Multi-Coil Induction Heating Frequency Control for Audible Noise
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Induction heating devices with multiple working coils experience interference noise due to differences in resonant frequencies falling within the audible frequency band when operated simultaneously, causing user inconvenience and potential device malfunction perception.
Innovation Solution
A method and device that control the induction heating device by adjusting the driving frequencies of multiple working coils based on target frequencies and reference values to minimize frequency differences, employing a coupling, separation, or normal mode to reduce interference noise.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If multiple working coils are operated simultaneously at different resonant frequencies, then each coil can perform heating function independently, but interference noise is generated when frequency difference falls within audible band
Solution Approach 1:
The patent dynamically adjusts the operating frequency of working coils based on real-time detection. When interference noise is detected, the control unit changes the frequency of at least one coil to move the frequency difference outside the audible band (20-20000 Hz), while maintaining the heating function. This dynamic frequency adjustment resolves the contradiction by allowing simultaneous operation of multiple coils without generating audible interference noise.
Solution Approach 2:
The patent changes the operating parameter (frequency) of the working coils to eliminate interference noise. By detecting the frequency difference between coils and adjusting at least one coil's frequency when the difference falls within the audible band, the system maintains heating productivity while preventing harmful noise generation.
2Object-affected harmful factors
If frequency adjustment is performed to reduce interference noise, then audible noise is prevented, but additional control complexity is required
Solution Approach 1:
The patent implements a feedback control mechanism where the control unit continuously monitors the frequency difference between working coils and detects interference noise. Based on this feedback, the system automatically adjusts the frequency of affected coils to eliminate audible noise. This feedback-based approach manages control complexity by using simple detection and adjustment logic rather than complex predictive control.
Solution Approach 2:
The system performs self-adjustment by automatically detecting frequency differences and adjusting coil frequencies without external intervention. The control unit autonomously identifies when interference noise occurs and implements frequency changes to resolve the issue, reducing the need for complex external control mechanisms.
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
Effectively reduces interference noise by equalizing or adjusting frequencies to prevent audible noise, ensuring smooth operation and user satisfaction.
Implementation Method 1
an induction magnetic field occurs around the working coil disposed in the induction heating device. When a magnetic line of force of the induction magnetic field passes through the bottom of the container including a metal component that is placed on the induction heating device, an eddy current occurs in the bottom of the container
Implementation Method 2
an eddy current occurs in the bottom of the container. When the eddy current flows through the bottom of the container, the container itself is heated
Implementation Method 3
As power is supplied to each working coil, each working coil generates a resonant frequency
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A method for controlling an induction heating device according to an embodiment of the present disclosure includes driving a first working coil at a first target frequency, receiving a driving command for a second working coil, stopping the driving of the first working coil and driving the second working coil at a preset first adjustment frequency, and determining a second target frequency of the second working coil corresponding to the driving command for the second working coil.