Bridgeless PFC Single Choke Circuit Topology
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Solution Overview
Problem
Traditional bridgeless power factor correctors require two chokes, leading to lower utilization rates, increased space occupation, and higher power losses due to bridge diodes, which reduces conversion efficiency.
Innovation Solution
A bridgeless power factor corrector utilizing a single choke element, controlled by two switches and diodes, with a capacitor and rectify diodes, operates effectively during both positive and negative half cycles to achieve power factor correction without bridge diodes, thereby reducing power losses and space requirements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If two chokes are used in traditional bridgeless PFC, then energy storage and release can be achieved during both half cycles, but the utilization rate of chokes is low and occupied space is large
Solution Approach 1:
The patent merges the functions of two separate chokes into a single choke element. The single choke L1 performs both energy storage during positive half cycles and energy storage during negative half cycles, eliminating the need for separate chokes 23_1A and 23_2A. This consolidation reduces occupied space while maintaining the required energy storage capability for bridgeless operation.
Solution Approach 2:
The single choke L1 is designed to perform multiple functions: storing energy during positive half cycles, storing energy during negative half cycles, and enabling bridgeless operation for both half cycles. This multi-functional design replaces the specialized two-choke configuration, improving space utilization while maintaining reliability.
2Ease of manufacture
If bridge diodes are used in traditional PFC, then rectification can be achieved, but power losses are high and conversion efficiency is reduced
Solution Approach 1:
The patent extracts and removes the bridge diode configuration from the circuit. Instead of using four bridge diodes (28_1A, 28_2A, 29_1A, 29_2A) for rectification, the design uses only two rectify diodes D1 and D2 in a bridgeless configuration. This extraction eliminates the high power losses associated with traditional bridge diodes while maintaining the necessary rectification function through alternative circuit topology.
Solution Approach 2:
The patent inverts the traditional approach by eliminating the bridge diode structure entirely. Rather than using bridge diodes for rectification and accepting their power losses, the design inverts the strategy by using the choke and switch network to achieve bridgeless operation, thereby reducing power losses and improving conversion efficiency.
3Adaptability or versatility
If two chokes are used in traditional bridgeless PFC, then operation during both half cycles is enabled, but utilization rate of chokes is lower
Solution Approach 1:
The patent combines the functionality of two chokes into one, where the single choke L1 handles both positive and negative half cycle operations. This merging ensures that the choke is actively utilized during both half cycles, achieving full utilization rather than having one choke idle at any given time, thus improving productivity while maintaining adaptability.
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 single-choke design enhances conversion efficiency, reduces power losses, and optimizes space usage by allowing the choke to store and release energy in both half cycles, improving overall performance.
Implementation Method 1
a choke element Lp, a first switch Sw1, a second switch Sw2... The choke element has a first terminal Lp_1 and a second terminal Lp_2... configured to provide a power factor correction for the AC power source
Data Source
AI summary
A bridgeless power factor corrector with a single choke is electrically connected to an AC power source. The bridgeless power factor corrector includes a choke element, a first switch, a second switch, a first diode, a second diode, a capacitor, a first rectify diode, and a second rectify diode. The choke element is electrically connected between the first switch and the second switch. The first switch and the second switch are controlled to be turned on or turned off by a first control signal and a second control signal, respectively, to provide a power factor correction for the AC power source when the AC power source is in a positive half cycle or a negative half cycle. Furthermore, a method of operating the bridgeless power factor corrector is provided.