Capacitors inject reactive power into the system, raising the voltage, while reactors absorb reactive power, thereby lowering the voltage. These devices are controlled based on the system’s voltage requirements, helping to regulate and stabilize the voltage profile.
Power Factor Correction Capacitors: Installing power factor correction capacitors at the terminals of the generator can help improve the power factor and control the reactive power output. Capacitors supply reactive power, thereby reducing the burden on the generator to produce reactive power, leading to improved overall efficiency.
Note that the negative sign means that the capacitor is absorbing negative reactive power VARs which is equivalent to stating that the capacitor is supplying reactive power to the external circuit or system. For a three-phase system, multiply Q by 3 to get the total reactive power supplied by the Capacitor. Thank you!
This means that a capacitor does not dissipate power as it reacts against changes in voltage; it merely absorbs and releases power, alternately. A capacitor’s opposition to change in voltage translates to an opposition to alternating voltage in general, which is by definition always changing in instantaneous magnitude and direction.
The flow of electrons “through” a capacitor is directly proportional to the rate of change of voltage across the capacitor. This opposition to voltage change is another form of reactance, but one that is precisely opposite to the kind exhibited by inductors.
Capacitive reactance is the opposition that a capacitor offers to alternating current due to its phase-shifted storage and release of energy in its electric field. Reactance is symbolized by the capital letter “X” and is measured in ohms just like resistance (R). Capacitive reactance decreases with increasing frequency.