A converter station has two line-commutated converters for energy transmission via a bipolar high voltage direct current transmission line. In a first operating mode of the converter station the two converters are electrically connected in an anti-parallel circuit to the same pole of the high voltage direct current transmission link and one of the converters is operated as a rectifier and the other converter is operated as an inverter in an network. In a second operating mode the two converters are connected to different poles of the high voltage direct current transmission link and both converters are operated as either rectifiers or inverters in the AC network. In both operating modes a station active power exchanged between the converter station and the AC network is controlled by active power specifications for converter active powers which are exchanged between the converters and the AC network.

A converter station has two line-commutated converters for energy transmission via a bipolar high voltage direct current transmission line. In a first operating mode of the converter station the two converters are electrically connected in an anti-parallel circuit to the same pole of the high voltage direct current transmission link and one of the converters is operated as a rectifier and the other converter is operated as an inverter in an network. In a second operating mode the two converters are connected to different poles of the high voltage direct current transmission link and both converters are operated as either rectifiers or inverters in the AC network. In both operating modes a station active power exchanged between the converter station and the AC network is controlled by active power specifications for converter active powers which are exchanged between the converters and the AC network.

A device for suppressing harmonic distortions at the output of variable frequency drive (VFD) comprising at least one passive harmonic filter (PHF) which has a set of storage elements and a set of inductive elements. Wherein said inductive elements are mounted on a magnetic core. Said PHF comprising at least two lines connected in parallel (parallel lines) with similar sets of elements.

Described technical solution expanding the possibility of operating the VFD/VSD with different frequencies of the supply voltage, and also allows to maintain the THD/TDD values within 5% regardless of active power fluctuations.

An apparatus for an alpha trim adjustment includes a phase delay circuit that creates a phase delay for a gate signal for a switching cycle. The gate signal is for a phase of a three-phase, phase shifted alternating current (AC) input of a multi-pulse motor drive powering a direct current (DC) motor. The apparatus includes an alpha trim circuit that modifies the phase delay with an alpha trim adjustment to create an adjusted phase delay for the switching cycle, a delay application circuit that applies the adjusted phase delay to the gate signal.

A plurality of uninterruptible power supplies of an uninterruptible power supply system controls start or stop of shared current supply from power converters to a load based on shared current commands, which indicate command values for determining a value of shared current to be supplied from the power converters of the plurality of uninterruptible power supplies to the load.

A plurality of uninterruptible power supplies of an uninterruptible power supply system controls start or stop of shared current supply from power converters to a load based on shared current commands, which indicate command values for determining a value of shared current to be supplied from the power converters of the plurality of uninterruptible power supplies to the load.

An apparatus for an alpha trim adjustment includes a phase delay circuit that creates a phase delay for a gate signal for a switching cycle. The gate signal is for a phase of a three-phase, phase shifted alternating current (AC) input of a multi-pulse motor drive powering a direct current (DC) motor. The apparatus includes an alpha trim circuit that modifies the phase delay with an alpha trim adjustment to create an adjusted phase delay for the switching cycle, a delay application circuit that applies the adjusted phase delay to the gate signal.

A system for controlling a plurality of power converters in a power system so as to turn each of the plurality of power converters into an ON state or an OFF state as a function of a sensed input power and a sensed output power such that one or more of the plurality of power converters in the ON state are operating in an optimal power efficiency range.

A plurality of uninterruptible power supplies of an uninterruptible power supply system controls start or stop of shared current supply from power converters to a load based on shared current commands, which indicate command values for determining a value of shared current to be supplied from the power converters of the plurality of uninterruptible power supplies to the load.

A plurality of uninterruptible power supplies of an uninterruptible power supply system controls start or stop of shared current supply from power converters to a load based on shared current commands, which indicate command values for determining a value of shared current to be supplied from the power converters of the plurality of uninterruptible power supplies to the load.