Hybrid Fuel Cell Power Conversion With Fewer Converters
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The high cost of fuel cell systems for industrial vehicles due to the need for multiple converters to operate hybrid energy sources, such as fuel cells, batteries, and supercapacitors, limits their power efficiency and increases operational expenses.
Innovation Solution
A fuel cell system with a first converter connected to the fuel cell stack and battery to adjust power output, a second converter for bi-directional power flow with the battery, and a power relay assembly controlled by a controller to manage power flow between the supercapacitor and converters, optimizing power distribution and reducing the number of converters required.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If multiple converters are provided to operate hybrid energy sources (fuel cell, battery, super capacitor) in a hybrid type, then power efficiency is enhanced, but the system cost increases due to the high price of converters
Solution Approach 1:
The first converter is designed to perform multiple functions: it converts power from the fuel cell stack and also converts power from the battery to charge the super capacitor. This multi-functionality allows the system to operate hybrid energy sources efficiently while reducing the total number of converters needed, thereby lowering system cost while maintaining power efficiency.
Solution Approach 2:
The patent merges the functions of multiple converters into a single first converter. Instead of having separate converters for fuel cell power conversion and battery-to-super-capacitor power conversion, both functions are combined in one converter, reducing component count and system cost while maintaining the ability to operate all hybrid energy sources effectively.
2Adaptability or versatility
If at least three converters are provided to operate each energy source in the hybrid type, then power conversion capability is improved, but the device complexity increases
Solution Approach 1:
The first converter serves multiple purposes: converting fuel cell power to drive the motor and converting battery power to charge the super capacitor. This multi-functionality maintains comprehensive power conversion capability while reducing the number of converters from three to two, thereby reducing device complexity.
Solution Approach 2:
The controller acts as an intermediary that intelligently manages power flow between different energy sources and the first converter. It determines when to draw power from the fuel cell, when to charge the battery, and when to charge the super capacitor, maintaining versatile power conversion capability through intelligent control rather than through multiple physical converters.
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 configuration minimizes costs by reducing the number of converters needed while enhancing power efficiency and control, allowing for efficient operation of hybrid energy sources in fuel cell systems.
Implementation Method 1
A fuel cell system may generate electrical energy by using a fuel cell stack. For example, when hydrogen is used as fuel of the fuel cell stack
Implementation Method 2
a hybrid power net employing a high voltage battery as a sub-power source
Implementation Method 3
A fuel cell system applied to the vehicle used in the industrial field includes a battery and a super capacitor in addition to a fuel cell
Data Source
Figure 1
Figure 2A
Figure 2B
AI summary
A fuel cell system includes a first converter to convert power, which is output from a fuel cell stack or a battery, into power in a specific level, a second converter to convert power which is input to or output from the battery, a power relay assembly to control power flow between a super capacitor and the first converter, and a controller to control outputs of the first converter and the second converter, depending on a starting state or an operating state of the fuel cell system, and to control an operation of the power relay assembly.