The relationship between KVA and KW

On the nameplate of the generator, the rated capacity (KVA), rated power (KW), and power factor (COS) will be indicated.

KVA: The rated capacity of a generator is the (vector) sum of active and reactive power.

KW: The active power output by the generator, which is often referred to as the rated power

COS: the angle coefficient between the active power and the rated capacity in the generator load,

The actual load of the generator is a mixed load of various loads. Simple classification is: resistive load (resistance), inductive load (inductance), capacitive load (capacitor).

Various Heaters - Resistive Loads (Linear Loads)

Various electric loads – inductive + resistive mixed loads (linear loads)

Various electronic loads - mixed load of inductive + capacitive + resistive (non-linear load)

The relationship between KVA and KW is as follows:

Generator rated power KW = generator rated capacity (KVA) x power factor (COS).

According to the generator standard, the generator design must meet:

1. The three-phase generator must meet the working condition of the power factor of 0.8 (lag)

2. The power factor of a single-phase generator can be 0.9 (lag) or 1.0.

Notice:

1. The generator load cannot be capacitive (that is, the power factor is advanced). At this time, the operation of the generator will be seriously affected and the machine will be lost.

2. For non-linear loads, the selection of generators should be enlarged and selected after application calculation.

3. For the motor load, consider the maximum starting KVA at the moment of starting the motor, and select an appropriate generator.