Unbalance and Power Loss
Unbalance and Power Loss
(OP)
Hi,
my question is: Does unbalance current increase the power losses? and how?
Thank you very much
my question is: Does unbalance current increase the power losses? and how?
Thank you very much






RE: Unbalance and Power Loss
If they are not equal, then the resulting sum of I^2 will be greater than 3 * I^2 computed from the balanced case.
You can show if mathematically by setting one phase equal to I; the next equal to I + a and the last equal to I - a. This gives you the same average current. Now compute the sum of I^2 and you'll get 3 * I^2 plus the term 2 * a^2.
It's a bit more complicated if you add a neutral, but the same result applies.
RE: Unbalance and Power Loss
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If we learn from our mistakes I'm getting a great education!
RE: Unbalance and Power Loss
When synchronous machines are unsymmetrically loaded, the symmetry of the stator currents is disturbed and a counter-rotating negative phase-sequence current is set up. This current results in double-frequency eddy currents being induced in the rotor, causing additional heat losses and local overheating of the rotor as well as mechanical vibrations.
Regards.
Slava
RE: Unbalance and Power Loss