Since a power converter including a modular multilevel converter uses a large number of cells each combining a plurality of switching elements and a DC capacitor, there is a problem of conduction loss due to the switching elements. The conduction loss is reduced by connecting a bypass circuit between terminals of each of the cells, controlling to open and close the switching element, and controlling to short-circuit the bypass circuit connected to the cell controlled to output zero voltage.

Power supply units (PSU) provide for digital current-sharing loop control to ensure output voltage regulation during dynamic load transients by (i) delaying an internal current signal to match a delay in a shared current signal, and (ii) controlling the output amplifier based on the shared current signal and the delayed local current signal to maintain the respective local DC electrical power in proportion to contributions by other ones of the more than one PSU to the shared DC electrical power and thereby avoid instability in dynamic response to a load transient induced by the power consuming component.

A hybrid rectifier is provided including a top diode for conducting current during a positive current portion of a line current, a top transistor connected in parallel to the top diode, a bottom diode for conducting current during a negative current portion of the line current, and a bottom transistor connected in parallel to the bottom diode. A hybrid-rectifier controller is connected to the top transistor and the bottom transistor for implementing a transistor control strategy such that, during the positive current portion of the line current, the top diode conducts current and the bottom transistor conducts current only when the line current is below a sinusoidal reference current. Similarly, during the negative current portion of the line current, the bottom diode conducts current and the top transistor conducts current only when the line current is above the sinusoidal reference current.

A hybrid rectifier is provided including a top diode for conducting current during a positive current portion of a line current, a top transistor connected in parallel to the top diode, a bottom diode for conducting current during a negative current portion of the line current, and a bottom transistor connected in parallel to the bottom diode. A hybrid-rectifier controller is connected to the top transistor and the bottom transistor for implementing a transistor control strategy such that, during the positive current portion of the line current, the top diode conducts current and the bottom transistor conducts current only when the line current is below a sinusoidal reference current. Similarly, during the negative current portion of the line current, the bottom diode conducts current and the top transistor conducts current only when the line current is above the sinusoidal reference current.

A hybrid rectifier is provided comprising a top diode for conducting current during a positive current portion of a line current, a top transistor connected in parallel to the top diode, a bottom diode for conducting current during a negative current portion of the line current, and a bottom transistor connected in parallel to the bottom diode. A hybrid-rectifier controller is connected to the top transistor and the bottom transistor for implementing a transistor control strategy such that, during the positive current portion of the line current, the top diode conducts current and the bottom transistor conducts current only when the line current is below a sinusoidal reference current. Similarly, during the negative current portion of the line current, the bottom diode conducts current and the top transistor conducts current only when the line current is above the sinusoidal reference current.

A hybrid rectifier is provided comprising a top diode for conducting current during a positive current portion of a line current, a top transistor connected in parallel to the top diode, a bottom diode for conducting current during a negative current portion of the line current, and a bottom transistor connected in parallel to the bottom diode. A hybrid-rectifier controller is connected to the top transistor and the bottom transistor for implementing a transistor control strategy such that, during the positive current portion of the line current, the top diode conducts current and the bottom transistor conducts current only when the line current is below a sinusoidal reference current. Similarly, during the negative current portion of the line current, the bottom diode conducts current and the top transistor conducts current only when the line current is above the sinusoidal reference current.

There is provided an electrolyser power system comprising: a transformer arrangement having: at least one primary winding connectable to an AC power source; and a plurality of secondary windings; a first rectifier arrangement comprising: an AC input connected to a first secondary winding of the transformer arrangement; and a first DC output; a second rectifier arrangement comprising: an AC input connected to a second secondary winding of the transformer arrangement; and a second DC output; and a plurality of discrete electrically coupled electrolyser modules, wherein each electrolyser module is electrically connected between the first and second DC outputs.

There is provided an electrolyser power system comprising: a transformer arrangement having: at least one primary winding connectable to an AC power source; and a plurality of secondary windings; a first rectifier arrangement comprising: an AC input connected to a first secondary winding of the transformer arrangement; and a first DC output; a second rectifier arrangement comprising: an AC input connected to a second secondary winding of the transformer arrangement; and a second DC output; and a plurality of discrete electrically coupled electrolyser modules, wherein each electrolyser module is electrically connected between the first and second DC outputs.

An energy supply device for supplying electric loads with electric energy, includes a DC link; a first mains connection to which a first AC voltage grid can be connected as intended; a first rectifier which is designed to rectify an AC voltage corresponding to an AC voltage across the first mains connection or based thereon and to feed the rectified voltage into the DC link; a second mains connection to which a second AC voltage grid can be connected as intended; a second rectifier which is designed to rectify an AC voltage corresponding to an AC voltage across the second mains connection or based thereon; a controllable DC-to-DC converter to a first side of which a voltage rectified by means of the second rectifier is applied, and a second side of which is connected to the DC link; a first current converter which is fed from the DC link and is designed to supply a first electric load with electric energy; a power measuring apparatus which is designed to measure electric power consumed at the first mains connection; and a control apparatus which has a data link to the power measuring apparatus and which is designed to control the DC-DC converter according to the electric power consumed at the first mains connection.

A converter station for the transmission of electrical power has a diode rectifier with a DC terminal and an AC terminal. At least one transformer is connected to the AC terminal. In order to render the converter station as compact as possible, the diode rectifier is arranged in an insulating material.