. Electrical world. FIG. I.—SUB-ST.\TI0X .\T ,30 cycles. Since the consolidation of these three plants a compro-mise frequency of 63 cycles has been adopted. At Shawinigan Falls there are installed two 3,750-kw generatorsoperating at 180 revolutions and 30 cycles and generating 2,300 voltsof two-phase current. By means of transformers the two-phase•current is changed to three-phase current of 55,000 volts, which FIG. 2.—FIVE FREQUENCY CH.\XGERS .VT MOXTRE.\L. from 44,000 volts to 2,300 volts. The five groups of frequencychangers which are clearly shown in Fig. 2, change the curren
. Electrical world. FIG. I.—SUB-ST.\TI0X .\T ,30 cycles. Since the consolidation of these three plants a compro-mise frequency of 63 cycles has been adopted. At Shawinigan Falls there are installed two 3,750-kw generatorsoperating at 180 revolutions and 30 cycles and generating 2,300 voltsof two-phase current. By means of transformers the two-phase•current is changed to three-phase current of 55,000 volts, which FIG. 2.—FIVE FREQUENCY CH.\XGERS .VT MOXTRE.\L. from 44,000 volts to 2,300 volts. The five groups of frequencychangers which are clearly shown in Fig. 2, change the currentfrom 2,300 volts three-phase 30 cycles to 2,300 volts three-phase 60 cycles. As the picture shows, the frequency changersare set in a row with their shafts parallel. The machine on theleft is (he 30-cycIc motor: the machine to the right is the 60-cycIe. FIG. 3.—ONE OF THE I065-KW. FREQUEXCV-CHANGER UNITS. is transmitted from Shawinigan to Maisonneuve, a distance of 85miles. In the sub-station at Maisonneuve, a suburb of 30-cycle, three-phase current is stepped down from 44,000 voltsto 2,300 volts. The long-distance line between Shawinigan Fallsand Maisonneuve is the longest line east of the Rocky Mountains, generator; the exciter which is shown on the right-hand side of theset serves as starting motor and also excites the two rating of each set is 1,068 kw at 2,300 volts 60 cycles. 100 percent, power factor, or 800 kw at 75 per cent, power factor. Thespeed of the frequency changers is 450 revolutions, the motor being Februarv 13, 1904. ELECTRICAL WORLD and ENGINEER. 309 an 8-poIe machine, the generator a i6-pole machine. Fig. 3 showsone of the sets. The stationarj armatures can be moved parallelto the shaft so as to expose the armature and fields for inspection
Size: 2135px × 1170px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1800, bookdecade1880, booksubjectelectri, bookyear1883
