FIELD: electrical engineering; control systems for resonance-tuned pulse-width modulated inverters of induction heater plants.
SUBSTANCE: proposed method that makes it possible to control any process parameter (output voltage, current, and power) as well as to extend process parameter control range when feeding electric load whose parameters are varying within wide range involves generation of control pulses and their supply to transistors shaping forward and backward current half-waves in load. Novelty is that process parameter levels enabling and inhibiting control pulse supply are first ones being set. In the course of operation current value of process parameter is measured within several last resonant-frequency cycles and compared with set levels. If mean current value of process parameter is below enabling level, instruction enabling control pulse supply is activated. If this value is higher than or equal to level inhibiting control signal supply, enable instruction is deactivated and null space multiple of integer number of resonant-frequency half-cycles is introduced, this space being anticipated by reverse-polarity pulse at resonant-frequency half-cycle. This method allows for enhancing subharmonic frequency and reducing output current amplitude of inverter.
EFFECT: enlarged functional capabilities.
1 cl, 2 dwg
