Hybrid Vehicle SOC Threshold Adjustment for Regenerative Energy
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Hybrid vehicles face inefficiencies in managing traction battery state of charge (SOC), leading to suboptimal fuel economy and reduced electric vehicle mode operation due to inadequate prediction and response to regenerative energy events.
Innovation Solution
A vehicle control system with a controller that adjusts the SOC threshold for engine shutdown based on predicted regenerative energy changes during a drive cycle, ensuring optimal energy capture and battery management by considering vehicle speed and elevation changes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the engine is shut down when SOC exceeds a fixed threshold, then battery overcharging is prevented, but regenerative energy capture is reduced because the engine may shut down before high-energy regenerative events
Solution Approach 1:
The controller performs preliminary action by predicting future regenerative energy events based on anticipated vehicle speeds and elevation changes before they occur. This allows the system to proactively adjust the SOC threshold downward in advance of high-energy regenerative events, ensuring the battery is ready to capture maximum energy when the events occur, rather than reacting after the fact.
Solution Approach 2:
The SOC threshold is made dynamic rather than fixed. The controller continuously adjusts the SOC threshold based on predicted regenerative energy events, vehicle operating conditions, and drive cycle characteristics. This dynamic adjustment allows the threshold to adapt in real-time, lowering before anticipated high-energy events to maximize capture while maintaining reliability during normal operation.
2Loss of energy
If the SOC threshold is lowered to maximize regenerative energy capture, then more energy is recovered during braking, but engine operational time increases reducing fuel efficiency
Solution Approach 1:
The controller performs preliminary action by predicting future regenerative energy events based on anticipated vehicle speeds and elevation changes before they occur. This allows the system to proactively adjust the SOC threshold downward in advance of high-energy regenerative events, ensuring the battery is ready to capture maximum energy when the events occur, rather than reacting after the fact.
Solution Approach 2:
The SOC threshold is made dynamic rather than fixed. The controller continuously adjusts the SOC threshold based on predicted regenerative energy events, vehicle operating conditions, and drive cycle characteristics. This dynamic adjustment allows the threshold to adapt in real-time, lowering before anticipated high-energy events to maximize capture while maintaining reliability during normal operation.
3Duration of action of moving object
If the engine operates longer to maintain a higher SOC threshold, then fuel economy decreases, but the battery has more capacity for electric vehicle mode operation
Solution Approach 1:
The controller performs preliminary action by predicting future regenerative energy events based on anticipated vehicle speeds and elevation changes before they occur. This allows the system to proactively adjust the SOC threshold downward in advance of high-energy regenerative events, ensuring the battery is ready to capture maximum energy when the events occur, rather than reacting after the fact.
Solution Approach 2:
The SOC threshold is made dynamic rather than fixed. The controller continuously adjusts the SOC threshold based on predicted regenerative energy events, vehicle operating conditions, and drive cycle characteristics. This dynamic adjustment allows the threshold to adapt in real-time, lowering before anticipated high-energy events to maximize capture while maintaining reliability during normal operation.
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 fuel efficiency and extends electric vehicle mode operation by strategically managing battery SOC, maximizing regenerative energy capture and reducing engine operational time when SOC is high, thereby improving overall energy management in hybrid vehicles.
Implementation Method 1
The fraction battery provides power for vehicle propulsion and accessory features. During operation, the traction battery may be charged or discharged based on the operating conditions including a battery state of charge (SOC), driver demand and regenerative braking.
Data Source
AI summary
A hybrid vehicle includes an engine; a traction battery; and a controller or a vehicle control system having a controller. The controller is programmed to respond to a state of charge (SOC) of the traction battery. When the SOC is greater than a predicted SOC the controller is programmed to decrease a SOC threshold at which the engine is shut down to reduce the SOC. The SOC threshold is defined by a difference between a maximum SOC and an expected change in the SOC associated with predicted regenerative energy for a drive cycle.