Handbook of Electric Power Calculations, Third Edition
A powerful calculations tool for electric power engineers and technicians, this book offers essential, step-by-step procedures and examples for solving a wide array of electric power problems.
TABLE OF CONTENTS Handbook of Electric Power Calculations, Third Edition
INDUCTIVE REACTANCE OF BUNDLED TRANSMISSION LINE
INDUCTIVE REACTANCE OF BUNDLED TRANSMISSION LINE
Calculate the inductive reactance per phase at 377 rad/s for the bundled transmission line whose conductors are arranged in a plane shown in Fig. 9.6. Assume conductors are ACSR Crow.
Figure 9.6: A bundled transmission line.
Calculation Procedure
1. Determine GMD
Assume distances are between bundle centers and transposition of phases. Then, GMD=[(9 2)(18)] 1/3=11.07 m. From Table 9.2, GMR c=0.034 ft (0.01 m). The GMR should include all conductor spacings from each other in the usual product form with, in this case, three values of GMR c. Because of redundancy, GMR=(0.01 0.45 2) 1/3=0.127 m.
2. Calculate Inductive Reactance per Phase
X L=377 2 10 7 ln(11.07/0.127)=0.337 10 3 ?/m (0.544 ?/mi).
Related Calculations. For a two-conductor bundle, GMR=(GMR c D) 1/2 and for a four-conductor bundle, GMR=(GMR c D 32 1/2) 1/4. In each case, D is the distance between adjacent conductors.
For a two-conductor bundle, GMR=(GMR c D) 1/2, and for a four-conductor bundle, GMR=(GMR c D 32 1/2) 1/4. In each case, D is the distance between adjacent conductors. For an n-conductor bundle as depicted in Fig. 9.7, GMR=( n GMR c A n 1) 1/ n, where A is the radius of the bundle. Similarly, for an n-conductor bundle, r equiv=( n r A n 1)
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