Having above information, it is possible to find fitting cubicle for the elements of the capacitor bank. Because the device is going to operate at the mains, where higher order harmonics are present, power capacitors. The arrangement of the elements inside the enclosure should be easily available for maintenance and replacement, and each element should be clearly marked according to the t. The next step is to chose appropriate power capacitors. It means, that one needs to pay attention to its rated voltage and power. Since the capacitors will be working in series with rea. The last step is to select the protection of the capacitors as well as the contactors. In order to do so, one has to skim the catalogue cards of the manufacturers. Contactors for th. The short circuit protection of the capacitors is provided by the switch disconnectors. For the capacitors the fuse link rated current should be 1.6 time of the rated reactive current of the cap.
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Excellent. 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. The capacitor bank was to be power capacitor based with automatic control by power factor regulator.
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.
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.
What is a capacitor bank?
The capacitor bank was to be power capacitor based with automatic control by power factor regulator. This type of device was chosen as a compensator, because of its price compared i.e. to active filters.
How much power does a power capacitor lose per kvar?
Generally, we can assume that the power loss of the power capacitor (including wires, discharging resistor and contactors) is approximately 7W per / kvar – for acceptor circuit (capacitor and reactor). According to the formula: Where: Taking into account the rules above, following cubicle was selected: Table 2 – Enclosure dimensions
Why does the power factor decrease after connecting capacitors manually?
This phenomenon will occur when the CT is installed at load side or inside the capacitor cabinet. If only load current is sampled, the power factor will remain almost the same after connecting capacitors manually; if only cabinet current is sampled, the power factor will decrease after connecting capacitors manually.