Capacitor Equivalent Circuit Model DC Bias Correction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for deriving equivalent circuit models of capacitors do not accurately reflect changes in characteristic values due to DC bias voltage, requiring separate models for each voltage level and lacking continuity between models at different bias voltages.
Innovation Solution
A method that uses a dimensionless coefficient to correct the characteristic values of resistive, capacitive, and inductive elements based on material-specific changes, allowing a single equivalent circuit model to accurately simulate capacitor characteristics across varying DC bias voltages by expressing these changes as an approximate function of the applied voltage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If separate equivalent circuit models are derived for each DC bias voltage value, then the accuracy of capacitor characteristic representation at each voltage level is improved, but the device complexity and the number of models required increase significantly
Solution Approach 1:
The patent merges multiple separate equivalent circuit models (one for each DC bias voltage level) into a single unified model. This is achieved by introducing a voltage-dependent scaling factor that adjusts the characteristic values of circuit elements based on the applied DC bias voltage, allowing one model to represent capacitor behavior across the entire voltage range from 0 to rated voltage.
Solution Approach 2:
The patent creates a universal equivalent circuit model that can simulate capacitor characteristics at any DC bias voltage level within the rated range. The model uses a scaling factor derived from measured data at different voltage points to universally represent voltage-dependent behavior, eliminating the need for voltage-specific models while maintaining accuracy.
2Measurement precision
If multiple equivalent circuit models are created for different DC bias voltages, then the representation accuracy at each voltage level is improved, but the ease of operation and continuity between models deteriorate
Solution Approach 1:
The patent combines multiple voltage-specific models into one continuous model using a scaling factor that smoothly transitions with DC bias voltage. This eliminates discontinuities between models and allows users to perform simulations across the full voltage range without manually switching between different models or ensuring continuity.
3Ease of operation
If a single equivalent circuit model is used for all DC bias voltages, then the ease of operation and simplicity are improved, but the accuracy of representing voltage-dependent characteristic changes deteriorates
Solution Approach 1:
The patent introduces dynamic adjustment of circuit element parameters through a voltage-dependent scaling factor. Instead of using fixed characteristic values, the model dynamically scales resistance, capacitance, and inductance values based on the applied DC bias voltage, allowing the single model to accurately represent voltage-dependent behavior while maintaining simplicity.
Solution Approach 2:
The patent changes the parameters of the equivalent circuit model based on DC bias voltage levels. By deriving a scaling factor from measured characteristic values at different voltage points and applying it to the circuit elements, the model accurately captures parameter variations with voltage while remaining a single unified structure.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A method for deriving an equivalent circuit model of a capacitor is provided which makes it possible to derive, with high accuracy and with ease, an equivalent circuit model having characteristics in accordance with a direct current voltage applied to a capacitor. In the present invention, characteristic values of predetermined resistive elements R2 to R6 and capacitive elements C1, C7, and C8 forming an equivalent circuit model of a capacitor 1 change in response to a DC bias voltage v2 being applied to the capacitor 1, and the change is attributable to the material of a dielectric 2 forming the capacitor 1. However, by multiplying the characteristic values of the resistive elements R2 to R6 and the capacitive elements C1, C7, and C8 held while the DC bias voltage v2 is not applied by a dimensionless coefficient 15 in accordance with an application rule 16, the characteristic values of the resistive elements R2 to R6 and the capacitive elements C1, C7, and C8 are corrected to values in accordance with the voltage of the DC bias voltage v2 applied to the capacitor 1.