Adjustable Fly-back Converter Controller for Power Factor Correction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing converters, such as fly-back and buck-boost converters, suffer from relatively high distortion power factors, leading to unwanted losses in the grid and power generators, and existing solutions like dual-stage power factor correction circuits are expensive.
Innovation Solution
A controller that adjusts the duration of the conducting time of the switch in fly-back and buck-boost converters proportionally to the sum of the instantaneous voltage signal amplitude and a design parameter, reducing distortion by increasing the duration with increased voltage and decreasing it with decreased voltage, thereby improving the power factor.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If dual-stage power factor correction circuits are used, then distortion power factor is improved, but device complexity and cost increase
Solution Approach 1:
The patent combines power factor correction and voltage regulation functions into a single-stage converter circuit. The controller integrates both PFC control and output voltage regulation in one unified circuit architecture, eliminating the need for separate dual-stage circuits while achieving both distortion reduction and voltage stability.
Solution Approach 2:
The single-stage converter is designed to perform multiple functions simultaneously: power factor correction, distortion reduction, and output voltage regulation. The controller manages both PFC and voltage control within the same circuit, making the converter universal in handling multiple power quality issues without requiring additional dedicated circuits.
2Measurement precision
If dual-stage power factor correction circuits are used, then distortion power factor is improved, but manufacturing cost increases
Solution Approach 1:
The patent merges power factor correction and voltage regulation into a single integrated circuit stage, reducing the total component count and assembly complexity. This single-stage design requires fewer semiconductor devices, passive components, and interconnections, directly lowering manufacturing costs compared to dual-stage architectures.
Solution Approach 2:
The patent employs a cost-effective single-stage converter design that eliminates expensive dual-stage circuitry. By using readily available components in a simplified single-stage configuration, the overall bill of materials and manufacturing expenses are reduced while still achieving the required power factor performance.
3Measurement precision
If the duration of conducting time is adjusted proportionally to voltage signal amplitude, then distortion is reduced, but control complexity increases
Solution Approach 1:
The controller uses feedback from the voltage signal amplitude to dynamically adjust the switch conducting time duration. The control circuit continuously monitors the input voltage and modulates the switch duty cycle proportionally, creating a closed-loop system that automatically compensates for voltage variations and maintains optimal power factor without complex external control mechanisms.
Solution Approach 2:
The patent implements dynamic adjustment of the switch conducting time based on real-time voltage signal amplitude. The control circuit dynamically modifies the duty cycle in proportion to the instantaneous voltage, enabling the converter to adapt to varying line conditions and maintain high power factor across different operating points without requiring complex static control circuits.
Data Source
Figure 1~2
Figure 3~4
Figure 5
AI summary
In fly-back and buck-boost converters (21, 22), to reduce distortions and to increase distortion power factors, arrangements (1) are introduced for adjusting control signals generated by controllers (2) for controlling switches (3) of the converters. The arrangements (1), in response to increased / decreased amplitudes of voltage signals from voltage supplies (4) for feeding the converters, increase / decrease durations of conducting times of the switches (3). This way, unwanted losses in the grid and power generators are avoided. The converters are relatively low cost single stage converters. Preferably, the durations are substantially proportional to sums of the amplitudes of the voltage signals and design parameters. These design parameters may comprise amplitudes of other voltage signals such as output voltages. Arrangements (1) are provided for controllers (2) that can only produce fixed durations as well as for controllers (2) that can produce adaptable durations via adaptable external elements.