A power converter apparatus is provided with: a plurality of leg circuits, each including two switch circuits connected in series between input terminals; a transformer including a primary winding and a secondary winding, the primary winding having a first terminal and a second terminal; and at least one capacitor. The at least one capacitor is connected between the first terminal or the second terminal of the primary winding of the transformer, and a node between the two switch circuits in at least one leg circuit among the plurality of leg circuits. The first terminal of the primary winding of the transformer is connected to at least two nodes between the switch circuits in at least two first leg circuits among the plurality of leg circuits, via at least two first circuit portions having at least one of capacitances and inductances different from each other, respectively.

A power conversion system for an aircraft on-board power system converts high voltage DC to low voltage DC and vice versa. The system includes switching means configured so that the system operates in a plurality of configurations, each forming an isolated DC/DC converter.

Systems and methods are provided for generating signals. The signal generator system includes a transformer unit and a plurality of converters. The transformer unit includes a primary input side and a secondary output side connectable to a load. The primary input side includes a plurality of parallel input sections and the secondary output side includes a plurality of output sections connected in series with each output section corresponding to one of the input sections. Each converter has a converter input, a converter output, and a switch module positioned between the converter input and the converter output. The switch module is operable to control a direction of current flow through the converter output. The switch module is adjustable between a plurality of switch states, and each converter is adjustable between a plurality of operational modes. The plurality of operational modes include at least one active mode and at least one inactive mode.

An induction heating cooker includes a first coil, a second coil, a third coil, a first inverter circuit configured to supply a first high-frequency current to the first coil, a second inverter circuit configured to supply a second high-frequency current to the second coil, a third inverter circuit configured to supply a third high-frequency current to the third coil, a controller, and a load determining unit configured to determine a material of a heating object, wherein when a material of the heating object placed above the first coil is a magnetic material and a material of the heating object placed above the second coil includes a non-magnetic material, the controller operates the first inverter circuit and the second inverter circuit, and stops an operation of the third inverter circuit, and controls such that a frequency of the second high-frequency current is higher than a frequency of the first high-frequency current.

The invention relates to an inductive power transmission with a resonant circuit, the resonant circuit including a transmitting/receiving coil or a transmitting and receiving coil for transmitting and/or receiving electromagnetic energy, a coupling capacitor, a tuning capacitor, and a switching device, wherein the switching device is connected in series to the coupling capacitor and the tuning capacitor, and wherein, furthermore, the switching device is designed to activate and/or disconnect a signal generator and to modify a quality factor or to modify the resonance frequency of the resonant circuit.

Controlling a DC-AC inverter of an electric machine, where the electric machine comprises a resonant main exciter having rotary transformer. A voltage level of DC power received at a DC-AC inverter is monitored and the frequency of AC power generated by the DC-AC inverter and supplied to the rotary transformer is controlled based at least in part on the voltage level of the DC power.

Unique systems, methods, techniques and apparatuses for a ZVT ZCT resonant converter with a variable resonant tank are disclosed. One exemplary embodiment is a system comprising a bidirectional resonant converter comprising an input/output terminal, a switching device coupled with the input/output terminal, a resonant circuit coupled with the switching device and including a variable inductor, an output/input terminal coupled with the resonant circuit, and a DC biasing circuit operatively coupled with the variable inductor. The variable inductor comprises a toroidal core, a first winding wound around the toroidal core and coupled with the switching device and the output/input terminal, a second core structured to overlap a portion of the toroidal core, and a second winding wound around the second core and coupled with the DC biasing circuit. The DC biasing circuit is controllable to vary the inductance of the variable inductor by saturating a portion of the toroidal core.

A high-frequency resonant power conversion system for transferring power from an oscillator to a load or vice-versa, the system including components with at least one fluctuating parameter and is configured to control the value of a defined variable selected from: a certain current, a certain voltage, a phase difference between a certain voltage and a certain current, and a certain power; the system further including a virtual impedance creation loop which is configured to create a virtual component, the virtual component forming a basis for changing amplitude and a phase of the oscillator, thereby to compensate for a deviation from the controlled variable due to the fluctuations.

Controlling a DC-AC inverter of an electric machine, where the electric machine comprises a resonant main exciter having rotary transformer. A voltage level of DC power received at a DC-AC inverter is monitored and the frequency of AC power generated by the DC-AC inverter and supplied to the rotary transformer is controlled based at least in part on the voltage level of the DC power.

A method of controlling highly regulated power and frequency from a high frequency power supply system to provide a highly regulated power and frequency to a workpiece load where the highly regulated power and frequency can be independent of the workpiece load characteristics by inverter switching control and an inverter output impedance adjusting and frequency control network that can include precision variable reactor pairs with a geometrically-shaped moveable insert core section and a stationary split-bus section with a complementary geometrically-shaped split bus section and a split electric terminal bus section where the insert core section can be moved relative to the stationary split-bus section to vary the inductance of the variable reactors.