Winding connection for single phase two leg electric transformer

Claim 2

In a single-phase electric transformer having a two-legged magnetizable core and a plurality of inductively coupled winding coils on each leg of said core, said winding coils on each said core leg being radially superposed in concentric relation, an auxiliary winding comprising the innermost coil on each said core leg, said innermost coils having unequal numbers of turns and being connected in series circuit relation, a high voltage main winding comprising the outermost coil on each said core leg, said outermost coils having equal numbers of turns and being connected in parallel circuit relation, a low voltage main winding having two radially intermediate coils on each said core leg, each outer intermediate winding coil having equal numbers of turns and each inner intermediate winding coil having equal numbers of turns, and means cross-connecting the outer intermediate coil on each core leg in series with the inner intermediate coil on the other core leg and connecting said cross-connected series circuits in parallel to constitute said low voltage main winding, each adjacent pair of inner and outer intermediate winding coils having such turn relation that the sum of the flux linkages in each said series circuit is substantially the same.

Claim 3

A single-phase electric transformer of high transmission voltage rating comprising a magnetizable core having two active legs in substantially parallel spaced relation, and four inductively coupled winding coils on each said core leg, the coils on each said core leg being radially superposed in concentric relation, the radially innermost pair of coils on said legs having unequal numbers of turns and other similarly positioned pairs of coils having equal numbers of turns, means connecting said radially innermost pair of coils in series circuit relation to constitute an auxiliary winding of low current and voltage rating, means connecting the radially outermost pair of coils in parallel circuit relation to constitute a high voltage main winding, and means cross-connecting the outer intermediate coil on each core leg in a series circuit with the inner intermediate coil on the other core leg and connecting said series circuits in parallel to constitute a low voltage main winding, adjacent inner and outer intermediate coils on each said core leg having a differential turn relation sufficient to prevent the flow of circulating current within said low voltage main winding.

Claim 4

A single-phase electric transformer of high transmission voltage rating comprising a magnetizable core having two active legs in substantially parallel spaced relation, and four inductively coupled winding coils on each said core leg, the coils on each said core leg being radially superposed in concentric relation, the radially innermost pair of coils on said legs having unequal numbers of turns and other similarly positioned pairs of coils having equal numbers of turns, means connecting said radially innermost pair of coils in series circuit relation to constitute an auxiliary winding of low current and voltage rating, means connecting the radially outermost pair of coils in parallel circuit relation to constitute a high voltage main winding, and means cross-connecting the outer intermediate coil on each core leg in a series circuit with the inner intermediate coil on the other core leg and connecting said series circuits in parallel to constitute a low voltage main winding, adjacent inner and outer intermediate coils on each said core leg having a differential turn relation sufficient to prevent the flow of circulating current within said low voltage main winding.

Claim 5

An autotransformer according to claim 1 in which said high voltage and low voltage main windings are electrically connected to a common terminal.

Claim 6

A single phase electric power transformer comprising a magnetizable core having two legs in substantially parallel spaced-relation, at least four coils on each said leg radially superposed in concentric relation, the radially innermost coils on said legs being of low current-carrying capacity relative to the other coils and being of unequal numbers of turns, means connecting said innermost coils in series circuit relation to constitute a low power auxiliary winding, means connecting the radially outermost coils on said legs in parallel circuit relation to constitute a high voltage main winding, said high voltage main winding forming a loop circuit path for circulating current induced by ampere-turn unbalance in said series connected innermost coils, leakage flux due to said circulating current increasing the inductive reactance of said auxiliary winding, means connecting an inner intermediate coil on each said leg in series circuit relation with an outer intermediate coil on the other leg, said inner and outer coils on each leg having unequal numbers of turns, and means connecting said series circuits in parallel to constitute a low voltage main winding, the turn inequality of adjacent inner and outer intermediate coils compensating unequal change in leakage reactance of such coils on the respective core legs due to ampere turn unbalance of said series-connected innermost coils and providing the same total flux linkages through each said series circuit.

Claim 7

A single phase electric power transformer comprising a magnetizable core having two legs in substantially parallel spaced-relation, at least four coils on each said leg radially superposed in concentric relation, the radially innermost coils on said legs being of low current-carrying capacity relative to the other coils and being of unequal numbers of turns, means connecting said innermost coils in series circuit relation to constitute a low power auxiliary winding, means connecting the radially outermost coils on said legs in parallel circuit relation to constitute a high voltage main winding, said high voltage main winding forming a loop circuit path for circulating current induced by ampere-turn unbalance in said series connected innermost coils, leakage flux due to said circulating current increasing the inductive reactance of said auxiliary winding, means connecting an inner intermediate coil on each said leg in series circuit relation with an outer intermediate coil on the other leg, said inner and outer coils on each leg having unequal numbers of turns, and means connecting said series circuits in parallel to constitute a low voltage main winding, the turn inequality of adjacent inner and outer intermediate coils compensating unequal change in leakage reactance of such coils on the respective core legs due to ampere turn unbalance of said series-connected innermost coils and providing the same total flux linkages through each said series circuit.

Claim 8

An electric power transformer according to claim 4 wherein said low voltage and high voltage main windings have a common electrical terminal and are disposed in aiding voltage relation between their electrically remote terminals, said auxiliary winding being electrically isolated from said main windings.