Fuel Cell Compressor Control Using Sensorless Airflow Estimation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The complexity of compressor systems in fuel cell systems, particularly the need for complex data communication and sensor-based monitoring, leads to potential faults and increased costs, making them less reliable and more expensive.
Innovation Solution
A compressor system with a single or cascaded compressor stage driven by a synchronous motor, where the air mass flow is calculated theoretically using motor current and speed, eliminating the need for sensors and reducing cabling, and integrating the control directly into the compressor control unit to regulate the motor based on target values from the fuel cell control unit.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If sensor-based monitoring and complex data communication are used to monitor and control oxygen supply, then measurement precision and control accuracy are improved, but device complexity and susceptibility to faults increase
Solution Approach 1:
The patent extracts and eliminates the sensor component from the system. Instead of using sensors to measure air mass flow and transmit data through complex communication channels, the invention calculates the air mass flow theoretically based on motor operating parameters (current, speed, frequency) that are already available for compressor control, thereby removing the sensor and its associated cabling while maintaining measurement capability
Solution Approach 2:
The compressor control unit performs self-measurement by calculating air mass flow from its own operating parameters. The control unit uses its internal data about motor current, speed, and frequency to determine the air mass flow without external sensors, enabling the system to monitor its own state using already-available information
2Measurement precision
If sensors and complex cabling are installed for monitoring air mass flow, then measurement capability is improved, but ease of manufacture and system reliability worsen due to increased fault susceptibility
Solution Approach 1:
The patent removes sensors and their cabling from the system. By calculating air mass flow theoretically from motor parameters (current, speed, frequency) that are already measured for control purposes, the invention eliminates the sensor component that would introduce potential failure points, thereby improving system reliability while maintaining measurement capability
Solution Approach 2:
The patent uses motor operating parameters (current, speed, frequency) as intermediaries to determine air mass flow. Instead of directly measuring air mass flow with a sensor, the system uses these electrical parameters as mediators that can be easily measured and from which air mass flow can be calculated, avoiding the need for physical sensors in the air path
3Ease of operation
If multiple components including sensors and complex communication interfaces are used, then control accuracy is improved, but ease of operation and maintenance worsen due to increased system complexity
Solution Approach 1:
The patent merges the air mass flow measurement function with the existing compressor control unit. By integrating the theoretical calculation of air mass flow into the control unit that already manages compressor operation, the invention combines multiple functions (motor control, parameter monitoring, and air mass flow determination) into a single device, simplifying the overall system structure while maintaining control accuracy
Solution Approach 2:
The compressor control unit is given multi-functionality by enabling it to perform both motor control and air mass flow measurement/calculation. This universal approach allows the same control unit to handle multiple tasks (controlling compressor speed, monitoring electrical parameters, and determining air mass flow) without requiring separate dedicated components for each function
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 simplifies the design, reduces susceptibility to faults, lowers costs, and enhances the reliability of the fuel cell system by eliminating the need for sensors and cabling, while allowing integration into existing systems without significant modifications.
Implementation Method 1
The compressor stage (24) comprises a compressor (26) and a motor (28) that drives the compressor (26). The motor (28) is preferably a synchronous motor, in particular a permanently energized synchronous motor.
Data Source
AI summary
A compressor system is provided for a fuel cell system having at least one compressor stage with an electric motor. The compressor stage is set up to suck in and compress an air mass flow along a fluid path using the motor and to discharge the compressed air mass flow as a reactant feed. The compressor system also has a control unit configured to determine a current for supplying the electric motor and a rotational speed of the electric motor or a frequency of the current of the electric motor. In addition, the control unit is configured to ascertain a theoretical air mass flow value in the fluid path as a function of the current and the speed or as a function of the current and the frequency, and to control the motor as a function of the theoretical air mass flow value.