System and method for controlling induction heating devices with series connected switching devices

A method for controlling an induction heating device comprising a plurality of resonant loads, the method comprising:

• supplying D.C. power from a power supply to a first node in connection with a plurality of resonant loads arranged in parallel;
• conducting current from the power supply from a second node of each of the resonant loads into a first side of a plurality of first switching devices, wherein one of the first switching devices is in connection with the second node of each one of the resonant loads on the first side;
• selectively conducting the current from a second side of the first switching devices in a biased configuration for each of the resonant loads, wherein the current is selectively conducted from the second side of each of the first switching devices to a common node of a common second switching device;
• at least one of:
• conducting the current through a first rectifying device interposed between each of the resonant loads and the first switching devices;
• and
• conducting the current through a second rectifying device interposed between the power supply and each of the resonant loads;
• and
• selectively conducting the current through the common second switching device at a common frequency.

An induction heating device comprising:

• a power supply configured to supply D.C. power via a D.C. bus referenced to a ground connection;
• a plurality of resonant loads comprising an inductor and a capacitor in parallel, each of the resonant loads in connection with a D.C. bus;
• a plurality of first switching devices comprising a first side and a second side, wherein one of the first switching devices is in connection with each one of the resonant loads on the first side and each of the first switching devices is connected to a common node on the second side;
• a second switching device in connection with the common node of each of the first switching devices, wherein a selective activation of each of the first switching devices in combination with an activation of the second switching device supplies current to the resonant load in connection with the one or more activated first switching devices;
• and
• a rectification device is connected in series with each of the resonant loads between the power supply and the first switching devices.