A power supply, including a primary pre-converter, coupled to supplying mains, configured to receive an AC voltage at low frequency and output a high DC voltage, and further configured to receive the high DC voltage and to output the alternating current; a primary converter, disposed on a primary side of the power supply, coupled to the high DC voltage from the primary pre-converter; an isolating transformer to receive the high frequency AC voltage and output a high frequency secondary AC voltage, and to receive a high frequency secondary AC current and to output primary high frequency AC current; and an output converter, on a secondary side of the power supply, wherein the output converter is configured to receive high frequency AC voltage from the isolating transformer and to output a DC voltage of a first or second polarity to an output, and wherein the output converter is configured to receive DC current of a first or second direction from the output and to output a high frequency AC current to the isolating transformer.

A method and apparatus for secondary side current mode control of a converter are provided. In the method and apparatus, an output voltage of the converter is detected, where the converter has primary and secondary windings that are galvanically isolated in respective primary and secondary sides. A secondary control signal is generated in the secondary side based at least in part on the output voltage and a reference voltage. The secondary control signal is converted to a primary control signal provided in the primary side. The converter is driven in the primary side based at least in part on the primary control signal and a current sense signal indicative of a current flowing through the primary winding.

A power supply, including a primary pre-converter, coupled to supplying mains, configured to receive an AC voltage at low frequency and output a high DC voltage, and further configured to receive the high DC voltage and to output the alternating current; a primary converter, disposed on a primary side of the power supply, coupled to the high DC voltage from the primary pre-converter; an isolating transformer to receive the high frequency AC voltage and output a high frequency secondary AC voltage, and to receive a high frequency secondary AC current and to output primary high frequency AC current; and an output converter, on a secondary side of the power supply, wherein the output converter is configured to receive high frequency AC voltage from the isolating transformer and to output a DC voltage of a first or second polarity to an output, and wherein the output converter is configured to receive DC current of a first or second direction from the output and to output a high frequency AC current to the isolating transformer.

A power reception device 3 includes: an estimation circuit 28 estimating a load resistance of an entire contactless power feed apparatus 1; and a reception-side communicator 27 transmitting an estimated value of the load resistance of the entire contactless power feed apparatus 1 to a power transmission device 2. The power transmission device 2 has a power supply circuit 11 supplying AC power to a transmission coil 12 supplying power to the power reception device 3. The power transmission device 2 further includes a control circuit 18 decreasing an input/output gain of a transmission-side DC-DC converter 31 included in the power supply circuit 11 by a predetermined amount when the estimated value of the load resistance is less than a predetermined allowed lower limit, and maintaining or increasing the input/output gain when the estimated value of the load resistance is equal to or greater than the predetermined allowed lower limit.

A method and apparatus for secondary side current mode control of a converter are provided. In the method and apparatus, an output voltage of the converter is detected, where the converter has primary and secondary windings that are galvanically isolated in respective primary and secondary sides. A secondary control signal is generated in the secondary side based at least in part on the output voltage and a reference voltage. The secondary control signal is converted to a primary control signal provided in the primary side. The converter is driven in the primary side based at least in part on the primary control signal and a current sense signal indicative of a current flowing through the primary winding.

A passive boost network configured to boost and output an AC power signal having a predetermined frequency, can include: an input port; an output port configured to provide the AC power signal; first and second passive components coupled in series between first and second terminals of the input port; a third passive component coupled in series with the second passive component between first and second terminals of the output port; and where the first passive component is one of a capacitor and an inductor, and the second and third passive components are each the other of the capacitor and the inductor.

A vehicle includes an engine and alternator having a field coil and a plurality of output windings, a field current controller configured to receive an AC input and convert the AC input into a regulated DC output that is supplied to the field coil of the alternator, and a controller configured to monitor at least one operating parameter of the field current controller and to compare a monitored value of the at least one operating parameter to a threshold range.

A power supply, including a primary pre-converter, coupled to supplying mains, configured to receive an AC voltage at low frequency and output a high DC voltage, and further configured to receive the high DC voltage and to output the alternating current; a primary converter, disposed on a primary side of the power supply, coupled to the high DC voltage from the primary pre-converter; an isolating transformer to receive the high frequency AC voltage and output a high frequency secondary AC voltage, and to receive a high frequency secondary AC current and to output primary high frequency AC current; and an output converter, on a secondary side of the power supply, wherein the output converter is configured to receive high frequency AC voltage from the isolating transformer and to output a DC voltage of a first or second polarity to an output, and wherein the output converter is configured to receive DC current of a first or second direction from the output and to output a high frequency AC current to the isolating transformer.

A method and apparatus for secondary side current mode control of a converter are provided. In the method and apparatus, an output voltage of the converter is detected, where the converter has primary and secondary windings that are galvanically isolated in respective primary and secondary sides. A secondary control signal is generated in the secondary side based at least in part on the output voltage and a reference voltage. The secondary control signal is converted to a primary control signal provided in the primary side. The converter is driven in the primary side based at least in part on the primary control signal and a current sense signal indicative of a current flowing through the primary winding.

A power supply system for arc furnace is described. The power supply system includes a power converter and a polyphase transformer. The power supply system further includes first disconnecting means connecting the input of the power converter to the primary circuit, second disconnecting means connecting the output of the power converter to the primary circuit, and the power supply system further includes a control circuit configured to control the power converter to supply the electrode and to stabilize the courant and the voltage delivered by the grid to reduce reactions in the grid when the first disconnecting means are open and the second disconnecting means are closed, and to control the power converter to stabilize the courant and the voltage delivered by the grid to reduce reactions in the grid when the first disconnecting means are closed and the second disconnecting means are open.