Power Factor Correction Using Auxiliary Winding and Rectifiers
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Solution Overview
Problem
Existing switching mode power supplies face challenges in achieving cost-effective and space-efficient power factor correction, especially in slim designs, due to the need for separate active power factor correction circuits for each power supply, which are expensive and space-consuming, and passive correction systems are inadequate for varying power factors.
Innovation Solution
A power supply system utilizing a single power factor correction integrated circuit for multiple power supplies, with an auxiliary winding on the first transformer to generate a higher voltage, allowing current to pass from the first power supply to the second power supply for active power factor correction, reducing the need for multiple correction circuits and minimizing space requirements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If separate active power factor correction circuits are used for each power supply, then power factor correction is effective, but system cost and space requirements increase
Solution Approach 1:
The patent merges the power factor correction function from multiple separate circuits into a single shared correction circuit that serves multiple power supply units. The correction circuit is implemented once at the input stage and benefits all downstream power supplies, eliminating redundant components and reducing overall system complexity while maintaining correction effectiveness.
Solution Approach 2:
The single power factor correction circuit is designed to universally serve multiple power supply units simultaneously. By positioning the correction circuit at the common input stage before the power is distributed to different power supply modules, one correction circuit performs the function that would otherwise require multiple separate circuits, achieving multi-functionality and cost reduction.
2Ease of manufacture
If passive power factor correction systems are used, then implementation is simple, but correction amount cannot be adjusted for varying power factors
Solution Approach 1:
The patent employs dynamic control of the power factor correction circuit through PWM switching technology. The correction amount is adjusted in real-time based on the actual power factor conditions and power supply requirements. The duty cycle of the switching element is dynamically modified to achieve the desired correction level, allowing the system to adapt to varying power factor conditions while maintaining simple implementation through integrated circuit control.
3Reliability
If chokes are used for passive power factor correction in secondary supply, then power factor is corrected, but component size and cost increase
Solution Approach 1:
The patent replaces the mechanical/physical choke component with an electronic active power factor correction circuit implemented through switching elements and control logic. This substitution eliminates the need for large magnetic cores and heavy inductors, achieving power factor correction through electronic switching and control instead of passive magnetic components, thereby dramatically reducing component size and weight.
Solution Approach 2:
The patent changes the operating parameters of the power factor correction by using high-frequency switching (10 kHz - 1 MHz) instead of low-frequency choke operation. This parameter change allows the use of much smaller magnetic components or eliminates the need for large chokes entirely, as the correction is achieved through rapid switching cycles that require minimal energy storage in magnetic fields.
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
This solution enables efficient power factor correction for multiple power supplies using a single circuit, reducing system costs and space requirements, while maintaining effective power factor correction across varying power conditions.
Implementation Method 1
at least one auxiliary winding on the first transformer for generating a higher voltage than an input voltage of a power input of the power supply system
Data Source
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AI summary
Present invention discloses a switching power supply system which comprises; a first power supply (S1) at least one independently controllable second power supply (S2) wherein the system further comprises at least one auxiliary winding (T1a) on the first transformer (T1) of the first power supply (S1) for generating a higher voltage than an input voltage of a power input of the power supply system; a first rectification means (8a) allowing a first current to only pass from the power input of the power supply system to the power input of the second power supply (S2) and a second rectification means (8b) allowing current to pass only from the output of the auxiliary winding (T1a) to the power input of the second power supply (S2). Within the system of the invention, the power factor of the several power supplies can be corrected using a single power factor correction system.