US1401682A - Electrical distributing system - Google Patents

Description

LLIWUWULIJ G. FACCIOL'I. ELECTRICAL DISTRIBUTINGSYSTEM.

APPLICATION FILED NOV, 26. I920;

Patented Dec, 27, 1921.

Fig.3.

Inventor: Giuseppe F'a c: cioli,

His Attorney.

* UNITED STATES PATENT orrice QIUSEPIE FACCIOLI, OF PITTSFIELD, MASSACHUSETTS, ASSIGNOR T0 GENERAL ELEC- TRIC COMPANY, A CORPORATION OF NEW YORK.

ELECTRICAL DISTRIBUTING SYSTEM.

Specification of Letters Patent.

Patented. Dec. 27, 1921;

Application filed November 26, 1920. Serial No. 426,360.

To all whom it may concern:

Be it known that I, GIUsEPPn FACOIOLI, a citizen of the United. States, residing at Pittsfield, in the county of Berkshire, State of, Massachusetts, have invented certain new and useful Improvements in Electrical Distributing Systems, of which the following is a specification.

My invention relates to electrical distributing systems, and has for its object an improved arrangement of parts for controlling the same. Y

More particularlymy invention relates to three-wire systems supplying distributing transformers, and provides improved connections therefor, by which the loads on the distributing transformers may be selected by a simple switching operation at the central station.

Where distributingtransformers on threewire systems have a variety of loads thereon, as where there is a lighting load and a power load, it may occur that approximately maximum values of both loads are thrown on the system at substantially the same time. By reason of the different natures of the loads it is generally assumed that maximum values of the two loads will not occur simultaneously, but theexpe-rience of central station operators is that twosuch loads invariably overlap in the course of the days run and during such overlapping period, or period of the so-called peak load, the supply system and its transformers may easily become overloaded.

By my invention this occurrence is made impossible for Iemploy a novelarrangement of thetransformers and connections which enables the central station operator or load despatcher to select at will by a simple switching operation, which load is to be supplied with power.

For a more complete understanding of the nature and objects of my invention reference should be had to the following detailed description taken in connection with the accompanying drawing, in which Figure 1 shows in diagrammatic fashion an electrical distributing system provided with my invention; Fig. 2 shows the same system in which the central station switch has been shifted to cut out one of the loads; Fig. 3shows-in similar fashion a system embodying a modified arrangement of parts,

while Figs. 4:, 5 and 6 show portions of such a s stem.

eferring now to the drawin s, A and B represent the windings on the secondary or supply side of two main transformers, here assumed to be at the central station. The windings A and B supply the three feeders 10, 11 and 12 with electricalenergyacross which are connected the primaries P and P of two distributing transformers whose secondaries S and S supply the loads on the system. The two primaries P and P are connected so as to have the feeder 11 in common, the secondaries being similarly connectedto their loads through the distributing wires 20, 21 and 22. The loads on the secondaries are indicated as of two kinds, a power load being shown at 25 and lighting loads at 26 and 26 respectively.

The power load 25 as shown in Fig. 1 is shown as a pure resistance and is connected cross the two secondaries S and S in series without connection to the common return wire'21. The power load indicated at 25, however, need not be a pure resistance but may be any load presumably having characteristics as to constancy, durationand time of demand which differ from the characteristics of the lighting loads at 26 and 26'. Such loads may be series lighting loads, as indicated at 25 in Fig. 5. or motor loads, as are indicated at 25" in Fig. 6. t

The lighting loads 26 and 26 are individually connected across the secondaries S and S. the load 26 being connected to wires 20 and 21 to be across secondary S while load 26 is connected to wires 21 and 22 to be across secondary S The switching device for cutting out at will, what in the instance illustrated is the power load 25, comprises a reversing switch for changing the polarity of one of the main transformers with respect to the feeders at 10, 11 and 12. A two-throw reversing switch K is connected across feeders 11 and 12 and has its poles 30, 31 and 32 connected to the terminals of the supply winding of the main transformer B. The pole 30 1s electrically connected to pole 31 so that in one position of switch K pole 31 is connected to feeder 11 and pole 32 to feeder 12 while in the other position pole 32 is connected to feeder 11 and pole 30 (or its equivalent pole 31) to feeder '12. This latter position of the switch K is shown in F ig.2, the'forrner being shown r and d as in series. In this position it is therefore seen that there is an E. M. F. to

them with current, the

supply current to each of the loads'26 and 26" and an E. M. F. of subst-antitlly twice the magnitude of that across the lighting loads to supply current to the power load. 7

Should the load despatcher at the central station at sometime determine thatthe combined loads at 25, 26 and 26 exceed the desired maximum, or for any other reason, hemay out out the power load by throwing switch K from the position indicated in Fig. 1 to the position indicated in Fig. 2. V

In the position shown in Fig. 2, the main transformerat B now hasreversed polarity with respect to the feeders 11 and 12 so that the polarity of-primary winding P is reversed, as indicatedby the arrow d which is reversed with respect to arrow 0. It is thus seen that in this second position of switch K the E. M.Fs. of the supply transformers are bucking so that while there is an E. M. F. acting across each load '26 and 26' to supply resultant E. M. F. from the series connection of the transformers across the power load is zero; hence no current will flow to the power load.

This same effect, however, may be had from a switching device other than a double throw switch.1 "A device for effecting the connections shown in Fig. 3 will also pro duce buckin E. M. Fs. inthesupply transformers. n Fig. 3, the connections are changed from' the series arrangement of Fig. 1' to one in which the main transformers A and B arein multiple and the feeder 12 connected to vfeeder 10. Then since the supply transformers are in multiple the lighting loads 26 and 26 willhave F. across the same to supply current thereto but the load at 25 which is across the sec- -ondaries ofthe supply transformers in series has a zero resultant E. MrF, 'thereacross. This latter arrangement has the obvious advantage that the lighting loadsat 26 and 26 need not be balanced inorder to distribute themselves in an economical manner across the transformers A and B, because the t two loads are in multlple which are supplied by the transformers A and B which are themselves also in multiple'by this connection.

Having now described anembodiment of my invention which is "at present the best means known to me for jcarrying'the same into effect, 1 would haveit understood that thisismerely illustrative andthat I do not mean to "be'limited thereby t the precise tr nsformeraof a plurality of s'upplytrans: V rormers fed therefromand havinga feeder in common, a plurality of loads having different characteristics connected across the supply transformers individually and in series re gectively, and a switching. device for changing the polarity of a main transformer with respect to its feeders whereby a zero resultant M. F may be had from the series'connection of said supply transformers. V V r 2. In an electrical distributingsy'stem, the combination with a plurality of main transformers, of a plurality of supply transformers fed therefrom and having a feeder in common, a plurality of loads having different characteristics connected across the s pply transformers individually and in series respectively, and a double-throw switch for changing the polarity of main transformer with respect to {its feeders whereby a zero resultant l /LF. is im: pressed across the load on the series connection of said supply transformers, V V V 3. In an electrical distributing system, the

combination with two maintransformers,"

of two supply transformers fed therefrom and havi one feeder incommon, loads con-- 'nected across the supply transformers individually, another load having a characteristic different from the first, said load connected across said supply transformers in series, and a switching device for'reVerS- the polarity of a main transformer with respect to its feeders whereby the E. i

M. Fs. of the supplytransformers acrossthe second named load may be 111 series or bucking relation a. in an l distributing system, the combination with t /c main transformers, of two" supply transformers fed therefrom and having one loads connected across the supply trans ers, whereby a zeroresultant E. M. F, may i f de in commony 115 ormers individually, another loadhav ng V be had from the series connection of said I loads.

6. In an electrical distributing system, the combination with two main sources of current, of two loads connected across the sources of current individually and having one feeder in common, another load connected across the sources of current in series,

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