"The work done by electric power can be divided into two part, one is the work on resisted load, which is effective power KW ,the other is the work on reactance load, which is ineffective power KVAR . The vectors of these two powers are perpendicular to each other, and summation of the two factors is the apparent power."
http://emis.erl.itri.org.tw/english/ECTH/list2-3.asp



--------------------------------------------------
Note added at 29 perc (2006-07-30 09:47:08 GMT)
--------------------------------------------------

„true power” a szinonimája
„effective power: In alternating-current power transmission and distribution, the product of the rms voltage and amperage, i.e., the apparent power, multiplied by the power factor, i.e., the cosine of the phase angle between the voltage and the current. Note: Only effective power, i.e., the actual power delivered to or consumed by the load, is expressed in watts. Apparent power is properly expressed only in volt-amperes, never watts. Synonym true power. See figure by clicking on the "Pict" icon below.”
http://www.atis.org/tg2k/_effective_power.html


--------------------------------------------------
Note added at 58 perc (2006-07-30 10:15:51 GMT)
--------------------------------------------------

„real power” egy másik szinonimája
“In reactive circuits, energy storage elements such as inductance and capacitance may result in periodic reversals of the direction of energy flow. The portion of power flow that, averaged over a complete cycle of the AC waveform, results in net transfer of energy in one direction is known as real power. That portion of power flow due to stored energy, that returns to the source in each cycle, is known as reactive power.”
http://en.wikipedia.org/wiki/Electric_power


--------------------------------------------------
Note added at 1 óra (2006-07-30 10:19:17 GMT)
--------------------------------------------------

Akit a három teljesítmény kapcsolata is érdekel:
http://en.wikipedia.org/wiki/Image:Power_Triangle_01.png