Name: Waveform Analysis
Author: lgili

Waveform Analysis

Waveform analysis specialist for power electronics simulators. Covers FFT-based harmonic decomposition, THD, power factor, RMS/average/peak calculations, steady-state detection, and spectral leakage mitigation. Use when processing simulation output waveforms for quality metrics, harmonic content, or determining when the simulation has reached periodic steady state. Trigger for terms like "FFT", "harmonic", "THD", "RMS", "power factor", "steady state", "spectral leakage", "windowing", "DFT", "harmonic distortion", "cycle detection", or "convergence to steady state".

lgili0 starsApr 9, 2026

Occupation
Categories: Data Analysis

Overview

Use this skill when the simulation has produced waveform data and needs to be post-processed: extracting RMS values, harmonic content, power quality metrics, or detecting when the simulation has reached a periodic steady state.

Default stance:

Do not report results until the simulation has reached steady state — transient data pollutes all metrics.
FFT requires exactly N complete cycles of the periodic signal — windowing or spectral leakage otherwise corrupts the harmonic analysis.
RMS and average must be computed over complete switching periods, not arbitrary windows.
THD is defined relative to the fundamental — for inverter output, fundamental is at grid frequency; for converter ripple, fundamental is at switching frequency.
Always report the frequency resolution and number of cycles used when presenting FFT results.

Core Workflow

Detect steady state.
- Simulation reaches periodic steady state when the waveform at t repeats at t + T_sw (within tolerance).
- Check both voltage and current waveforms at representative nodes.

Overview

Default stance:

Do not report results until the simulation has reached steady state — transient data pollutes all metrics.
FFT requires exactly N complete cycles of the periodic signal — windowing or spectral leakage otherwise corrupts the harmonic analysis.
RMS and average must be computed over complete switching periods, not arbitrary windows.
THD is defined relative to the fundamental — for inverter output, fundamental is at grid frequency; for converter ripple, fundamental is at switching frequency.
Always report the frequency resolution and number of cycles used when presenting FFT results.

Core Workflow

Detect steady state.
- Simulation reaches periodic steady state when the waveform at t repeats at t + T_sw (within tolerance).
- Check both voltage and current waveforms at representative nodes.

Topic	Reference	Load when
FFT and spectral analysis	`references/spectral-analysis.md`	Setting up FFT, windowing, identifying harmonics, interpreting spectra
Steady-state detection	`references/steady-state-detection.md`	Detecting convergence to periodic steady state in simulation output
Power quality metrics	`references/power-quality-metrics.md`	Computing THD, power factor, DPF, crest factor, or checking against standards

Waveform Analysis

Overview

Core Workflow

Waveform Analysis

Overview

Core Workflow

Reference Guide

Bundled Scripts

Constraints

MUST DO

MUST NOT DO

Output Template

Primary References

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