Handbook of Electrical Engineering

412 HANDBOOK OF ELECTRICAL ENGINEERING

b 1 =

sin( 2 × 66. 753 )−sin( 2 × 66. 215 )− 2 × 0. 00939

2 ( 0. 4033 − 0. 3947 )

=

0. 7253 − 0. 7381 − 0. 01878

0. 0172

=− 1 .834 indicating a lagging power factor

From (15.8), (15.9) and (15.10)

Ir=+

761. 1

π

√

3

2

0. 798 =+236.8 amps

Ii=−

761. 1

π

√

3

2

1. 834 =−544.2 amps

and

I=

761. 1

π

√

3

2

( 0. 76802 + 1. 8342 )^1 /^2

=593.46 amps per phase

From (15.13), (15.14) and (15.15) the volt-amperes at the bridge AC terminals are,

Ssec=Psec+jQsec

Where

Psec=

3 × 346. 0 × 761. 1 × 0. 7980 × 1. 2247

3. 1415926

=246.09 kW

and

Qsec=

3 × 346. 0 × 761. 1 × 1. 834 × 1. 2247

3. 1415926

=565.52 kVAr

and
Ssec=616.75 kVA

The power factor of the fundamental current is,

cos Ø 1 =

246. 09

616. 75

=0.3990 lagging

or
a 1
c 1

=

0. 7980

√

0. 79802 + 1. 8342

=0.3990 lagging