Fuel Cell Power Limiting for Regenerative Energy Capture
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Fuel cell systems in mobile machines often consume excessive fuel due to inefficient power regulation, and energy storage devices like batteries are not optimized for regenerative energy capture, leading to suboptimal energy usage and reduced machine efficiency.
Innovation Solution
A power system control unit that determines an expected efficiency gain condition based on terrain and machine activity data, prognostically limits the fuel cell's power output and charges the energy storage device during regenerative energy opportunities, allowing the fuel cell to operate at partial load and capture regenerative energy effectively.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If the fuel cell is controlled to maintain charge of the battery, then the total power can be provided to the machine, but fuel consumption becomes excessive
Solution Approach 1:
The system performs preliminary action by capturing and storing regenerative energy during braking or deceleration events before it is lost. The energy storage device is charged in advance during these opportunities, so that the fuel cell does not need to consume excessive fuel to maintain battery charge during subsequent operation. This proactive energy capture resolves the contradiction by preparing energy reserves before they are needed.
Solution Approach 2:
The system converts what would normally be wasted energy (regenerative energy during braking) into a beneficial resource. By capturing and storing this otherwise lost energy, the system reduces the fuel cell's fuel consumption burden. This transforms a harmful energy loss into a useful energy source, resolving the contradiction between maintaining power supply and reducing fuel consumption.
2Power
If the fuel cell operates at full power output, then sufficient power is available for the machine, but fuel cell efficiency decreases
Solution Approach 1:
The system performs preliminary action by capturing regenerative energy in advance during braking events. This stored energy is available to supplement the fuel cell output later, allowing the fuel cell to operate at lower, more efficient power levels while still meeting the machine's total power requirements. The preliminary energy capture enables reduced fuel cell loading without sacrificing power availability.
Solution Approach 2:
The system changes the operating parameters of the fuel cell by reducing its power output level from full capacity to partial capacity operation. This parameter change allows the fuel cell to operate in its higher efficiency range while the energy storage device compensates for the reduced output. The parameter change resolves the contradiction by shifting the fuel cell's operating point to achieve both adequate power supply and improved efficiency.
3Speed
If the energy storage device is used to supplement peak power loads, then fast transient response is achieved, but the device is not optimized for regenerative energy capture
Solution Approach 1:
The energy storage device is designed with multi-functionality to serve both peak power supplementation and regenerative energy capture. The control system intelligently manages the device to perform both functions: providing fast transient response during peak loads and capturing regenerative energy during braking events. This universal application resolves the contradiction by making the device adaptable to multiple operational roles rather than optimizing for a single function.
Solution Approach 2:
The control system dynamically adjusts the energy storage device's operation based on real-time conditions. During braking events, the device captures regenerative energy; during peak load demands, it provides supplemental power. This dynamic switching between functions allows the device to adapt to varying operational requirements, resolving the contradiction between transient response optimization and regenerative energy capture optimization.
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 reduces fuel consumption, extends the machine's operational range, and improves energy efficiency by selectively limiting fuel cell power output and utilizing regenerative energy, enhancing the overall performance and efficiency of the power system.
Implementation Method 1
Fuel cells consume hydrogen or another fuel source such as an alcohol fuel or traditional hydrocarbon fuel to generate electricity
Implementation Method 2
charging the energy storage device during occurrence of the expected efficiency gain condition, using at least one of regenerative electric power from a regenerative energy device of the machine
Data Source
AI summary
Operating a machine includes supplying electric power from a fuel cell to a power bus connected to an electric motor and an energy storage device in a machine operated at a work site, and determining an expected efficiency gain condition based on at least one of terrain data of the work site or machine activity data of the machine. Operating a machine further includes prognostically limiting a power output of the fuel cell based on the determining an expected efficiency gain condition, and charging the energy storage device during occurrence of the expected efficiency gain condition using at least one of a regenerative energy device or the fuel cell. The energy storage device may be discharged during prognostically limiting a power output of the fuel cell so as to share a load demand of the power bus between the fuel cell and the energy storage device. Related apparatus and control logic is also disclosed.