Capacitor Capacitance Estimation via Ripple Voltage Analysis
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing capacitor capacitance monitoring techniques require separate measurement of load current to account for load fluctuations, complicating the estimation process.
Innovation Solution
A capacitor capacitance estimation device that uses a filter to remove load fluctuation influences, extracts carrier frequency components from AC voltage signals, and estimates capacitance based on processed time-series data without needing load current measurement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If separate measurement of load current is performed to account for load fluctuations in capacitance monitoring, then measurement precision of capacitance is improved, but device complexity increases
Solution Approach 1:
The patent extracts the load fluctuation information directly from the capacitor voltage signal itself by analyzing ripple voltage characteristics, rather than requiring separate load current measurement. This isolation of the needed information from the voltage signal eliminates the need for additional current sensors and simplifies the measurement system while maintaining capacitance measurement precision.
Solution Approach 2:
The capacitor voltage sensor serves multiple functions: it simultaneously provides both the capacitor voltage information needed for capacitance calculation and the ripple voltage information needed to assess load fluctuations. This multi-functionality eliminates the need for separate load current measurement devices, reducing system complexity while maintaining measurement accuracy.
2Reliability
If separate measurement of load current is performed to account for load fluctuations, then reliability of capacitance diagnosis is improved, but ease of operation deteriorates
Solution Approach 1:
The system uses the existing capacitor voltage signal to self-diagnose load fluctuation effects without requiring external load current measurement. The ripple voltage analysis within the voltage signal enables the system to automatically compensate for load variations, maintaining diagnosis reliability while simplifying operation to a single voltage measurement.
3Productivity
If ripple voltage peak hold value is used for capacitance monitoring, then productivity is improved, but measurement precision deteriorates due to load fluctuation influence
Solution Approach 1:
The patent introduces ripple voltage analysis as an intermediary parameter that mediates between the capacitor voltage signal and the capacitance calculation. By using ripple voltage characteristics to assess and compensate for load fluctuation effects, the system maintains the simplicity and productivity of voltage-based monitoring while improving measurement precision through load condition awareness.
Data Source
AI summary
A capacitor capacitance estimation device including processing circuitry to segment a section signal into a plurality of signals and to generate a plurality of pieces of frequency domain data by converting each of the plurality of signals obtained by the segmentation into a plurality of component values in a frequency domain. Each of the plurality of signals having a predetermined duration. The processing circuitry further configured to extract a component value of a frequency corresponding to a carrier frequency from the plurality of component values in each of the plurality of pieces of frequency domain data, to use the extracted component value as a value at time corresponding to the corresponding one of the extracted signals, and to generate time-series data representing a plurality of the extracted component values in a time series, to estimate a capacitance of a capacitor from processed and filtered time-series data.