1919.] 
Departmental Reports. 
149 
Table 9. 
Transmission at 100,000 Volts, Three-phase, 50 Cycles. 
Power delivered, 13,500 kw., power factor, 0-95; spacing of conductors, 
10ft.; symmetrical; size of conductors, 19/13; distance of trans¬ 
mission, 100 miles. 
— 
Symbols. 
Power to be delivered per phase 
Kw. 
4,500 
Voltage to neutral at delivery end.. 
57,700 
/18° 11' 
V r 
Power factor at delivery end 
No. 
0-95 
Cos- 1 0-95 
Z 
18° 11' 
e 
Current per phase 
Amps. 
82 
Ir 
Surge impedance 
406-1 
\13° 39' 
n 
Cosh Im 
0-9847 
/0° 28' 
. . 
Sinh lm 
0-1812 
/76° 24' 
• . 
V r cosh lm 
= 57700 /18° 11' x 0-9847 /0° 28' 
= 56700 /18° 39' 
= 53800 + i 18150 
nl r sinh lm 
= 406 1 \13° 39' x 82 x 0-1812 /76°24' 
= 6040 /62° 45' 
= 2765 + i 5370 
V r cosh lm + nl r sinh lm 
= 56565 + i 23520 .. 
61,500 
/22° 33' 
V s 
Ratio V s /V r 
No. 
1-063 
I r cosh lm 
= 82 x 0-9847 /0° 28' 
= 80-6 /0° 28' 
= 80-6 + i 0-6529 
V r 
— sinh lm 
n 
= 57700 /18° 11' x 0-1812 /76° 24' 
406-1 \13° 39' 
= 25-8 /108° 14' 
= — 8*05 -f i 24*4 
Ir cosh lm -f — l sinh lm 
n 
= 72-55 + i 25-05 .. 
76-8 
/19° 06' 
T 
Phase difference between V s and I s 
/3° 27' 
S 
Power input 
= V s I s cos 3 C 27' 
= 61500 x 76-8 x 0-998 
Kw s 
4,720 
Power received per phase.. 
Kw r 
4,500 
Loss 
Kw 
200 
Efficiency 
% 
95-4 
Ref. 
T 1 
T 4 
T 4 
E 2 
E 4 
Note.—P osition of current at receiving or substation end of the line taken as a datum. 
T refers to tables, E to equations. 
12—Science. 
