Hybrid Vehicle SOC Control for Regenerative Power
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional control devices for hybrid vehicles face challenges in optimizing fuel consumption when using look-ahead assistance control and extended regeneration control together, leading to situations where regenerative electric power cannot be collected efficiently due to SOC reaching upper or lower limits during downward slopes and congested segments.
Innovation Solution
A control device that adjusts the target SOC by using information-acquisition means and assistance control to perform downward slope and congestion controls, and extended regeneration control, with a target remaining capacity correction mechanism to prevent SOC from reaching limits, ensuring optimal regenerative power collection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If the vehicle runs a downward slope segment with extended regeneration control to increase regenerative electric power, then fuel consumption is improved, but the SOC reaches the upper limit and prevents further regenerative power collection
Solution Approach 1:
The control device performs preliminary action by setting the target SOC lower before the vehicle enters the downward slope segment. This advance preparation ensures that when regenerative braking occurs during the descent, the SOC has headroom to increase without reaching the upper limit, thereby maintaining regenerative power collection capability throughout the entire slope segment
Solution Approach 2:
The control device dynamically adjusts the target SOC based on the vehicle's location and driving conditions. During the pre-use segment before a downward slope, the target SOC is set lower than the standard target, and this dynamic adjustment is made based on predictions from the scheduled traveling route information, allowing optimal regenerative power collection at the right time and place
2Loss of energy
If the vehicle uses look-ahead assistance control to set target SOC for downward slope segments, then fuel consumption is reduced, but the SOC reaches the lower limit and prevents further optimization
Solution Approach 1:
The control device uses feedback by continuously monitoring the actual SOC and comparing it with the dynamically adjusted target SOC. Based on this feedback and the predicted regenerative power amount from extended regeneration control, the system refines its control strategy to ensure the SOC reaches but does not exceed the target, optimizing both fuel consumption and power collection efficiency
Solution Approach 2:
The control device changes the target SOC parameter dynamically based on driving conditions and location. By adjusting the target SOC lower before downward slope segments and higher before congested segments, the system optimizes the balance between fuel consumption reduction and regenerative power collection efficiency under different operating 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
The control device improves fuel efficiency by preventing SOC from reaching upper or lower limits, allowing for increased regenerative power collection and reduced fuel consumption during hybrid vehicle operations.
Implementation Method 1
when rotation of an axle is transmitted to the motor, a generator generates electric power (namely, the motor generates electricity), and the storage battery is charged also by the electric power. That is, kinetic energy of the vehicle is converted into electrical energy
Data Source
AI summary
When it is judged that a downward slope segment exists in a scheduled traveling route, the control device of a hybrid vehicle sets a target remaining capacity SOC* in a pre-use segment in a downward slope segment and the downward slope segment to a “low-side remaining capacity Sd which is ΔSd smaller than a standard remaining capacity Sn.” Furthermore, when it is presumed that a rise amount of a remaining capacity by an extended regeneration control is large in the pre-use segment and the downward slope segment, the target remaining capacity SOC* is set to a “low-side remaining capacity Sd which is a sum of ΔSd and ΔS1 smaller than the standard remaining capacity Sn.”