Induction Heating Inverter Circuit with Relay-Based Phase Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional induction heating devices face limitations in flex mode operation due to lack of circuit configuration for current direction inversion and individual object detection, leading to restricted heating regions and inaccurate detection of object placement between working coils.
Innovation Solution
An improved object-detection algorithm and circuit structure that allows current direction inversion and switching, enabling concurrent operation of multiple working coils at different phases and frequencies, and accurate detection of object placement for enhanced heating region control and user convenience.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If multiple working coils are arranged in flex zone or dual zone arrangement to heat multiple objects concurrently, then the heating capacity and versatility are improved, but the circuit structure complexity increases and current direction control becomes limited
Solution Approach 1:
The patent applies universality by designing a single inverter circuit that can serve multiple working coils (WC1, WC2, WC3) with different operational requirements. The inverter is configured to provide both in-phase and anti-phase current directions to different coils, enabling the same circuit to handle multiple heating zones and operational modes without requiring separate dedicated circuits for each coil, thus reducing overall system complexity while maintaining versatility.
Solution Approach 2:
The patent implements dynamics through relay-based switching mechanisms that dynamically change the circuit configuration. Relays R1-R4 enable real-time switching between different current directions (in-phase and anti-phase) and different operational modes (flex zone, dual zone, single zone) based on detection results. This dynamic reconfiguration allows the system to adapt its circuit structure to match the detected object placement, optimizing heating performance while managing circuit complexity.
2Ease of operation
If working coils are controlled at in-phase and same frequency to operate concurrently, then the circuit operation is simplified, but the heated region becomes concentrated on coil edges and heating uniformity deteriorates
Solution Approach 1:
The patent applies inversion by introducing anti-phase current control for working coils. Instead of all coils operating in-phase, the inverter can supply current in opposite phases to adjacent coils based on object detection results. This phase inversion shifts the heating pattern from edge-concentrated to more uniform distribution across the entire coil region, improving heating uniformity while the inverter maintains simplified operation through automated phase selection based on detection algorithms.
3Productivity
If object detection is performed individually for each working coil, then the detection process is simple and fast, but objects located between coils are not accurately detected and heating control precision is reduced
Solution Approach 1:
The patent merges individual coil-based object detection with region-based object detection algorithms. The system performs detection for each working coil individually and then combines these results to determine overall object placement status across multiple regions. This combined detection approach maintains the speed benefits of individual detection while achieving the accuracy of comprehensive region analysis, enabling correct identification of objects positioned between coils and improving heating control precision.
4Device complexity
If the same inverter is used to synchronize multiple working coils via relays, then the device complexity is reduced, but the current direction switching capability is limited and heating region control becomes restricted
Solution Approach 1:
The patent segments the control of multiple working coils by configuring the single inverter to operate in different operational modes (first operational mode, second operational mode, third operational mode). Each mode corresponds to different relay configurations that enable specific current direction patterns. This segmentation allows the inverter to provide differentiated current control to different coils based on detection results, enhancing heating region control versatility while maintaining reduced device complexity through unified inverter architecture.
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
The solution improves heating region control and output control, reducing heating time and enhancing heating intensity adjustment accuracy, resulting in improved user satisfaction and efficient cooking performance.
Implementation Method 1
as power is applied to the induction heating device, a high-frequency voltage of a predetermined magnitude is applied to the working coil. Accordingly, an inductive magnetic field is generated around the working coil disposed in the induction heating device
Implementation Method 2
When the flux of the inductive magnetic field thus generated passes through a bottom of the loaded object containing the metal as loaded on the induction heating device, an eddy current is generated inside the bottom of the loaded object
Implementation Method 3
When the resulting eddy current flows in the bottom of the loaded object, the loaded object itself is heated
Data Source
AI summary
An induction heating device includes: a first board including a first working coil, a first inverter configured to apply a resonant current to the first working coil, a first current transformer configured to adjusting a magnitude of the first resonant current, a first control unit configured to control the first inverter; and a second board including a second working coil, a second inverter configured to apply a resonant current to the second working coil, a second current transformer configured to adjust a magnitude of the second resonant current, a first relay configured to selectively connect the second working coil to the second current transformer or to the first working coil, a second relay configured to selectively connect the second working coil to the first working coil or to the second resonant capacitor, and a second control unit configure to control the second inverter, the first relay, and the second relay.