Interleaved PFC Bridge Arm Inductor Utilization

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Solution Overview

Problem

Existing Power Converter designs exhibit low utilization of inductors due to different boost circuits for positive and negative half cycles, leading to inefficient power component utilization.

Innovation Solution

The design incorporates multiple bridge arm units with series-connected switches and inductors, allowing for interleaving control of Power Factor Correction (PFC) circuits, ensuring the inductor remains in a working state and is fully utilized by operating the second bridge arm units in an interleaving paralleled manner at any phase difference.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If separate boost circuits are used for positive and negative half cycles, then the circuit can process AC power, but the inductor utilization is low

Engineering Contradiction:
ImproveAC power processing capabilityVSAvoidinductor utilization
Core Design Contradiction:
Adaptability or versatilityVSProductivity

Solution Approach 1:

The patent merges the positive and negative half-cycle processing into a single unified circuit topology where one inductor serves both half-cycles. The bridge arm units are configured to allow the same inductor to be charged during one half-cycle and discharged during the other, eliminating the need for separate inductors for each half-cycle and doubling the utilization rate of each inductor.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The inductor is pre-charged during the positive half-cycle in preparation for the negative half-cycle discharge, and vice versa. This preliminary charging action ensures that the inductor is always ready to transfer energy when needed, maintaining continuous power processing while maximizing inductor utilization across both half-cycles.

Inventive Principle:
Principle #10Preliminary action

2Ease of operation

If separate boost circuits are used for positive and negative half cycles, then half-cycle processing is simplified, but power component utilization is inefficient

Engineering Contradiction:
Improvehalf-cycle processing simplicityVSAvoidpower component utilization efficiency
Core Design Contradiction:
Ease of operationVSLoss of energy

Solution Approach 1:

The patent establishes continuous useful action by configuring the bridge arm units so that while one inductor is charging, another is discharging, and vice versa. This continuous interleaved operation ensures that power components are always engaged in useful work rather than idle, significantly improving overall utilization efficiency while maintaining operational simplicity through the unified topology.

Inventive Principle:
Principle #20Continuity of useful action

3Adaptability or versatility

If traditional PFC circuits are used, then power factor correction is achieved, but circuit losses are high

Engineering Contradiction:
Improvepower factor correctionVSAvoidcircuit losses
Core Design Contradiction:
Adaptability or versatilityVSLoss of energy

Solution Approach 1:

The patent employs periodic interleaved operation of multiple bridge arm units where switches are turned on and off in alternating sequences. This periodic switching pattern allows for continuous power factor correction while distributing the stress and losses across multiple components operating in alternation, reducing overall circuit losses compared to traditional single-circuit PFC approaches.

Inventive Principle:
Principle #19Periodic action

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 approach enhances inductor utilization, improves power conversion efficiency, and reduces circuit losses by maintaining the inductor in a continuous working state, while also providing diode clamps for Electro Magnetic Interference (EMI) and lightning surge protection.

Implementation Method 1

the power supply charges the boost circuit inductor L1 through the PFC primary switch S1 and the fly-wheel diode D4 to store energy

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 2

The upper side of the first bridge arm unit and the upper side of the second bridge arm unit are connected with the first end of the capacitor

Methodology Applied
Scientific EffectCapacitance: Capacitance

Data Source

PatentEP2276157B1Power converter, device and method for interleaving controlling power factor correction circuits
Publication Date: 2015.01.07 HUAWEI TECH CO LTD
  • EP2276157B1 patent drawingFigure 1
  • EP2276157B1 patent drawingFigure 2~3
  • EP2276157B1 patent drawingFigure 4

AI summary

A Power Converter, a device, and a method for interleaving controlling Power Factor Correction (PFC) circuits are disclosed. The Power Converter includes a first bridge arm unit, a second bridge arm unit, and a capacitor. The upper side of the first bridge arm unit and the upper side of the second bridge arm unit are connected with the first end of the capacitor, and the lower side of the first bridge arm unit and the lower side of the second bridge arm unit are connected with the second end of the capacitor. The first bridge arm unit includes two diodes series-connected in the same direction, and the joint of the two diodes is connected with the first end of the power supply. The second bridge arm unit includes two switches series-connected in the same direction and one inductor, and the first end of the inductor is connected with the joint of the two switches, while the second end of the inductor is connected with the second end of the power supply. Thus, the utilization of the inductor is improved.