Control arrangement for converter
AssigneeFried. Krupp Gesellschaft mit beschrankter Haftung
InventorHerbert Seeger
Life of this patent
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Abstract
A control arrangement for a converter of the type including a direct current motor driving a three-phase generator with at least one exciter coil of the generator and/or of the motor being fed from the three-phase mains of the generator via a series connected transformer and a rectifier. At least one secondary winding of the transformer is connected in a closed series circuit which further includes a controlled thyristor, and two other secondary windings of the transformer which other windings are connected in parallel. In dependence on the parameter of the converter to be regulated, the control current of the thyristor is varied to provide a two-point regulation of the saturation current for the transformer flowing through the closed series circuit.
Claims9
In combination with a converter including a direct current motor having at least one exciter coil, a three-phase generator driven by said motor and having at least one exciter coil, and a circuit including a three-phase transformer, whose input is connected to the three-phase mains connected to the output of said generator, and a series connected three-phase rectifier, for feeding current to at least one of said exciter coils;
- a control means for controlling a selected parameter of said converter, said control means comprising in combination:
- at least one closed circuit including the series connection of a secondary winding of said transformer, a controlled thyristor, and two further secondary windings of said transformer which are connected in parallel with each other;
- and means responsive to said selected parameter for varying the control current of said thyristor to provide a two-point regulation of any saturation current for said transformer flowing through said closed circuit.
The apparatus of claim wherein:
- said selected parameter is the number of revolutions of said three-phase current generator;
- said exciter coil is an exciter coil of said d.c. motor;
- said transformer is a three-phase voltage transformer having three primary windings which are connected to the three-phase mains and are connected in a Y;
- said rectifier has its inputs connected to secondary windings of said transformer and its output connected to said exciter coil of said d.c. motor;
- said at least one closed circuit includes two diodes each of which being connected in series with each of the said two further secondary windings of said transformer which are connected in parallel with each other;
- and said means for varying the control current of said thyristor includes means for producing a d.c. voltage proportional to the number of revolutions of said three-phase generator, a first Zener diode connected to the control electrode of said thyristor, and circuit means connected to said d.c. voltage producing means and said first Zener diode for causing said thyristor to be quenched when the number of revolutions of said generator rises to a given value.
Dependencies are inferred from the claim text.