Hybrid Powertrain Power Split Control Under SOC Constraints
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing hybrid power train systems face challenges in optimizing power output distribution, particularly during transient load situations and over time, due to factors like battery state-of-charge, component degradation, and varying operating conditions.
Innovation Solution
A method and system for controlling power output distribution in a hybrid power train, utilizing a controller that determines optimal operating decisions based on real-time data such as state-of-charge, state-of-health, and operating conditions, while also considering future requirements to prevent system limits and extend component life.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If the electric motor manages the transient portion of the load, then the response to transient load situations is improved, but the battery may reach its charge limit
Solution Approach 1:
The controller performs preliminary assessment of future operating conditions and battery state-of-charge before allocating transient load to the electric motor. By predicting upcoming conditions and current battery charge levels, the system pre-determines whether the battery can safely handle transient demands without risking charge depletion, thus resolving the contradiction between rapid response and charge capacity preservation
2Use of energy by moving object
If fuel economy behaviors are implemented, then fuel consumption is reduced, but battery charge cycles increase rapidly reducing component service life
Solution Approach 1:
The controller dynamically adjusts battery charge cycle parameters by monitoring state-of-charge levels and modifying charge/discharge rates based on predicted operating conditions. When fuel economy behaviors would cause excessive cycling, the controller modifies the charging parameters to reduce cycle frequency and depth, thereby extending battery service life while maintaining acceptable fuel economy performance
3Reliability
If the electric motor power output is limited due to heating, then component reliability is improved, but the maximum power output is reduced
Solution Approach 1:
The controller dynamically adjusts the electric motor's power output limits based on real-time temperature conditions and predicted thermal trends. Rather than imposing static power limits, the system continuously monitors motor temperature and adjusts available power capacity accordingly, allowing maximum power output when cooling conditions permit while ensuring reliability when thermal limits are approached
4Productivity
If the hybrid power train optimizes for current operating conditions, then immediate performance is improved, but future operating flexibility is reduced
Solution Approach 1:
The controller performs preliminary optimization by considering both current and predicted future operating conditions simultaneously. Rather than optimizing solely for immediate performance, the system forecasts upcoming load demands and component states, then adjusts current power allocation strategies to maintain both immediate productivity and future adaptability, ensuring the hybrid power train remains flexible for anticipated operating scenarios
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A method includes determining a machine shaft torque demand and a machine shaft speed, in response to the machine shaft torque demand and the machine shaft speed, determining a machine power demand, determining a power division description between an internal combustion engine, a first electrical torque provider, and a second electrical torque provider, determining a hybrid power train configuration as one of series and parallel, determining a baseline power division description in response to a vehicle speed and the machine power demand, determining a state-of-charge (SOC) deviation for an electrical energy storage device electrically coupled to the first electrical torque provider and the second electrical torque provider, and adjusting the baseline power division description in response to the SOC deviation and the hybrid power train configuration.