Induction heating system and method

An excitation system of an induction heater for use on an airplane for heating food, beverage, or both, the system comprising:

• a voltage supply connector adapted for receiving a mains AC voltage from an aircraft voltage supply having multiple phases, and
• multiple excitation units connected to the voltage supply connector, each of which excitation units provided for a respective phase of the multiple phases, each excitation unit comprising:
• a rectifier for rectifying a respective portion of the mains AC voltage,
• a load circuit with an inductor that is excited by a load circuit AC voltage generated in the excitation unit, and
• an AC voltage generator for generating an amplitude-modulated load circuit AC voltage through amplitude modulation of an AC voltage signal with the frequency of the mains AC voltage, wherein the AC voltage signal has a frequency that is predetermined and is generated from a rectified voltage output from the rectifier.

An induction heater for use on an airplane, the induction heater comprising:

• a voltage supply connector adapted for receiving an aircraft voltage supply having at least two phases and supplying a mains AC voltage;
• and
• at least one excitation unit provided for each phase of the aircraft voltage supply and connected to the voltage supply connector, each excitation unit comprising:
• a rectifier for rectifying a respective portion of the mains AC voltage,
• a load circuit with an inductor that is excited by a load circuit AC voltage generated in the excitation unit,
• an AC voltage generator for generating an amplitude-modulated load circuit AC voltage through amplitude modulation of an AC voltage signal with the frequency of the mains AC voltage, and
• a filter element for attenuating harmonics generated within the excitation unit to mitigate deleterious effects on the aircraft voltage supply,
• wherein the AC voltage signal has a frequency that is predetermined and is generated from a rectified voltage output from the rectifier.

A method for heating food, beverage, or both in airplanes using induction heating, the method comprising:

• exciting at least one load circuit including an inductor with a load circuit AC voltage;
• generating the load circuit AC voltage from an AC voltage signal having a predetermined frequency by amplitude-modulating the AC voltage signal with a frequency of a mains AC voltage from a voltage supply;
• and
• controlling the power supplied to the load circuit by omitting individual pulses during generation of the AC voltage signal.

A method for heating food, beverage, or both in an airplane using induction heating, the method comprising:

• exciting at least one load circuit including an inductor with a load circuit AC voltage;
• generating the load circuit AC voltage from an AC voltage signal having a predetermined frequency higher than a frequency of an airplane mains AC voltage by amplitude-modulating the AC voltage signal with the frequency of the airplane mains AC voltage;
• and
• attenuating harmonics of the load circuit AC voltage from reaching an airplane mains AC voltage supply by filtering the harmonics with a filter element.