US707334A - System of distribution. - Google Patents

Description

No. 707,334. Patented Aug. 19,v |902. JgF. KELLY.

SYSTEM 0F DISTRIBUTION.

(Application led May 20, 1902.)

(No Model.)

UNITED STATES PATENT OFFICE.

JOHN F. KELLY, OF PITTSFIELD, MASSACHUSETTS.

SYSTEM OF DISTRlBUTlON.

SPECEFIGATION forming 'part or Ietters atent No. 707,334, dated August 19, 1902'.

Application filed May 20,1902. Serial No. 108,160. (No model.)

To @ZZ wto'nt t muy concern:

Beit known that I, JOHN F. KELLY, a citizen of the United States, residing at Pittsiield, in the county of Berkshire, State of Massachusetts, have invented certain new and useful Improvements in Systems of Distribution, of which the following is a full, clear, and exact description.

My invention relates to systems of distribution by alternating currents, and has for its object to provide a means for supplying alternating currents to circuits containing arc-lamps or other devices reacting in a similar manner Without disturbing' the main generating source.

At the present time there are a variety of Ways of supplying arc-lamps from constantpotential circuits, all of which lead to the introduction of self-induction into the local supply-circuit connected to the mains, and consequently to very low power factors, especially at light loads. In some of these systems a self-induction coil more or less 4variable is placed in series with the arc-lamps, the whole series being in parallel with the ordinary constant -potential transformers. In others self-regulating constant-potential constant-currenttransformersare used. The power factor in both these arrangements is, however, low at all times and extremely low at light loads. Now it is well known that an alternating-current generator may be made so as to maintain automatically a constant current in a circuit of varying impedance, the speed of the generator being constant, and I make use of this fact in connection with my invention, since I have discovered that by using such a generator and operating it by an alternating-current motor, preferably of the synchronous type, supplied from constant-potential mains, the power factor in the series circuit will be prevented from reacting on the main circuit, the system operating just as it would if the motors carried any other kind of variable load.

The system may be either polyphase or single phase, the corresponding changes in the motor and generator not affecting the principle of its operation.

My invention is illustrated in the accompanying drawings, in which- Figure l represents a system embodying my invention. Figs. 2 and 3 represent means heretofore used for supplying arc-lamps in series from constant-potential mains.

Referring more particularly to the drawings, A represents a two-phase alternatingcurrent generator supplying a constant potential to the mains l 2 3 4.

B represents a two-phase motor of the ordinary synchronous type supplied from the constant-potential mains l 2 3 4.-. y

C represents a single-phase alternatingcurrent generator so constructed as to maintain a constant current upon the circuit D when operated at a constant speed.

D is the circuit containing the arc-lamps E in series.

F F are two ordinary constant-potential transformers supplying incandescent lamps in parallel.

Upon an examination of this system it will be seen that the synchronous motor B will maintain thespeed of the generator C constant and will act like any other motorunder varying loads, giving such power factors as would normally correspond to the rating with any ordinary load. The load on the motor will,

however, be substantially proportional to the number of translating devices in circuit on the series generator, and this latter' will maintain a constant current for the series devices. lt will further be seen that although the power factor in the series circuit will be low at light loads, this power factor is prevented from reacting on the main circuit, since the connection with the main circuit is a mechanical and not an electrical one, and the motor operates just as it would with any corresponding load of a mechanical nature. If devices are used, such as shown in Figs. 2 and 3, in which G is a variable in duction-coil for maintaining the current in the series circuit constant and His a self-regulating constant-potential constant-current transformer, the low-power factor of the series circuit is either directly or indirectly impressed upon the mains with corresponding disturbances of the system, which by my invention are done away with.

Nhat I claim is- 1. In a system of distribution, the combination of a constantpotential alternatingcurrent generator', [an alternating-current IOO motor connected in parallel thereto and a constant-current generator operated by said motor supplying translating devices in series.

2. In a system of distribution, the combination of a constant-potential generator, a synchronous motor supplied thereby, a constant-current generator operated by said motor and supplying translating devices in series.

3. In a system of distribution, the combination of a constant-potential generator, a synchronous alternating-current motor supplied thereby, an alternating-constant-current generator operated by said motor and supplying translating devices in series.

4. In a system of distribution, the combination of a polyphase constant-potential generator, a polyphase synchronous motor oper- May, 1902.

JOHN F. KELLY. Witnesses:

L. VREELAND, H. B. BROWNELL.

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