Method and apparatus include a first stage converter configured to generate a half sine wave, and a second stage converter in electrical communication with the first stage converter and configured to transform the half sine wave into a power signal. The second stage converter may further supply the power signal to an electrical grid. In one example, the second stage converter may include an isolated, unregulated, resonant direct current/alternating current (DC/AC) converter.

Methods and apparatus for active EMI cancellation in a switch mode power supply are provided herein. For example, an apparatus comprises an active EMI cancellation circuit coupled to a switch mode power supply circuit comprising an isolation transformer, wherein the active EMI cancellation circuit is positioned such that current flow through an EMI coupling capacitor substantially matches displacement current flow through a primary-to-secondary interwinding capacitance of the isolation transformer.

Methods and apparatus which use a microinverter comprising integrated neutral forming function for off-grid facilities are provided herein. For example, a microinverter configured for use with an AC storage system comprises switching circuitry connected at an AC output of the microinverter, a three-line connector connected at the AC output and comprising a neutral line connected between two lines configured to connect to at least one of a single phase grid system or a split phase grid system, wherein the neutral line is connected to the microinverter at a point that maintains a mid-way voltage between the two lines voltage.

A transformer for a power converter, comprising: a first auxiliary subcore, a central subcore, and a second auxiliary subcore, each respective subcore comprising a lower plate, at least one pair of central spacers, and an upper plate, the lower plate, at least one pair of central spacers, and the upper plate of each subcore, being respectively separated by a gap; the first auxiliary subcore and the central subcore being separated by a gap; the second auxiliary subcore and the central subcore being separated by a gap; a primary coil, encircling a first spacer of the first auxiliary subcore and a first spacer of the central subcore; and a secondary coil, encircling a second spacer of the second auxiliary subcore and a second spacer of the central subcore.

A current fed high-frequency isolated matrix converter and the corresponding modulation and control schemes are provided. The converter includes a current source full-bridge converter, a high-frequency transformer, a matrix converter, and a three-phase filter. An optimized space vector modulation solution is used for controlling the converter, and by comparing magnitudes of three-phase filter capacitor voltages to determine an action sequence of space vectors, switch tubes are turned on at zero voltage. A current source full-bridge circuit adopts a commutation strategy of a secondary clamping, and by calculating a leakage inductive current commutation time, full-bridge switch tubes are turned off at zero current to achieve safe and reliable commutation, and having advantages of a low system loss, a high efficiency, and a high power density.

A switched mode power converter is provided herein and comprises a cycloconverter comprising a plurality of switches, wherein each switch of the plurality of switches is a native four quadrant bi-directional switch with a common drift region configured to allow current flow in a first direction from a first source terminal to second source terminal and in a second direction from the second source terminal to the first direction.

Various embodiments of the present disclosure relate to power conversion using a planar transformer assembly that provides medium-voltage isolation at high frequencies. A planar transformer comprises primary and secondary planar windings configured to generate an isolated output. Each primary and secondary winding is interleaved on layers of a printed circuit board using one or more vias within the layers of the printed circuit board. The planar transformer also comprises a magnetic core and a field-shaping apparatus coupled with the printed circuit board. The field-shaping apparatus is configured to shape an electric field generated by the windings. The primary windings can be coupled to a DC source via switching devices while the secondary windings can be coupled via switching devices to one or more DC ports followed by AC inverters configured to generate three single-phase AC outputs for medium voltage applications.

A distributed energy conversion system may include one or more DC power sources and two or more inverters to convert DC power from the power sources to AC power. The AC power from the two or more inverters may be combined to provide a single AC output. A module may include one or more photovoltaic cells and two or more inverters. An integrated circuit may include power electronics to convert DC input power to AC output power and processing circuitry to control the power electronics. The AC output power may be synchronized with an AC power distribution system.

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.

According to one aspect of the present disclosure, there is provided an apparatus that includes first, second, and third power converter stages connected to a transformer module. At least one of the first, second, and third power converter stages is a multi-level power converter stage that has multiple configurations to generate different output voltages from an input voltage.