The aim of project called „Reactive power compensation panel” was to design capacitor bank with rated power of 200kVar and rated voltage of 400V adapted for operation with mains, where higher order harmonics are present.
How many compensation banks can a capacitor assemble?
Due to reduced active power losses inside the capacitors, today it is possible to assemble compensation banks up to 400 kvar or more within one cubicle of dimensions (B × H × W) = 600 mm × 2000 mm × 400 mm (without reactors). 1. Installation requirements
How does a capacitor bank work?
The voltage and current signal from the system is sampled and taken as input to measure the power factor and if it falls short of the specified value by utility, then the device automatically switch on the capacitor banks to compensate for the reactive power.
How long does the automatic switch of capacitor bank take?
After every tripping, the automatic switch of Capacitor Bank takes 10 minutes time interval. Thereafter it brings the capacitor bank back to normal service only when the current valued more than 52 Amps. The automatic switch keeps the capacitor bank in service for a system voltage ranging only between 9 KV to 12 KV.
Since the detuning factor for the project was given as p=7%, one knows that the capacitor bank needs to be equipped with reactors. For this reason, some calculations have to be performed, in order to fit the power of the capacitors and its rated voltage taking into account reactive power of a detuning reactors.
How to choose series of capacitors for PF correction?
Considering power capacitor with rated power of 20 kvar and rated voltage of 440V supplied by mains at Un=400V. This type of calculation is true, if there is no reactor connected in series with capacitor. Once we know the total reactive power of the capacitors, we can choose series of capacitors for PF correction.
How to determine power cables to a compensation bank?
In determining the power cables to the compensation bank, their cross-section must not depend on the nominal current but on a higher value. According to the European standards EN 60831-1 for LV capacitors and EN 60871-1 for MV capacitors, they must be constructed to lead the nominal current steadily by 1.3 times.