Propulsion Control Apparatus for Electric Vehicle Power Conversion

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Solution Overview

Problem

Conventional hybrid vehicles require three power converters to utilize overhead wire power, leading to increased costs, size, and mass due to the need for a DC/AC converter, AC/DC converter, and DC/DC converter for engine, generator, and power storage device integration.

Innovation Solution

A propulsion control apparatus with a first power converter providing AC/DC, DC/AC, and DC/DC conversion functions and a second power converter providing similar functions, allowing for the elimination of redundant converters by integrating these functions into two converters.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If three power converters (inverter, AC/DC converter, DC/DC converter) are used to enable overhead wire power usage in hybrid vehicles, then the vehicle can utilize multiple power sources (engine, generator, power storage device), but the cost, size, and mass increase significantly

Engineering Contradiction:

Improveoverhead wire power usage capabilityVSAvoidnumber of power converters

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent combines the functions of the inverter (DC/AC converter) and the DC/DC converter into a single integrated power converter unit. This merging eliminates the need for separate AC/DC and DC/DC converters when overhead wire power is available, reducing the total number of power converters from three to two while maintaining all necessary power conversion capabilities for hybrid vehicle operation

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The integrated power converter is designed to perform multiple functions: it can operate as an inverter to convert DC from the power storage device to AC for the motor, and simultaneously function as a DC/DC converter to manage power flow between the overhead wire, generator, and power storage device. This multi-functionality allows a single converter to replace what would traditionally require three separate converters

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Adaptability or versatility

If three power converters are installed to support engine, generator, and power storage device integration with overhead wire power, then complete power management is achieved, but the apparatus size and mass increase

Engineering Contradiction:

Improvepower source integrationVSAvoidapparatus size

Core Design Contradiction:

Adaptability or versatilityVSVolume of moving object

Solution Approach 1:

By merging the inverter and DC/DC converter functions into a single integrated power converter, the physical space required for power conversion equipment is reduced. The patent demonstrates that this consolidation maintains complete power management capability across all power sources (engine, generator, power storage device) while occupying less volume than three separate converters would require

Inventive Principle:

Principle #5Merging (Combining)

3Adaptability or versatility

If three power converters are used for comprehensive power conversion needs, then all power sources can be managed, but the cost increases

Engineering Contradiction:

Improvemulti-power source managementVSAvoidmanufacturing cost

Core Design Contradiction:

Adaptability or versatilityVSEase of manufacture

Solution Approach 1:

The integration of inverter and DC/DC converter functions into a single power converter unit reduces the total number of components that need to be manufactured, procured, and installed. This merging reduces material costs, assembly costs, and maintenance costs while preserving the ability to manage multiple power sources (engine, generator, power storage device) with overhead wire power capability

Inventive Principle:

Principle #5Merging (Combining)

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

Enables the use of conventional hybrid vehicles with overhead wire power without increasing the number of power converters, reducing costs, size, and weight by consolidating conversion functions within two power converters.

Implementation Method 1

an AC/DC conversion function, a DC/AC conversion function, and a DC/DC conversion function are provided in the first power converter

Methodology Applied

Scientific EffectAC/DC conversion:

Implementation Method 2

an AC/DC conversion function, a DC/AC conversion function, and a DC/DC conversion function are provided in the first power converter

Methodology Applied

Scientific EffectDC/AC conversion:

Implementation Method 3

an AC/DC conversion function, a DC/AC conversion function, and a DC/DC conversion function are provided in the first power converter

Methodology Applied

Scientific EffectDC/DC conversion:

Data Source

PatentEP2875982B1Device and method for controlling propulsion of electric vehicle

Publication Date: 2019.08.21 MITSUBISHI ELECTRIC CORP

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AI summary

A propulsion control apparatus of an electric motor vehicle includes a first power converter 21 that operates as a DC/AC converter, an AC/DC converter, or a DC/DC converter, a first power converter 21 that operates as a DC/AC converter, an AC/DC converter, or a DC/DC converter, a first power storage device 22 and a second power storage device 52 functioning as a direct-current power supply source that is charged using direct-current power supplied from a direct-current common section 90 or a first input output end side or discharges direct-current power to the direct-current common section 90 or the first input and output end side, and a control device 100 that controls operations of the first power converter 21, the second power converter 51, the first power storage device 22, and the second power storage device 52.