Vehicle Static Elimination via Self-Discharge Ionization
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Solution Overview
Problem
The power supply unit for a vehicle's drive motor can generate static electricity during operation, leading to reduced controllability and degradation of running performance due to electrostatic charging, particularly affecting the inverter and converter components.
Innovation Solution
A self-discharge-type static eliminator is integrated into the vehicle's power control unit and power supply system, producing negative air ions to neutralize positive charges and reduce potential differences, thereby preventing electrostatic charging and maintaining optimal performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the power control unit is housed in an insulated case, then the unit is protected from external electrical interference, but static electricity accumulates on the case and components, reducing controllability
Solution Approach 1:
A conductive member is introduced as an intermediary between the insulated case and the inverter/converter components. This member provides a controlled electrical connection that allows static charge dissipation while maintaining the overall insulation of the case. The conductive member acts as a mediator that resolves the contradiction by enabling necessary electrical connectivity without compromising the protective insulation.
Solution Approach 2:
The electrical conductivity parameter of the case structure is modified by introducing a conductive member with specific conductivity properties. This creates a localized conductive path within the otherwise insulating case, allowing static electricity to be dissipated through controlled areas while maintaining insulation in other areas. The parameter change enables the system to simultaneously achieve protection and static elimination.
2Reliability
If insulating materials are used for the case and wheels, then electrical isolation is achieved, but static charges cannot dissipate, leading to degraded performance
Solution Approach 1:
The case structure is segmented into insulating portions and a conductive member portion. The insulating case portions maintain electrical isolation and protection, while the segmented conductive member provides dedicated static dissipation pathways. This segmentation allows the system to simultaneously achieve electrical isolation for protection and controlled conductivity for static elimination, resolving the contradiction between reliability and productivity.
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 eliminates static electricity, enhancing the controllability of the power control unit and preventing degradation of the vehicle's running performance by transferring static charges from the inverter and converter to the outside air, where they are neutralized, thus maintaining stable torque output and operational efficiency.
Implementation Method 1
a self-discharge-type static eliminator that gives rise to negative air ions in outside air according to the positive potential of the member
Implementation Method 2
gives rise to negative air ions in outside air according to the positive potential of the case member that is electrostatically charged
Implementation Method 3
a potential difference between the member and inside air of the case main body increases, so that static charges are transferred from the inside air of the case main body to the member
Data Source
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AI summary
A vehicle includes a power control unit having at least one of an inverter and a converter, a drive motor that produces torque for running the vehicle when electric power is supplied from the power control unit to the drive motor, a vehicle body kept insulated from a road surface, a case main body in which the power control unit is housed, a case member that is connected to the case main body where the case member is insulated from the case main body, or where electric resistance is large, and a static eliminator that neutralizes and eliminates positive charges on the case member and lowers a positive potential of the case member, by self-discharge for producing negative air ions in outside air according to the positive potential of the case member that is electrostatically charged.