Dear All,
There is an existing installation which has already been equipped with automatic power factor correction capacitors to correct the overall system power factor to 0.95 lagging and the capacitor bank is doing its job well.
I understand that very little kW saving is achieved due to the reduced cable losses between the distribution transformer and the main switchboard where the capacitors are being installed. Theoretically the reduced cable losses shall be reflected in the electricity bill however due to the saving being extremely little, the payable amount for kWH still remains as per the usage.
In order to see substantial saving in several kW by reducing the cable losses, the plant engineer suggested to install static power factor correction to the existing loads in addition to the existing capacitor bank in the main switchboard.
Just for the information, the existing cables (supplying loads located approx. 30 to 100m from the main switchboard) were critically sized and it appears that static correction in each feeder of large loads can result savings in the range of 0.5kW to 1kW. The engineer is of the opinion that kVA reduction in each feeder this will provide a cumulative saving due to the reduced cable losses.
I'm of the opinion that no savings can be achieved because the existing capacitor bank is decently supplying the loads with the required kVAR. No doubt the loads are drawing KVA however the additional current due to low power factor in which accounts for the I2R losses is now compensated by the capacitor bank. By installing static correction,the I2R losses on the cable which has no effect at all on the system will be saved. I appreciate some advice on this.
Thanks,
Regards,
Kana