Abstract: The present disclosure describes devices and methods for improving the power efficiency and control of an induction heating system. In particular, the induction heating system includes a series resonant bridge inverter circuit and a control circuit. The inverter circuit includes one or more induction coils that are structured to inductively couple to the cookware to heat the cookware and a current sensor structured to sense a coil current signal across the one or more inductor coils. In particular, the current sensor is structured to generate a positive sensed voltage signal corresponding to a positive portion of the coil current signal and a negative sensed voltage signal corresponding to a negative portion of the coil current. The control signal is structured to control switching of a first and a second set of switches based on the positive and negative sensed voltage signals.

Abstract: Aspects of hybrid modulation control for DC-to-AC converters are described. In one embodiment, a hybrid modulation pattern is generated. The hybrid modulation pattern separates switch gating control into multiple control regions for a half cycle of the waveform. A first control region modulates according to a first modulation technique and a second control region modulates according to a second modulation technique. The switches of a resonant converter are controlled according to the hybrid modulation pattern to generate the waveform.

Abstract: This disclosure provides systems, methods, and apparatus for multi-level inverters. A hybrid binary cascaded multilevel inverter (BCMLI) is discussed that includes a plurality of H-bridge cells connected in a cascaded formation. DC input voltages of some of the H-bridge cells are provided by DC voltage sources. But inputs of other H-bridge cells coupled with capacitors instead. The H-bridge cells are operated to provide an AC output voltage at the output terminals of the inverter. One or more floating capacitor voltage controllers are used to vary one or more switching instances of the H-bridge cells such that a desirable level or charge is maintained across the one or more capacitors coupled with the input terminals of the H-bridge cells.

Abstract: A distributed single-stage on-board charging device comprises a first transformer having a first primary winding and a first secondary winding; a first capacitor connected to the first primary winding; a first inductor connected to the first capacitor, wherein the first capacitor is located between the first inductor and the first transformer; a first transistor connected to the first capacitor and the first inductor; a first diode connected to the first secondary winding; a second transformer having a second primary winding and a second secondary winding, wherein the first transformer and the second transformer are connected in parallel; a second capacitor connected to the second primary winding; a second inductor connected to the second capacitor, wherein the second capacitor is located between the second inductor and the second transformer; and a second transistor connected to the second capacitor and the second inductor.

Abstract: A power converter. The power converter comprising: two or more multi-phase AC sources; an AC-DC converter circuit for each of the multi-phase AC sources, each AC-DC converter circuit being connected to a respective multi-phase AC source via a multi-phase input and configured to rectify a received multi-phase current into a DC current; a transformer, which is connected between the multi-phase AC inputs; a DC-link, shared between each of the AC-DC converter circuits; a load, connected to the DC-link and able to receive DC current therefrom; and a common mode filter, located within the DC-link, and configured to reduce a circulatory current which, when the power converter is in use, flows from the transformer through one of the AC-DC converter circuits, through the DC-link and through a further of the AC-DC converter circuits back to the transformer.

Abstract: The present disclosure describes devices and methods for improving the power efficiency and control of an induction heating system. In particular, the induction heating system includes a series resonant bridge inverter circuit and a control circuit. The inverter circuit includes one or more induction coils that are structured to inductively couple to the cookware to heat the cookware and a current sensor structured to sense a coil current signal across the one or more inductor coils. In particular, the current sensor is structured to generate a positive sensed voltage signal corresponding to a positive portion of the coil current signal and a negative sensed voltage signal corresponding to a negative portion of the coil current. The control signal is structured to control switching of a first and a second set of switches based on the positive and negative sensed voltage signals.

Abstract: A distributed single-stage on-board charging device comprises a first transformer having a first primary winding and a first secondary winding; a first capacitor connected to the first primary winding; a first inductor connected to the first capacitor, wherein the first capacitor is located between the first inductor and the first transformer; a first transistor connected to the first capacitor and the first inductor; a first diode connected to the first secondary winding; a second transformer having a second primary winding and a second secondary winding, wherein the first transformer and the second transformer are connected in parallel; a second capacitor connected to the second primary winding; a second inductor connected to the second capacitor, wherein the second capacitor is located between the second inductor and the second transformer; and a second transistor connected to the second capacitor and the second inductor.

Abstract: A DC-DC power conversion apparatus and a DC-DC power conversion method are provided. The DC-DC power conversion apparatus includes a switching circuit, a main transformer circuit, a main rectifier circuit, an auxiliary transformer circuit and an auxiliary rectifier circuit. The switching circuit provides an input power to a primary winding of the main transformer circuit or a primary winding of the auxiliary transformer circuit by time-division. An AC input terminal of the main rectifier circuit is coupled to a secondary winding of the main transformer circuit. An AC input terminal of the auxiliary rectifier circuit is coupled to a secondary winding of the auxiliary transformer circuit. A power output terminal of the auxiliary rectifier circuit is coupled to a reference voltage terminal of the main rectifier circuit for lifting a voltage of the power output terminal of the main rectifier circuit.

Abstract: A modular reconfigurable medium voltage transformer configured for data centers, VOLT/VAR control, AC and DC charging, and vehicle-to-grid applications is disclosed. The modular reconfigurable transformer includes a plurality of modules configured to be connected to or disconnected from each other to provide multiple transformer configurations.

Abstract: A DC-DC power conversion apparatus and a DC-DC power conversion method are provided. The DC-DC power conversion apparatus includes a switching circuit, a main transformer circuit, a main rectifier circuit, an auxiliary transformer circuit and an auxiliary rectifier circuit. The switching circuit provides an input power to a primary winding of the main transformer circuit or a primary winding of the auxiliary transformer circuit by time-division. An AC input terminal of the main rectifier circuit is coupled to a secondary winding of the main transformer circuit. An AC input terminal of the auxiliary rectifier circuit is coupled to a secondary winding of the auxiliary transformer circuit. A power output terminal of the auxiliary rectifier circuit is coupled to a reference voltage terminal of the main rectifier circuit for lifting a voltage of the power output terminal of the main rectifier circuit.

Abstract: A hybrid switch comprising two semiconductor switches connected in parallel but having different voltage drop characteristics as a function of current facilitates attainment of zero voltage switching and reduces conduction losses to complement reduction of switching losses achieved through zero voltage switching in power converters such as high-current inverters.

Abstract: A new current loop control system method is proposed for a single-phase grid-tie power conditioning system that can be used under a standalone or a grid-tie mode. This type of inverter utilizes an inductor-capacitor-inductor (LCL) filter as the interface in between inverter and the utility grid. The first set of inductor-capacitor (LC) can be used in the standalone mode, and the complete LCL can be used for the grid-tie mode. A new admittance compensation technique is proposed for the controller design to avoid low stability margin while maintaining sufficient gain at the fundamental frequency. The proposed current loop controller system and admittance compensation technique have been simulated and tested. Simulation results indicate that without the admittance path compensation, the current loop controller output duty cycle is largely offset by an undesired admittance path. At the initial simulation cycle, the power flow may be erratically fed back to the inverter causing catastrophic failure.

Abstract: An apparatus for DC fast charging of an electric vehicle includes an active front end AC-DC converter and an isolated DC-DC converter. The active front end AC-DC converter is adapted to rectify a medium voltage alternating current (AC) from a utility grid to a high voltage direct current (DC). The isolated DC-DC converter is adapted to transform the high voltage DC to a low voltage DC for charging the electric vehicle.

Abstract: A photovoltaic (PV) integrated variable frequency drive system having a variable frequency drive and an energy source. The variable frequency drive having a back end inverter, a DC bus electrically connected to the back end inverter, and an active front end electrically connected to the DC bus to facilitate bi-directional power flow to and from a power grid. The energy source being electrically connected to the DC bus.

Abstract: A hybrid switch comprising two semiconductor switches connected in parallel but having different voltage drop characteristics as a function of current facilitates attainment of zero voltage switching and reduces conduction losses to complement reduction of switching losses achieved through zero voltage switching in power converters such as high-current inverters.

Abstract: The present invention relates to a photo-voltaic interface for integration of photo-voltaic modules in a power system. The photo-voltaic interface includes a power conversion system adapted to convert power to a pre-determined voltage and current type, a control and monitoring system adapted to allow monitoring and control of power flow to optimize grid operation, and a communications system adapted to allow remote monitoring of the photo-voltaic interface to detect defective components.

Abstract: A circuit is provided to reduce power loss on switching. A pair of auxiliary switching devices is switched on before a pair of switching devices. The switching devices are switched on after a corresponding capacitor to the auxiliary switching devices is discharged to zero. Thus, the power loss of the switching devices is reduced.

Abstract: A circuit is provided to reduce power loss on switching. A pair of auxiliary switching devices is switched on before a pair of switching devices. The switching devices are switched on after a corresponding capacitor to the auxiliary switching devices is discharged to zero. Thus, the power loss of the switching devices is reduced.

Abstract: A photovoltaic (PV) integrated variable frequency drive system having a variable frequency drive and an energy source. The variable frequency drive having a back end inverter, a DC bus electrically connected to the back end inverter, and an active front end electrically connected to the DC bus to facilitate bi-directional power flow to and from a power grid. The energy source being electrically connected to the DC bus.

Abstract: This present invention relates to a paralleled power conditioning system with circulating current filter, comprising: an input terminal for receiving a input power; a plurality of power conditioning units; and a load. Each power conditioning unit includes: a DC/DC converter coupled to the input for receiving the input power so as to convert the input power to a DC voltage; a DC/AC inverter coupled to the DC/DC converter for converting the DC voltage to a AC voltage; and a filter coupled to the DC/AC inverter for eliminating the noise generated by the AC voltage and the circulating current among the plurality of power conditioning units so as to generate a filter voltage. The load is connected to the plurality of power conditioning units. The plurality of power conditioning units are connected in parallel to the load.