Power conversion device for electric range, and control method thereof

A power conversion device for an electric range which is provided with a plate on which an object to be heated is seated and an interface unit for receiving a user's selection of the number of outputs, comprising:

• a power supply unit for providing a rectified voltage;
• a switching element;
• a working coil which is disposed under the plate and inductively heats the object to be heated by applying the rectified voltage by switching of the switching element;
• a resonance capacitor which is disposed in parallel with the working coil;
• a comparator for generating a switching timing reference signal by comparing the rectified voltage and a voltage at both ends of the switching element;
• a control unit for determining a resonance frequency according to the object to be heated and the number of outputs that are input through the interface unit, determining a delay time according to a difference between the frequency of the switching timing signal and the resonance frequency, and outputting a switching control signal that turns on after the delay time has passed since the falling edge of the switching timing reference signal;
• and
• a storage unit for storing a delay time according to a difference between the resonance frequency and the switching timing reference signal.