The proposed transformer control device is based on the magnetization principle and includes a voltage comparator unit, intermediate amplifiers and power amplifiers The introduction of an additional intermediate amplifier and the connection of the inputs of the intermediate amplifiers in series opposition makes it possible to separately magnetize each yoke of the transformer The separate magnetization of the transformer yokes instead of their differential magnetization substantially reduces the no-load current of the transformer, brings down the mean power required to control the magnetization of the yokes in the continuous voltage adjustment range, and thus raises the transformer's efficiency

Transformer control device

An AC regulator controls the voltage applied to a load by using pulse-width-modulated correction signals. Any deviation of load voltage from that desired is sensed and converted to pulse-widthmodulated signals. These signals switch alternate halves of a secondary winding of a transformer connected in a buck-boost arrangement. The net voltage applied to the secondary winding is a function of the pulse-width modulation and a net correction voltage is coupled to the primary winding which is series connected between line and load. The invention also has application to line transient generation because of the overall high speed of response of the circuit.

Buck-boost pulse-width-modulated line regulator

Unsaturating saturable core transformer

Servo system controlled by electrical signals

1,067,067. Transformers. STABILAC PTY. Ltd. May 12,1964 [May 21, 1963], No. 19752/64. Heading HIT. [Also in Division H3] In a static induction regulator comprising two saturable transformers provided with input power windings in series across an A.C. power line and output power windings in series opposition with each other, even harmonic feedback windings shunted by rectifying elements are provided on each transformer and control currents are applied to control windings on each transformer in such sense that as the output voltage from one transformer increases the output voltage from the other transformer decreases. In the arrangement of Fig. 1 (not shown) and Fig. 2, each transformer has a divided or separate pair of flux paths 6A, 6B and 11A, 11B respectively and the input power windings 3A, 3B, 3C, 3D and 8A, 8B, 8C, 8D are wound in four sections to form a parallel arrangement on each transformer, the two parallel arrangements being connected in series. Rectifiers (7), (12) are connected between points on the two input power windings 3, 8 respectively of equal potential with respect to fundamental frequencies and odd order harmonics so as to form even harmonic feedback windings. By applying appropriate control currents to control windings 5A, 5B and 10A, 10B the sum of the individual input winding saturation voltages is made equal to or slightly lower than the line voltage and as a result of the constant voltage characteristics of each transformer the voltage across each will be equal to the line voltage. An alternative arrangement of windings on the saturable transformers is as in Fig. 7 (not shown), wherein input power windings (3), (8) and output windings (4), (9) are wound on the centre legs of two shell type lamination structures and the control windings (5A), (5B) and (10A), (10B) are wound on the outer legs and are shunted by rectifiers to act as even harmonic feedback windings. Separate control and even harmonic feedback windings may be used.

Transformer control device

References

Buck-boost pulse-width-modulated line regulator

Unsaturating saturable core transformer

Servo system controlled by electrical signals

Static induction regulator employing transformers with even-harmonic feedback

Related Papers (5)

Dc-ac inverter having controlled magnetization reversal of isolation transformer core

Power transformer voltage regulation by core flux biassing - using feedback control network which generates biassing currents through auxiliary windings on transformer core

Transformer for direct and/or alternating currents

Zero-voltage/zero-current switching type dc-dc converter

Shifting coil type compensation transformer