GB242145A - Improvements in and relating to electrical power transmission systems - Google Patents

Abstract

242,145. Zßvada, B. March 14, 1925. Dynamos and motors combined for transmitting power; equalizing load on generator. - In a power transmission system comprising a direct current. generator G<1> supplying energy to a reversible motor j<1> and means for regulating the voltage of the generator throughcut a range of positive and negative values, a prime mover A' is coupled to an asynchronous alternating current machine C<1> electrically connected to the power supply and coupled to the generator G<1> and so regulated that when the generator is under no load or low loads the asynchronous machine C<1> acts automatically to feed the line r<1>, s<1>, t<1> but otherwise acts as a motor fed by the line to assist the prime mover A<1> in driving the generator G<1>. A fly-wheel B<1> for taking up part of suddenly increased loads may be enclosed in a fluid-tight casing that is exhausted or filled with rarified gas or steam. The prime mover A<1> may be a reciprocating engine or a turbine, and the fly-wheel may be omitted. An adjustable resistance, c<1> for regulating the slip of the asynchronous machine C<1> may also be used to compensate lag of phase. The operations of switching, interrupting or stopping to regulate the slip may be controlled by a relay or motor responsive to the current and voltage of the machine C<1>. A single exciter D<1> may be used for several machines. The generator G<1> may be disconnected from its driving shaft when C<1> is acting on a generator to supply energy to the bus bars R', S', T'. The stuffing-boxes for the shaft of the fly-wheel contain a fluid packing. In the form shown in Fig. 3, smooth or ribbed discs w on the fly-wheel shaft rotate in compartments partly filled with fluid, which they set in motion so as to form fluid rings or seals capable of sustaining a difference of pressure. In another form the stuffing-boxes are formed as centrifugal pumps with one or more stages, which maintain a circulation of fluid from the inside of the fly-wheel casing to the outside. The fluid may be mercury or oil. The latter may be circulated for lubricating purposes.