Hello my friends...

Through my studying for Synchronous Generators , we used two characteristics as shown in attached photo,
first frequency-real power charac. and their relation equation is P=Sp(Fnl-Fsys.)
and second one, Terminal voltage-reactive power charac. and their relation equation is Q=Sq(Vt nl-Vt sys.)

My question is Why are we relating frequency with real power and relating Terminal voltage with reactive power ?? What are Reasons?

 

Because AC has frequency.

http://en.wikipedia.org/wiki/AC_power

 

Because AC has frequency.

http://en.wikipedia.org/wiki/AC_power

Okay, but reactive power also has the same frequency ??
why voltage relate with reactive??

 

Okay, but reactive power also has the same frequency ??
why voltage relate with reactive??

Voltage is related to reactive power because you can use voltage to calculate reactive power.

Reactive power is Q.

AC voltage is Vrms.

Reactive power can only be in inductors and capacitors because they store energy. Inductor stores energy in magnetic field. Capacitor stores energy in electric field. So we need their reactance: XL and XC, since we don't know ahead of time which element we are dealing with, we will use X to denote reactance.

Therefore: \(Q=\frac{V_{RMS}^{2}}{|X|}\)

 

Presumably this is the context.
http://www.openelectrical.org/wiki/index.php?title=Infinite_Bus

 

I guess reactive power reflects stored energy in reactive impedance & real power energy input or output in mechanical (rotational) energy. Excess stored reactive impedance energy tends to boost voltage whereas changes in mechanical spinning energy tend to change rotational frequency.

 

shteii01 and t_n_k
thank you for your useful information