Phasor Conjugate Power Sign Check Tool

Description

Compute real and reactive power from voltage and conjugate-current phasor components.

Sinusoidal electrical calculations need a common frequency, phase reference and RMS or peak convention. Phasor sums, complex power and composite RMS describe different operations; a sign label alone does not establish a physical connection or waveform.

Compute real and reactive power from voltage and conjugate-current phasor components.

When to use this tool

Use Phasor Conjugate Power Sign Check when checking a stated phasor, power or RMS convention.

How to use the tool and how it works

Enter voltageReal, voltageImag, currentReal, currentImag. Use the units and conventions below.
Run the tool. Correct any format, range, or cross-field input error before interpreting the output.
Read active, reactive. Use the output convention below.

Return active = voltageReal*currentReal+voltageImag*currentImag and reactive = voltageImag*currentReal-voltageReal*currentImag, the real and imaginary parts of voltage times conjugate current.^[1]

Input field	Meaning and units	Accepted input
voltageReal	Real RMS voltage phasor component for ordinary watt/var interpretation.	Required. Finite number.
voltageImag	Voltage Imag	Required. Finite number.
currentReal	Current Real	Required. Finite number.
currentImag	Current Imag	Required. Finite number.

Output field	Interpretation	Returned shape
active	Active	Required. Finite number.
reactive	Reactive	Required. Finite number.

json

{
  "input": {
    "voltageReal": 2,
    "voltageImag": 1,
    "currentReal": 3,
    "currentImag": -1
  },
  "output": {
    "active": 5,
    "reactive": 5
  }
}

Limitations and assumptions

For ordinary watts and vars use RMS phasors on one frequency and passive-load reference basis. Peak phasors require a separate one-half scale; no such scaling is inserted.
Inputs must satisfy both the field types and the cross-field conditions above. Invalid input causes an error; a successful false flag or documented placeholder is a different result.
Numeric calculations use binary floating point unless exact decimal-integer arithmetic is explicitly stated. No hidden measurement tolerance or decimal rounding is added; nonfinite or out-of-contract results are rejected. Numeric signed-zero results are exported as zero.

Alternative or Complementary methods

Use compatible measured waveforms and a complete circuit or harmonic model when signals are distorted, references differ or practical limits matter.

References

Calculation and input contract: electricity/phasor-conjugate-power-sign-check — tool.io

Similar or alternative tools

Electricity: Reactive Power Sign Convention Crosswalk
Accept sourceConvention and targetConvention as load-positive or generator-positive.
Electricity: Complex Power Real Imaginary Pair
Return realPower = voltageReal*currentReal+voltageImaginary*currentImaginary and reactivePower = voltageImaginary*currentReal-voltageReal*currentImaginary.