Multistate Switch Unit Circuit for Power Factor Correction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current power factor correction converters in communications power supplies suffer from low conversion efficiency and power density due to high inductance ripple current and large size, especially with interleaving technology and bidirectional switch bridgeless PFC circuits.
Innovation Solution
A power factor correction converter design incorporating multiple groups of bidirectional switches, an autotransformer, and a boost inductor forms a multistate switch unit circuit, allowing for reduced ripple and inductance, with the boost inductor being charged and discharged multiple times in a switching period, thereby improving efficiency and density.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If interleaving technology and bidirectional switch bridgeless PFC is used, then power factor correction is achieved, but inductance ripple current is high and conversion efficiency is low
Solution Approach 1:
The patent divides the single boost inductor into multiple interleaved inductors (L1, L2, L3, L4), each operating at different phases. This segmentation reduces the ripple current from each individual inductor while maintaining the overall power factor correction function, directly addressing the high inductance ripple current problem.
Solution Approach 2:
The patent combines multiple bidirectional switch groups (S1-S2, S3-S4, S5-S6, S7-S8) with their respective inductors to work together in an interleaved configuration. This merging of multiple PFC circuits operating in parallel achieves reduced ripple current and improved conversion efficiency compared to a single PFC circuit.
2Power
If interleaving technology is used, then power factor correction is achieved, but device size is large and power density is low
Solution Approach 1:
By segmenting the single large inductor into multiple smaller interleaved inductors, the patent reduces the volume required for each individual inductor component. The distributed configuration allows for more compact magnetic core design and better thermal management, improving power density.
Solution Approach 2:
The patent utilizes multiple phases and time domains through interleaved operation, effectively adding a temporal dimension to the power processing. This allows the system to achieve the same power handling capability with smaller individual components by distributing the load across multiple time-phased channels.
3Device complexity
If bidirectional switch bridgeless PFC is used, then circuit complexity is reduced, but effective value of current through switching transistor is great
Solution Approach 1:
The patent divides the total current handling among multiple bidirectional switch groups (S1-S2, S3-S4, S5-S6, S7-S8), each managing a portion of the total power. This segmentation reduces the current magnitude through each individual switching transistor while maintaining the overall bridgeless PFC functionality.
Solution Approach 2:
The patent merges multiple lower-current switch groups to achieve the same total current handling capability as a single high-current switch group would provide. This approach reduces stress on individual transistors while maintaining circuit simplicity through the bridgeless topology.
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 design reduces ripple currents and inductance, enhancing conversion efficiency and power density, and allows for a more compact circuit while maintaining better power factor and harmonic distortion indexes.
Implementation Method 1
an autotransformer, a boost inductor... A front end of each group of bidirectional switches is correspondingly connected to a coil of the autotransformer
Implementation Method 2
a boost inductor... the boost inductor is charged twice and discharged twice in one switching period
Implementation Method 3
a bus filter capacitor... Two ends of the load are connected to two ends of the bus filter capacitor, respectively
Data Source
AI summary
A power factor correction converter and a power factor correction conversion device, includes two groups of bidirectional switches, an autotransformer, a boost inductor, a bus filter capacitor, two front bridge arms; and a rear bridge arm; the front end of each group of bidirectional switches are connected to a coil of the autotransformer in one-to-one correspondence, and a rear end of each group of bidirectional switches is connected to one end of an AC input power grid; a central tap of the autotransformer is connected to an output end of the boost inductor, and an input end of the boost inductor is connected to the other end of the AC input power grid; a front end of each group of bidirectional switches is connected to a front bridge arm, and a rear end is connected to the rear bridge arm.