9. ELECTRIC MACHINERY A. DIRECT-CURRENT MACHINES NOTES ON Modern eleCTRIC RAILWAY PRACTICE Albert H. Armstrong Vol. xviii-1901, pp. 589-601 Consideration of the requirements of different classes of electric railway service leading up to a discussion of the relative merits of directcurrent series and induction motors for interurban and trunk line operation. Discussion, incorporated with that of paper by Ernst J. Berg on “Electric Railway Apparatus." A VARIABLE RELUCTANCE METHOD OF MOTOR SPEED CONTROL G. Fred Packard Vol. xix-1902, pp. 1131-1141 Reference to earliest work in this direction. Description of the Johnson method of varying the reluctance at the pole face, while maintaining the commutating fringe. Performance tests and flux distribution curves of a Stow motor built on these principles. Discussion, pp. 1142-1143, by Messrs. Chas. P. Steinmetz, William Esty, G. Fred Packard, P. H. Thomas and E. B. Raymond. N. W. Storer THREE-WIRE SYSTEM FOR VARIABLE SPEED MOTOR WORK Vol. xx-1902, pp. 127-133 Description of the operation of adjustable speed motors from threewire generator, giving advantages of the system and the range of speed variation when combined field and armature control are used. Discussion, incorporated with that of paper by F. O. Blackwell on "Continuous Current Motors for Machine Tools." F. 0. Blackwell CONTINUOUS-CURRENT MOTORS FOR MACHINE TOOLS Vol. xx-1902, pp. 159-165 Power characteristics and requirements of various classes of machine tools. Brief mention of the different methods of speed control of electric motors and the advantages and limitations of each. Discussion (including that of paper by R. T. E. Lozier on "The Operation of Machine Shops by Individual Electric Motors"; paper by N. W. Storer on "Three-Wire System for Variable Speed Motor Work"; paper by H. B. Coho on "The Storage Battery as a Factor in Speed Control"; paper by P. O. Keilholtz on "Electrically Operated Coat Hoist Having Variable Speed Control"; paper by Geo. W. Fowler on "A Series-Parallel System of Speed Control;" and paper by H. Ward Leonard on "Multiple-Unit, Voltage Speed Control for Trunk Line Service"), pp. 166-195, by Messrs. Gano S. Dunn, Chas. F. Scott, H. E. Heath, S. T. Dodd, Arthur Williams, Philip Lange, Chas. Day, R. T. E. Lozier, N. W. Storer, Barr, R. H. Pierce, Peter Junkersfeld, O. E. Osthoff, D. C. Jackson, B. J. Arnold, G. B. Foster, Ernest Gonzenbach, V. R. Lansingh, H. H. Cutler, E. J. Pearson and H. R. King. Relative merits of various methods of speed control of direct-current motors. Conditions which determine the choice between individual and group drive. Effects of motor drive and suitable speed control on shop efficiency. Advantages and disadvantages of the Ward-Leonard system of locomotive driven from single-phase circuits. METHODS OF SPEED CONTROL Wm. Cooper Vol. xx-1902, pp. 197-213 Outline of the general power requirements of the different classes of machine tools. Description of method of choosing proper size of motor for given service and speed range from a speed horse-power diagram for combining multiple-voltage and field regulation; numerical examples. Set of general rules for determining motor size. No discussion. THE FACTORS WHICH AFFECT THE ENERGY LOSSES IN ARMATURE CORES J. Walter Esterline and C. E. Reid Vol. xxii-1903, pp. 445-460 Description of apparatus for experimental investigation of armature core losses. Analysis of core losses and results of tests showing effect of teeth, core section, solid poles, laminated poles and other factors of such losses. Discussion, pp. 461-466, by Messrs. J. W. Esterline, Henry Pikler, W. E. Goldsborough, W. S. Franklin, Leonard Wilson, C. O. Mailloux and A. E. Kennelly. Effect of number of poles and of pole arc upon armature core losses. PRE-DETERMINATION OF SPARKING IN DIRECT-CURRENT MACHINES W. L. Waters Vol. xxiii-1904, pp. 365-378 Early methods of designing commutator machines, followed by development of sparking constant for different types of series and shunt-wound machines. Discussion, incorporated with that of paper by E. H. Anderson on "Effect of Self-Induction on Railway Motor Commutation." EFFECT OF SELF-INDUCTION ON RAILWAY MOTOR COMMUTATION E. H. Anderson Vol. xxiii-1904, pp. 379-391 Experimental study of commutation with oscillographic records of pressures between commutator segments under various conditions and of potential rise in field and armature windings due to interruption and restoration of power at free running speeds. Discussion (including that of paper by W. L. Waters on "Predetermination of Sparking in Direct-Current Machines"), pp. 443-457, by Messrs. W. L. Waters, E. R. Douglas, R. B. Treat, Thorburn Reid, E. H. Anderson, W. S. Franklin, Clarence P. Feldman and H. Ward Leonard. General remarks on commutation reaction and predetermination of the limitation of commutation. LIMITS OF INJURIOUS SPARKING IN DIRECT-CURRENT COMMUTATION Thorburn Reid Vol. xxiv-1905, pp. 611-642 Mathematical investigation of destruction of commutator surface based on the theory that all injury results from contact surface energy due to current density and sliding friction. Equations for determining maximum energy density and maximum temperature rise. Derivation of equations given in the appendix. Discussion, pp. 643-648, by Messrs. Gano S. Dunn, Charles P. Steinmetz, W. L. Waters, Thorburn Reid and J. N. Dodd. General remarks on contact energy theory of damage done by commutation. Sebastian Sentius LIMITATIONS IN DIRECT-CURRENT MACHINE DESIGN Vol. xxiv-1905, pp. 689-712 Development of a system of design based upon experimental data and commercial guarantees, with investigation of the limits imposed by commutation difficulties. Discussion, pp. 713-716, by Messrs. Gano S. Dunn, W. L. Waters, Charles P. Steinmetz and Sebastian Sentius. Actual limits in size of direct-current machines. Factors which modify author's conclusions. C. H. Bedell DIRECT-CURRENT MOTOR DESIGN as influeNCED BY THE USE Vol. xxv-1906, pp. 329-339 Flux distribution curves taken from interpole motors. Some factors in the design of interpoles and advantages from their use. Discussion, pp. 340-348, by Messrs. H. F. T. Erben, C. H. Bedell, W. L. Waters, N. J. Neall, S. Sentius, S. S. Wheeler, David Hall, L. D. Nordstrum and Chas. P. Steinmetz. General remarks on the advantages of interpoles on constant and adjustable speed shunt motors, turbo-generators and series railway motors. E. H. Anderson COMMUTATING-POLE DIRECT-CURRENT RAILWAY MOTORS Vol. xxvi-1907, pp. 1407-1417 Brief review of troubles encountered in the design of railway motors, leading up to commutation which is treated more in detail. Theory of action of commutating poles in series motor and possibilities as to voltage and service capacity which it introduces into direct-current railway engineering. Discussion, pp. 1418-1419, by Messrs. Gano Dunn, J. C. Lincoln, E. H. Anderson and W. N. Smith. Flashing and creeping distances on 600-volt ordinary and 1200-volt commutating pole railway motors. Brent Wiley CHARACTERISTICS OF MOTORS FOR LARGE SHEARS Vol. xxvii-1908, pp. 321-334 Discussion of the characteristics of different types of direct-current and alternating-current motors for driving large bloom shears, with actual load curves and full data of the machines tested. No discussion. CALCULATION OF IRON LOSSES IN DYNAMO ELECTRIC MACHINERY I. E. Hanssen Vol. xxviii-1909, pp. 993-1001 Experimental study of stream lines in various types of armatures, with a simple method for predetermining the total iron loss. Discussion, pp. 1002-1004, by Messrs. R. E. Hellmund, A. E. Averett, V. Karapetoff and I. E. Hanssen. Remarks on the accuracy of the author's method. POLE-FACE LOSSES C. A. Adams, A. C. Lanier, C. C. Pope and C. O. Schooley Vol. xxviii-1909, pp. 1133-1156 Theoretical and experimental investigation of pole-face losses, establishing quantitative relations between such losses and the principal variables for both solid and laminated pole shoes. Comparison of calculated losses with test values. No discussion. ACYCLIC (HOMOPOLAR) DYNAMOS J. E. Noeggerath Vol. xxiv-1905, pp. 1-18 Theory of operation of various types of homopolar generators with brief description of the design features, the construction and the performance characteristics of an actual turbo-homopolar generator. Discussion, pp. 19-27, by Messrs. F. B. Crocker, A. E. Kennelly, C. Cartwright, F. V. Henshaw, J. E. Noeggerath, H. E. Heath, W. H. Pratt, G. H. Stickney and C. M. Green. General remarks on the advantages and limitations of the homopolar generator. B. SYNCHRONOUS MACHINES Ernst J. Berg Vol. xviii-1901, pp. 603-630 Discussion of the characteristics and limitations of generators, converters, motor-generators and motors for different kinds of electric railway service. Extended consideration of the relative merits of directcurrent series, and polyphase induction motors in a given numerical instance, comparing performance, efficiency and cost. Discussion (including that of paper by Albert H. Armstrong on "Notes on Modern Electric Railway Practice"), pp. 631-666, by Messrs. Paul Janet, Chas. P. Steinmetz, G. Gillon, Chas. Janisch, Bion J. Arnold, C. O. Mailloux, E. P. Roberts, L. B. Stillwell, A. H. Pott, C. F. Scott, P. K. Stern, H. C. Spaulding, F. S. Holmes, Ernst J. Berg, A. H. Armstrong and N. C. Sawers. General remarks on the stability of the induction motor for traction purposes. PARALLEL RUNNING OF ALTERNATORS Ernst J. Berg Vol. xviii-1901, pp. 753-757 Development of equation covering the principles of parallel operation of alternators, showing the effect of armature reaction, the cause of hunting and remedy. Discussion, incorporated with that of paper by W. I. Slichter on “Angular Velocity in Steam Engine in Relation to Paralleling of Alternators." A METHOD OF COMPOUNDING ALTERNATING-CURRENT GENERATORS AND MOTORS, DIRECT-CURRENT GENERATORS, SYNCHRONOUS MOTOR-GENERATORS Frank George Baum AND SYNCHRONOUS CONVERTERS Vol. xix-1902, pp. 745-757 Description of original methods of compounding alternating-current generators, synchronous motors, direct-current generators, synchronous converters, synchronous motor generators and transmission systems. Use of the Baum regulation diagram. Discussion, incorporated with that of paper by Chas. P. Steinmetz on "Notes on the Theory of the Synchronous Motor." NOTES ON THE THEORY OF THE SYNCHRONOUS MOTOR Chas. P. Steinmetz Vol. xix-1902, pp. 781-801 Development of the phase characteristics of the synchronous motor, followed by analytical investigation of electro-mechanical resonance or surging and the conditions which determine the stability of a synchronous motor. Discussion (including that of paper by Frank George Baum on “A Method of Compounding Alternating-Current Generators and Motors, Direct-Current Generators, Synchronous Motor-Generators and Synchronous Converters"; paper by M. LeBlanc on "Formula for Calculating |