๐ŸŽ“Academic Preprints & Open Educational Resources (OER)
๐Ÿ›ก๏ธCC BY 4.0 Open Access
๐Ÿ“ŠFigshare & Harvard Dataverse DOIs

Engineering Research & Technical Whitepapers

Peer-referenced technical reports, mathematical modeling frameworks, and continuous-duty electrical engineering preprints published by the PowerLab Open Energy Research Group. All papers are open-access under Creative Commons CC BY 4.0 and registered with persistent DOIs for academic courseware, syllabus citation, and laboratory benchmarking.

PL-TR-2026-EVSE01Electric Vehicles2026-08-26

Continuous-Duty Thermal Sizing, Conductor Terminal Limits, and Branch Circuit Ampacity Requirements for Residential Level 2 EVSE

A rigorous mathematical and code-compliance analysis of continuous-load thermal mechanics in residential Level 2 Electric Vehicle Supply Equipment (EVSE). Evaluates the 125% continuous duty multiplier under NFPA 70 (NEC Article 625.42), terminal temperature ratings under NEC 110.14(C) (60ยฐC vs 75ยฐC limits), conductor ampacity derating adjustments under NEC Table 310.16, and Joule heating dynamics (IยฒR) in residential enclosures.

๐Ÿ›๏ธ NFPA 70 / NEC Article 625 (Electric Vehicle Power Transfer Systems)๐Ÿ›๏ธ NFPA 70 / NEC Section 110.14(C) (Temperature Limitations of Terminations)๐Ÿ›๏ธ NFPA 70 / NEC Table 310.16 (Allowable Ampacities of Insulated Conductors)๐Ÿ›๏ธ SAE J1772 / SAE J3400 (NACS Charging Standard)๐Ÿ›๏ธ UL 2594 (Electric Vehicle Supply Equipment)
Read Paper Online โ†’๐Ÿ“„Download PDF๐ŸŽ“Academia.eduโ†—
PL-TR-2026-HVAC01Home Energy2026-08-28

Thermal Degradation Kinetics, Auxiliary Electric Resistance Staging, and Seasonal HSPF2/COP Derating in Cold-Climate Air-Source Heat Pumps

A thermodynamic evaluation of air-source heat pump (ASHP) performance across sub-freezing ambient temperature spectra (-20ยฐC to +10ยฐC). Models vapor-compression Carnot limits, refrigeration enthalpy drops, coefficient of performance (COP) nonlinear decline, defrost cycle parasitic consumption, and the financial impact of staging auxiliary electric resistance elements (strip heat) versus dual-fuel natural gas systems.

๐Ÿ›๏ธ AHRI Standard 210/240-2023 (Performance Rating of Unitary Air-Conditioning & Heat Pumps)๐Ÿ›๏ธ ASHRAE Standard 90.1 (Energy Standard for Buildings)๐Ÿ›๏ธ U.S. Department of Energy 10 CFR Part 430 Appendix M1๐Ÿ›๏ธ ISO 5151 (Non-Ducted Air Conditioners and Heat Pumps)
Read Paper Online โ†’๐Ÿ“„Download PDF๐ŸŽ“Academia.eduโ†—
PL-TR-2026-GEN02Home Energy2026-08-27

Deterministic Modeling of Inductive Motor Inrush Currents and Non-Coincident Load Stacking for Residential Backup Power Systems

Presents a deterministic load sizing framework for emergency residential generators under NEC Article 702 and ISO 8528-5. Investigates transient sub-transient reactance (X''d), Locked Rotor Amperage (LRA) voltage dip envelopes during inductive motor starts (compressors, well pumps, sump pumps), sequential soft-starting step curves, and fuel-type derating factors (Gasoline vs Propane vs Natural Gas).

๐Ÿ›๏ธ NFPA 70 / NEC Article 702 (Optional Standby Systems)๐Ÿ›๏ธ NEMA MG-1 (Motors and Generators - Locked Rotor KVA/HP Codes)๐Ÿ›๏ธ ISO 8528-5 (Reciprocating Internal Combustion Engine Driven Alternators)๐Ÿ›๏ธ IEEE Standard 446 (Orange Book - Emergency & Standby Power)
Read Paper Online โ†’๐Ÿ“„Download PDF๐ŸŽ“Academia.eduโ†—
PL-TR-2026-SOL03Solar Photovoltaics2026-08-30

Ground View Factor Transposition, Snow Albedo Dynamics, and Sub-Zero Open-Circuit Voltage Expansion in Photovoltaic Arrays

Examines anisotropic sky diffuse and ground-reflected albedo transposition models (Perez & Hay-Davies) across seasonal solar panel tilt configurations. Quantifies high-latitude snow albedo capture enhancements (+25% to +40% diffuse boost), sub-zero temperature coefficient open-circuit voltage expansion (NEC 690.7), and string inverter maximum DC input voltage limits.

๐Ÿ›๏ธ NFPA 70 / NEC Article 690.7 (Maximum Voltage Calculation)๐Ÿ›๏ธ IEC 61724-1 (Photovoltaic System Performance Monitoring)๐Ÿ›๏ธ NREL PVWatts V8 (Solar Resource Physical Algorithm)๐Ÿ›๏ธ ASHRAE Climatic Design Conditions (Extreme Minimum Dry Bulb)
Read Paper Online โ†’๐Ÿ“„Download PDF๐ŸŽ“Academia.eduโ†—
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Student Laboratory Exercises & Courseware

Turnkey computational laboratory exercises and problem sets designed for undergraduate electrical engineering courses, clean energy degree programs, and vocational IBEW/NECA apprenticeships. Each module pairs first-principles physical derivations with side-effect-free, open-access simulation engines.

Lab Unit 01EE 301 / Energy Systems Engineering & CTE ApprenticeshipsUndergraduate / Advanced Vocational

Battery Electrochemical Peukert Capacity Derating, C-Rate Kinetics, and Quiescent Inverter Tare Losses

Quantitative analysis of non-linear lead-acid vs. LiFePO4 discharge envelopes, Peukert exponent derating, and continuous standby parasitic load under IEEE 485.

Students model real-world battery bank autonomy across varying discharge rates (0.05C to 1.0C). The exercise contrasts empirical Peukert derating across lead-acid (k = 1.15โ€“1.30) vs. LiFePO4 (k = 1.02โ€“1.05) chemistries, revealing how low-load inverter tare dissipation can reduce autonomy by over 50%.

๐ŸŽฏ Key Learning Objectives
  • Calculate effective amp-hour and watt-hour capacity using the generalized Peukert equation normalized to rated discharge period H.
  • Evaluate depth-of-discharge (DoD) cycling life tradeoffs under IEEE 485 stationary storage guidelines.
  • Quantify continuous inverter tare power dissipation (Ptare) impact on autonomy during low-power emergency medical or telecommunication loads.
๐Ÿ“ IEEE 485 (Sizing Lead-Acid Batteries for Stationary Systems)๐Ÿ“ UL 1973 (Batteries for Stationary & Microgrid Applications)๐Ÿ“ IEC 62619 (Secondary Lithium Cells & Batteries)
Lab Unit 02Solar PV Engineering / Applied Physics / Microgrid DesignUndergraduate / Clean Energy Certificate

Photovoltaic Ground View Factor Transposition, Snow Albedo Dynamics, and Sub-Zero Voc Expansion

Mathematical modeling of anisotropic sky diffuse transposition, high-latitude snow albedo reflection gains, and cold-temperature open-circuit voltage expansion under NEC 690.7.

Investigates the ground view factor (1 - cos ฮฒ)/2 in tilted photovoltaic arrays. Students quantify diffuse irradiance amplification across high-albedo winter ground cover and calculate temperature-adjusted string Voc peaks to protect MPPT power electronics from cold-weather destruction.

๐ŸŽฏ Key Learning Objectives
  • Model plane-of-array (POA) irradiance using Perez anisotropic transposition and ground-reflected albedo components.
  • Determine maximum historical DC string voltage under NEC 690.7 using ASHRAE extreme dry-bulb design temperatures.
  • Optimize seasonal fixed-tilt vs. latitude-based tilt angles for winter self-reliance versus annual generation maximization.
๐Ÿ“ NFPA 70 / NEC Article 690.7 (Maximum Voltage Calculation)๐Ÿ“ IEC 61724-1 (Photovoltaic Performance Monitoring)๐Ÿ“ NREL SAM / PVWatts V8 Model Guidelines
Lab Unit 03Power Distribution / Commercial Electrification / IBEW ApprenticeshipsTechnical Apprenticeship / Upper Division EE

Continuous-Duty Thermal Sizing, Conductor Terminal Limits, and Branch Circuit Ampacity for Level 2 EVSE

Rigorous electrical design applying the 125% continuous duty multiplier under NEC 625.42 and terminal temperature termination derating under NEC 110.14(C).

Students evaluate continuous-load thermal mechanics in electric vehicle branch circuits. Focuses on terminal lug heating (IยฒR), 60ยฐC vs. 75ยฐC conductor termination limits, and the code hazard of using 6 AWG Romex (NM-B) for 48A charging.

๐ŸŽฏ Key Learning Objectives
  • Apply the mandatory 125% continuous duty overcurrent protective device multiplier under NFPA 70 / NEC 625.42.
  • Identify terminal temperature column limitations (NEC 110.14(C)) and distinguish between NM-B (60ยฐC capped) vs. THHN conduit systems.
  • Calculate steady-state conductor resistive power dissipation and voltage drop over extended branch circuit runs.
๐Ÿ“ NFPA 70 / NEC Article 625 (Electric Vehicle Power Transfer Systems)๐Ÿ“ NFPA 70 / NEC Section 110.14(C) (Termination Limitations)๐Ÿ“ UL 2594 (Electric Vehicle Supply Equipment)
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Open Benchmark Datasets & Replication Repositories

Verified empirical tabular datasets and reproducible calculation packages registered with persistent DataCite DOIs across Harvard Dataverse and Figshare. Freely accessible for university electrical engineering courseware, lab validation, and DER infrastructure modeling.

FigshareDOI: 10.6084/m9.figshare.33321774120 Records โ€ข CSV / Replication Package

Level 2 EVSE Continuous-Duty Conductor & Terminal Temperature Benchmark Dataset

Continuous-duty Joule heating (IยฒR), conductor temperature rise, and 60ยฐC vs 75ยฐC terminal temperature envelopes under NEC 625.42.

Benchmark matrix tabulating 120 continuous load runs (16A to 80A), wire gauge thermal limits (14 AWG to 2 AWG Cu/Al), conduit fill ampacity derating, and contact resistance thermal runaway thresholds.

FigshareDOI: 10.6084/m9.figshare.33470950240 Records โ€ข CSV / Tabular Matrix

Cold-Climate Air-Source Heat Pump COP Degradation & Balance Point Dataset

Sub-freezing ambient temperature spectra (-20ยฐC to +10ยฐC) COP degradation, flash-injection capacity curves, and auxiliary resistive staging economics under AHRI 210/240.

Empirical thermodynamic performance matrix for variable-speed inverter vapor scroll heat pumps across outdoor temperatures, evaluating sensible heating capacity, electrical power draw, and balance point transition curves.

Harvard Dataverse180 Records โ€ข Tabular Matrix

Residential Standby Generator Motor Inrush & Sub-Transient Voltage Dip Matrix

Locked Rotor Amperage (LRA) sub-transient reactance (X''d) voltage dip envelopes and fuel derating factors (Gasoline vs Propane vs Natural Gas) under ISO 8528-5.

Transient response benchmark tracking 0.1s to 0.5s instantaneous voltage sag and frequency recovery curves across single-phase induction motor compressor starts with and without solid-state soft starters.

Read Paper & Mathematical Model โ†’๐Ÿ”’ Accession Pending (Harvard Dataverse)
Harvard Dataverse160 Records โ€ข Tabular Matrix

Ground-Reflected Snow Albedo & Sub-Zero Photovoltaic Voc Expansion Dataset

Anisotropic diffuse transposition capture and sub-zero open-circuit voltage expansion envelopes under NEC 690.7 and IEC 61724-1.

Multi-tilt empirical transposition dataset evaluating ground-reflected albedo (rho = 0.20 grass to rho = 0.80 fresh snow) and cold-weather string voltage expansion across high-latitude solar installations.

Read Paper & Mathematical Model โ†’๐Ÿ”’ Accession Pending (Harvard Dataverse)

Academic Courseware Adoption & Syllabus Integration

PowerLab whitepapers and computational models are specifically designed for direct adoption into undergraduate engineering curricula, vocational electrical apprenticeship training (IBEW/NECA/NJATC), and graduate research:

  • Zero Paywalls or Student Logins: All formulas, source code, and whitepaper datasets are available without student registration or paywall gating.
  • Permanent DOI Archiving: Preprints and benchmark datasets are mirrored across Harvard Dataverse and Figshare with permanent Digital Object Identifiers.
  • Interactive Syllabus Companion: Every technical report links directly to its companion browser-local simulation engine for class assignments and lab exercises.
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