Electronic – Find the maximum power

circuit analysispower

The task says:

Determine the positive maximum power p (t), for the load connected to
the voltage 230 V. The power consumption was 1350 W and the power
factor was 0.85.

People have put this on hold because they said I did not try to solve it myself, I did but I did not write what I was doing because It led me to the wrong answer.

So I am gonna try again:
P = 1350 W

I know that power is a sine function so my initial thought is that giving me voltage and power factor is nothing more than trying to trick me.

I tried to solve it like this:

I know that \$p(t) = P\sqrt2sin(wt+φ)\$ so positive maximum should be \$P\sqrt2\$ which gives me 1909 but that answer is wrong.

after that I tried to find apparent power \$ S = \frac{1350}{0.85} = 1588\$ and multiply that with \$\sqrt2\$ and that would give me 2246 VA. (But that is also incorrect). The correct solution is 2938 W, and don't know why is that solution and not what i firstly tried

Any help is greatly appreciated

Best Answer

The quoted task seems to be about P(t), power as a function of time or instantaneous power. The instantaneous voltage, real current, reactive current, total current, and power are shown below. Power has been divided by 100 to make a more readable graph. The "positive maximum power" of the task is the positive peak of the power waveform. I determined that graphically as 2938 watts. I will leave it to the student to determine it analytically.

enter image description here

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