Fuel Cell Stack Inverter Segmentation for Cost and Reliability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional multi-stack fuel cell assemblies are not cost-effective and require a DC bus, which leads to increased manufacturing and operating costs, and they cannot continue operation if one fuel cell stack fails or produces less power, lacking individual stack current control and electrical isolation.
Innovation Solution
A multi-stack assembly with fuel cell stack groups connected in series, each with a dedicated inverter, and a controller to manage fuel flow and inverter power draw based on actual fuel flow and power requirements, eliminating the need for a DC bus and allowing continued operation even if one stack fails.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a DC bus is used to connect multiple fuel cell stacks, then the number of inverters required is reduced, but the assembly cannot continue operation if one fuel cell stack fails and manufacturing costs increase
Solution Approach 1:
The system divides the fuel cell assembly into independent stack-inverter units, where each fuel cell stack is paired with its own dedicated inverter. This segmentation allows individual stacks to operate independently, so if one stack fails, others can continue running without being affected. The DC bus connecting multiple stacks into a single electrical system is replaced by direct connections between each stack and its dedicated inverter.
2Productivity
If a DC bus is used to connect multiple fuel cell stacks, then inverters can share the DC current, but manufacturing and operating costs increase due to customization requirements
Solution Approach 1:
The system uses standardized, modular stack-inverter units that can be replicated and scaled without customizing a complex DC bus system. Each unit is self-contained with its own inverter, allowing for easier manufacturing and assembly. The power output capacity is achieved by simply adding more standardized units rather than customizing a centralized DC bus configuration.
3Reliability
If individual inverters are assigned to each fuel cell stack, then continued operation is possible if one stack fails, but the number of inverters increases
Solution Approach 1:
Each fuel cell stack is equipped with its own dedicated inverter, making the system self-sufficient at the stack level. When one stack fails, its associated inverter simply stops drawing power from that stack while continuing to operate with other healthy stacks connected to the same inverter. This self-service approach eliminates the need for complex centralized control and allows automatic continued operation without requiring additional inverters beyond what would be needed for a DC bus configuration.
4Productivity
If a DC bus is used, then power can be distributed to multiple inverters, but individual stack current control is not possible
Solution Approach 1:
The system segments the power conversion function by assigning a dedicated inverter to each fuel cell stack. This allows each inverter to independently control the current drawn from its associated stack based on individual stack performance and requirements. Power distribution to multiple inverters is achieved through the modular architecture where each inverter can draw from one or more stacks, combining the benefits of individual control with flexible power distribution.
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 reduces manufacturing costs, allows for increased power output without affecting fuel cell durability, and enables individual inverter control, ensuring efficient operation and reliability by minimizing power losses and optimizing performance.
Implementation Method 1
A fuel cell is a device which directly converts chemical energy stored in hydrocarbon fuel into electrical energy by means of an electrochemical reaction
Implementation Method 2
The DC current produced by the fuel cell stack can be converted to conventional AC power using an inverter
Data Source
Figure 1
Figure 2
Figure 3A
AI summary
A multi-stack assembly receiving fuel from a fuel supply and producing power output for consumption by a load, the assembly comprising a plurality of fuel cell stacks for producing DC power and forming a plurality of fuel cell stack groups, wherein each of the stack groups includes at least one fuel cell stack, a plurality of inverters corresponding to the plurality of fuel cell stack groups, wherein each of the inverters draws a predetermined amount of DC power from a corresponding fuel cell stack group and converts the DC power to AC power; and a controller for controlling each of the inverters to draw the predetermined amount of DC power from the corresponding fuel cell stack group so as to satisfy power requirements of the load.