Hydraulic Pump Control for Dual-Battery Charge Balancing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In heavy-duty electric working machines with separate electric systems for each axle, battery packs often discharge unevenly, leading to premature charging stops before the battery packs powering the front axle are fully discharged.
Innovation Solution
A computer system with processing circuitry that controls a hydraulic system by determining the charge levels of two separate electric energy storage systems and activating a charge balancing operating mode when the second charge level exceeds the first by a threshold amount, adjusting the rotational speed of the electric motors to balance the charge levels without affecting pump displacement based on hydraulic power demand.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If separate electric systems are provided for each axle, then each axle can be powered independently, but battery packs discharge unevenly causing premature charging stops
Solution Approach 1:
The patent merges the control of two separate electric energy storage systems into a unified charge balancing system. The control unit coordinates power distribution between the first and second battery packs, allowing them to discharge at different rates while maintaining overall system balance, thus eliminating premature charging stops caused by uneven discharge
2Productivity
If battery packs discharge at their natural rates, then each battery pack operates independently, but charge imbalance occurs requiring charging stops before all batteries are depleted
Solution Approach 1:
The control unit continuously monitors the charge levels of both battery packs and dynamically adjusts power distribution based on real-time feedback. When one battery pack reaches a certain charge level threshold, the control unit redirects power demand to the other battery pack, ensuring balanced discharge and maintaining charge level equilibrium throughout operation
3Use of energy by moving object
If the hydraulic system uses variable displacement pumps, then pump displacement adjusts automatically to hydraulic power demand, but charge balancing becomes more complex with multiple control parameters
Solution Approach 1:
The control unit acts as an intermediary between the hydraulic system and the dual battery system. It receives hydraulic power demand signals, processes them through charge balancing logic, and outputs coordinated control commands to both variable displacement pumps and battery management systems, simplifying the overall control architecture while achieving both hydraulic efficiency and charge balancing
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 improves the total battery range of the working machine, reducing the frequency of charging stops and enhancing mission efficiency by balancing the discharge of battery packs.
Implementation Method 1
a first pump driven by a first electric motor, and the second pressure supplier comprises a second pump driven by a second electric motor
Data Source
AI summary
A system and method for controlling a hydraulic system of an electric working machine. The hydraulic system includes a first pump driven by a first electric motor powered by a first battery, and a second pump driven by a second electric motor powered by a second battery, the pumps being variable displacement pumps arranged to automatically adjust pump displacements in dependence on hydraulic power demand. The hydraulic system further including a common hydraulic valve system. The method includes determining first and second charge levels of the first and second batteries, respectively, and activating a charge balancing operating mode in response to determining that the second charge level exceeds the first charge level by a threshold amount. In the charge balancing operating mode, the first electric motor is controlled to a lower rotational speed than the second electric motor and a lower power consumption than the second electric motor.