Wireless Energy Transmission Object Detection via Inductance Monitoring
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Solution Overview
Problem
Existing wireless energy transmission systems face challenges in reliably detecting small or distant conductive or magnetizable objects within the energy transmission path, which can cause overheating and disrupt energy transfer due to eddy currents and hysteresis losses, compromising operational safety.
Innovation Solution
An energy transmission system with a detection device that monitors the inductance of the transmitting coil by applying an electrical load to the receiving coil, amplifying the magnetic field, and controlling the magnetic field exposure to accurately detect objects, including smaller or less susceptible ones, through changes in inductance, current, frequency, or quality factor.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If an object detection method based on inductance measurement is used, then object presence can be detected, but small or distant objects cannot be reliably detected
Solution Approach 1:
The patent changes the electrical parameter state of the receiving coil by connecting different electrical loads (short circuit, resistive load, capacitive load) to modify the magnetic field strength in the energy transmission path. This amplifies the effect of objects on the transmitting coil's inductance, enabling reliable detection of small or distant objects that would otherwise be undetectable
Solution Approach 2:
The receiving coil acts as an intermediary element that, when loaded with electrical loads, amplifies the magnetic field in the energy transmission path. This intermediary mechanism enhances the interaction between the magnetic field and objects, making their presence detectable through inductance changes in the transmitting coil
2Measurement precision
If a strong magnetic field is applied to detect objects, then detection sensitivity improves, but objects may overheat due to eddy currents and hysteresis losses
Solution Approach 1:
The patent employs periodic switching between detection mode (with electrical load for high magnetic field) and normal operation mode. During brief detection intervals, the receiving coil is connected to electrical loads to amplify the magnetic field for object detection, then switched to normal operation, thereby limiting cumulative heating while maintaining detection sensitivity
Solution Approach 2:
The system uses feedback from inductance measurements to detect object presence and adjusts or terminates energy transmission accordingly. When an object is detected through inductance changes, the system can reduce or stop transmission to prevent overheating, creating a closed-loop control that balances detection sensitivity with safety
3Productivity
If the receiving coil operates with normal electrical load, then energy transmission efficiency is maintained, but object detection sensitivity is reduced
Solution Approach 1:
The system dynamically switches the electrical load on the receiving coil between two states: normal operation mode (with standard electrical load for efficient energy transmission) and detection mode (with amplified load such as short circuit, resistive load, or capacitive load for enhanced object detection). This dynamic adaptation allows the system to optimize for either productivity or measurement precision based on operational requirements
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
Enhances the detection accuracy of objects in the energy transmission path, preventing overheating and ensuring safe operation by throttling or aborting energy transfer when necessary, while allowing for controlled magnetic field exposure to avoid dangerous heating.
Implementation Method 1
a transmission device with a transmission coil and a reception device with a reception coil, the coils being able to be inductively coupled to one another for the purpose of transmitting energy
Implementation Method 2
By providing an electrical load at the terminals of the receiving coil, a voltage induced in the receiving coil acts in a similar way to a current source, so that the receiving coil generates or amplifies its own magnetic field
Implementation Method 3
If an electrically conductive object enters the area of the electromagnetic field, eddy currents can form that heat up the object
Implementation Method 4
If the object can be magnetized, the object can also be heated by remagnetization or hysteresis losses
Data Source
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AI summary
An energy transmission system comprises a transmitting device with a transmitting coil and a receiving device with a receiving coil, wherein the coils can be coupled together inductively for the transmission of energy such that an energy transmission path exists between them. The energy transmission system further comprises an electrical load for connecting with terminals of the receiving coil, a detection device for detecting an electrical parameter indicating the inductance of the transmitting coil while the electrical load is connected to the receiving coil and a determination device for determining an object in the region of the energy transmission path on the basis of the parameter detected.