Fuel Cell Current Sensor Magnetization Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing fuel cell systems face inaccuracies in current measurement due to offset generation and demagnetization of magnetic cores over time, which are not adequately addressed by conventional origin point learning methods, leading to inconsistent and inaccurate current sensing.
Innovation Solution
A fuel cell system with a current sensor featuring a preliminarily magnetized magnetic core and a temperature sensor, where a controller switches between two driving modes: a first mode with lower current values and a second mode with higher current values based on accumulated temperature thresholds to maintain accurate magnetization and compensate for demagnetization effects.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If origin point learning is performed only at activation or when switching element is suspended, then device complexity is reduced, but measurement precision deteriorates due to offset generation over time
Solution Approach 1:
The patent implements periodic origin point learning at specific intervals during fuel cell operation, rather than only at activation. The controller performs origin point learning when the fuel cell operates at low current conditions (below a predetermined threshold), creating periodic calibration opportunities that maintain measurement precision without excessive complexity
Solution Approach 2:
The system uses the fuel cell's own operational characteristics to trigger origin point learning. When the fuel cell naturally operates at low current conditions during normal operation, the controller automatically performs origin point learning without external intervention, making the system self-calibrating
2Strength
If maximum current value is increased to improve magnetization, then magnetic core magnetization is improved, but measurement precision deteriorates due to demagnetization effects
Solution Approach 1:
The patent dynamically changes the current parameter based on operating conditions. The controller adjusts the maximum current value applied to the magnetic core according to the accumulated temperature value, applying higher current when temperature is low (to improve magnetization) and lower current when temperature is high (to prevent demagnetization), thereby maintaining optimal magnetization state
Solution Approach 2:
The system uses temperature feedback to control the magnetization process. The controller monitors the accumulated temperature value of the current sensor and uses this feedback to determine the appropriate maximum current value for origin point learning, creating a closed-loop control system that adapts to thermal conditions
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 ensures accurate current measurement by maintaining consistent magnetic core magnetization, reducing inaccuracies and maintaining measurement precision over the system's operational lifespan.
Implementation Method 1
applying a current larger than a saturation current to a magnetic core preliminarily magnetizes the magnetic core
Implementation Method 2
a current sensor including a preliminarily magnetized magnetic core and a Hall element
Data Source
AI summary
The present disclosure is made in order to reduce inaccuracy of current sensors. A fuel cell system includes a converter configured to convert output voltage of the fuel cell, and a current sensor including a preliminarily magnetized magnetic core and configured to measure current flowing in the converter from the fuel cell. A controller operates in a first driving mode in which a maximum current value in a target circuit of current measurement by the current sensor is lower than a current value for preliminary magnetization of the magnetic core, and a second driving mode in which the maximum current value in the target circuit is higher than the maximum current value in the target circuit in the first driving mode. When an accumulated temperature value of the current sensor in the first driving mode exceeds a threshold, the second driving mode is executed, followed by the first driving mode.