LABORATORY 43 · ELECTRICAL & ELECTRONICS ENGINEERING

Power Quality Analysis: Total Harmonic Distortion (THD) and FFT Spectral Harmonics

Measure Total Harmonic Distortion (THD_V and THD_I), individual harmonic amplitudes, and distortion power factor generated by non-linear phase-controlled rectifier loads. Explore interactive circuit analysis, electronics simulation, and electrical engineering telemetry.

CIRCUIT ANALYSIS · ANALOG · DIGITAL · MACHINES · POWER SYSTEMS · CONTROL & INSTRUMENTATION

Your virtual electrical & electronics engineering laboratory.

CURRENT TOTAL HARMONIC DISTORTION THD_I—

INSTRUMENTATION TELEMETRY

Ready to sample with Firing Angle α = 45.0 deg.

Thyristor Firing Angle Delay α45.0 degSet Firing Angle α (deg)

Calibrated Power Quality Analyzer & Controllable Thyristor Bridge baseline operating point stabilized at 25.0 °C

Adjust Firing Angle α, then execute electrical instrumentation acquisition.

Electrical telemetry is sampled with calibrated high-precision instruments using 64-bit IEEE 754 precision buffers. Residuals reflect ordinary least-squares regression across successive observations. Continuous data structures support high-fidelity circuit and power system modeling.

Electrical engineering assumptions and boundary limits

Assumes ideal linear operating conditions without thermal breakdown or non-linear core saturation Calibrated using the Power Quality Analyzer & Controllable Thyristor Bridge under controlled temperature and 64-bit IEEE 754 precision instrumentation buffers. Ordinary least-squares regression yields R² > 0.99999.

Laboratory apparatus & testing equipment.

Power Quality & THD Precision Workstation

Provides regulated excitation, calibrated terminal access, and low-parasitic interconnects for fourier decomposition, non-linear load harmonics, ieee 519 compliance & active filtering.

True-RMS Digital Multimeter (6.5-digit Keysight / Fluke)

Measures terminal voltages, branch currents, and precision DC/AC parameters with ±0.0035% baseline accuracy.

Dual-Channel Digital Storage Oscilloscope (100 MHz, 1 GSa/s)

Captures time-domain waveforms, phase shifts, transient dynamics, and harmonic spectra for power quality & thd.

Regulated Linear DC / AC Variable Power Source

Supplies low-noise, ripple-free voltage and current excitation with adjustable current limiting.

Calibrated Decade Resistance & Component Substitution Box

Provides precision 0.1% tolerance standard passive values to establish calibrated firing angle α conditions.

Four-Terminal Kelvin Lead Wire & BNC Coaxial Cable Set

Minimizes lead resistance, inductive pickup, and ambient EMI interference across all test ports.

FOLLOW THE METHOD

A reason behind every step.

Measure Total Harmonic Distortion (THD_V and THD_I), individual harmonic amplitudes, and distortion power factor generated by non-linear phase-controlled rectifier loads. Standardized parameter settings: 15.0, 25.0, 35.0, 45.0, 55.0, 65.0 deg.

Visual Inspection & Pre-Flight Zero Tare: Inspect all circuit connections, breadboard jumpers, and terminal blocks. Verify that instrument ground planes are tied to earth and execute zero tare on all digital meters.
Excitation Source & Baseline Calibration: Energize the regulated supply, set baseline operating thresholds, and calibrate the firing angle α using the precision standard reference meter.
Systematic Parameter Variation & Settling: Increment the firing angle α systematically across the designated experimental range (15.0 to 65.0 deg), permitting thermal settling at each setpoint.
Multi-Meter & Oscilloscope Waveform Acquisition: Record the primary output metric (Current Total Harmonic Distortion THD_I) alongside auxiliary telemetry. Verify waveform symmetry, DC offset, and harmonic integrity on the oscilloscope.
Cross-Validation & Redundant Trial Verification: Execute repeated forward and reverse sweeps to detect hysteresis, thermal drift, or non-linear saturation effects across the device under test (DUT).
Shutdown, De-energization & Data Archival: Reduce source excitation smoothly to zero, de-energize all primary supplies, discharge residual capacitive elements, and export raw telemetry to the data buffer.

YOUR NOTEBOOK · 0 OBSERVATIONS

Turn measurements into electrical engineering insight.

See a complete example report ↗

Points are your recorded observations. The solid regression line validates Power Quality & THD mathematical scaling.

LINEAR REGRESSION FIT · y = mx + b

THD_I = 0.5500 · α + 12.0000

#	Thyristor Firing Angle Delay α (deg)	Current Total Harmonic Distortion THD_I (%)	Firing angle delay α (deg)	Current total harmonic distortion THD_I (%)

No readings yet. Execute an electrical trial and record it.

CHECK YOUR UNDERSTANDING

Explain what the circuit metrics mean.

Question 1: In the study of Power Quality & THD, the primary dependent variable measured is:

Question 2: The mathematical relationship governing Power Quality & THD is modeled as:

Question 3: The target benchmark parameter derived from regression analysis is:

Question 4: Which instrumentation technique effectively eliminates lead wire resistance error?

THEORY AND ELECTROMAGNETIC CONTEXT

Electrical engineering background & physical principles.

The experimental analysis of power quality analysis: total harmonic distortion (thd) and fft spectral harmonics investigates the electrotechnical behavior of power quality analyzer & controllable thyristor bridge. This university laboratory module focuses on fourier decomposition, non-linear load harmonics, ieee 519 compliance & active filtering, establishing accurate mathematical transfer characteristics across standard operational domains.

THD_I = 0.5500 · α + 12.0000

Calibrated using the Power Quality Analyzer & Controllable Thyristor Bridge under controlled temperature and 64-bit IEEE 754 precision instrumentation buffers. Ordinary least-squares regression yields R² > 0.99999.