Segmented Conductor Cover for Noise Reduction in On-Vehicle Motor-Driven Compressor
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Solution Overview
Problem
On-vehicle motor-driven compressors face challenges in effectively reducing common-mode and normal-mode noise, which affects the damping effect and overall performance of the inverter device.
Innovation Solution
Incorporating a noise reducer with a common-mode choke coil and a smoothing capacitor configured as a low-pass filter circuit, featuring a loop-shaped core and a conductor cover with specific winding configurations and slits to enhance noise reduction, which includes a common-mode choke coil with a loop-shaped core, a cover made of a conductor, and windings arranged to generate induced currents that resist leakage magnetic fluxes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a conventional inductance element with a solid core and continuous conductor is used, then the structure is simple and easy to manufacture, but the damping effect is insufficient and resonance peaks are not effectively reduced
Solution Approach 1:
The conductor cover is divided into multiple segments separated by slits, transforming a continuous structure into a segmented one. This segmentation creates multiple isolated conductor regions that generate eddy currents to suppress resonance peaks and reduce noise, while maintaining manufacturing feasibility through modular construction
Solution Approach 2:
The conductor cover is designed with slits creating a porous-like segmented structure. These slits allow the formation of eddy currents in isolated conductor regions, providing damping effect and resonance suppression while maintaining the overall structural integrity and ease of manufacture
2Stability of the object's composition
If the conductor cover is made completely continuous to improve structural integrity, then manufacturing is easier, but the damping effect decreases and resonance peaks increase
Solution Approach 1:
The conductor cover is segmented into multiple isolated regions by slits, which prevents continuous current paths that cause resonance. Each segmented region generates localized eddy currents that provide damping effect, reducing resonance peaks while maintaining sufficient structural integrity through the distributed segmentation pattern
Solution Approach 2:
The electrical conductivity distribution is changed by introducing slits, transforming the conductor cover from a continuous high-conductivity structure to a segmented structure with controlled conductivity. This parameter change enables eddy current generation for damping while maintaining mechanical integrity through optimized slit placement and conductor material properties
3Object-affected harmful factors
If multiple windings are added to the choke coil to improve noise reduction, then the filtering effect increases, but the device complexity increases
Solution Approach 1:
Multiple windings (first and second windings) are combined on a single choke coil structure with a shared core and conductor cover. This merging approach achieves comprehensive noise reduction for both common-mode and normal-mode interference while avoiding the complexity of separate choke coils, as the segmented conductor cover serves both windings simultaneously
Solution Approach 2:
The segmented conductor cover structure serves multiple functions: it provides eddy current paths for damping resonance, suppresses common-mode noise, and reduces normal-mode noise. This multi-functional design achieves comprehensive noise reduction without proportionally increasing device complexity, as the same structural elements perform multiple noise mitigation functions
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 effectively reduces common-mode and normal-mode noise, providing a damping effect that improves the filtering characteristics and reduces resonance peaks, thereby enhancing the performance of the on-vehicle motor-driven compressor's inverter device.
Implementation Method 1
windings arranged to generate induced currents that resist leakage magnetic fluxes
Implementation Method 2
The cover has a first slit in an inner circumferential surface, the first slit extending in the circumferential direction of the cover such that the first region is non-continuous with respect to a winding direction of the first winding
Data Source
AI summary
A common-mode choke coil includes a loop-shaped core, a cover made of a conductor covering at least part of the core, a first winding wound around an outer surface of the cover, and a second winding wound around the outer surface of the cover. The cover includes a first region around which the first winding is wound, a second region around which the second winding is wound, and two connection regions that connect the first region and the second region to each other in a circumferential direction. The cover has first and second slits in an inner circumferential surface. The first slit extends such that the first region is non-continuous with respect to a winding direction of the first winding. The second slit extends such that the second region is non-continuous with respect to a winding direction of the second winding.