. Report of the Electric Railway Test Commission to the president of the Louisiana Purchase Exposition . es show at once such items as rate of acceleration, max-imum speed, rate of coasting, and rate of braking. The power input to the car at any instant is shown by the line vol-tage and the current at that instant. The average power used by thecar can be deduced by averaging the instantaneous power, and maybe verified by a recording wattmeter. The schedule speed can also bededuced from the curve showing instantaneous speeds and can be veri-fied by the time and distance. The power input when th
. Report of the Electric Railway Test Commission to the president of the Louisiana Purchase Exposition . es show at once such items as rate of acceleration, max-imum speed, rate of coasting, and rate of braking. The power input to the car at any instant is shown by the line vol-tage and the current at that instant. The average power used by thecar can be deduced by averaging the instantaneous power, and maybe verified by a recording wattmeter. The schedule speed can also bededuced from the curve showing instantaneous speeds and can be veri-fied by the time and distance. The power input when the car is running at any uniform speed givesat once the train resistance for that speed. From the current input toany motor of the equipment and the voltage at its terminals, the electric INTRODUCTION 15 50-53C Current, Speeld and ■■ 1 1—1Time Curves. oFfn \ =-— A3-40O s ~A \ / SChLUL/Ln. orccD V 50-500 \ 1 1 \ \, ^^ i ^0-500 1 N ^^ A ^PER E5 F ER( :a5^ ^ 1 .^ ^ ^ 10; 100 1 1 4^% L ^^ ^ ^ \ 40 80 1^0 160 200 240 230 520 360 SECONDS Fig. 1. —Currents, Speed and Time Z 3 4 3 6 7 HOURS Fig. 2. — Time Temperature Curves. 16 ELECTRIC RAILWAY TEST COMMISSION losses which take place in this motor can be readily found. These in-stantaneous losses, averaged for the time of the entire cycle, give theaverage losses which determine the heat input. By running the car backwards and forwards, over a given track re-peating as nearly as possible each time a given cycle of accelerationmaximum speed, coasting, braking, and duration of stop, a conditionsimilar to actual service is obtained. The temperature of the variousparts of the various motors can then be measured at intervals untilthese temperatures become constant, which indicates that the heatingeffect of the current introduced into the motors is just balanced by thecooling effect due to the speed of the car. A time and temperaturecurve can then be plotted showing the rise in temperature of the motorsduring the run until
Size: 2152px × 1161px
Photo credit: © Reading Room 2020 / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookauthorlouisian, bookcentury1900, bookdecade1900, bookyear1906
