An induction heating and wireless power transferring device that includes: a first working coil and a second working coil that are coupled in parallel; a rectification unit configured to rectify alternating current (AC) power to direct current (DC) power; a first inverter unit configured to convert the DC power into resonant current, and apply the converted resonant current to the first working coil or the second working coil; a first switch coupled to the first working coil and configured to turn on or off the first working coil; a second switch coupled to the second working coil and configured to turn on or off the second working coil; and a control unit configured to control the first inverter unit, the first switch, or the second switch to detect whether a target object is located on the first working coil or the second working coil.

An induction heating apparatus includes a working coil; an inverter configured to perform switching operation to thereby apply a resonance current to the working coil; and a controller configured to provide a control signal with a fixed frequency to the inverter to thereby control the switching operation. The controller changes a pulse width of the control signal based on a predetermined cycle that is set based on a temperature of the inverter.

Systems and methods for using parasitic capacitance of a transformer as an element in a resonant converter are provided. Aspects include determining a parasitic capacitance associated with a transformer, determining a resonant circuit configuration based at least in part on the parasitic capacitance associated with the transformer, and providing a resonant converter comprising the resonant circuit and the transformer.

According to an aspect, a power supply system includes a plurality of power converters configured to deliver a system load current to a load, where the system load current is a combination of individual load currents provided by the plurality of power converters, and a system performance controller configured to detect a value of the system load current. The system performance controller is configured to determine, using power loss information, values for the individual load currents such that a composite efficiency achieves a threshold condition. The system performance controller is configured to generate control signals to operate the plurality of power converters at the determined values.

A resonant DC/DC converter which has a first DC link, preferably including a first DC link capacitor; a DC/AC converter which has a first plurality of N>1 converter bridges connected in parallel to the first DC link; each converter bridge comprising a plurality of switches each of which may be switched between a conducting state and a non-conducting state. The resonant DC/DC converter also includes an AC intermediate circuit having an input connected to an output of the DC/AC converter and comprising: a transformer, preferably a medium frequency transformer, having a primary side and a secondary side; the primary side comprising at least one primary winding; a first plurality of N capacitors, wherein for each converter bridge, a different one from the first plurality of capacitors is connected between said converter bridge and the at least one primary winding.

A system for use in generating a power signal includes a first stage circuit having: a first input line coupled to a first stage first parallel line having a first stage first switch positioned thereon, a second input line coupled to a first stage second parallel line having a first stage second switch positioned thereon, and a first stage third parallel line oriented in parallel with the first stage first parallel line and the first stage second parallel line between a positive rail and a negative rail, the first stage third parallel line having a first capacitor positioned thereon. The system further includes a second stage circuit having a resonant inverter coupled between the positive rail and the negative rail and configured to output the power signal.

A system for controlling a power signal for zero voltage switching (ZVS) includes a voltage zero crossing detection module to detect a zero voltage condition in response to an inverter voltage from a resonant inverter crossing zero volts, and a current zero crossing detection module to detect a zero current condition in response to an inverter current from the resonant inverter crossing zero amps. The system further includes a phase detect module to detect actual phase data corresponding to an actual phase angle between the inverter voltage and the inverter current based on the zero voltage and zero current condition. The system further includes a comparator to determine a phase difference between a desired phase between the inverter voltage and the inverter current and the actual phase angle. The system further includes a controller to adjust a property of a resonant inverter to reduce the phase difference.

A power apparatus applied in an SST structure includes a first AC-to-DC conversion unit, a first DC bus, an isolated transformer, a DC-to-AC conversion unit, a second AC-to-DC conversion unit, and a second DC bus. The first AC-to-DC conversion unit has a first bridge arm and a second bridge arm. The first DC bus provides a first DC voltage. The isolated transformer has a primary side and a secondary side. The DC-to-AC conversion unit has a third bridge arm and a fourth bridge arm. The second AC-to-DC conversion unit has a fifth bridge arm and a sixth bridge arm. The second DC bus provides a second DC voltage.

A resonance control method for differentiated phase correction under asymmetric positive and negative bilateral frequency domains includes a differentiated phase correction resonance control link with an independent phase correction angle at each resonance point, a decoupling link and a delay compensation link. As a high power converter has the characteristic of asymmetric positive and negative bilateral frequency domains under resonance control with decoupling, stability margin of a control link is enhanced while a negative-sequence current suppression capability is realized by means of differentiated phase correction at positive and negative resonance poles.

Aspects of the invention overcome a monolithic approach to conventional low-frequency LPTs by using a high-frequency solid-state alternating current ac/ac modular power-conversion approach. Embodiments of the invention enable the ability to incorporate new technologies without in all cases redoing a LPT design from scratch. Furthermore, given that LPTs are for the long term, aspects of the invention ensure that they are durable, efficient, and fault tolerant with overloading capability.