Hybrid Construction Machine Battery Lifetime Management
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Solution Overview
Problem
Conventional hybrid construction machines face challenges in extending the lifetime of electricity storage devices due to repeated high charge/discharge cycles, and setting a low target electricity storage rate can lead to insufficient energy supply during heavy load operations, affecting vehicle body movement.
Innovation Solution
A hybrid construction machine with a mode selection device that adjusts the target electricity storage rate based on load conditions, using a controller to manage charge/discharge power and limit hydraulic pump maximum power, allowing for gradual changes in electricity storage rate to prevent degradation and ensure adequate energy supply.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the target electricity storage rate is set high to ensure sufficient energy supply during heavy load operations, then the vehicle body movement is maintained, but the electricity storage device degrades faster due to repeated high charge/discharge cycles
Solution Approach 1:
The patent applies dynamics by making the target electricity storage rate variable rather than fixed. The control device dynamically adjusts the target electricity storage rate based on the operation mode (work mode, travel mode, idle mode) and actual electricity storage rate, allowing the system to adapt between preserving battery life during light loads and ensuring sufficient energy during heavy loads.
Solution Approach 2:
The patent changes the parameter of target electricity storage rate based on operating conditions. Different operation modes correspond to different target rates: work mode uses higher targets to ensure energy availability, while travel and idle modes use lower targets to reduce degradation. This parameter adjustment resolves the contradiction between reliability and device lifetime.
2Duration of action of stationary object
If the target electricity storage rate is set low to extend the electricity storage device lifetime, then degradation is reduced, but energy supply becomes insufficient during heavy load work
Solution Approach 1:
The system dynamically adjusts the target electricity storage rate based on the detected operation mode. During heavy load work (work mode), the target rate is set higher to ensure sufficient energy supply. During light load operations (travel mode, idle mode), the target rate is lowered to extend battery lifetime, thus resolving the contradiction through dynamic adaptation.
Solution Approach 2:
The patent implements parameter changes by setting different target electricity storage rates for different operation modes. The control device monitors the operation mode and adjusts the target parameter accordingly, ensuring that energy supply sufficiency is maintained during heavy loads while extending device lifetime during light loads.
3Use of energy by moving object
If the electricity storage device repeats charge/discharge at high rates, then energy availability is improved, but the degradation of the electricity storage device accelerates
Solution Approach 1:
The patent implements periodic action by adjusting the charge/discharge behavior according to operation cycles. The control device periodically evaluates the operation mode and adjusts the target electricity storage rate accordingly, allowing high charge/discharge rates only when necessary (work mode) and using lower rates during normal operations (travel, idle modes), thus balancing energy availability with device durability.
Solution Approach 2:
The patent changes the operating parameters of the electricity storage device based on mode. By adjusting the target electricity storage rate parameter according to operation mode, the system controls the charge/discharge rates: higher rates are permitted during work mode when energy availability is critical, while lower rates are enforced during travel and idle modes to preserve device durability.
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 extends the lifetime of the electricity storage device by reducing high charge/discharge rates during light loads and increasing them during heavy loads, ensuring continuous vehicle body movement while prioritizing energy storage and fuel efficiency.
Implementation Method 1
a motor generator that is connected mechanically to the engine... controlling charge/discharge power of the motor generator
Implementation Method 2
a hydraulic pump that is connected mechanically to the engine; a hydraulic actuator that is driven by pressurized oil from the hydraulic pump
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A motor generator (27) is connected mechanically to an engine (21) and a hydraulic pump (23). The hydraulic pump (23) delivers pressurized oil to cylinders (11D) to (11F) in a working mechanism (11), a traveling hydraulic motor (25) and a revolving hydraulic motor (26). The revolving hydraulic motor (26) drives a revolving device (3) in cooperation with a revolving electric motor (33). The motor generator (27) and the revolving electric motor (33) are connected electrically to an electricity storage device (31). An HCU (36) sets a target electricity storage rate (SOC0) of the electricity storage device (31) and a pump output limit (POLO) of the hydraulic pump (23) corresponding to a mode selected by a mode selection device (38). The HCU (36) controls the engine (21), the motor generator (27), the revolving electric motor (33) and the electricity storage device (31) corresponding to the target electricity storage rate (SOC0) and the pump output limit (POLO).