The Application of Phase-locked Loop Frequency Tracking in the Intelligence-type Induction Heating Power Supply

摘要

As the induction heating power was working, its load resonant frequency constantly changes. In order to improve the efficiency of power supply, it requires that the inverter output frequency can follow changes in natural frequency of the load, namely the frequency tracking control. Aiming at the deficiency of the frequency tracking control system, this paper presents a method that the phase-locked loop (PLL) tracking system works on real-time control of the output frequency of the power supply, and introduces a phase-locked mathematical model which fits the inverter power supply, and offers a simulated analysis by using PSPICE. Through experiments, the system proves to be good at frequency tracking.