DC-Link Pre-Charge Circuitry for Battery Impedance Measurement
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional electrochemical impedance spectroscopy (EIS) systems for battery health assessment in electric vehicles require additional energy and circuitry to generate stimulus signals, leading to increased energy consumption and costs.
Innovation Solution
Utilize the DC-link pre-charge circuitry in electric vehicles to generate a stimulus signal for EIS analysis by leveraging the energy typically wasted during inrush current limitation, reducing the need for separate excitation circuitry and power sources.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional EIS systems use separate excitation circuitry and power sources to generate stimulus signals, then measurement precision is improved, but use of energy and device complexity increase
Solution Approach 1:
The pre-charge circuitry is designed to perform dual functions: limiting inrush current during battery charging and generating stimulus signals for EIS measurements. The inverse buck circuitry and capacitors used for pre-charging are repurposed to create the excitation signal, eliminating the need for separate excitation circuitry and reducing overall system energy consumption.
Solution Approach 2:
The system uses its own pre-charge circuitry to generate the stimulus signal needed for EIS measurements, rather than relying on external or dedicated excitation sources. The pre-charge circuitry serves itself by providing the excitation signal during the pre-charge phase, making the system self-sufficient and reducing additional energy requirements.
2Measurement precision
If conventional EIS systems use separate excitation circuitry to generate stimulus signals, then measurement precision is improved, but device complexity and costs increase
Solution Approach 1:
The pre-charge circuitry is designed to perform dual functions: limiting inrush current during battery charging and generating stimulus signals for EIS measurements. The inverse buck circuitry and capacitors used for pre-charging are repurposed to create the excitation signal, eliminating the need for separate excitation circuitry and reducing overall system energy consumption.
Solution Approach 2:
The patent combines the pre-charge function and stimulus signal generation function into a single integrated circuitry system. The pre-charge circuitry and EIS measurement system are merged, allowing the same hardware components to serve both purposes simultaneously, thereby reducing device complexity and component count.
3Loss of energy
If the pre-charge circuitry generates stimulus signals during inrush current limitation, then energy consumption is reduced, but the periodic waveform quality for EIS analysis must be maintained
Solution Approach 1:
The patent converts the typically wasted energy during inrush current limitation into a useful stimulus signal for EIS measurements. The periodic waveform generated while limiting inrush current is not discarded but instead utilized as the excitation signal, transforming energy that would otherwise be lost into a beneficial measurement resource.
Solution Approach 2:
The pre-charge circuitry generates a periodic waveform during the pre-charge phase, which is then used as the stimulus signal for EIS measurements. The periodic nature of the waveform is maintained and leveraged for accurate impedance measurements, ensuring that the rhythmic charging/discharging of the capacitor creates a suitable excitation signal across different frequency ranges.
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 reduces energy consumption and costs associated with EIS systems while providing accurate battery health assessments by utilizing existing pre-charge circuitry to generate stimulus signals for impedance measurements.
Implementation Method 1
the pre-charge circuitry is configured to limit an inrush current during charging of the at least one battery, including charging the first capacitor with a periodic waveform
Implementation Method 2
the EIS circuitry is further configured to measure an impedance of the battery based on the response signal
Data Source
AI summary
Systems, apparatuses, and methods for electrochemical impedance spectroscopy (EIS) for use with batteries are provided, including for a pre-charge circuit on electric vehicles that may be used to generate a stimulus signal for EIS analysis of one or more batteries. An exemplary system may comprise a battery, a pre-charge circuitry, and EIS circuitry. The pre-charge circuitry comprising an inverse buck circuitry with a first capacitor and configured to limit an inrush current during loads connection, which includes charging the first capacitor with a periodic waveform. The EIS circuitry receives the periodic waveform and transmits it as a stimulus signal to the battery. The EIS circuitry receives a response signal from the battery in response to the stimulus signal and generates an impedance of the battery based on the response signal.