Run a harmonic design study

Use the circuit you draw to predict balanced three-phase voltage and current distortion, compare the modeled point of common coupling (PCC) with IEEE 519-2022 design limits, and screen for resonance. These are steady-state design predictions; they do not establish measured site compliance.

Set up the circuit

1. Connect a utility supply, buses and supported equipment. Drives start with a documented six-pulse DC-choke spectrum. In the equipment's Study tab, select another typical or manufacturer profile, edit the complete spectrum, or import your own CSV/JSON values.
2. Open Diagram Settings > Harmonics. A single unambiguous utility interface supplies an automatic PCC candidate. For other boundaries, select the PCC bus and its physical supply terminals and directions.
3. Enter the fixed maximum-demand current and its source for current-limit comparison. Keep that reference unchanged when comparing operating scenarios. You can override the utility fault-current basis with cited supply data.
4. Enable a driving-point scan when checking resonance. Choose the order range and number of samples.

Changes save immediately and support one-step undo. Imported spectra must explicitly include every order from 2 through 50. Magnitude-only profiles add in phase across sources for a worst-case PCC envelope; EKX does not assume cancellation.

No maximum-demand reference means the current-limit comparison is unavailable. Valid voltage distortion and network results remain available. Internal buses are diagnostic results and do not receive an IEEE verdict.

Run and inspect

1. Choose Run harmonics from the canvas study controls.
2. Read the bus annotations for voltage distortion, PCC TDD and design-limit status.
3. Open Harmonics in the project navigation for saved runs, per-order tables, charts, limit citations and recorded assumptions.

The voltage comparison uses the rated-voltage basis. TDD uses the fixed maximum-demand current, while diagnostic THD uses the solved fundamental. A rounded display value does not decide whether a limit is met.

Engineering edits mark affected saved results stale. Rerun to assess the new model. You can still inspect historical runs with their original inputs, including runs whose original scenario was deleted.

Compare capacitor and reactor scenarios

Use scenarios to change the energized steps of a capacitor bank or choose a supported reactor-equipped drive profile. The bank's Rated kvar describes the entire bank; Energized Steps, on its Equipment tab, selects the connected fraction. The study models the bank as a shunt capacitor with the energized steps of each scenario. A physical input reactor uses its entered rating and impedance separately from the source spectrum.

Select a saved run in Compare harmonic run to compare distortion and scan curves. EKX identifies different boundary, utility, demand or frequency bases. It does not calculate an improvement percentage between unlike bases.

A physical reactor alone does not justify lower source emissions. Select documented reactor-equipped data where applicable. Tuned passive-filter design and active-filter sizing are outside this study.

Export the evidence

Use Export CSV for recorded spectra, comparisons, scans and source provenance. Use Export report for a harmonic report in Markdown, HTML or Word, with the recorded inputs and assumptions. Saved report content remains available when old study runs are pruned.

Equipment schedules include installed source profiles and relevant passive, transformer, utility and cable models. Enabled harmonic annotations also carry into the diagram's PDF export.

Project exports preserve the engineering inputs and immutable study evidence. A restored project remaps equipment references and requires a new run; historical hashes are not rewritten to imply that an old calculation ran on the restored project.

Supported scope

This release supports balanced three-phase design studies, orders 2–50, documented current spectra, supported transformer displacement and sequence paths, capacitor switching and input reactors. Unsupported grounding, sequence or equipment models make only the affected result unavailable, with the reason shown. Single-phase and unbalanced networks, measurement statistics, active-filter sizing and ETAP library import are outside this release.

Harmonics uses the same plan eligibility and shared run allowance as short circuit. A whole harmonic study counts as one run, including its internal solves and scan. Viewers can inspect saved results but cannot run studies or change inputs.