Answer Posted / yousef madhi
Suppose That the line voltage on DELTA connection
V(line)= V
and the line current I(line)= I
as we know in DELTA connection the phase voltage equal the line voltage and the phase current equal to the line current times 1/root(3)
then V(phase)=V(line) = V
and I(phase)=I(line)/root(3) = I/root(3)
In STAR connection if again the line voltage equal to V(line)= V , the phase voltage will equal to line voltage time 1/root(3)
V(phase)=V(line)/root(3) = V/root(3)
and as per Ohm's Law (V=I*Z) and in both connection (star & Delta) we have the same winding impedance, any change in Voltage will change the current in the same amount.
so the phase current for star connection will be equal to
I(phase-star)= I(phase-delta)/root(3)
=(I/root(3))/root(3)
= I/3
and as we know in star connection the line current equal to the phase current
I(line)=I(phase)= I/3
Conclusion:
the line current in star connection is reduced by 1/3 time the line current in delta connection
| Is This Answer Correct ? | 18 Yes | 0 No |
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