Aircraft Emergency Power Cell Charging via Voltage Curvature Detection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The lifetime of electric power cells in aircraft emergency power supply modules is reduced due to overcharging, which increases their temperature and degrades their performance.
Innovation Solution
An electric aircraft emergency power supply module that includes a controller to monitor the voltage of the power cell and determine the second derivative of the voltage signal, using positive-to-negative zero crossings to simulate the behavior of a temperature-sensitive element, thereby controlling the charging to prevent overcharging.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If the electric power cell is charged to a large extent or close to full charging level, then the charging capacity is improved, but the temperature of the electric power cell increases and its lifetime is reduced
Solution Approach 1:
The system continuously monitors the voltage of the electric power cell during charging and uses this feedback to control the charging process. The controller determines the second derivative of the voltage signal and detects positive-to-negative zero crossings to dynamically adjust charging, preventing overcharging and temperature increase while maximizing charging capacity.
Solution Approach 2:
The invention changes the charging control parameter from direct voltage or current control to control based on the second derivative of voltage. By monitoring how the rate of voltage change evolves (positive-to-negative zero crossing of d²V/dt²), the system identifies the optimal charging endpoint, allowing full charging without exceeding safe temperature limits.
2Reliability
If a temperature sensitive element is used to control charging stop, then the lifetime of the electric power cell is improved, but the device complexity increases
Solution Approach 1:
Instead of using a physical temperature-sensitive element that would require additional hardware, the invention creates a virtual copy of temperature behavior through mathematical processing of voltage data. The controller calculates the second derivative of voltage and uses positive-to-negative zero crossings to simulate what a temperature sensor would detect, achieving temperature-based control without physical temperature sensing components.
Solution Approach 2:
The invention replaces the mechanical/physical temperature sensing system with an electrical/mathematical system. Rather than using thermal sensors, thermocouples, or temperature-dependent circuit elements, the system uses voltage measurement and mathematical differentiation to infer temperature-related charging state, substituting physical temperature measurement with electrical signal processing.
3Adaptability or versatility
If the electric charger is modified to accommodate different types of power cells, then the adaptability is improved, but the ease of replacement is reduced
Solution Approach 1:
The charging control system is designed to be universal and adaptable to different power cell types without requiring modification. The controller automatically determines the second derivative of the voltage signal and detects positive-to-negative zero crossings, which is a method that works across different cell chemistries. This universal approach allows easy replacement of power cells while maintaining consistent, safe charging control.
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 method ensures the power cells are charged to their full capacity without overcharging, optimizing their operational time and lifetime, and allows for easy replacement of different types of power cells without modifying the charger.
Implementation Method 1
at least one voltage sensor for measuring the electric voltage of the at least one electric power cell
Implementation Method 2
determining the second derivative of the voltage indication signal with respect to time; and, on the basis of a positive-to-negative zero crossing of the second derivative of the voltage indication signal, simulating the behavior of a temperature sensitive element
Data Source
AI summary
An electric aircraft emergency power supply module, which is connectable to an electric charger, comprises: at least one electric power cell for storing and supplying electric energy; at least one voltage sensor for measuring the electric voltage (U) of the at least one electric power cell; and a controller for controlling a charging of the at least one electric power cell. Controlling the charging of the at least one electric power cell includes receiving a voltage indication signal (U(t)), indicative of the electric voltage (U) of the at least one electric power cell over time (t), from the at least one voltage sensor; determining the second derivative (U″(t)) of the voltage indication signal (U(t)) with respect to time (t); and on the basis of a positive-to-negative zero crossing of the second derivative (U″(t)) of the voltage indication signal (U(t)), simulating the behavior of a temperature sensitive element.