Research On High Frequency Induction Heating Power By CPDM Control

This article briefly introduces the basic theory and characteristics of induction heating and discusses the development and status of induction heating power sources. After the analysis and comparison on the main circuit topology of induction heating, the research of main circuit topology was decided. All kinds of power control methods of the induction heating power are analyzed and compared in detail by simulation. A novel power controlstrategy——Composite Pulse-Density-Modulation (CPDM) is introduced in this paper. Thework principle of power is introduced,.The simulation results confirm that the CPDM control strategy can realize that switching devices of induction heating power sources work in the soft-switching state, Switching losses small ,the power factor is closed to 1. The system is Easy to implement digital control, Current is easy for frequency tracking with light loads, Very suitable for high frequency induction heating power.In order to verify the validity and the feasibility of the CPDM control method, an induction heating power supply controlled by CPDM is designed. The special DSP chip of TMS320F2812 that produced by TI Company is used as main controller of the power to work on the power supply with the hardware and software design respectively. The experimental results show that the CPDM controlled induction heating power has excellent power regulating performances, and the power conversion efficiency is higher due to lower switching losses.