Calculators

Substation, protection and grid engineering tools

Every tool shows its formula or standard clause and a worked example. Live tools are first in each discipline; dashed cards are on the roadmap.

Substation Automation & IEC 61850

Logical nodes, SCL files, GOOSE and functional descriptions for substation automation engineers.

IEC 61850In developmentIEC 61850 Functional Description Builder
IEC 61850In developmentSCL Viewer & Checker (SCD / ICD / CID / SSD)
IEC 61850In developmentIEC 61850 Logical Node Reference
IEC 61850In developmentGOOSE & Sampled Values Bandwidth Calculator
IEC 61850In developmentPRP / HSR Latency Budget
IEC 61850In developmentIED & Signal Naming Checker (IEC 81346)

Protection & Control

Relay curves, CT sizing, distance and differential settings, coordination.

ProtectionIEEE C37.112-2018 · IEC 60255-151IDMT Overcurrent Relay Curve CalculatorTrip time for IEEE and IEC inverse curves, with TCC plot.Open calculator ProtectionAdiabatic thermal withstand onlyGrounding Conductor Sizing: Thermal Area & TapeCalculate minimum grounding-conductor thermal area and tape thickness from fault current, clearing time and a verified material k factor.Open calculator ProtectionClassical single-machine infinite-bus dynamicsPower Swing Calculator: Classical Rotor-Angle ModelExplore rotor angle and slip frequency with a classical swing-equation model. Compare mechanical input with electrical transfer capability.Open calculator ProtectionDuration scaling from an existing validated studyArc Flash Incident Energy Scaling CalculatorScale a validated incident-energy result when only arc duration changes. This comparison tool does not perform a complete IEEE 1584 calculation.Open calculator
ProtectionIn developmentCT Knee-Point & Saturation Check (IEEE C37.110)
ProtectionIn developmentDistance Protection Zone Reach
ProtectionIn developmentTransformer Differential (87T) Slope & Compensation
ProtectionIn developmentOvercurrent Coordination Plotter (TCC)
ProtectionIn developmentANSI Device Number ⇄ IEC 61850 LN Reference
ProtectionIn developmentBreaker Failure (50BF) Timing

SCADA, RTU & HMI

DNP3 and point lists, scaling, polling and HMI conventions for telecontrol.

SCADALinear instrumentation scalingAnalog Scaling CalculatorRaw counts ⇄ engineering units with slope and span.Open calculator
SCADAIn developmentPoint List / Signal List Builder
SCADAIn developmentDNP3 Data Type & Variation Reference
SCADAIn developmentPolling Cycle & Channel Bandwidth
SCADAIn developmentAlarm Rationalization Checklist (ISA-18.2)

Transmission & Grid

Transformers, fault current, power flow quantities and reactive compensation.

GridIEEE Std 100 definitions · IEC 60050Three-Phase Power CalculatorAmps ⇄ kW ⇄ kVA ⇄ kVAR at any power factor.Open calculator GridIEEE C57.12.00 · IEEE 141 (Red Book) · IEC 60909 (note)Transformer Full-Load & Fault Current CalculatorFull-load amps and available fault current from kVA and %Z.Open calculator GridIEEE 1036 (shunt capacitors) · IEC 60831Power Factor Correction CalculatorCapacitor kvar to reach a target power factor.Open calculator GridThree-phase per-unit normalizationPer-Unit Calculator: Impedance & Base ConversionConvert ohms, per-unit impedance and percent impedance. Calculate base current and change between three-phase MVA and line-to-line kV bases.Open calculator GridFortescue symmetrical components · IEC 60909 / IEEE power-system analysisSymmetrical Components CalculatorABC phase phasors → V1, V2 and V0 sequence components.Open calculator GridAC nodal power balance · Newton–RaphsonLoad Flow Calculator: AC Power Flow & Bus VoltagesSolve a small AC power-flow network for bus voltages, branch MW/MVAr and losses. Includes an editable five-bus example and Newton–Raphson iteration.Open calculator GridSix-position ideal-breaker topology · balanced AC load flowTransmission Ring-Bus Load Flow CalculatorCalculate ring-bus section voltages, incoming-circuit power and losses. Open or close six breakers to study bus splitting and source connectivity.Open calculator GridStator-referred per-phase induction motor circuitInduction Motor Starting Current & Torque CalculatorCalculate induction-motor RMS winding current, slip, air-gap power and torque from a stator-referred per-phase equivalent circuit.Open calculator GridDistributed RLGC equations · analytical lossless step arrivalsTransmission Line Calculator: RLGC, Delay & ReflectionsCalculate distributed-line AC characteristic impedance and propagation constants, plus lossless travel time and the first two step-wave arrivals.Open calculator GridRMS phasor nodal analysisUnbalanced Three-Phase Wye Load CalculatorCalculate phase currents, neutral current, neutral displacement and total power for an unbalanced wye load with connected or floating neutral.Open calculator
GridIn developmentRadial Short-Circuit Study
GridIn developmentLine Impedance from Conductor Geometry
GridIn developmentSurge Impedance Loading

Fundamentals

Voltage drop, Ohm’s law and conductor sizes for everyday checks.

BasicsNEC Ch. 9 Table 8 · IEC 60228 · IEC 60364-5-52Voltage Drop CalculatorDrop in volts and %, plus the smallest compliant conductor.Open calculator BasicsOhm’s law · Joule’s lawOhm's Law & Power CalculatorAny two of V, I, R, P give you the rest.Open calculator BasicsASTM B258 (AWG) · IEC 60228 (metric sizes)AWG ⇄ mm² ⇄ kcmil Wire Size ConverterAWG, kcmil and mm² with nearest standard sizes.Open calculator BasicsReduced steady-state heat-balance modelCable Ampacity Calculator: Thermal-Balance EstimateEstimate steady-state cable current using a reduced thermal model. Enter AC resistance, thermal resistance, temperature limits and other cable losses.Open calculator
BasicsIn developmentConductor Ampacity (NEC 310.16 / CSA C22.1)