Hybrid Drive Control Strategy for Load Point Shifting
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Hybrid drive systems for work machines face inefficiencies due to problematic transition behavior between operating modes, particularly in load point shifting, recuperation, and boost modes, where power or torque distribution regulators struggle to maintain optimal charging states, leading to reduced combustion engine efficiency and potential exceeding of charge limits in the storage unit.
Innovation Solution
A control device that adjusts the theoretical charging state of the charge storage unit based on previous mode operations, allowing the hybrid drive to adapt and maintain charge levels within permissible limits, ensuring sufficient service life, and optimizing efficiency by shifting the charging state during load point shifting, recuperation, and boost modes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a power or torque distribution regulator maintains a fixed theoretical charging state value, then the charge storage unit charging state can be stabilized, but the combustion engine efficiency deteriorates during mode transitions
Solution Approach 1:
The patent applies dynamics by making the theoretical charging state value adaptive rather than fixed. The control device dynamically adjusts the theoretical charging state value based on the actual charging state deviations that occur during mode transitions. This allows the system to adapt to changing operating conditions and eliminate unnecessary compensatory actions that would reduce combustion engine efficiency.
Solution Approach 2:
The patent implements feedback by using the actual charging state deviations observed during mode transitions to adjust the theoretical charging state value. The control device monitors the charging state changes during recuperation or boost modes and uses this information to optimize the theoretical value for subsequent load point shifting operations, creating a closed-loop control system that improves overall efficiency.
2Reliability
If the regulator compensates for charging state increases during recuperation by reducing charge in load point shifting mode, then the charging state can be maintained, but the combustion engine efficiency worsens
Solution Approach 1:
The patent applies preliminary action by adjusting the theoretical charging state value in advance before mode transitions occur. By anticipating the charging state changes that will occur during recuperation or boost modes, the control device pre-optimizes the theoretical value to prevent unnecessary compensatory actions during subsequent load point shifting operations.
Solution Approach 2:
The system transitions from a static theoretical charging state value to a dynamic one that adapts based on previous mode operations. This dynamic adjustment eliminates the need for rigid compensation strategies that would force the combustion engine to operate at suboptimal efficiency points.
3Device complexity
If heuristics are used for operating strategy, then hardware demands are reduced, but consumption reduction and parameterization expense worsen
Solution Approach 1:
The patent introduces an intermediary approach by combining the simplicity of heuristic rules with the optimization capabilities of model-based methods. The adaptive theoretical charging state value acts as a mediator that captures the essential optimization logic without requiring complex real-time calculations, thus reducing hardware demands while maintaining effective consumption reduction.
4Productivity
If optimizing methods are used for operating strategy, then consumption reduction is improved, but hardware demands worsen
Solution Approach 1:
The patent extracts the essential optimization logic from complex optimizing methods and encapsulates it in the adaptive theoretical charging state value. By taking out only the critical adjustment mechanism needed for mode transitions, the system achieves significant consumption reduction without implementing the full complexity of advanced optimizing methods, thus reducing hardware demands.
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 the hybrid drive's ability to utilize charge quantities effectively across modes without exceeding charge limits, maintaining efficiency and extending the service life of the charge storage unit by dynamically adjusting the charging state, thereby improving overall performance and reducing the risk of charge depletion during frequent mode transitions.
Implementation Method 1
a generator (44) which can be driven by the combustion engine (40)
Implementation Method 2
an electric engine (62) supplied by the charge storage unit (78)
Implementation Method 3
a charge storage unit (78), in particular a battery, a capacitor or a flywheel
Data Source
AI summary
A hybrid drive includes a combustion engine, a generator driven by the combustion engine, a charge storage unit, and an electric engine. The hybrid drive can be driven in a load point shifting mode, a recuperation mode, and a boost mode. In the load point shifting mode, a power or torque distribution regulator specifies the torques supplied by the combustion engine and the electric engine in the sense of a maintenance of a predetermined theoretical value of the charging state of the charge storage unit. The theoretical value of the charging state of the charge storage unit is shifted in the load point shifting mode, as a function of the charging state changes of the charge storage unit in a previously carried out recuperation or boost mode.