Common-Mode Filter With Fluxgate Sensing for EV Charging EMI
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Solution Overview
Problem
Existing common mode current filters for electric and hybrid vehicle charging systems are bulky and costly, limiting their miniaturization and performance enhancement, while also posing challenges in combining safety standards with reduced size and cost requirements.
Innovation Solution
A common mode current filter with a magnetic core and multiple electrical windings, incorporating a fluxgate magnetometer within the coils to detect current unbalances, optimizing the system's dimensions and cost by integrating safety monitoring without increasing size or cost.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If traditional common mode inductors are used for EMI/RFI filtering, then electromagnetic interference is prevented, but the device occupies significant space and increases system cost
Solution Approach 1:
The patent combines the EMI/RFI filtering function with the residual current detection function into a single integrated device. The common mode inductor structure incorporates a fluxgate magnetometer that can detect both electromagnetic interference and residual currents, eliminating the need for separate filtering components and reducing overall device space.
Solution Approach 2:
The integrated device performs multiple functions simultaneously: it provides common mode EMI/RFI filtering while also enabling residual current detection for safety monitoring. This multi-functionality allows a single component to replace what would traditionally require multiple separate devices, thereby reducing the total space occupied in the charging system.
2Object-affected harmful factors
If traditional common mode inductors are used for filtering, then electromagnetic interference is reduced, but system cost increases
Solution Approach 1:
By merging the filtering and detection functions into one integrated device, the patent reduces the total component count and assembly complexity. This integration lowers manufacturing costs through reduced material usage, fewer assembly steps, and simplified supply chain management compared to using separate filtering components.
Solution Approach 2:
The multi-functional integrated device provides both EMI/RFI filtering and residual current detection capabilities, eliminating the need to purchase and install multiple separate components. This universality directly reduces system cost while maintaining all necessary safety and filtering functions.
3Reliability
If multiple safety devices are added to meet safety standards, then safety performance improves, but device complexity and size increase
Solution Approach 1:
The patent merges safety monitoring functionality into the existing filtering structure by incorporating a fluxgate magnetometer within the common mode inductor. This integration allows residual current detection without adding separate safety devices, thereby improving safety performance while maintaining simple device architecture.
Solution Approach 2:
The integrated device simultaneously provides EMI/RFI filtering and residual current detection for safety monitoring. This multi-functionality meets multiple safety and performance requirements with a single component, avoiding the complexity of combining multiple separate safety devices.
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
The solution provides an efficient and versatile filtering system that minimizes electromagnetic interference while ensuring stringent safety standards, maintaining system compactness and affordability.
Implementation Method 1
a fluxgate magnetometer positioned within the coils of each electrical winding
Implementation Method 2
fluxgate magnetometer positioned inside the coils of each electrical winding
Implementation Method 3
common mode inductors to prevent electromagnetic interference (EMI) and radio-frequency interference (RFI)
Data Source
AI summary
A common mode current filter includes a magnetic core, multiple electrical windings, each extending between two ends and including multiple coils wound around the magnetic core, and a fluxgate magnetometer positioned inside the coils of each electrical winding.