Hybrid Vehicle Control Device for Dynamic Regenerative Power Management
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing hybrid vehicle control systems do not optimally manage regenerative electric power during braking, leading to potential overcharging of the battery and inefficient fuel usage, as they lack a condition-based approach for executing waste electric-power control.
Innovation Solution
A control device for a hybrid vehicle that includes an internal combustion engine, a first motor generator, and a second motor generator, which optimizes the timing of regenerative electric power management by using the first motor generator as an electric motor and adjusting the load based on the battery's state of charge and vehicle running conditions, prioritizing charging or waste electric-power control based on predetermined thresholds and running conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If regenerative electric power is actively used to charge the battery during braking, then fuel efficiency is improved, but the battery may become overcharged during continuous downhill driving
Solution Approach 1:
The patent applies dynamics by making the predetermined value dynamic rather than fixed. The control device changes the predetermined value based on running conditions (urban areas vs. mountain roads with continuous downhill). This allows the system to adapt the waste electric-power control threshold according to the specific driving situation, enabling active waste electric-power control during downhill driving to prevent battery overcharge while maintaining fuel efficiency during normal urban driving.
2Reliability
If waste electric-power control is performed by forcing engine rotation during braking, then battery overcharge is prevented, but fuel efficiency deteriorates due to unnecessary engine operation
Solution Approach 1:
The patent applies parameter changes by modifying the predetermined value threshold based on running conditions. In urban areas where fuel efficiency is prioritized, the predetermined value is set higher, making waste electric-power control less likely to activate. In mountain roads with continuous downhill where battery overcharge risk exists, the predetermined value is lowered, allowing waste electric-power control to activate more readily. This dynamic parameter adjustment resolves the contradiction by optimizing the trade-off between battery protection and fuel efficiency according to specific operating conditions.
3Ease of operation
If a fixed predetermined value is used for waste electric-power control, then control simplicity is maintained, but optimal control timing cannot be achieved under varying driving conditions
Solution Approach 1:
The patent resolves this contradiction by implementing a dynamic predetermined value that changes based on running conditions. The control device includes a determination unit that detects whether the vehicle is in urban areas or mountain roads with continuous downhill, and accordingly adjusts the predetermined value. This dynamic approach maintains relative control simplicity through automated condition-based adjustment while achieving optimal control timing adaptation to varying driving conditions.
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 solution optimizes regenerative electric power management during braking, preventing battery overcharging and improving fuel efficiency while ensuring secure deceleration by adjusting the timing and ratio of waste electric-power usage based on the vehicle's state and conditions.
Implementation Method 1
a second motor generator that is connected to drive wheels and is driven by electric power supplied from at least one of the battery and the first motor generator, the battery being chargeable with regenerative electric power obtained by operating the second motor generator as a generator during braking of the drive wheels
Implementation Method 2
a first motor generator that generates electric power using power of the internal combustion engine
Data Source
AI summary
A vehicle includes a first motor generator that generates electric power using power of an engine, a battery, and a second motor generator that is connected to drive wheels and is driven by electric power supplied from the battery and the first motor generator. An ECU of the vehicle drives the first motor generator as an electric motor with a regenerative electric power, executes a braking control, in which a load of the first motor generator functions as the engine, when an SOC is equal to or more than a threshold value of a waste electric-power start, and changes the threshold of the waste electric-power start based on a running condition of the hybrid vehicle.