energy saving through current balancing
energy saving through current balancing
(OP)
Anybody there can help me finding out percentage wise how much can one save in KW when currents are balance in a 3 phase system with an example ?
I read somwhere that if in a electrical 3 phase motor phase currents are unbalanced , one can try changing the phase cables at the motor terminals , pushing one to the next one and so on , in order to prevent motor turn rotation and measure again to see if they are not any more unbalanced . is it true ? where can I read about it ?
finally if in the secondary side of a bank transformer one measures 210 volts and the 3 phase motor are rated 230 volts , if I raise the voltage through the taps to 230volts , would I save energy ? if yes , how much , 2% or what ?
Thank you for your coming help on this matter.
I read somwhere that if in a electrical 3 phase motor phase currents are unbalanced , one can try changing the phase cables at the motor terminals , pushing one to the next one and so on , in order to prevent motor turn rotation and measure again to see if they are not any more unbalanced . is it true ? where can I read about it ?
finally if in the secondary side of a bank transformer one measures 210 volts and the 3 phase motor are rated 230 volts , if I raise the voltage through the taps to 230volts , would I save energy ? if yes , how much , 2% or what ?
Thank you for your coming help on this matter.





RE: energy saving through current balancing
Will not attempt to answer all your questions here but can provide some comment to the questions raised in the second paragraph of your post.
Yes, the level of phase imbalance can in some cases be reduced by 'rolling the phases'. This is particularly true in cases where variations in supply voltage and motor impedance work together (add) creating a larger phase imbalance. The principle behind rolling the phases is to have these variations subracting from each other, thereby minimising imbalance.
I have tried 'rolling the phases' on several occassions now and have been pleasantly surprised with the outcome each time. This is certainly an Eng-tip worth recommending to others.
Regards,
GGOSS
RE: energy saving through current balancing
http://www.franklinelect.com/Manual/AIM_29.htm
http://www.joliet-equipment.com/voltage_unbalance.htm
RE: energy saving through current balancing
RE: energy saving through current balancing
Phase rolling is worth a try, but the influence of various combinations of loads on the same bus bears a degree of scrutiny. The procedure is most effective in one-motor/one-transformer situations.
RE: energy saving through current balancing
Pincrease=Pwatt230V-Pwatt210=(230**2 - 210**2)/R=8800/R, Watts
Now, if R=10Ohms then
Pwatt210=4410 Watts
Pwatt230=5290 Watts
Pincrease=880 Watts
RE: energy saving through current balancing
Regards,
GGOSS
RE: energy saving through current balancing
RE: energy saving through current balancing
*Voltage increasing raises losses in core due to material histeresis. This part of losses is quite small and not dependable from motor load.
*Voltage decreases puts down torque of asyncronous motor
in power 2.
*If load has M=const not function of speed (conveyor),
then rotor slips and current increases dramatically (active and inductive).
*If load has Vent shape - low voltage may bring motor to unstable part of mechanical characteristics - really bad.
*Non symmetric voltage bribgs odd harmonics to magnetic field and creates heat, decreases useful torque.
Thanks,
Vladimir.