Abstract: A power factor correction circuit comprising: a global voltage input; and means for deriving a reference current from the global voltage; whereby the means for deriving the reference current comprises a leading phase admittance cancellation, LPAC, transfer function and a filter, whereby the reference current is derived from a sum of an output of the LPAC transfer function and an output of the filter.

Abstract: A magnetic core section of a transformer or an inductor, includes a substantially rectangular core section body having opposing sides joined by opposing ends, and further comprising interlocking features provided at each of the ends, shaped to interlock with interlocking features of complementary core sections.

Abstract: A bobbin for receiving a transformer winding includes a non-metallic tubular body having at least one wall having an outer surface onto which the transformer winding is wound, in use, and an inner surface defining a passage to receive a transformer core, in use, the bobbin comprising a plurality of openings formed through the wall(s) from the outer surface to the inner surface. The bobbin also includes a thermally conductive material provided in the openings.

Abstract: A power factor correction circuit comprising: a global voltage input; and means for deriving a reference current from the global voltage; whereby the means for deriving the reference current comprises a digital leading phase admittance cancellation, DLPAC, transfer function and a filter, whereby the reference current is derived from a sum of an output of the DLPAC transfer function and an output of the filter, and further comprising means for compensating for delays in the DLPAC function.

Abstract: An auto-transformer rectifier system comprising an 18-pulse (or multiple of 18-pulse) autotransformer rectifier unit ATRU having three, or a multiple of three, diode bridge rectifiers and a balancing resistor to balance the power flow through the diode bridge rectifiers, wherein the balancing resistor has a variable resistance, and further comprising a controller configured to identify imbalances between power flows of the respective diode bridge rectifiers and to adjust the resistance of the balancing resistor in response to the detected imbalance.

Abstract: A bootstrap gate driver charging circuit arranged to drive the gate of an upper switch (QU) and a lower switch (QL) connected in series to provide an AC output voltage (400) voltage by alternatively turning on and off according to a predetermined duty cycle of alternate upper switch turn-on and lower switch turn-on phases, the bootstrap gate driver charging circuit comprising: an input terminal; an output terminal; an H-bridge inverter with an inverter input and an inverter output; a charging path; and a bootstrap capacitor. The input inverter is electrically connected to the input terminal, the inverter output is electrically connected to a first end of the bootstrap capacitor, the charging path is electrically connected between a second end of the bootstrap capacitor and a gate driver supply voltage; wherein in response to the lower switch being turned ON and providing a path to ground with respect to the supply voltage.

Abstract: A zero-sequence blocking transformer includes a first core part, a first pair of windings wound around the first core part, a second core part and a second pair of windings wound around the second core part, the first core and the second core having a geometry to generate a leakage inductance.

Abstract: A power factor correction circuit comprising: a global voltage input; and means for deriving a reference current from the global voltage; whereby the means for deriving the reference current comprises a digital leading phase admittance cancellation, DLPAC, transfer function and a filter, whereby the reference current is derived from a sum of an output of the DLPAC transfer function and an output of the filter, and further comprising means for compensating for delays in the DLPAC function.

Abstract: A power factor correction circuit comprising: a global voltage input; and means for deriving a reference current from the global voltage; whereby the means for deriving the reference current comprises a leading phase admittance cancellation, LPAC, transfer function and a filter, whereby the reference current is derived from a sum of an output of the LPAC transfer function and an output of the filter.

Abstract: A transformer coil structure includes a core defining an axis around which is wound a primary winding, and two secondary windings wound around the core over or under the primary winding. The windings are separated into two or more columns along the axial direction of the core by one or more gaps extending radially through the windings to the core.

Abstract: An auto-transformer rectifier system comprising an 18-pulse (or multiple of 18-pulse) autotransformer rectifier unit ATRU having three, or a multiple of three, diode bridge rectifiers and a balancing resistor to balance the power flow through the diode bridge rectifiers, wherein the balancing resistor has a variable resistance, and further comprising a controller configured to identify imbalances between power flows of the respective diode bridge rectifiers and to adjust the resistance of the balancing resistor in response to the detected imbalance.

Abstract: A zero-sequence blocking transformer includes a first core part around which is wound a first winding and a second core part around which is wound a second winding, and a third core part to create an additional leakage flux path. The concept of this disclosure can be applied to any known core structure by adding an additional leakage flux component part. In the case of a known toroidal core, the additional component part may be a rod of magnetic material fitted into the gap between the two windings to intentionally create an additional leakage flux path. Alternatively, an EE core geometry can be used and the additional leakage flux path is created by forming an air gap or adding a magnetic material insert in the leg which does not carry a winding.