US2000736A - Multiple-rate power metering - Google Patents

Description

y 1935- J. P.BALLANTINE 2,000,736

MULTIPLE RATE POWER METERING Filed Nov. 19, 1932 15- @(DGQ) FIG. 11

Patented May 7, 1935 I it I mom invent on .rel tes:to;.kitesratins and reelsms e c r cpowe s eter 21 1118 povnersena insand di tribu in ystems; ther arep r s Ofthe d y, v y of c ursei om oneseasonlof theyear 'to gnother durihg whichthe demand for p wer d c nes tol ss than th desirable minimum the t m shou d eoarr i e. Under these conditions in water power systerns it is not uncomm nto find-i ne es r t l t wat r oto wast which could'be used profitably if the fofi-peak demand for power could be increased. While the situation in systems operating on oombustible fuel is not so clearly un favoroblere1a tive to ,ofi-' peak rpower periods, itjs folind-that even in those sys ems the large fixed charges make it desirable to increase the use of power during off-peak periods as much; as possible. Perhaps-one ofthe' o t important or atpros nti erldi fco dis:

ra es heu eakpowe i t et nvolved nm'te in g th i'scu to rr enerellypay :t

ome p i e os vk owstteho "o :ieners used ho h t isused a t epeako theids ap t teowes de es onnflsr th se w a oe r i e itab e ti he-t: th -Qns1imer .w li

m nt eiiort :fiq us ower:otl eslessoon i nth per od :pf-theds eflfher hsss been is s s s. li t r latin t t e p we ndustr h Pos ib i i fi.- eakpowe a;.1. ate tha ur ng-the ssstifrda fill i tii wh c e s-n tu afl oons erabl i al i tia-to overcome. -What isneeded in this-regardis m rpa es nstalle I theimeter n o fl h i nd k eakr e s dt rt eson:v n n M i ven io Pro s. w m t ods? r n 311 .8 we h relati e y vimlplewand inexpensive to pu into; opera tion;,-.;and

means w h w l :m te libo di a a d of a P ma ical aking nt c n .v

the ordinaryiand ofI-peak hours of the s day.

What constitutesmy T int option is set forthi in the-specification ioll owing and 1 S-S' l1CCiI 1Qt lyqd ef; v. .l

could be extended easilyio fined-in theeppeiidedfolaims.

1 1M! invention stsh wn dhflairiiwtioififi e .7

O di a ly th wdifll, ki i-1.

showsm y, invention ;-ii1 -a f referred eni- HFIEHre 131: shows.-

oslersco smnedso the 1 11s ita iice s one no can Figures and show a. detailof J orpartof Figure 1;. v

r :In the metering of ordinaryand ofl-peak power,

at he o in r rate ans loiriresi te iiis LthePfi-Z peak energy separately, soiit cah'be chargedfor at a lower off-peak rate; proof registering less than t the actual amountof 'oif-peakenergy so that the ofi-peak ratewill be automatically lowered below the ordinary rate when the aet ai meter rteaJdihg" is billed at the ordinary rate. @h'flttpfiithridi is the simpler of I the 'two-to put into efieoti V One way of accomplishing this is'sho' Figure I, another in Figure 11; *Ip Figureclock t, p'reierably -'e1ectrioa1ly driveiydfives a -i cam 2. I The ca'm 2 I :is 'driven' by }the accus -as to complete one revolution intwemy-rour-'r1ours. Usually ther''is a's in'gleqier iod of ab'c'iutgsix-ijours or less during the day vwhen off-pealg poiveh is available. -'On eam Z =the -9lro oonespondizig to rest of the cam. Camjis madeof two similar ports 2a and ZbQ Figure v ,=ea, oh part with a. portion of its are at the larger radius; The two parts I M439:

meters, this type of meter is n c n shown invFi u e wit u cha 1th? to s. isen lt rrz ssiasl 'I;. i 1, s tru r-w d nes l, ase w qiiwhe therein qqe sot w some; Ulis s i ,nating watt hour meters.

with airgaps arranged so that in the normal operation the magnetic material is not saturated magnetically. Under this condition the magnetic fiux density existingin the iron is on the (straight part of the magnetization characteristic of the material, and the flux is substantially 'propor- 1 tional to the total ampere turns in t he circuit,

When an alternating voltage is-applied to such gear l1 engages another driving gear 20, depending upon the angular position of cam 2. These twoagears are driven by a shaft 2| which in turn is driven by the driving disc l3 of the meter. During ordinary periods, the angular position of cam 2 is such that-the; gears l6 and I9 are engaged,

as shown. in Figure II. During off-peak periods, the cam 2 forces gears I6 and I? over, disengaging a circuit the flux is built up in the magnetic mate- -1gears, i 6 v and I9 and engaging gears l1 and 20.

rial so that thevoltage is represented by ithe equationz 1 I (1) approximately. In"this'equ'ationE is efiective' voltage, is frequency, 12. is number of turns, and c is maximum instantaneous fiux. The equation where is flux, n is number of turns, I is current, ,u. is permeability, A is airgap area, and Z is airgap length gives the relationship between flux and currents f .The'fiux in the magnetic circuit can be computed from either of the above equations. In the first onev it isseen that can be computed independently of the knowledge of I, so for the purpose of explanation of, this invention I need notbe consideredn In the first equation, 1' can be expressed in terms-ofn asfollows: I 4

inverse proportion to theincrease of n.

Inasmuch as the torque inan induction meter -is an increasing function of 3 an increase inn,

the number of turns in the circuit, will cause the meter-to have a. lower torque-and to register at a lower rate. By weakening the field of the voltage coilthe right amount, any amount of slowing down can be accomplished. Usually the rate for off-peak poweris about one-half that for the ordinary period, so what is done in such an instance is to'make the meter run only half as fast for a given'amount of energypassing through it during'the off-peak period as during-the ordi nary period. This causes register M to indicate only half as 'many kilowatt-hours of energy as actuallypass through the meter during the offpeak period. 3 The result is that the total reading" of-the meter when paid for at the ordinary rate will automatically admit halfthe off -peak period energy'free of charge, or stating it another way, will-charge only half-price for each off-peak kilowatt-hour. Adjustment of tap 9 on coil I l makes itffeasible to change-the ratio of ofi-peak energy toordinary energy at, will. If the meterwere adjusted'toregister only one-third'of the number of kilowatt-hours passing through. it during offpeak periods, the eifect wou1d, of course, be to admit two-thirds of-the off-peak energy free, A or,"

Theratio of the diameter of gear 20 to that of so the dial is driven-at a lower speed for a given speed of the driving disc when gears l1 and 20 are engaged than when gears l6 and H! are engaged. Accordingly, the off-peak energy is only partly registered as explained for Figure I.

- In some instances it is desirable to indicate the ordinary and off-peak energy separately by two registers in the same meter. Figure III provides a mechanism for accomplishing this. The cam 2 and linkage l5 coact as described for Figure II in shifting a gear 25 on a drive shaft 2| which is connected with the driving disc {3. Two registers l 4 and 24 are provided to meter the ordinary and off-peak power individually. During ordinary periods cam 2 is in such position that gear 25 engages and drives gear 26 causing register M to indicate the kilowatt-hours of energy passing through the meter. During off-peak hours, gear 25 is caused by cam 2 to engage and drive gear 21 so that register 24 indicates the kilowatt-hours of energy passing through the meter. The result is that register l4 indicates all energy used in ordinary periods and register 24 all energy in off-peak periods. The two readings can then be charged for separately at their respective rates. FiguresIV and V show certain details of cam 2. Cam 2 iscomposedof'two parts 2a and 2b which are similar in shape and size. They are placed against each other on shaft 3| on which they are held against a shoulder 32 by a thumb screw 30, The two cam parts 2a and 2b have portions'of their circumference at a greater radius than the rest of it, furthe purpose of imparting motion to otherparts ofthe meter such as the arm 4 in Figure I, or linkage l5 in Figure II. The length of arc at the greater radius is such as to correspond to the minimum length of the off-peak period with which'the meter is likely to Mooncerned. This is 'not the same in all situations but'in most installations is from three to four hoursout of twenty-four. The entire circumference of the cam represents twenty-four hours, sofrom one-eighth to one-quarter of its circumference is at the greater radius. When the two parts 2a and 2b are brought into coincidence the part of the total circumference at the greater radius is the minimum period, for example, four hours. If now one of; the parts-2a or 217 is rotated slightly relativeto the other, the resultant,

part of the circumference of the combined parts at the greater circumference is greaterthan the minimum amount. By rotating the part still further, the amount of circumferenceof the greater radius may be increased to nearly twice the minimum, in this example, eight hours. By holding both cam parts 2a and 2b to prevent their rotating relative to each other and turning them together, the ofi-peak registering, period can be placed at any position desired in the twenty-four hours, corresponding to a. complete revolution. In most instances, theoff-peak period in a day is from four to six hours long, so, two cam parts each three or three andone-half hours long would accommodate most practical requirements. For other conditions of eitherlshorter or longer periods, cam parts of different peak periods can be used, or anexactly similar one can be placed with the initial two, giving a range of nearly three to one in the choiceof duration of .the oilpeak period metering. By separating the two minimum off-peak parts ofthe circumferences or" the two parts 2a and 21), two 'oif peakperiods at different parts of the day can be accommodated. This is not usually required.

Dial or register indications may bein any units,

not necessarily those usually used in power practice. If desired, any arbitrary system of numbers can be used during the'ordinary and oif-peak' periods. For example, actual energy unitsmay be indicated in off-peak periods and some multiple of theenergy units used indicated in ordinary periods. read in monetary units directlyif the rate per energy unit were a fixed quantity; If the occurrence of an ofi-peak period is weekly instead of daily, the cams and clock must be changed for slow-er rotation.

In the figures, which are diagrammatic, many mechanical and electrical details of meters and registering mechanism have for convenience been,

omitted. These are known in the art, and the exact form in which they are used in my inven- Also, the dials could be calibrated to tion is not subject to limitations other than those imposed by the requirements of good design in metering equipment. i

What I claim is: V i V 1. In a multiple rate metering system the comcoil with taps, and means for changing said taps for changing the rate of metering;

2. In a multiple rate metering system the combination of metering means including a voltage coil in which the number of turns in service is changed for changing the rate of metering.

3. In a multiple rat e metering system the combination of metering means including a voltage V 5; In a multiple rate metering system the tombination of a tapped voltage coil, contact making, 7

-bination of metering means including a voltage 7 means for changing said taps and timingmeans for controlling the changing of the taps of said coil;

6. In a multiple rate metering system'the combination of a tapped voltage coil and clock operated means for changing the taps of said coil.

7. In a multiple rate metering system, the combination of an alternating current Watthour meter of the induction type including the usual parts and-a tapped voltage coil, and means for changing said taps.

JOHN PERRY BALLANTINE.

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