Inductor Power Loss Analysis Using FEA
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Solution Overview
Problem
Inductors designed for fundamental frequencies often experience unexpectedly high losses and excessive heating when exposed to non-fundamental frequencies, leading to rework or scrapping due to inaccurate power loss estimation.
Innovation Solution
A method and system using electromagnetic field simulation finite element analysis software to determine power loss in inductors by calculating the ratio of AC resistance to DC resistance and summing winding and core losses at various frequencies, allowing for accurate estimation of power loss at non-fundamental frequencies.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If rules of thumb based on 60 Hz or 50 Hz designs are used to estimate power loss, then design simplicity is improved, but measurement precision of power loss deteriorates
Solution Approach 1:
The patent changes the fundamental parameter from single-frequency (60/50 Hz) design rules to multi-frequency analysis. By incorporating frequency as a variable parameter and using finite element analysis to calculate Rac/Rdc ratios at different frequencies, the method achieves accurate power loss prediction across the full frequency spectrum while maintaining systematic design procedures.
Solution Approach 2:
The patent replaces empirical mechanical design rules with electromagnetic field simulation. By substituting the mechanical/rules-based approach with finite element analysis software that solves Maxwell's equations, the system achieves precise power loss calculation without relying on inaccurate thumb rules, while the software automation maintains design efficiency.
2Loss of time
If inductors are designed based on 60 Hz or 50 Hz designs, then design time is reduced, but reliability under non-fundamental frequencies deteriorates
Solution Approach 1:
The patent performs preliminary multi-frequency power loss analysis during the design phase using finite element simulation. By calculating Rac/Rdc ratios and estimating power loss at all expected operating frequencies before manufacturing, the method prevents reliability failures without requiring time-consuming post-manufacturing testing or rework.
Solution Approach 2:
The patent implements a feedback mechanism where simulated power loss results at different frequencies are fed back into the design process. The Rac/Rdc ratio calculations and power loss estimates provide feedback that allows designers to optimize winding configurations and core selections to ensure reliable performance across the full frequency spectrum.
3Measurement precision
If accurate power loss determination at non-fundamental frequencies is achieved through electromagnetic field simulation, then measurement precision is improved, but device complexity increases
Solution Approach 1:
The patent introduces finite element analysis software as an intermediary tool that bridges the gap between complex electromagnetic theory and practical design. The software acts as a mediator that automatically performs the complex field calculations, allowing designers to obtain accurate power loss predictions without needing to manually solve complex differential equations or perform sophisticated measurements.
Solution Approach 2:
The patent creates a virtual copy of the inductor through finite element modeling. By building a digital twin that replicates the electromagnetic behavior of the physical inductor, the system enables accurate power loss analysis at multiple frequencies without requiring physical prototypes or complex measurement apparatus for each frequency point.
4Adaptability or versatility
If inductors are exposed to non-fundamental frequencies, then adaptability of the power supply system is improved, but loss of energy increases due to unexpected heating
Solution Approach 1:
The patent performs preliminary power loss analysis at all expected operating frequencies including non-fundamental frequencies during the design phase. By proactively identifying and quantifying power loss at harmonic frequencies and other non-fundamental frequencies, the method enables designers to select appropriate core materials and winding configurations that minimize energy losses across the full frequency spectrum.
Solution Approach 2:
The patent treats frequency as a critical design parameter rather than a fixed value. By analyzing power loss as a function of frequency and incorporating the Rac/Rdc ratio variation with frequency, the method enables optimization of inductor parameters (core material, winding geometry, lamination structure) to maintain low energy losses across variable frequency operation.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach enables precise determination of power loss in inductors across a range of frequencies, preventing excessive heating and reducing the need for rework by providing accurate design specifications.
Implementation Method 1
the rules of thumb and fudge factors used when designing inductors are based on the inductor being exposed to only 60 Hz. or 50 Hz. frequencies. Inductors built based on 60 Hz. or 50 Hz. designs that are exposed to frequencies that are above (or even below) 60 Hz. or 50 Hz. can have unexpectedly high losses
Implementation Method 2
Core loss of the inductor is determined at the one or more frequencies using a core loss versus frequency curve
Data Source
AI summary
Described herein are embodiments of a method and system for determining power loss in an inductor. In accordance with one aspect, a method is provided of determining power loss in an inductor. The method comprises modeling an inductor's windings and core using electromagnetic field simulation finite element analysis software executing on a computer. A ratio of AC resistance to DC resistance (Rac/Rdc) for the inductor is determined at one or more frequencies using the electromagnetic field simulation finite element analysis software. DC resistance (Rdc) of the windings is determined based on material properties and shape of the windings. The DC resistance is used to determine AC resistance (Rac) using the ratio, Rac/Rdc. Winding power loss at the one or more frequencies is determined based on the AC resistance (Rac). Core loss of the inductor is determined at the one or more frequencies using a core loss versus frequency curve. Winding power loss and core loss are summed at each of the one or more frequencies to determine total power loss at the respective frequency.