Capacitors improvement

The dramatic reductions in alkaUes and carbon concentrations have led to significant improvements in the electrical quaUty as measured by the performance of tantalum capacitors. 

Note If a power capacitor is connected after the relay, say across the motor terminals, to improve the p.f. of the machine, then only the corrected value of the current musi be used. For example, if a capacitor bank of 130 kVAr is used for an individual correction of the machine then... 

By installing p.f. improvement capacitors to compensate the no-load magnetizing current of the circuit being switched (Section 23.1 3). These may be installed in the same switching circuit to switch together with the inductive load,... 

These capacitors differ from standard p.f, improvement capacitors, as they are designed to withstand higher test voltages and have a low internal inductance. They should preferably be non-inflammable, synthetic liquid impregnated and provided with a built-in discharge resistance. For specifications refer to VDE 0675 and VDE 0560 III,... 

Power Capacitors Behaviour, Switching Phenomena and Improvement of Power Factor... 

Power capacitors behaviour, switching and improvement of power factor... 

Shunt capacitor - connected across the inductive circuit to improve its p.f. 

The rating of a capacitor unit will thus vary in a square proportion of the effective harmonic voltage and in a direct proportion to the harmonic frequency. This rise in kVAr, however, will not contribute to improvement of the system p.f. but only of the overloading of the capacitors themselves. 

This will be the surge frequency of the switching circuit when the sixth capacitor is switched on a circuit that has five capacitor units already switched. The improved value of this switching frequency, /s, af si the introduction of inductance 42.93 uH in each capacitor circuit will become. 

Consider Figure 23.29(a), where, the p.f. of a power circuit is to be improved from cos 0, to cos 02- If kVAri is the reactive component of power at p.f. cos 0, which is to be improved to kVAr2, at p.f. co.s 0i, through the reactive power coinpensation, then the reactive component of power compensated or kVAr rating of the required capacitor banks... 

Power capacitors behaviour, switching and improvement of power factor 23/761 Tabfe 23.6 Chari for selection of capacitor rating, to improve the existing p.f. to a higher level... 

Recommended capacitor ratings for direct switching with induction motors, to improve power factor to 0.95 or better at... 

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