Heating Element Power Regulation with Cycle Stealing for Harmonic Control
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Solution Overview
Problem
Current heating systems with binary on/off operation cause significant thermal oscillations and inefficiencies due to the use of PID controllers, leading to non-compliance with EN61000-3-2 harmonic standards and excessive energy consumption.
Innovation Solution
A power regulation method using the cycle stealing technique with fine power adjustments in multiple levels, avoiding binary action and thermal oscillations by applying power in bands of more than one cycle, and a control system with a digital controller for precise power management.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If binary on/off action is used for heating control, then the system is simple to operate, but thermal oscillations occur and temperature stability deteriorates
Solution Approach 1:
The patent applies periodic action by using cycle stealing technique where the heating element is activated in periodic cycles rather than continuous operation. The controller selectively activates heating cycles based on temperature requirements, creating a periodic heating pattern that maintains temperature stability while avoiding binary on/off oscillations. This is evident in the control method that regulates power by applying heating in discrete cycles rather than simple on/off switching.
2Power
If cycle stealing technique is applied within single period, then power regulation is achieved, but high harmonics are generated exceeding EN61000-3-2 standards
Solution Approach 1:
The patent applies segmentation by dividing the heating control into multiple discrete cycles rather than attempting regulation within a single period. The cycle stealing technique is implemented across multiple heating cycles, where the controller selectively activates or skips individual cycles to achieve power regulation. This segmentation of control across multiple periods reduces harmonic emissions by distributing the power regulation action over time, preventing the generation of high-amplitude harmonics that would occur with single-period modulation.
Solution Approach 2:
The patent applies dynamics by making the cycle activation pattern adaptive and variable rather than fixed. The controller dynamically adjusts which heating cycles are activated based on real-time temperature feedback and power requirements. This dynamic cycle-by-cycle control allows the system to regulate power while maintaining harmonic emissions within standards, as the variable cycle pattern prevents repetitive harmonic generation at fixed frequencies.
3Device complexity
If binary on/off action is used, then device complexity is low, but energy efficiency deteriorates due to thermal oscillations
Solution Approach 1:
The patent applies periodic action through cycle stealing where heating is delivered in selective periodic cycles rather than continuous operation. This periodic heating pattern allows the system to maintain lower average power consumption while achieving the same heating effect over time, improving energy efficiency. The controller activates heating cycles only when necessary based on temperature feedback, avoiding energy waste from continuous operation and reducing thermal oscillations that cause energy loss.
4Stability of the object's composition
If gradual power application is implemented, then thermal oscillations are reduced, but control system complexity increases
Solution Approach 1:
The patent applies segmentation by breaking down continuous power regulation into discrete cycle-by-cycle control decisions. Rather than using complex continuous modulation, the controller makes simple binary decisions for each heating cycle (activate or skip), achieving gradual power application through the pattern of activated cycles. This segmented approach maintains temperature stability while keeping control logic relatively simple, as each cycle decision is independent and based on straightforward temperature feedback.
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
Achieves stable temperature control, reduces thermal oscillations, improves energy efficiency, and complies with EN61000-3-2 harmonic standards, enhancing the durability and acoustic performance of heating elements.
Implementation Method 1
power regulation method for a Joule heating system that includes a resistive load
Data Source
Figure 1~2
Figure 3-A~3-B
Figure 4-A~4-B
AI summary
The invention relates to a power regulation method for a heating element and control system for implementing said method, the method comprising the application of the cycle stealing technique to adjust the power supplied to the resistive load at multiple levels, such that the modulation period is enlarged, reducing the frequency of the current signal that modulates the carrier, in order to reduce the generation of harmonics. The control system comprises a controller (2) connected to a power regulator (3) acting on the heating element (1), such that said controller (2) adjusts the power supplied by the regulator (3) to the resistive load of the heating element (1) by the cycle stealing technique in fine steps.