High frequency power supply system with closely regulated output for heating a workpiece

A high frequency power supply system for heating a workpiece load in a welding process or an annealing process, the high frequency power supply system comprising:

• a full bridge inverter or a half-bridge inverter comprising a plurality of bridge switching devices and a pair of inverter output leads forming a single phase inverter output;
• an inverter output impedance adjusting and frequency control network having a control network input connected to the pair of inverter output leads and a control network output connected to the workpiece load, the inverter output impedance adjusting and frequency control network comprising a plurality of variable impedance elements wherein at least one pair of the plurality of variable impedance elements comprises a pair of variable reactors, the pair of variable reactors comprising a geometrically-shaped moveable insert core and a stationary split-bus, the stationary split-bus comprising:
• a geometrically-shaped split bus section having a geometric complementary shape to the geometrically-shaped moveable insert core to provide an adjustable position of insertion of the geometrically-shaped moveable insert core into the geometrically-shaped split bus section to vary an inductance of the pair of variable reactors from a minimum inductance value when the geometrically-shaped moveable insert core is fully inserted into the geometrically-shaped split bus section to a maximum inductance value when withdrawn from the geometrically-shaped split bus section to a position where a variable energy field in a shaped interleaving space between the geometrically-shaped moveable insert core and the geometrically-shaped split bus section is at a maximum value;
• and
• a split electric bus terminal section for an electrical connection of the geometrically-shaped pair of reactors in the inverter output impedance adjusting and frequency control network;
• an actuator connected to the geometrically-shaped moveable insert core for an insertion and a withdrawal of the geometrically-shaped moveable insert core into and from the geometrically-shaped split bus section;
• and
• a system microprocessor controller having one or more inverter control outputs to the plurality of bridge switching devices and one or more variable impedance control outputs to the plurality of variable impedance elements in the inverter output impedance adjusting and frequency control network for an adjustable power transfer from the pair of inverter output leads to the workpiece load and a variable output frequency from the pair of inverter output leads to the workpiece load independent of a workpiece impedance of the workpiece load.