Electrical assembly

An electrical assembly, comprising:

• 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 plurality 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,
• wherein 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.

A method of operating an electrical assembly, the electrical assembly comprising:

• 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 plurality 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,
• wherein the method comprises the step of selectively operating 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.