When an abnormality occurs in a first voltage detector (4a), a control circuit (7) in an uninterruptible power supply device controls an inverter (3) in synchronization with an output signal (VI2D) from a second voltage detector (4b) to match a phase of a two-phase AC voltage (VO1, VO2) output from the inverter (3) with a phase of a two-phase AC voltage (VI1, VI2) supplied from a commercial AC power supply (51), and then turns on a semiconductor switch pair (S9, S10) and a bypass switch pair (S7, S8). Accordingly, even when an abnormality occurs in the first voltage detector (4a), the two-phase AC voltage can be supplied to a load (53) without instantaneous interruption.

A DC/DC converter, including a piezoelectric element; a first switch, coupling a first electrode of the piezoelectric element to a first terminal of application of a first voltage; a second switch, coupling the first electrode of the piezoelectric element to a first terminal of supply of a second voltage; and at least one third switch connecting the first electrode to a second electrode of the piezoelectric element, said switches being cyclically controlled, at an approximately constant frequency with, between each turning-on of one of the switches, a phase where all switches are off.

A DC/DC converter, including a piezoelectric element; a first switch, coupling a first electrode of the piezoelectric element to a first terminal of application of a first voltage; a second switch, coupling the first electrode of the piezoelectric element to a first terminal of supply of a second voltage; and at least one third switch connecting the first electrode to a second electrode of the piezoelectric element, said switches being cyclically controlled, at an approximately constant frequency with, between each turning-on of one of the switches, a phase where all switches are off.

An electrical converter includes an inverter configured to provide at least one input AC voltage from an input DC voltage (VE). The electrical converter further includes an AC-to-AC voltage converter configured to provide an output AC voltage from the at least one input AC voltage such that the output AC voltage has an amplitude that depends on a frequency of the at least one input AC voltage. A rectifier is configured to provide an output DC voltage from the output AC voltage.

A power converter to convert power between a first converter voltage at a first converter port and a second converter voltage at a second converter port is presented. It contains a first capacitor network, an inductor and a first switching matrix to arrange the first capacitor network and the inductor within different states. One of the states is a bypass state enabling current to flow from the first converter port or from ground through the first capacitor network to the second converter port without going through the inductor. Another state is an inductor state enabling current to flow from the first converter port or from ground through the inductor to the second converter port. The power converter also includes a control unit to control the first switching matrix repeatedly in a recurrent sequence of the different states.

A power converter to convert power between a first converter voltage at a first converter port and a second converter voltage at a second converter port is presented. It contains a first capacitor network, an inductor and a first switching matrix to arrange the first capacitor network and the inductor within different states. One of the states is a bypass state enabling current to flow from the first converter port or from ground through the first capacitor network to the second converter port without going through the inductor. Another state is an inductor state enabling current to flow from the first converter port or from ground through the inductor to the second converter port. The power converter also includes a control unit to control the first switching matrix repeatedly in a recurrent sequence of the different states.

An inverter for a photovoltaic apparatus, said inverter comprising a DC electric bus having a plurality of electric lines forming corresponding DC input channels for said inverter. The inverter comprises a choke filter comprising a single magnetic circuit and a plurality of choke windings enchained with said magnetic circuit. Said choke windings are electrically connected in series with corresponding line conductors of said electric lines, which have a same voltage polarity. Said choke windings are arranged so that AC electric currents flowing along said choke windings generate magnetic fluxes having concordant directions. In a further aspect, the invention relates also to a choke filter for a DC electric bus of a photovoltaic apparatus.

A DC charging circuit includes a first inverter module corresponding to a first battery; a second inverter module corresponding to second battery; and DC terminals tapping off a high-side of the first inverter module and a low-side of the second inverter module. A front-end switching circuit is also described. The front-end switching circuit controls charging input from a DC source to at least one inverter circuit, each inverter circuit corresponding to at least one respective battery. The front-end switching circuit is an add-on for interfacing to high voltage DC inputs.

A DC charging circuit includes a first inverter module corresponding to a first battery; a second inverter module corresponding to second battery; and DC terminals tapping off a high-side of the first inverter module and a low-side of the second inverter module. A front-end switching circuit is also described. The front-end switching circuit controls charging input from a DC source to at least one inverter circuit, each inverter circuit corresponding to at least one respective battery. The front-end switching circuit is an add-on for interfacing to high voltage DC inputs.

An electrical converter includes an inverter configured to provide at least one input AC voltage from an input DC voltage. The electrical converter further includes an AC-to-AC voltage converter configured to provide an output AC voltage from the at least one input AC voltage such that the output AC voltage has an amplitude that depends on a frequency of the at least one input AC voltage. A rectifier designed is configured to provide an output DC voltage from the output AC voltage.