. Railway and locomotive engineering : a practical journal of railway motive power and rolling stock . first put into commercial use on the Chicago,Milwaukee and St. Paul, 3,000-volt freight to Fig. 1, which shows the regenerative con-nections of one-half of one of these locomotives, the ex-citer is so connected that the exciter armature currentis the sum of the motor field current and the regeneratedcurrent. Control of the exciter field is obtained by meansof a motor operated rheostat, automatically controlled by 216 August, 1926 RAILWAY AND LOCOMOTIVE ENGINEERING 217 a
. Railway and locomotive engineering : a practical journal of railway motive power and rolling stock . first put into commercial use on the Chicago,Milwaukee and St. Paul, 3,000-volt freight to Fig. 1, which shows the regenerative con-nections of one-half of one of these locomotives, the ex-citer is so connected that the exciter armature currentis the sum of the motor field current and the regeneratedcurrent. Control of the exciter field is obtained by meansof a motor operated rheostat, automatically controlled by 216 August, 1926 RAILWAY AND LOCOMOTIVE ENGINEERING 217 a current limit relay, which is connected in the exciterarmature circuit. The current limit relay thus is respon-sive to the sum of the motor armature and field currents.•Control of the braking speeds is obtained by changing thesetting of the current limit relay by means of the brakinghandle on the master controller. Compensation for sudden surges in current, due tochanges in line voltage or grade, is obtained by a com-bination of several factors, the differential series field (^0y(^cA?y c^3. Fig. 1—Regenerat nections for one-halfFreight Locomotive I of the exciter, the exciter armature reaction and the re-sistance drop in the exciter armature circuit. For ex-ample, assume a sudden decrease in line voltage. Thiswill tend to rapidly increase the regenerated current andconsequently the current through the exciter compensating factors will then operate as follows:the differential series field and the exciter armature re-action will tend to weaken the exciter field and reducethe exciter voltage, thus reducing the motor field the increased resistance drop will cause the exciterarmature circuit to absorb more of the exciter voltage and. thus further reduce the field current and generated voltageof the traction motors. Likewise a sudden decrease inregenerated current will be compensated for in just theopposite manner. Thus the inherent characteristi
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Keywords: ., bookcentury1900, bookdecade1900, booksubjectrailroa, bookyear1901
