An electrical assembly includes a converter-based electrical device and a transformer for connecting the converter-based electrical device to an AC electrical network, a first transformer side of the transformer connected to the converter-based electrical device, a second transformer side of the transformer for connection to the AC electrical network, the transformer including a number of taps, the transformer including a tap changer operable to selectively connect to the or each tap to modify a turn ratio of the transformer. The transformer includes a controller configured to selectively operate the tap changer in an AC voltage modification mode, responsive to an abnormal operating state of the electrical assembly, to modify the turn ratio of the transformer so as to modify an AC voltage at the first transformer side.

The multi-voltage control assessor for providing a set of standard voltages useful in testing electrical devices and systems is disclosed. The Multi-Voltage Control Assesor (MVCA) is a portable, small suitcase sized device containing transformers, switches, safety devices and cabling that, when operated safely by a competent person, can provide common voltages to power controls, relays and small devices intended for troubleshooting purposes. It can also temporarily substitute for a control transformer for a critical device, as necessary. It is not recommended for this to be a full time use, only until a suitable replacement can be installed.

Disclosed are a grid-connected power conversion system and a control method thereof. The grid-connected power conversion system includes a fuel cell stack generating a DC voltage, a power conversion system (PCS) converting the DC voltage supplied from the stack into an AC voltage, a multi-input transformer including a primary coil having a plurality of voltage input terminals and a secondary coil transforming a magnitude of the voltage applied to the primary coil and outputting the transformed voltage, the plurality of voltage input terminals determining the number of turns of the primary coil differently from each other, one of the plurality of voltage input terminals receiving the AC voltage converted in the PCS, and a controller selecting the one of the plurality of voltage input terminals of the multi-input transformer based on the magnitude of the DC voltage generated from the stack and determining whether to replace the stack.

A static-neutralization system includes a plurality of alternating current (AC) static bars that is coupled to a common, high-voltage power supply. The power supply includes a transformer that steps up AC mains electricity to deliver high-voltage, AC power to the static bars. A monitoring circuit is provided in the power supply that determines the ionization current of the static bars through isolation of the second harmonic of the total load current. By monitoring the ionization current, the power supply can identify when the ion generation efficiency of the static bars falls beneath a user-defined threshold. The monitoring circuit additionally determines the discharge voltage of the static bars through isolation of the fourth harmonic of the total output voltage. By monitoring the discharge voltage, a voltage-suppression circuit can suspend delivery of power to the static bars upon detecting a full-discharge event, which often results from dielectric breakdown.

A static-neutralization system includes a plurality of alternating current (AC) static bars that is coupled to a common, high-voltage power supply. The power supply includes a transformer that steps up AC mains electricity to deliver high-voltage, AC power to the static bars. A monitoring circuit is provided in the power supply that determines the ionization current of the static bars through isolation of the second harmonic of the total load current. By monitoring the ionization current, the power supply can identify when the ion generation efficiency of the static bars falls beneath a user-defined threshold. The monitoring circuit additionally determines the discharge voltage of the static bars through isolation of the fourth harmonic of the total output voltage. By monitoring the discharge voltage, a voltage-suppression circuit can suspend delivery of power to the static bars upon detecting a full-discharge event, which often results from dielectric breakdown.

An apparatus for a load tap changer includes a first primary winding electrically connected to a first contact, the first contact configured to connect to one of a plurality of taps in a load tap changer; a second contact, the second contact configured to connect to one of the plurality of taps in the load tap changer; a magnetic core; and a control circuit including: a secondary winding configured to magnetically couple to the first primary winding and the magnetic core; and an electrical network electrically connected to the secondary winding, the electrical network being configured to prevent magnetic saturation of the magnetic core during switching of the first or second contact.

Systems and methods for an alternating current (AC) input selection for a power transformer are disclosed. In particular, a connector is provided that is pre-wired to utilize internal wiring in the power transformer to provide a desired connection. A first option allows two transformers' input winding to be in series while a second option allows the two transformers' input winding to be in parallel. By moving the wiring into the connector, installation is simplified as the wiring has already been done. The installer need only attach the correct plug based on the desired voltage and couple the plug to the transformer. Further, the manipulation of thick wires is also avoided by the installer, further simplifying the installation process.

Systems and methods for an alternating current (AC) input selection for a power transformer are disclosed. In particular, a connector is provided that is pre-wired to utilize internal wiring in the power transformer to provide a desired connection. A first option allows two transformers' input winding to be in series while a second option allows the two transformers' input winding to be in parallel. By moving the wiring into the connector, installation is simplified as the wiring has already been done. The installer need only attach the correct plug based on the desired voltage and couple the plug to the transformer. Further, the manipulation of thick wires is also avoided by the installer, further simplifying the installation process.

A generator control unit includes a plurality of permanent magnet generator (PMG) inputs, a transformer including a multi-configuration input winding and at least one output winding. Each PMG input in the plurality of PMG inputs is connected to the multi-configuration input winding at a corresponding input winding input.

The present disclosure is intended to provide a smaller laser oscillator that can be manufactured at a reduced cost. Provided is a laser oscillator for producing a laser beam, the laser oscillator including: a housing; a transformer arranged in the housing, connected to a power supply, and supplying power to a first device that consumes a predetermined amount of power; and a power factor correction unit arranged in the housing, having a power factor correction circuit that brings a power factor close to 1, connected to the power supply, and supplying power to a second device that consumes a relatively larger amount of power than the first device.