AN4121

Three-phase systems

Doc ID 023243 Rev 1

19/26

Figure 13.

Per-phase powers in (a) a delta-connected load and (b) wye-connected

load

In the case of

phase:

Since the line current in the balanced delta-connected loads,

If this equation is substituted into equation 3.51, the total active load becomes:

Equation 1

In

Therefore, the phase active power and the total active power are:

θ

=

=

=

=

cos

I

V

P

P

P

P

phase

line

3

2

1

θ

=

=

cos

I

V

3

P

3

P

phase

line

Total

phase

line

I

3

I

=

θ

=

cos

I

V

3

P

line

line

Total

3

V

V

line

θ

=

=

=

=

cos

I

V

P

P

P

P

line

phase

3

2

1

θ

=

=

cos

I

V

3

P

3

P

line

phase

Total