A brief analysis of the future development trends of high-frequency induction heating power supply

With the advancement of the times and the development of science and technology, induction heating power supplies, led by high-frequency induction heating power supplies, have been developing at a rapid rate. Today we will take a look at the future development trend of high-frequency induction heating power supplies in the heat treatment industry.

1) The main circuit power switching devices are self-switching, modular, integrated and intelligent, the switching frequency continues to increase and switching losses are further reduced.

2) Low-voltage and small-capacity devices often use 6-pulse rectifiers, while medium-voltage and large-capacity devices use 12-pulse and 24-pulse rectifiers to reduce harmonic interference to the power supply system and electromagnetic radiation interference to surrounding electronic equipment. 

3) The advancement of microprocessors has made digital control the development direction of modern controllers. In recent years, major companies in my country and abroad have launched DSP-based cores, equipped with required peripheral functional circuits, which are called DSP monolithic controllers integrated in a single chip. The price is greatly reduced and the size is reduced. Compact structure, convenient use and improved reliability. Compared with ordinary microcontrollers, DSP has 10 to 15 times greater digital processing capabilities, ensuring that the system has superior control performance. Digital control simplifies hardware, and various intelligent control algorithms will greatly improve control performance, realize complex control rules, and make the application of modern control theory in control systems a reality. It is easy to connect to upper-layer systems for data transmission, and is convenient for Fault diagnosis, enhanced protection and monitoring functions, thereby improving the intelligence level of the system.

4) The large-capacity technology of high-frequency induction heating power supplies can be divided into two categories from a circuit perspective: one is the series and parallel connection of devices, and the other is the parallel connection of multiple power supplies. In the series and parallel connection of devices, the voltage sharing problem of series devices and the current sharing problem of parallel devices must be carefully dealt with. Due to the discrete nature of device manufacturing processes and parameters, the number of series and parallel connections of devices is limited, and the more series and parallel connections there are, the worse the reliability of the device. Since MOSFET is a multi-carrier device and has no storage time, its switching time is much smaller than IGBT. In addition, MOSFET does not have the problem of secondary breakdown, has a rectangular safe area, small driving power, and is easy to be connected in parallel. Therefore, it is often suitable for high-frequency and high-power high-frequency induction annealing power supplies. The problem that may arise from using MOSFET is that because it is a high-speed switch, it has strict wiring requirements, and the high-voltage MOSFET has a large on-state loss, so IGBT should be used as much as possible at the same frequency. Increase the capacity of the power supply by changing the structure of the circuit.