Digital Power Supply Control to Reduce Harmonics and Flicker
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Solution Overview
Problem
Existing power supplies for high-powered loads, such as electric grills, introduce significant harmonic and flicker interference into the power grid, lacking precise control over multiple loads and efficiency, while prior solutions like variable resistors and bi-metal thermometers offer limited precision and efficiency.
Innovation Solution
A digital power supply using triacs and a microprocessor to deliver discrete power levels to heating elements, allowing independent control of multiple loads with reduced harmonic and flicker interference, and enabling wireless control and temperature monitoring.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If variable resistors are used to control power delivery to electric loads, then power control is achieved, but harmonics are introduced onto the electrical system and power efficiency decreases
Solution Approach 1:
The patent replaces variable resistors (mechanical/electrical component) with a microprocessor-based digital control system that uses triacs to switch power delivery. This substitution eliminates the continuous resistance adjustment that generates harmonics, replacing it with precise electronic switching control that delivers power in discrete levels without introducing harmful harmonic distortion into the electrical system.
Solution Approach 2:
The patent changes the control parameter from continuous resistance adjustment to discrete power level switching. The microprocessor controls triacs to deliver specific discrete power levels (e.g., 0%, 25%, 50%, 75%, 100%) to heating elements, replacing the continuous parameter adjustment of variable resistors with discrete state switching that avoids harmonic generation while maintaining power control capability.
2Ease of operation
If variable resistors are used to control power delivery to electric loads, then power control is achieved, but power efficiency decreases due to power burning
Solution Approach 1:
The patent replaces variable resistors (which dissipate power as heat) with a microprocessor-based digital control system using triacs. This substitution eliminates the continuous power dissipation inherent in resistance-based control, replacing it with solid-state switching that minimizes energy loss and improves overall power efficiency while maintaining full power control capability.
Solution Approach 2:
The patent changes from continuous resistance-based power control (which inherently wastes energy) to discrete power level switching via triacs. By delivering power in precise discrete levels through efficient switching rather than continuous resistance adjustment, the system eliminates unnecessary power dissipation and significantly improves energy efficiency.
3Ease of operation
If bi-metal thermometers are used to control power delivery, then power control is achieved, but control precision decreases and response time increases
Solution Approach 1:
The patent replaces bi-metal thermometers (mechanical sensing system) with a microprocessor-based digital control system using thermocouples or temperature sensors. This substitution provides precise digital temperature measurement and control, replacing the imprecise mechanical bimetallic strip system with electronic sensing that offers superior measurement precision and faster response times.
Solution Approach 2:
The patent changes from mechanical temperature sensing with discrete on/off control to digital temperature measurement with continuous or discrete power level control. The microprocessor reads temperature data from sensors and adjusts power delivery precisely, enabling accurate temperature control and significantly improving both measurement precision and response speed compared to bi-metal thermometer systems.
4Ease of operation
If bi-metal thermometers are used to control power delivery, then power control is achieved, but heating element lifespan decreases due to long on/off duty cycles
Solution Approach 1:
The patent replaces bi-metal thermometer-based on/off control (mechanical system with long duty cycles) with a microprocessor-based system using triacs for phase-angle or pulse-width modulation control. This substitution allows the heating element to operate at reduced power levels continuously rather than cycling between full on and full off, significantly reducing thermal stress and extending heating element lifespan.
Solution Approach 2:
The patent changes from binary on/off power delivery with long duty cycles to discrete power level control or continuous power modulation. By delivering reduced power levels through triac control rather than extended on/off cycling, the system maintains heating element temperature without subjecting it to repeated thermal expansion and contraction, thereby extending heating element operational life.
5Ease of operation
If half-wave control techniques are used to deliver power, then power delivery control is achieved, but power delivery is limited to stages rather than continuous range
Solution Approach 1:
The patent replaces half-wave control techniques (analog control with limited stages) with a microprocessor-based digital control system using triacs. This substitution enables precise control over multiple discrete power levels (e.g., 0%, 25%, 50%, 75%, 100%) or continuous power adjustment through pulse-width modulation or phase-angle control, significantly expanding the power delivery range and adaptability compared to traditional half-wave control.
Solution Approach 2:
The patent changes from analog half-wave control with limited power stages to digital control with multiple discrete power levels or continuous adjustment capability. The microprocessor can select from numerous power delivery levels by controlling triac firing angles or pulse widths, transforming the limited staged control into a versatile system capable of delivering power across a continuous or near-continuous range from 0% to 100%.
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 digital power supply provides precise power control, reduces harmonic and flicker interference, and extends the lifespan of heating elements by allowing short duty cycles, while complying with harmonic and flicker regulations.
Implementation Method 1
a heating element connected through a triac to a voltage line... deliver discrete power levels to the heating element
Data Source
AI summary
Provided is an apparatus and method for a digital power supply that can provide independent power control for two or more electrical loads. Some disclosed embodiments provide continuous, variable power and other disclosed embodiments provide discrete power levels. Disclosed embodiments may reduce the magnitude of harmonic currents and/or flicker introduced into a power system. Embodiments include a microprocessor that delivers power to electric loads using phase-controlled AC current. In some embodiments, the microprocessor may calculate a power array corresponding to a requested power for each electric load. Logic is provided for populating the power array in a pattern that reduces the magnitude of harmonic currents and flicker. Portions of the disclosure include a band controller for delivering power to achieve and maintain a desired target temperature, and a wireless controller for controlling temperature from a remote device.