How to convert ?

Sorry

[Guillaume]

If the definition of Pr is Pr = E^2, then the only correct result is Pr = 2.2007e+04 + 9.7496e+02i.

If the definition of Pr is Pr = ‖E‖^2, then the only correct result is Pr = 22030.

You certainly can't swap one for the other.

[Star Strider]

@Guillaume —

The second is correct, but only partially so. Complex power is actually referred to in phasor notation:

Pr = [abs(E).^2  angle(E)*180/pi]

Pr =
        22030       1.2683

here indicating a positive phase lag in degrees (inductive load).

Answer 1

[Star Strider]

Use the abs function, then square the result:

E=1.4839e+02 + 3.2852e+00i;
Pr = abs(E).^2

Pr =
        22030

This gives a lightly different result than 2.2009e+04 because of the lower precision in the numbers you posted.

Answer 2

[Thorsten]

abs(E)^2