Patent GB-162961-A (GB)
Title: Improvements in and relating to electrical distribution and power transmission systems
IPC: H02P5/685
Filed: 1920-06-21
Abstract: 162,961. Igranic Electric Co., Ltd., (Cutler-Hammer Manufacturing Co.). June 21, 1920. Phase, changing; vapour and vacuum or low-pressure apparatus, arrangements of.-A station 1, Fig. 1, comprises an alternator G, the terminals of which are bridged by an impedance 9 or by the primary winding of a transformer. The mid-point of the impedance 9 is connected to earth, and its ends are connected to the anodes 12, 13 of an electrionic rectifier 11. The rectified current passes through a line resistance r, in order that the full voltage across the resistance may control the voltage of the grids 16, 17 to regulate automatically the line current. The line L is connected to the midpoint of an impedance 22 bridging the terminal of an alternator G<1> connected to section L<1> of the line through a rectifier 23. The current supply to the section L<1> is regulated by means of an electrionic device 27 connected in the field circuit of the alternator. The grid circuit of the device 27 contains a battery 32 and a regulating resistance r<1>. The current in the section L is passed to a second section L" through an electrionic device 37 having four anodes 38, 39, 40, and 41, four grids 43, 44, 45, and 46, and a single cathode 42. The potentials of the grids are raised successively and sequentially by means of a generator 48 and semi-circular slip rings 49, 50, 51, 52, thereby rendering the four paths of the device 37 successively conductive. The anodes 38 and 40 are connected to the terminals of the windings 35, 36 of a synchronous motor M, and, in order to maintain the current impulses supplied to the section L<11> of the same magnitude, batteries 55 and 56 are placed in the series with the anodes 39 and 41 to compensate for the voltage drop in the motor windings 35 and 36. In the modification shown in Fig. 2, the anodes of the electrionic device 80 are connected to the primary windings 81 - - 84 of a transformer T, the secondary windings 85 - - 88 of which supply two-phase current to a motor M<4>. The grids of the device are connected to displaced semicircular contacts 100 - - 103 connected to a generator 98, and a slip ring 99 is connected to the generator 98 and to the cathode 93. To reduce the oscillations of the continuous current fed to the line section L<11> from the device 80, a transformer t is provided having a secondary winding connected in each of the grid circuits of the device 80. In the arrangement shown in Fig. 5, a two-phase alternator G<2> supplies a continuous current to line L<2> through an electrionic rectifier 124. A second two-phase alternator G1<SP>2> supplies a continuous current to the line L<1> through a second electrionic rectifier 124<1>. The line L<2> is connected to earth through the primary winding of a transformer T', and this winding is adapted to be short-circuited periodically by onehalf of an electrionic device 133. The line L<1> is connected to earth through the primary winding 140 of the transformer T<1>, and this winding is adapted to be short-circuited periodically by the other half of the electrionic device 133. The secondary winding 142 of the transformer T<1> supplies a single-phase motor M<2>. The potentials of the grids 138, 139 of the device 133 are supplied by an alternator 134. In the arrangement shown in Fig. 6, an alternator G' is connected to the circuit L<3>, L<4> through a. rectifying device. Singlephase current is supplied to a motor M<8> from the circuit L<3>, L<4> through electrionic devices 150, 151, the anode circuits of which contain the primary windings 153, 154 respectively of a transformer T<2>, the secondary winding 155 of which is connected to the stator of the motor M . The potentials of the grids 158 of the devices 150, 151 are sequentially varied by means of an alternator 152, and are controlled by a transformer t<3>, the primary winding of which is in the stator circuit of the motor M<8> and is shunted by a resistance r.