Bidirectional DCAC Converter for AC-DC Integration

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Solution Overview

Problem

The integration of AC and DC components in electromobility systems requires complex and costly power electronic converters due to the need to change current and voltage types, leading to increased costs and complexity.

Innovation Solution

A power circuit with a DC voltage connection that includes a node connecting a DCDC converter and a DCAC converter, allowing for bidirectional energy transmission and simultaneous use of AC and DC power, reducing the need for additional components and simplifying the connection process through automatic voltage detection and adjustment.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If complex power electronic converters are used to convert between AC and DC current types, then the system can integrate different power types, but the cost and device complexity increase significantly

Engineering Contradiction:

Improveintegration of AC and DC componentsVSAvoidcomplexity of power electronic actuators

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent makes the DCAC converter bidirectional, enabling it to perform both DC-to-AC conversion for traction and AC-to-DC conversion for charging. This multi-functionality eliminates the need for separate converters, reducing device complexity while maintaining the ability to integrate both AC and DC components in the hybrid electromobility system

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Use of energy by moving object

If separate power electronic actuators are used for converting electrical energy between different current types, then current type conversion is achieved, but the cost increases due to expensive electronic power components

Engineering Contradiction:

Improveconversion of electrical energyVSAvoidcost of electronic power components

Core Design Contradiction:

Use of energy by moving objectVSEase of manufacture

Solution Approach 1:

The bidirectional DCAC converter serves dual purposes: converting DC to AC for driving the electric machine during traction, and converting AC to DC for charging the energy storage device. This eliminates the need for separate power electronic actuators for each conversion direction, significantly reducing the cost of electronic power components while maintaining full conversion capability

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent merges the functions of multiple separate converters (DCAC converter for traction and a separate charger converter for charging) into a single bidirectional DCAC converter. This consolidation reduces the total number of expensive electronic power components required, thereby lowering the overall manufacturing cost of the system

Inventive Principle:

Principle #5Merging (Combining)

3Adaptability or versatility

If different current types are coupled in the system, then energy transmission between AC and DC components is enabled, but expensive electronic power components are required for control

Engineering Contradiction:

Improvecoupling of different current typesVSAvoidcost of control components

Core Design Contradiction:

Adaptability or versatilityVSEase of manufacture

Solution Approach 1:

The bidirectional DCAC converter is designed to handle both AC and DC current types through a single control system. The controller automatically adapts its control strategy based on the operating mode (traction or charging), eliminating the need for separate control electronics for each current type conversion, thereby reducing the cost of control components while maintaining full adaptability

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 solution enables efficient and cost-effective integration of AC and DC components, allowing for bi-directional energy use in both charging and traction, while reducing the complexity and cost of power conversion, and enabling simultaneous AC and DC charging.

Implementation Method 1

The DCAC converter is set up to convert a direct current into an alternating current or to convert an alternating current into a direct current

Methodology Applied

Scientific EffectPower conversion:

Implementation Method 2

The DCDC converter is set up to transmit electrical energy from the DC voltage connection to an energy storage connection

Methodology Applied

Scientific EffectPower conversion:

Data Source

PatentEP3286033B1Power circuit for power supply in an electrically driven vehicle and stationary energy supply system

Publication Date: 2021.09.01 VITESCO TECHNOLOGIES GMBH

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AI summary

The invention relates to a power circuit (10) for power supply in an electrically driven vehicle. The power circuit (10) comprises a direct voltage connection (20), an electrical traction drive (30), and a DCAC converter (40). Said converter has an alternating voltage side (42) which is connected to the traction drive (30). A DCDC converter (50) of the power circuit has two converter sides (52, 54). The first converter side (52) is connected to a direct voltage side (44) of the DCAC converter (40) via a coupling point (60). The direct voltage connection (20) is likewise connected to said coupling point (60). The invention further relates to a stationary energy supply system (200) which is designed to be complementary and to connect to the power circuit.