There is provided a transformer system (10) for converting a grid voltage (V.sub.grid) to a regulated voltage (V.sub.regulated) and output the regulated voltage (V.sub.regulated) to a power line (30), the transformer system (10) comprising: a first transformer (40) configured to step down the grid voltage (V.sub.grid) to an unregulated voltage (V.sub.unregulated) and provide the unregulated voltage (V.sub.unregulated) at an output of the first transformer (40); a shunt coupling transformer (50) connected in parallel with the output of the first transformer (40) and further connected to power electronics circuitry (60); and a series coupling transformer (70) connected in series with the output of the first transformer (40) and further connected to the power electronics circuitry (60). The power electronics circuitry (60) adds, via the series coupling transformer, a conditioning voltage (V.sub.conditioning) in series to the unregulated voltage (V.sub.unregulated) to generate the regulated voltage (V.sub.regulated). The first transformer, the series coupling transformer and the shunt coupling transformer are housed in a single transformer tank (80), and the power electronics circuitry is housed in a power electronics enclosure (90) separate from the transformer tank. Each of the transformer tank and the power electronics enclosure comprises one or more openings (95) through which electrical connections (97) between the shunt coupling transformer (50), the series coupling transformer (70) and the power electronics circuitry (60) pass.

There is provided a transformer system (10) for converting a grid voltage (V.sub.grid) to a regulated voltage (V.sub.regulated) and output the regulated voltage (V.sub.regulated) to a power line (30), the transformer system (10) comprising: a first transformer (40) configured to step down the grid voltage (V.sub.grid) to an unregulated voltage (V.sub.unregulated) and provide the unregulated voltage (V.sub.unregulated) at an output of the first transformer (40); a shunt coupling transformer (50) connected in parallel with the output of the first transformer (40) and further connected to power electronics circuitry (60); and a series coupling transformer (70) connected in series with the output of the first transformer (40) and further connected to the power electronics circuitry (60). The power electronics circuitry (60) adds, via the series coupling transformer, a conditioning voltage (V.sub.conditioning) in series to the unregulated voltage (V.sub.unregulated) to generate the regulated voltage (V.sub.regulated). The first transformer, the series coupling transformer and the shunt coupling transformer are housed in a single transformer tank (80), and the power electronics circuitry is housed in a power electronics enclosure (90) separate from the transformer tank. Each of the transformer tank and the power electronics enclosure comprises one or more openings (95) through which electrical connections (97) between the shunt coupling transformer (50), the series coupling transformer (70) and the power electronics circuitry (60) pass.

Provided are a coupled inductor and a power module including the coupled inductor. A coupled inductor includes: a magnetic core, a first winding and a second winding, where a first passage is formed in the magnetic core; a part of the first winding and a part of the second winding pass through the first passage, and the first winding crosses with the second winding outside the first passage. Another coupled inductor includes: a magnetic core, a first winding and a second winding, where the magnetic core has a first passage and a second passage in parallel, both run through the magnetic core from one end face thereof to another opposite end face, where the first winding and the second winding both penetrate the first passage and the second passage, such that differently-named terminals of the windings are located on the same end face of the magnetic core.

Provided are a coupled inductor and a power module including the coupled inductor. A coupled inductor includes: a magnetic core, a first winding and a second winding, where a first passage is formed in the magnetic core; a part of the first winding and a part of the second winding pass through the first passage, and the first winding crosses with the second winding outside the first passage. Another coupled inductor includes: a magnetic core, a first winding and a second winding, where the magnetic core has a first passage and a second passage in parallel, both run through the magnetic core from one end face thereof to another opposite end face, where the first winding and the second winding both penetrate the first passage and the second passage, such that differently-named terminals of the windings are located on the same end face of the magnetic core.

Methods and apparatus provide compensation for impedance changes in a network energized by an amplifier, such as a class E amplifier. In embodiments, bus voltage amplifier fundamental AC output voltage can be used to generate a feedback signal for adjusting impedance of one or more components in the network. In embodiments, the amplifier fundamental AC output voltage is determined from current to the load, wherein the load is coupled to the amplifier by an LCL impedance matching network.

Methods and apparatus provide compensation for impedance changes in a network energized by an amplifier, such as a class E amplifier. In embodiments, bus voltage amplifier fundamental AC output voltage can be used to generate a feedback signal for adjusting impedance of one or more components in the network. In embodiments, the amplifier fundamental AC output voltage is determined from current to the load, wherein the load is coupled to the amplifier by an LCL impedance matching network.

A phase shifting transformer for poly-phase alternating current includes source side terminals, load side terminals, an exciting unit, and a series unit. The exciting unit includes further coils that are magnetically coupled to primary coils and to the secondary coils of the exciting unit to provide further voltages. The further coils are connected in series between the source side terminals and the series unit, so that the voltages at the load terminals are combinations of the quadrature voltages and the further voltages with the source voltages, thus modifying the voltage phase displacement between the source side terminals and the load side terminals.

Provided are an inversely coupled inductor and a power module. The inversely coupled inductor includes a magnetic core, a first winding and a second winding, where a first passage is formed in the magnetic core; a part of the first winding and a part of the second winding pass through the first passage, and the first winding crosses with the second winding outside the first passage. The power supply module includes the above inversely coupled inductor, which is in turn stacked on, and electrically connected to, the packaged chip module. By arranging the two windings to cross with each other on the outside of the first passage of the magnetic core, the same type terminal (such as input pins or output pins) of the inversely coupled inductor can be located on the same side.

Provided are an inversely coupled inductor and a power module. The inversely coupled inductor includes a magnetic core, a first winding and a second winding, where a first passage is formed in the magnetic core; a part of the first winding and a part of the second winding pass through the first passage, and the first winding crosses with the second winding outside the first passage. The power supply module includes the above inversely coupled inductor, which is in turn stacked on, and electrically connected to, the packaged chip module. By arranging the two windings to cross with each other on the outside of the first passage of the magnetic core, the same type terminal (such as input pins or output pins) of the inversely coupled inductor can be located on the same side.

Provided are a coupled inductor and a power module including the coupled inductor. A coupled inductor includes: a magnetic core, a first winding and a second winding, where a first passage is formed in the magnetic core; a part of the first winding and a part of the second winding pass through the first passage, and the first winding crosses with the second winding outside the first passage. Another coupled inductor includes: a magnetic core, a first winding and a second winding, where the magnetic core has a first passage and a second passage in parallel, both run through the magnetic core from one end face thereof to another opposite end face, where the first winding and the second winding both penetrate the first passage and the second passage, such that differently-named terminals of the windings are located on the same end face of the magnetic core.