This disclosure includes novel ways of implementing a power supply that powers a load. A main battery source produces a main battery voltage; each of multiple auxiliary battery sources in a set produces a respective auxiliary battery voltage. A controller initially sets a battery supply voltage to the main battery voltage, the main battery voltage is supplied to a power converter. The controller then monitors a magnitude of the battery supply voltage and adjusts the battery supply voltage supplied to the power converter based on a comparison of the magnitude of the battery supply voltage with respect to a threshold level. The adjusted battery supply voltage is provided from a serial connection of the main battery source and a first auxiliary battery source in the set.

A method of operating a thyristor-based line-commutated multi-phase power converter on a multi-phase AC voltage connection point, which is supplied by an AC voltage network. Between the AC voltage connection point and an AC voltage connection of the power converter, a series circuit of modules is arranged for each phase. Each of the series circuits has a first electronic switching element, a second electronic switching element, and an electric energy storage device. The voltages of the phases of the AC voltage connection point are measured and, if an undervoltage is detected on a phase of the AC voltage connection point, an additional voltage adding to the voltage of that phase is generated by way of the series circuit of modules allocated to that phase in such a way that the voltage of that phase is increased, at least temporarily.

A DC-DC auto-converter module includes a positive source terminal, a negative source terminal, a positive load terminal, a negative load terminal, and a DC-DC converter. The negative source terminal cooperates with the positive source terminal to facilitate electrical connection of a DC power source thereto. The negative load terminal cooperates with the positive load terminal to facilitate connection of an electrical load thereto. The isolated DC-DC converter comprises an input circuit and an output circuit that is galvanically isolated from the input circuit. The DC-DC converter includes a positive input terminal, a negative input terminal, a positive output terminal, and a negative output terminal. At least one of the positive input terminal, the negative input terminal, the positive output terminal, and the negative output terminal is galvanically connected to at least one of the positive source terminal, the negative source terminal, the positive load terminal, and the negative load terminal.

An alternating-current (AC) voltage regulator including an isolated power supply, a control circuit, an amplifier, and an output. The isolated power supply is configured to receive an input voltage and output a direct-current (DC) signal isolated from the input voltage. The control circuit is configured to adjust a portion of the input voltage, and output an adjusted voltage. The amplifier is configured to output a differential signal. The differential signal is based on at least one selected from a group consisting of the isolated DC signal, the adjusted voltage, and a feedback loop. The output is configured to add the differential signal to the input voltage resulting in a regulated voltage, and output the regulated voltage.

An electronic brushless variable transformer. Variable autotransformers, use brushes, and as such, have moving parts requiring maintenance and periodic cleaning of the brushes. A variable transformer without brushes is advantageous in that it eliminates the cleaning and maintenance of brushes.

A bi-directional DC-DC converter assembly that processes and transfers differential power in a variable manner is disclosed. The converter assembly is coupled to an energy storage device and DC link, with the converter assembly including a first converter section coupled to the energy storage device and a second converter section coupled to the DC link and to the energy storage device. The converter assembly processes a first portion of the DC power output of the energy storage device and provides an unprocessed second portion of the DC power output of the energy storage device to the second converter section when providing power to the load, and processes a first portion of a regenerative power from the load and provides an unprocessed second portion of the regenerative power from the load to the first converter section when providing regenerative power to the energy storage device.

A power converter arrangement is described. The power converter includes a dc link and a power converter. The dc link is operably connected between a generator, or other power source, that provides an output voltage in use and a dc network. The power converter includes an inverter connected across the dc link in parallel with the generator, an isolation transformer having a primary tap changer and a secondary tap changer, and a rectifier. The rectifier has ac terminals connected to the secondary tap changer, a first dc terminal connected to the dc link, and a second dc terminal connected to the dc network. The dc terminal voltage of the rectifier is therefore summated with the output voltage of the generator to provide a converter output voltage.

A circuit arrangement for providing a DC voltage in a vehicle and a method for operating the circuit arrangement. The circuit arrangement includes at least one secondary-sided inductance of a vehicle-sided pick-up portion for receiving a magnetic field and for producing an electric output voltage, at least one rectifier for rectifying the output voltage of the at least one inductance, and at least one source element or drain element. The rectifier and the source element are connected such that an output voltage of the circuit arrangement is a sum of an output voltage of the rectifier and an output voltage of the source element or the rectifier and the drain element are connected such that an output voltage of the circuit arrangement is a difference between an output voltage of the rectifier and an input voltage of the drain element.

Apparatus for power conversion are provided. One apparatus includes a power converter including an input circuit and an output circuit. The power converter is configured to receive power from a source for providing power at a DC source voltage V.sub.S. The power converter is adapted to convert power from the input circuit to the output circuit at a substantially fixed voltage transformation ratio K.sub.DC=V.sub.OUT/V.sub.IN at an output current, wherein V.sub.IN is an input voltage and V.sub.OUT is an output voltage. The input circuit and at least a portion of the output circuit are connected in series across the source, such that an absolute value of the input voltage V.sub.IN applied to the input circuit is approximately equal to the absolute value of the DC source voltage V.sub.S minus a number N times the absolute value of the output voltage V.sub.OUT, where N is at least 1.

A power controller for an AC power converter connected in series with a load and receiving power from or delivering power to a power source, the power controller comprising: a radial control block controlling a radial component of an electrical parameter of the AC power converter; and a chordal control block controlling a chordal component of the electrical parameter of the AC power converter. Also provided is a power system comprising one or more loads each connected in series to a power converter each controlled by a power controller as described above. There is also provided a method of controlling an AC power converter connected in series with a load and receiving power from a power source, the method comprising: controlling a radial component of an electrical parameter of the AC power converter; and controlling a chordal component of the electrical parameter of the AC power converter.