Correcting Bus Power Factors Using Capacitor Banks - Intergraph Smart Electrical - Help - Hexagon

When running batch load association and calculating the electrical consumption for a bus, the software allows you to calculate the consumed reactive power of a capacitor bank that needs to be associated with the selected bus so that you can correct the power factor of that bus. Creating a capacitor bank that has the consumed reactive power you just calculated and associating this capacitor bank with the current bus corrects the bus power factor when calculating the electrical consumption of the bus.

The formula that Smart Electrical uses to calculate the required correction factor is as follows:

Where:

• Qcb = Reactive Power of the Capacitor Banks to be connected to the bus in order to have the required cosjd.

• P = The active power drawn from the bus.

• Q = The reactive power drawn from the bus before connecting the power factor compensating capacitor.

1. On the Bus tab of the Batch Load Association dialog, type a value under Required power factor. This value determines the required power factor for the selected bus.

2. Select the Loads tab.

3. Under Electrical consumption using coincidence factors, select the For all feeders option in order to make sure that the software performs a calculation that includes all downstream loads and not only the ones that are connected directly. Also, the software will recalculate the electrical consumption and the required corrective reactive power for the selected bus.

   If you choose to close the Batch Load Association dialog at this time, you can also run this calculation by selecting Actions > Calculate Bus Loads > Selected PDBs or Buses.

4. On the Batch Load Association dialog, select the Loads tab.

5. Under Required capacitor correction [kVAR], copy the calculated value. You can copy either total running load or the total peak load value as you require.

6. Select OK on the Batch Load Association dialog.

7. In the Electrical Index, create a new capacitor bank. For details, see Create Static Electrical Equipment.

8. On the Common Properties dialog for the new capacitor bank, select the Load Data tab.

9. Under Rated power and Absorbed power fields, paste in the Required capacitor correction [kVAR] value that you copied from the Batch Load Association dialog.

10. Select the Feeder Data tab and associate the current capacitor bank with the bus for which you ran the electrical consumption calculation.

11. Select OK to accept the values you entered and close the Common Properties dialog.

You can now open the Batch Load Association dialog and recalculate the bus load consumption for that bus. Under Power factor@Run and Power factor@Peak, you can see the newly calculated power factor values for the current bus associated with the new capacitor bank while the value under Required capacitor correction value is zero or close to zero.