Patent GB-190227486-A (GB)
Title: Improved Means for Controlling, or Regulating, the Supply of Electricity in Installations Subjected to Considerable Fluctuation in the Demands thereon.
Inventor: JOHNSON JAMES YATE
Filed: 1902-12-12
Granted: 1903-10-29
Abstract: 27,486. Johnson, J. Y., [Elektricitõts Akt.-Ges). Dec. 12. Motors, controlling.-Relates to methods of regulating the action of "buffer" machines, consisting of motors with heavy flywheels, which are used in the electric driving of winding-machines, rolling- mills, &c., and in other systems subject to demands which vary considerably, the object being to utilize in the electric form, when the demands are great, the energy stored in heavy rotating masses when the demands are small. In the continuous-current system shown in Fig. 1, current is supplied from mains B, C to lamps L and a motor M. The buffer machine P and its field winding N are connected across the mains. A generator Z, mechanically coupled to the motor P, is also arranged across the mains, and has its field winding n excited from any current source through a hand-operated or automatic regulator R, by means of which the voltage of the generator Z is varied. Or the excitation of the generator Z may, by suitable compounding, be made dependent upon the outer circuit. The current taken or given out by the machine P can in this arrangement be regulated within limits by suitably altering the voltage of the generator Z. A machine which generates a counter-electromotive force at starting may be used instead of starting-resistances in connection with the motor M. Fig. 3 shows a system in which the continuous current for the motor M is supplied by a transformer consisting of a three-phase motor D and a generator G- having an inertia mass. The voltage of the generator G may be regulated during the starting- period of the motor M, or a starting-machine A, generating a voltage counter to that of the generator G, may be employed. In addition to the primary rotating field of the motor D, a secondary field, rotating in the same or in the opposite direction, is induced by current supplied from the generator d of an auxiliary motorgenerator m, d to the armature of the motor D. The two field windings n, h of the motor mare arranged, one in parallel with the terminals of the generator G and the other in the main current circuit of the motor M, so that increased current through the winding h increases the speed of the motor-generator m, d in the case when the fields of the motor D rotate in one direction. The result of the increased speed is to reduce the speed of the motor-generator D, G, so that the inertia masses give out energy. Similarly, reduced current in the winding h reduces the speed of the motor-generator m, d, and increases that of the motor-generator D, G. Similar but increased effects are produced by altering the direction of one of the fields of the motor D. Auto-transformers may be used in place of the motor-generators, and hand or automatic regulation of the auxiliary transformer may be used instead of the direct action of the working-current described above. In some cases, the stored energy is not converted into the electric form ; for example, the motors of universal rolling-mills may be provided directly with inertia masses, the action of which is regulated as described.