Fuel Cell Power Supply Frost Start Detection Without DC/DC Converter
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Solution Overview
Problem
Existing power supply devices for fuel cell vehicles face challenges in starting up in frost conditions due to ice blockages, which can cause malfunctioning and require additional weight and design space for impedance spectroscopy using DC/DC converters.
Innovation Solution
An impedance spectroscopy device is integrated into the primary power grid to perform measurements on the fuel cell device, allowing for detection of frost start conditions and activation of heating or increased reactant flow without the need for a DC/DC converter, enabling a compact and efficient design.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a DC/DC converter is used to perform impedance spectroscopy measurements on the fuel cell device, then the detection of frost start conditions becomes reliable, but the weight and design space of the power supply device increase
Solution Approach 1:
The patent extracts the impedance spectroscopy measurement function from the DC/DC converter and implements it directly in the control unit. This separation removes the need for the additional DC/DC converter hardware, reducing weight and design space while maintaining the reliable detection capability through the preserved impedance measurement functionality.
Solution Approach 2:
The control unit is given multiple functions: it manages the fuel cell device operation, controls the battery, and performs impedance spectroscopy measurements. By making the control unit multi-functional, the patent eliminates the need for a separate DC/DC converter, thereby reducing the overall weight and design space of the power supply device while maintaining all necessary detection capabilities.
2Reliability
If a DC/DC converter is used to perform impedance spectroscopy measurements on the fuel cell device, then the detection of frost start conditions becomes reliable, but the design space of the power supply device increases
Solution Approach 1:
The patent extracts the impedance spectroscopy measurement function from the DC/DC converter and implements it directly in the control unit. This separation removes the need for the additional DC/DC converter hardware, reducing design space while maintaining the reliable detection capability through the preserved impedance measurement functionality.
Solution Approach 2:
The control unit is given multiple functions: it manages the fuel cell device operation, controls the battery, and performs impedance spectroscopy measurements. By making the control unit multi-functional, the patent eliminates the need for a separate DC/DC converter, thereby reducing the overall design space of the power supply device while maintaining all necessary detection capabilities.
3Reliability
If heating elements or increased reactant flow are used to mitigate frost start conditions, then the reliability of fuel cell operation in cold conditions improves, but the energy consumption increases
Solution Approach 1:
The patent performs impedance spectroscopy measurements to detect frost conditions before they severely impact operation. By detecting the presence of frost in advance, the system can initiate mitigation measures at optimal moments, potentially reducing the energy required for heating or reactant flow adjustment compared to reactive measures taken after frost causes significant problems.
Solution Approach 2:
The patent implements a feedback mechanism where impedance measurements continuously monitor the fuel cell device condition. Based on this feedback, the control unit adjusts operational parameters dynamically, optimizing the balance between reliability in frost conditions and energy consumption by applying mitigation measures only when and where needed.
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 solution allows for reliable detection and mitigation of frost start conditions, reducing weight and design space while maintaining efficient operation, and enabling self-heating through increased heat production per gram of H2, thus ensuring reliable power supply.
Implementation Method 1
The DC/DC converter includes a function for impedance spectroscopy, by which the moisture content within the fuel cell device, and therefore within the fuel cell stack, can be determined. With the impedance measurement, in particular with the impedance spectroscopy, conclusions can be drawn as to the membrane resistance within individual fuel cells, the mass transport of the reactants, the charge transfer resistance, and the capacitance of the double layer.
Implementation Method 2
If frost start conditions are found, a heating element may be activated, for example, in order to warm up the fuel cell device, thereby making parts blocked by ice once more accessible.
Implementation Method 3
Thanks to the low voltage of the fuel cell device, more heat per gram of H2 is produced by the individual fuel cells, so that the fuel cell device will warm itself and any ice will be melted.
Data Source
AI summary
A power supply device for the electrical power supply of at least one consumer has a primary power grid, in which a fuel cell device is present, having a secondary power grid, in which a battery is present, having an operating voltage range bounded at the top by a maximum voltage and at the bottom by a minimum voltage, and having an operating current strength range for powering the at least one consumer. An open circuit voltage of the fuel cell device corresponds at most to the maximum voltage of the battery, while there is present in the primary power grid an impedance spectroscopy device, which is designed to perform an impedance spectroscopy measurement on the fuel cell device or on individual fuel cells of the fuel cell device. A fuel cell vehicle has such a power supply device and a method for starting a power supply device.