Synthesis of two-frequency current by a parallel-to-series resonant LCLC-converter with multiple pulse-width modulation

Annotation: The methods to form a two-frequency inductor current in a resonant converter with multiple pulse-width modulation for systems of induction heating of complex surface shape bodies are considered. The study of the methods used to form and to regulate the frequency components of the inductor current is carried out. The approaches to assess the energy efficiency of two-frequency converters are proposed and its assessment is carried out for multiple PWM by the values of power factors and overall power. It is shown that the high-frequency harmonic is formed by two components: the one that is generated by multiple modulation and the one contained in the rectangular voltage of low frequency, the latter significantly affects the energy characteristics. The advantages in terms of energy of bipolar PWM over unipolar PWM are shown.

Keywords: resonant lclc-converter, multiple pulse width modulation, dual frequency induction heating, energy performance