Dynamic Waveform Correction for Induction Heating Power Supply
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Solution Overview
Problem
Existing induction heating devices face limitations in efficiently varying the frequency of working signals to regulate heating power, as current methods are inflexible and lack precise control over frequency modulation.
Innovation Solution
A method and arrangement for dynamic waveform correction of the power supply in induction heating devices, involving a frequency converter that shifts the working frequency between multiple base frequencies within a half wave duration, allowing for flexible frequency variation and phase control by passing zero crossings, and incorporating specific time spans for frequency modulation to reduce controlling effort.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the working frequency is varied to regulate heating power, then the heating power regulation is achieved, but the frequency control flexibility is limited
Solution Approach 1:
The patent implements dynamic frequency shifting within each half-wave cycle, where the working frequency is continuously adjusted rather than fixed. The frequency shifts from a first base frequency to a second base frequency by passing through zero-crossings, enabling adaptive control that responds to real-time conditions while maintaining regulatory flexibility
Solution Approach 2:
The invention applies periodic frequency shifting operations synchronized with the half-wave cycles of the rectified input signal. By performing frequency shifts at specific intervals aligned with zero-crossings, the system achieves regular control patterns that simplify the overall control architecture while maintaining adaptability
2Adaptability or versatility
If multiple frequency shifting operations are executed, then the frequency variation flexibility is increased, but the controlling effort increases
Solution Approach 1:
The system pre-plans frequency shifting operations to occur at specific half-wave intervals, determining in advance which zero-crossings will be passed and what base frequencies will be used. This preliminary planning reduces real-time controlling effort by eliminating the need for complex on-the-fly decisions
Solution Approach 2:
The patent maintains continuous frequency modulation across multiple half-waves by chaining frequency shifting operations together. The second base frequency of one operation becomes the starting point for the next operation, creating a continuous frequency variation pattern that reduces controlling effort compared to discrete, isolated adjustments
3Measurement precision
If the frequency shifting operation passes zero crossings, then the phase control precision is improved, but the operational complexity increases
Solution Approach 1:
The system uses zero-crossing detection as a feedback mechanism to trigger frequency shifting operations. By monitoring when the rectified signal crosses zero, the controller automatically initiates frequency shifts at precise moments, achieving high phase control precision through simple threshold-based feedback rather than complex timing calculations
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 enables flexible and efficient frequency modulation, allowing for repeated frequency shifting operations with various base frequencies and time lags, enhancing the regulation of heating power and reducing operational complexity.
Implementation Method 1
a frequency converter rectifies the input power signal into a half waves signal
Implementation Method 2
the frequency converter further converts the half waves signal into to a working signal, especially a working current signal
Implementation Method 3
in a frequency shifting operation a working frequency of the working signal is first increased from a first working base frequency to a maximum frequency and then decreased to a second base frequency
Implementation Method 4
power supply of an induction heating device
Implementation Method 5
induction heating device
Data Source
AI summary
A method for dynamic wave form correction includes providing an input power signal by an AC power source and rectifying the input power signal by a frequency converter into a half waves signal whose half wave is delimited by two subsequent zero-crossings. The time lag between the two zero-crossings defines a half wave duration. The frequency converter converts the half waves signal into a working current signal for supplying an induction heating device. In a frequency shifting operation, the frequency of the working signal is first increased from a first base frequency to a maximum frequency, and is then decreased to a second base frequency different from the first base frequency within a time period smaller than the half wave duration. A zero crossing of the half wave signal is passed within the frequency shifting operation. An arrangement for dynamic wave form correction of a power supply is also provided.