GB1146033A - Improvements in or relating to synchronous generator sets - Google Patents

Abstract

1,146,033. Automatic control of voltage and current. ELEKTRO - BAU A. G. March 31, 1966 [April 5, 1965], No. 14235/66. Heading G3R. [Also in Division H2] The Specification describes the stabilization of voltage and current of a synchronous generator set including a controller 11 and a synchronous exciter machine feeding the field winding 9 of a synchronous main generator via rectifiers 8 in which the exciter machine has field poles, each having associated with it a respective permanent magnet 1 and at least one exciting winding 2, 3 supplied by the controller 11 so that one or each exciting winding provides a controllable magnetic field. The field of the exciter machine can be varied by adjusting the current through the windings 2, 3 or by adjusting the position of a permanent magnet 1 arranged to slide within each pole Fig. 2 (not shown). The current through each winding 2, 3 is varied by a controller 11 which is connected to the secondary windings 13, 14 of a current transformer having its primary winding 12 connected in series with the stator winding of the main generator between the output terminals UV. The output from the generator may be rectified. Control circuits. Controller 11 may consist of circuits having variable resistors, rectifiers and Zener diodes to provide an adjustable current through the winding 2 Figs.4 and 6 (not shown). Alternatively Fig. 8 (not shown), winding 2 may be provided with a voltage stabilized by a Zener diode (31) and winding 3 may be provided with an adjustable voltage. Stabilization of voltage and current. A transistorized controller Fig. 10 (not shown), for maintaining the main generator output voltage constant and in addition a circuit Fig. 12 limiting the current drain from the generator as well as stabilizing the output voltage are described. The required generated voltage is set by potentiometer 30 and when the output voltage across UV tends to rise the Zener diode 31 conducts, which causes transistor 38 to conduct and alter the field produced by the winding 2 so as to stabilize the output voltage. In a similar manner, transistor 39 which is controlled by winding 14 of the transformer adjusts the field produced by the winding 2 so as to limit the maximum current drawn from the generator. The transistors 38, 39 may be connected in series with a resistor or the bias winding 15 of the transformer and across the winding 2 and a transistor may be used for short circuiting the resistor. The circuits include current limiting resistors 36, 37 and the rectifier circuits 26 may include controlled rectifiers controlled in dependence on voltage and current so as to replace the transistors 38, 39. Also the potentiometers 30 may be formed by bridge circuits consisting of linear or non-linear resistors.