This power supply device includes: a power interconnection path connecting a power interconnection port to a power conversion unit via a first switch; a stand-alone power supply path leading from an auxiliary input port via a second switch to an output port to which a load is connected; a storage-battery-side power supply path leading from a storage battery via the power conversion unit to the output port; and a control unit, the control unit causing the power conversion unit to charge/discharge the storage battery when interconnected with a commercial power grid, the control unit supplying power to the load via one of the stand-alone power supply path and the storage-battery-side power supply path when disconnected from the commercial power grid, the control unit switching the power supply path from the one to the other within an extremely short time period such as not to influence the load.

There is provided an electrical assembly for use in a power transmission network. The electrical assembly includes a converter including terminals for connection to an electrical network, where the first terminal is a DC terminal. The assembly also includes a DC power transmission medium connected to the DC terminal, and a circuit interruption device including switching element(s) and an energy absorption element, each switching element being switchable to divert a flow of current in the DC power transmission medium through the energy absorption element in order to reduce the flow of current in the DC power transmission medium; The assembly also includes a converter control unit programmed to operate the converter to control a DC voltage at the DC terminal in a leakage current reduction mode to control a voltage across the energy absorption element.

There is provided an electrical assembly for use in a power transmission network. The electrical assembly includes a converter including terminals for connection to an electrical network, where the first terminal is a DC terminal. The assembly also includes a DC power transmission medium connected to the DC terminal, and a circuit interruption device including switching element(s) and an energy absorption element, each switching element being switchable to divert a flow of current in the DC power transmission medium through the energy absorption element in order to reduce the flow of current in the DC power transmission medium; The assembly also includes a converter control unit programmed to operate the converter to control a DC voltage at the DC terminal in a leakage current reduction mode to control a voltage across the energy absorption element.

A power supply control device includes a control unit, and a power path that is connected to a primary external power system. If a connection state between the primary external power system and the power path is in a disconnected state, the control unit is configured to control power output of at least one power conditioner of at least one corresponding secondary external power generation unit, based on (a) an amount of power consumption of a specific load connected to the power supply control device through the power path, and (b) a power generation output of the secondary external power generation unit.

A power supply control device includes a control unit, and a power path that is connected to a primary external power system. If a connection state between the primary external power system and the power path is in a disconnected state, the control unit is configured to control power output of at least one power conditioner of at least one corresponding secondary external power generation unit, based on (a) an amount of power consumption of a specific load connected to the power supply control device through the power path, and (b) a power generation output of the secondary external power generation unit.

The invention provides the system supporting variable speed drive comprising a three-sided service cabinet embodiment. The cabinet comprising two heat exchange circuits limited by the basic elements of the cabinet embodiment, the first of which is configured to interact with an external environment and with the second heat exchange circuit, wherein the second heat exchange circuit which is configured without an ability to interact with the external environment includes a sealed cell for installing power electronics and the cell for installing a power connection and the cell for installing a measurement equipment. The cabinet comprising a dust and moisture filter, a plate heat exchanger, and a moisture removal device. The cabinet may be assembled with joined end-to-end metal sheets with curved joined ends which form strengthening ribs. The system supporting variable speed drive further comprising a cell for installing a passive filter or a filter compensation device or a capacitor bank preconfigured for compliance with variable speed drive and configured in such a way that it is dismountable in a form of a cabinet of the same height and depth as the cabinet of variable speed drive and closely aligned with the cabinet of variable speed drive. The cell for installing a power connection located on a side of the cell for installing a passive filter or a filter compensation device or a capacitor bank, wherein all connections between the cabinet of variable speed drive and the cell for installing a passive filter or a filter compensation device or a capacitor bank are made in the internal part of the embodiment.

The invention provides the system supporting variable speed drive comprising a three-sided service cabinet embodiment. The cabinet comprising two heat exchange circuits limited by the basic elements of the cabinet embodiment, the first of which is configured to interact with an external environment and with the second heat exchange circuit, wherein the second heat exchange circuit which is configured without an ability to interact with the external environment includes a sealed cell for installing power electronics and the cell for installing a power connection and the cell for installing a measurement equipment. The cabinet comprising a dust and moisture filter, a plate heat exchanger, and a moisture removal device. The cabinet may be assembled with joined end-to-end metal sheets with curved joined ends which form strengthening ribs. The system supporting variable speed drive further comprising a cell for installing a passive filter or a filter compensation device or a capacitor bank preconfigured for compliance with variable speed drive and configured in such a way that it is dismountable in a form of a cabinet of the same height and depth as the cabinet of variable speed drive and closely aligned with the cabinet of variable speed drive. The cell for installing a power connection located on a side of the cell for installing a passive filter or a filter compensation device or a capacitor bank, wherein all connections between the cabinet of variable speed drive and the cell for installing a passive filter or a filter compensation device or a capacitor bank are made in the internal part of the embodiment.

A downhole tool and a method for operating the downhole tool are disclosed. A first power signal is supplied to the downhole tool from a power source at a first frequency. A bidirectional chopper at the downhole tool chops the first power signal to generate a second power signal having a second frequency greater than the first frequency. The second power signal is used to operate the downhole tool.

A downhole tool and a method for operating the downhole tool are disclosed. A first power signal is supplied to the downhole tool from a power source at a first frequency. A bidirectional chopper at the downhole tool chops the first power signal to generate a second power signal having a second frequency greater than the first frequency. The second power signal is used to operate the downhole tool.

A voltage source converter (VSC) system of a high-voltage direct current (HVDC) system is disclosed. The system includes a number of line-commutated converter (LCC) transformers. Each LCC transformer is operable to transform alternate current (AC) voltage. A number of VSC converter units are connected in series and coupled to the plurality of LCC transformers. Each VSC converter unit is operable to convert between the AC voltage and direct current (DC) voltage. A bypass breaker is connected in parallel with at least one of the VSC converter units and operable to be closed to bypass the at least one VSC converter unit.