. The street railway review . synchronous motors direct connected to constant continuous currentdynamos. Continuous current stationary motors <lraw power fromthe lines through step-down transformers and rotaryconverters, like the load. For the 2,200 circuits that sup-ply service transformers for commercial arc and incandescent light-ing the transmitted energy passes through step-down transformersand synchronous motor-generators. These motor-generators raisethe frequency from 25 to 60 cycles per second. Finally the con-tinuous current three-wire system for incandescent
. The street railway review . synchronous motors direct connected to constant continuous currentdynamos. Continuous current stationary motors <lraw power fromthe lines through step-down transformers and rotaryconverters, like the load. For the 2,200 circuits that sup-ply service transformers for commercial arc and incandescent light-ing the transmitted energy passes through step-down transformersand synchronous motor-generators. These motor-generators raisethe frequency from 25 to 60 cycles per second. Finally the con-tinuous current three-wire system for incandescent lighting atabout 250 volts between outside wires is operated through step-down transformers and synchronous motors direct connected tocontinuous current generators. For this last named service rotaryconverters were at first tried, but were ;ound to lie impracticablebecause voltage fluctuations on the transmission line, due largely tothe railway and motor loads, were reproduced on the continuous cur- s \ \ \ i \ \ \ \ \ ymiMi. \\\ \\^ \\\ \\\ Sfisrierrv SUB-STATION TRANSFER Switches Put .y Pi>wer Line Onto Any Outgoing rent circuits by the rotary converters Since the adoption of motorgenerators this fluctuation of the service voltage is no longerpresent. Another case in which synchronous motor-geneiators deliverpower from a transmission line that carries both a lighting and amotor load is that of the Shawinigan sub-station in Montreal. Atthis sub-station the 85-mile transmission line from the generatingplant at Shawinigan Falls terminates. .As already pointed-out, thisline is composed of a single three-phase circuit of aluminum con-ductors, each of which has a cross-section of 183,750 circular the Montreal sub-station the ,10 cycle, three-phase current fromShawinigan Falls is delivered to transformers that lower the voltageto 2,300. The current then goes to five synchronous motor-generat-ors of 1,200 horse power capacity each, and is there conv
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Keywords: ., book, bookcentury1800, bookdecade1890, booksubjectstreetrailroads
