupled with the continuous improvement and optimization of drive circuits, the overall device loss has been significantly reduced.
In addition, since the power of the induction heating power supply is generally large, with the improvement of the reactive power requirements of the power grid, power sources with high power factors are the trend of future development.
Currently, with the introduction of resonant technology, on the one hand, the turn-on and turn-off losses of switching devices in the power supply are reduced. At the same time, phase-locked technology is used to lock the operating frequency of the inverter to the inherent resonant frequency of the slot, so that the power supply always operates at a load power factor of 1.
Intelligence refers to the power semiconductor integrated circuit itself, including voltage, under-voltage, over-current, and over-temperature detection and protection functions. The compound refers to a power module that includes one or more power device chips and the same number of diodes. The integration of protection circuits and compound circuits in smaller power modules reduces the number of components, reduces costs, and the circuits themselves have diagnostic and protective functions, which enhances reliability.
With the increase in automation level of induction heating production lines and the improvement of the reliability requirements of power supplies, induction heating power supplies are continuously developing in the direction of automatic control. The fully digital induction heating power supply with a computer's intelligent interface has become the goal of the next generation of development.
The use of induction heating methods for forging steel ingots enhances heat penetration, saves water and electricity, and is pollution-free. In casting and melting, it can achieve fine melting of ordinary steel, special steel, and non-ferrous metal materials.
At the same time, it can improve efficiency, and the metal composition is controllable and pollution-free. High-efficiency induction brazing is suitable for high-precision and large-batch workpieces, large-volume, immobile mother material local brazing, and welding various metal pipes. Various types of parts' surface heat treatment are widely used ininduction heating methods. Steel-plastic material manufacturing, aluminum-plastic film processing, and the sealing process in the food industry and pharmaceutical industry use induction heating methods extensively.