Capacitor Terminal Arrangement for Stray Inductance Reduction
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Solution Overview
Problem
Capacitors in alternating current circuits generate stray inductance, leading to loss and signal attenuation, affecting circuit stability and safety in motor controllers and vehicles.
Innovation Solution
A capacitor design with specific terminal configurations and arrangements that minimize stray inductance by separating and positioning lead-out terminals to cancel magnetic fields and reduce mutual inductance interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If lead-out terminals are connected to external load apparatus in conventional configurations, then electrical connection is established, but stray inductance is generated causing loss and signal attenuation
Solution Approach 1:
The patent positions lead-out terminals in three-dimensional space with specific spatial relationships - extending in different directions (first direction for first lead-out terminal, second direction perpendicular to first for second lead-out terminal) and using stacked arrangements. This dimensional positioning creates magnetic field cancellation effects that reduce stray inductance while maintaining electrical connectivity.
Solution Approach 2:
The patent employs asymmetric terminal configurations where lead-out terminals are positioned at different locations on the housing (first side vs second side), have different extension directions, and different heights. This asymmetry prevents symmetric magnetic field reinforcement and enables field cancellation, reducing stray inductance effects.
2Volume of moving object
If lead-out terminals are positioned close together for compact design, then device size is reduced, but magnetic field interference and mutual inductance increase
Solution Approach 1:
The patent utilizes three-dimensional spatial arrangement with terminals extending in multiple directions (first direction, second perpendicular direction) and stacked configurations. This dimensional approach allows compact footprint while maintaining sufficient magnetic field separation through vertical stacking and angular orientation rather than simple linear spacing.
Solution Approach 2:
The patent converts the potentially harmful magnetic fields generated by adjacent terminals into beneficial cancellation effects by strategically positioning terminals to create opposing magnetic field directions. The close proximity that would normally increase mutual inductance is instead used to enhance field cancellation when combined with appropriate angular and directional positioning.
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
Enhances stability and anti-interference capability by reducing stray inductance, ensuring safe and stable operation in motor controllers and vehicles.
Implementation Method 1
a magnetic field generated at the first lead-out terminal and a magnetic field generated at the second lead-out terminal can at least partially cancel each other, thereby reducing stray inductance on the capacitor
Implementation Method 2
A basic structure of a capacitor includes two metal plates with insulating media in between. Both ends of the two metal plates can be connected to different polarities of a circuit, respectively, to have a function of 'blocking a direct current while passing an alternating current' in the circuit.
Data Source
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AI summary
Provided are a capacitor, a motor controller, and a vehicle. The capacitor includes: a capacitor core, located in a housing; a first external terminal, electrically connected to a first end of the capacitor core and including a first lead-out terminal located outside the housing; a second external terminal, electrically connected to a second end of the capacitor core and including a second lead-out terminal located outside the housing; a third external terminal, electrically connected to the first end of the capacitor core and including a third lead-out terminal located outside the housing; and a fourth external terminal, electrically connected to the second end of the capacitor core and including a fourth lead-out terminal located outside the housing. The first lead-out terminal extends out of the housing in a first direction. The second lead-out terminal and the first lead-out terminal are stacked in a second direction perpendicular to the first direction.