Power Systems Fundamentals

Core power-systems calculations used daily in utility, industrial, and consulting engineering: three-phase power relationships, per-unit base conversions, symmetrical fault current, voltage drop on feeders, and power factor correction sizing. Each calculator shows a full worked solution referencing IEEE and CEC/NEC-style conventions.

Three-Phase Power Calculator

Solve for real, reactive, and apparent power and power factor from any two known values.

Per-Unit Conversion Calculator

Convert impedance between per-unit bases, or between ohms and per-unit.

Symmetrical Fault Current Calculator

Three-phase bolted fault current at a transformer secondary, from source and transformer impedance.

Voltage Drop Calculator

Percent voltage drop and receiving-end voltage for a feeder or branch circuit.

Power Factor Correction Capacitor Sizing

Required capacitor kVAR and per-phase capacitance to raise power factor to a target value.

Studies that use power systems fundamentals calculators

Study

Low-Voltage Feeder Study

Feeder sizing end to end from one set of inputs — transformer full-load current, three-phase load current, voltage drop over the run, conductor ampacity after derating, and the reactive power for a target power factor — each showing its full worked solution.

Study

Transformer Fault & Motor-Starting Study

Available fault current at a transformer secondary, from nameplate %Z and the utility's contribution — with symmetrical and asymmetrical duty from the combined X/R ratio, and the voltage dip a motor start causes on that same bus.