capacitor banks and passive filters 1

[unnikri57]

I am having a situvation where the PCC panel connected to the transformer secondary (up stream)is having a passive filter and a Motor control centre connected to PCC ( down stream ) having a capacitor bank.
Do we need both passive filter and capacitor banks in a installation.

 

[Gr8blu]

A filter is used to "clean up" harmonic content. The fact that it is between the upstream transformer secondary and the "point of common coupling" (PCC) might indicate it it there to prevent downstream harmonics from back-feeding to the transformer primary side - or it might be to keep the upstream stuff from muddying the downstream system. The capacitor bank is used to modify the power factor at the motor control center (MCC) and/or support the downstream voltage during transients.

The two components (cap bank and filter) do different things, so chances are good that both are necessary for the specific installation.

Converting energy to motion for more than half a century

 

[che12345]

unnikri57 (Electrical)(OP)24 Sep 24 01:56
'.. where the PCC panel connected to the transformer secondary (up stream)is having a passive filter and a Motor control centre connected to PCC ( down stream ) having a capacitor bank. Do we need both passive filter and capacitor banks in a installation'.
1. In this case, the study is the system Harmonics, the effect of harmonics on the pf cap bank.
2. Trafo sec PCC panel having passive filter, presumably is to filter the harmonic generated by your plant; in order to comply with the utility's limit.
3. Carry out a harmonic analysis and to study its effect on the pf capacitor. Whether the harmonic is low i.e. does NOT cause any over-loading (over-current) of the cap bank. NO passive filter is required in the MCC, where the pf cap bank is located.
Info: Cap voltage < 110% and current < 180% etc...
4. Any filter can be costly and the value may requires updating as the system load/harmonic level change.
Attention: All filters generate heat, i.e. power loss. Avoid if at all possible.
Che Kuan Yau (Singapore)

 

[Parchie]

@unnikri57 (Electrical)
Please share with us some details like voltage level, prevalent harmonics detected, size and capacity of PCC panel versus cap bank MVA. Gr8blu is correct, reactor in series with a cap will have the effect of filtering harmonics present in the POCC. Whether you need those or not depends on the presence/ absence of harmonics there.