Dual-Output Charging Circuit Multiplexing Power Transistors

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Solution Overview

Problem

Conventional on-board chargers (OBC) and DC/DC products have high costs and large volumes due to independent power circuit topologies, and suffer from significant cross regulation between output-port voltages in current circuit conversion systems.

Innovation Solution

A dual-output-port charging circuit is designed with a primary-side conversion circuit, a secondary-side first conversion circuit, and a secondary-side second conversion circuit, along with a controller that controls phase shift angles to separate the operation of power supply paths, eliminating cross regulation by multiplexing power transistors on the high-voltage side of the DC/DC conversion circuit and the primary-side conversion circuit of the OBC.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If OBC and DC/DC circuits are integrated into a single conversion system, then device complexity and volume are reduced, but cross regulation between output-port voltages occurs

Engineering Contradiction:
Improvecircuit integrationVSAvoidcross regulation
Core Design Contradiction:
Device complexityVSObject-generated harmful factors

Solution Approach 1:

The patent divides the integrated circuit into independent control regions by implementing separate control strategies for the first and second output ports. The controller independently adjusts switching duties and phase shift angles for each port, effectively segmenting the control process to eliminate cross regulation interference while maintaining circuit integration.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent dynamically changes control parameters (switching duties and phase shift angles) based on the operating state of each output port. By independently adjusting these parameters, the system optimizes voltage output for each port without causing cross regulation, resolving the contradiction between integration and voltage stability.

Inventive Principle:
Principle #35Parameter changes

2Object-generated harmful factors

If independent power circuit topologies are used for OBC and DC/DC, then cross regulation is avoided, but cost and volume increase

Engineering Contradiction:
Improvecross regulation avoidanceVSAvoidcomponent quantity
Core Design Contradiction:
Object-generated harmful factorsVSDevice complexity

Solution Approach 1:

The patent merges the OBC and DC/DC power circuits into a single integrated conversion system with shared components. By combining these circuits while implementing independent control strategies, the patent reduces component quantity and volume while preventing cross regulation through separate control parameters for each output port.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The integrated circuit is designed with multi-functionality, where a single conversion system performs both OBC and DC/DC functions. The controller universally manages both output ports using adaptive control strategies, allowing the system to fulfill multiple functions without requiring separate independent topologies.

Inventive Principle:
Principle #6Universality (Multi-functionality)

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 configuration allows the dual-output-port charging circuit to operate independently, reducing cross regulation and enabling efficient energy output without increasing component count or cost, thereby improving the integration of OBC and DC/DC power circuits into a single conversion system.

Implementation Method 1

a transformer connected to the three circuits

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 2

the third branch circuit comprises a resonant inductor and a resonant capacitor that are connected in series

Methodology Applied
Scientific EffectElectromagnetic resonance: Resonance

Data Source

PatentEP3971019B1Charging circuit having two output ports
Publication Date: 2023.06.28 HUAWEI DIGITAL POWER TECH CO LTD
  • EP3971019B1 patent drawingFigure 1
  • EP3971019B1 patent drawingFigure 2
  • EP3971019B1 patent drawingFigure 3

AI summary

A dual-output-port charging circuit is provided, and is configured to multiplex a power transistor on a high-voltage side of a DC/DC conversion circuit and a power transistor of a primary-side conversion circuit of an OBC, so that no cross regulation is generated. The dual-output-port charging circuit includes a primary-side conversion circuit (101), a secondary-side first conversion circuit (102), a secondary-side second conversion circuit (103), a transformer (104), and a controller (105). The primary-side conversion circuit (101) is an inverter circuit, and the secondary-side first conversion circuit (102) and the secondary-side second conversion circuit (103) each are a rectifier circuit. The primary-side conversion circuit (101) includes a plurality of first power switches, the secondary-side first conversion circuit (102) includes a plurality of second power switches, and the secondary-side second conversion circuit (103) includes a third power switch, a fourth power switch, a first winding, a fifth power switch, a sixth power switch, a second winding, a first resonant inductor, a resonant capacitor, and a low-voltage output end. The controller (105) controls the power switches, so that electric energy is output between the primary-side conversion circuit (101), the secondary-side first conversion circuit (102), and the secondary-side second conversion circuit (103).