Patent ID: 6249443
Filing Date: 2001-06-19
Classification: H01F,H02M

Abstract:
An autotransformer for converting three-phase AC power provided on first, second and third supply lines to nine-phase AC power on first through ninth output lines, the autotransformer comprising:a. first, second and third coils arranged such that there is 120 degree phase shift between coils, each coil including a plurality of serial windings linked together to form a polygon;b. a step-up input set including first, second and third input nodes between adjacent windings and separated by 120 degrees, the first, second and third input nodes linkable to the first, second and third supply lines, respectively; andc. first through ninth output nodes between adjacent windings which are linkable to the first through ninth output lines, respectively;d. wherein, the voltage magnitude at each of the nodes is measured by a vector between a neutral point and the node, the windings are sized and arranged such that the phase shift between adjacent output nodes is essentially 40 degrees, the voltage magnitudes at each of the output nodes are essentially identical, the voltage magnitudes at each of the step-up input set nodes are essentially identical and each step-up input node voltage magnitude is less than each output node voltage magnitude such that the transformer can be used as a step-up transformer.