Electric Vehicle Voltage Control for Reverse Driveability
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Solution Overview
Problem
Electric powered vehicles face challenges in achieving desired driveability during backward running while maintaining mileage improvements, as existing systems restrict system voltage, potentially limiting driving force when deliberate accelerator manipulation is required.
Innovation Solution
The system dynamically adjusts the upper limit of the system voltage during backward running to be higher than in forward running, alleviating restrictions on the system voltage, allowing for improved driveability while maintaining mileage improvements by incorporating a control device that sets the voltage conversion device to boost the input voltage accordingly.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If the system voltage is restricted to a lower upper limit value to improve mileage, then energy efficiency is improved, but the driving force available during backward running deteriorates
Solution Approach 1:
The patent applies dynamics by making the upper limit value of system voltage changeable based on running direction. The control device sets a first upper limit value for forward running and a second upper limit value (higher than the first) for backward running. This dynamic adjustment allows the system to optimize voltage restrictions for energy efficiency during forward running while providing sufficient driving force during backward running when greater power is needed for deliberate accelerator manipulation.
2Loss of energy
If the system voltage is restricted in forward running to improve mileage, then energy consumption is reduced, but the driveability during backward running deteriorates
Solution Approach 1:
The patent applies local quality by implementing different voltage restriction strategies for different running directions. The control device sets a first upper limit value for forward running that restricts system voltage to reduce energy consumption, and a second upper limit value for backward running that is higher than the first to ensure adequate driveability. This localized optimization allows energy efficiency improvements in forward running without compromising backward running performance.
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 enhances driveability in backward running while increasing mileage by appropriately setting the system voltage for both forward and backward operations, ensuring optimal performance and efficiency.
Implementation Method 1
a voltage conversion device, and a control device controlling the voltage conversion device. The voltage conversion device is provided between the drive device and the power storage device, and is configured to boost an input voltage (system voltage) of the drive device higher than the voltage of the power storage device
Data Source
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AI summary
When a determination is made that the shift range is other than the R range (NO at S10), an ECU sets the system voltage for forward running (S20). When a determination is made that the shift range is in the R range at S10 (YES at S10), the ECU sets the system voltage for backward running (S30). The system voltage for backward running is set to become higher than the system voltage applied for forward running for an identical level of acceleration requirement for the vehicle.