Induction Heating Inverter Control Using DC Link Power Estimation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing induction heating apparatuses require additional hardware circuits for power and current detection, leading to complex device configurations and increased manufacturing costs, with inaccurate power control due to reliance on external voltage and current measurements.
Innovation Solution
An induction heating apparatus that calculates output power value using existing elements, based on inverter circuit voltage and current measurements, employing a controller to adjust driving frequency and control the working coil accurately without additional hardware, utilizing a method that combines DC link voltage and switching functions to determine the actual power value.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If additional hardware circuits (shunt resistor, voltage sensing circuit, current sensing circuit) are added for power and current detection, then measurement precision is improved, but device complexity and manufacturing cost increase
Solution Approach 1:
The inverter circuit performs self-measurement of output power by utilizing its own internal switching signals and DC link voltage detection. The controller calculates output power by integrating the product of switching function and DC link voltage, eliminating the need for external power sensors and current shunt resistors. This self-service approach reduces device complexity while maintaining measurement precision.
Solution Approach 2:
The patent replaces physical hardware measurement circuits (voltage sensing circuits, current sensing circuits, shunt resistors) with a software-based calculation method. The controller uses digital signal processing to compute output power by integrating the product of detected DC link voltage and inverter switching function, substituting mechanical/electrical measurement systems with computational methods.
2Measurement precision
If additional hardware circuits are added for power and current detection, then measurement precision is improved, but manufacturing cost increases
Solution Approach 1:
The inverter circuit performs self-measurement of output power by utilizing its own internal switching signals and DC link voltage detection. The controller calculates output power by integrating the product of switching function and DC link voltage, eliminating the need for external power sensors and current shunt resistors. This self-service approach reduces device complexity while maintaining measurement precision.
Solution Approach 2:
The patent replaces physical hardware measurement circuits (voltage sensing circuits, current sensing circuits, shunt resistors) with a software-based calculation method. The controller uses digital signal processing to compute output power by integrating the product of detected DC link voltage and inverter switching function, substituting mechanical/electrical measurement systems with computational methods.
3Measurement precision
If traditional voltage and current measurement methods are used, then measurement precision is improved, but control speed and responsiveness decrease
Solution Approach 1:
The patent replaces physical hardware measurement circuits (voltage sensing circuits, current sensing circuits, shunt resistors) with a software-based calculation method. The controller uses digital signal processing to compute output power by integrating the product of detected DC link voltage and inverter switching function, substituting mechanical/electrical measurement systems with computational methods.
Solution Approach 2:
The controller continuously monitors and stores the DC link voltage and switching function data in real-time during inverter operation. This preliminary data collection enables immediate power calculation when needed, improving control responsiveness without requiring additional measurement hardware that would introduce signal processing delays.
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
Enables precise power control and improved responsiveness by calculating output power values in real-time, reducing complexity and costs by eliminating the need for extra hardware circuits and enhancing control speed.
Implementation Method 1
an alternating current may be applied to the working coil. Accordingly, an induction magnetic field may be generated around the working coil disposed in the induction heating apparatus
Implementation Method 2
an eddy current may be generated inside the bottom of the container. When the eddy current generated in this way flows through the container, the container itself may be heated
Implementation Method 3
An induction heating apparatus is a mechanism that heats a container by generating an eddy current in a metal container, using a magnetic field generated around a working coil
Data Source
AI summary
A method for controlling an induction heating apparatus comprises receiving a power level for a heating region, supplying a switching signal to an inverter circuit based on a predetermined reference frequency, measuring an output current value of the inverter circuit, measuring a DC link voltage value, calculating an output power value of the working coil based on the output current value of the inverter circuit and the DC link voltage value, determining a heating frequency of the inverter circuit based the result of comparison by comparing the output power value of the working coil with a required power value, and supplying a switching signal to the inverter circuit based on the heating frequency.