Working Vehicle Hydraulic Load Control for Battery Overcharge
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing electric or hybrid working vehicles face issues with overcharging of the electric storage device due to excess electrical energy generated during regenerative braking, which can damage the storage device.
Innovation Solution
A control system that dissipates excess electrical energy through the existing hydraulic system by directing hydraulic fluid to hydraulic actuators when the electric storage device is fully charged, preventing overcharging without additional power dissipating components.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If regenerative braking is used to generate electrical energy, then energy efficiency is improved, but the electric storage device may be damaged due to overcharging
Solution Approach 1:
The patent converts the harmful excess electrical energy that would cause overcharging into a beneficial force by using it to drive the hydraulic pump through the load motor. This transforms the problematic regenerative braking energy into useful hydraulic work, maintaining energy efficiency while preventing damage to the electric storage device
Solution Approach 2:
The patent introduces the hydraulic system as an intermediary between the traction motor and the electric storage device. When the storage device is fully charged, the hydraulic system acts as a buffer that absorbs excess energy through fluid circulation and pressure regulation, preventing direct overcharging while still utilizing the regenerative energy
2Reliability
If additional power dissipating components are added to prevent overcharging, then electric storage device reliability is improved, but device complexity increases
Solution Approach 1:
The patent makes the existing hydraulic system multi-functional by enabling it to perform both its original hydraulic actuation function and a new energy dissipation function. The hydraulic pump and fluid system can now serve dual purposes: normal hydraulic operations and excess energy absorption, eliminating the need for separate power dissipating components
Solution Approach 2:
The patent merges the energy dissipation function with the existing hydraulic system components. The load motor, hydraulic pump, and fluid circuit are combined to create an integrated energy management system that prevents overcharging without requiring additional standalone dissipation components, thereby maintaining reliability while avoiding increased complexity
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
Prevents overcharging of the electric storage device by dissipating excess energy through the hydraulic system, maintaining the vehicle's functionality and safety without additional components.
Implementation Method 1
a traction motor having a driving state, in which the traction motor is configured to propel the working vehicle using power from the electric storage device, and a regenerative braking state, in which the traction motor is configured to perform regenerative braking and generate electrical energy
Implementation Method 2
dissipating excess electrical energy generated by the traction motor through the existing hydraulic system
Implementation Method 3
dissipate excess electrical energy via the hydraulic circuit associated with the hydraulic actuator, pump and control valve
Data Source
AI summary
A working vehicle includes an electric storage device; a traction motor configured to propel the working vehicle and to generate electrical energy when braking; a hydraulic system including a hydraulic pump driven by a load motor, a hydraulic actuator and a control valve; and a control system. The control system is configured to determine a state of charge of the electric storage device; induce additional load on the hydraulic system by directing the load motor to drive the hydraulic pump and actuating the control valve to direct flow of hydraulic fluid to the hydraulic actuator when the state of charge is at or above a predetermined threshold.