Induction Cooktop Ferrite Saturation Control
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Solution Overview
Problem
In inductive energy transmission using an induction hob, ferrites can become saturated, leading to unwanted magnetic field penetration into adjacent metal parts, inefficiency in energy transfer, and potential overload or damage to the power supply due to excessive currents.
Innovation Solution
The method involves using a transmitter coil and receiver coil with ferrites arranged on the side away from the opposing coil, and a flat metal sheet for shielding, with current regulation to maintain the ferrites within the saturation limit, ensuring efficient energy transfer and preventing overheating.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If high current is used to increase energy transmission, then energy transfer capability is improved, but ferrite saturation occurs causing magnetic field leakage and efficiency loss
Solution Approach 1:
The patent implements a control unit that continuously monitors the current through the transmitter coil and adjusts it based on the saturation state of the ferrites. This feedback mechanism ensures the current is regulated to at most 5-10% above the saturation current, optimizing energy transmission while preventing excessive saturation that would cause energy loss and magnetic field leakage.
Solution Approach 2:
The patent dynamically adjusts the current parameter through the transmitter coil based on operating conditions. By controlling the current to be at most 5-10% above the saturation current rather than using fixed high current, the system optimizes the balance between energy transmission capability and energy transfer efficiency, preventing ferrite saturation losses.
2Object-affected harmful factors
If ferrites are used to guide magnetic field, then magnetic field control is improved, but ferrite saturation causes magnetic field penetration into metal parts
Solution Approach 1:
The patent introduces a metal shielding plate positioned between the ferrites and the metal parts below the induction hob. This intermediary shielding plate prevents magnetic field leakage from saturated ferrites from penetrating into the metal parts, eliminating the harmful effect while preserving the magnetic field guiding function of the ferrites.
Solution Approach 2:
The patent acknowledges that ferrite saturation is inevitable at high power operation and converts this harmful effect into a manageable condition. By allowing controlled saturation (current at most 5-10% above saturation current) and using shielding plates to manage the resulting magnetic field leakage, the system maintains high energy transmission capability while preventing damage to metal components.
3Power
If current is increased beyond saturation point, then energy transmission is maximized, but power supply may be overloaded or damaged
Solution Approach 1:
The control unit continuously monitors the current through the transmitter coil and adjusts it based on the saturation state of the ferrites. This feedback mechanism ensures the current is regulated to at most 5-10% above the saturation current, optimizing energy transmission while preventing excessive saturation that would cause energy loss and magnetic field leakage.
Solution Approach 2:
The patent implements protective measures in advance by limiting the current to at most 5-10% above the saturation current. This preemptive current limitation prevents the power supply from being overloaded or damaged, cushioning against potential failures before they occur while still maintaining effective energy transmission.
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 enhances the efficiency of inductive energy transmission by preventing ferrite saturation, reducing energy loss, and avoiding excessive current loads, thereby improving the reliability and safety of the energy transfer process.
Implementation Method 1
The method uses a transmitter coil and a receiver coil to inductively transmit energy
Implementation Method 2
The magnetic field in the transmitter coil and/or in the receiver coil is guided by ferrites
Implementation Method 3
Ferrites can become saturated, leading to unwanted magnetic field penetration into adjacent metal parts
Implementation Method 4
a flat metal sheet for shielding, with current regulation to maintain the ferrites within the saturation limit
Data Source
Figure 1~2
Figure 3~5
Figure 6~7
AI summary
For inductive energy transfer between a transformer coil (acting as an induction heating coil) and a receiver coil in an induction cooktop, the transformer coil is part of a transformer resonant circuit, and the receiver coil is part of a receiver resonant circuit. The magnetic field in each coil is guided by ferrites located on opposite sides. A support plate for the induction heating coil is positioned below the ferrites of the transformer coil. The current through the transformer coil is monitored and regulated so that the ferrites are nearing saturation and the magnetic fluxes induced in the ferrites reach a maximum corresponding to saturation. To achieve this, the current through the transformer coil is regulated so that it is no more than 10% above the saturation current at which saturation begins in the ferrites.