Motor Controller Buck Converter for EV Battery Charging

Solution Overview

Problem

Electric vehicles require a separate DC-DC converter to charge batteries with different voltages, which increases weight and reduces internal space, and poses challenges in charging batteries when the engine is not driven.

Innovation Solution

A driving apparatus with a motor, engine, and motor controller that includes a buck converter configuration using a field coil and armature coil, allowing selective charging of batteries with different voltages without a separate DC-DC converter, enabling charging even when the engine is stopped.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a separate DC-DC converter is used to charge batteries with different voltages, then charging capability is improved, but weight and volume increase

Engineering Contradiction:

Improvecharging capabilityVSAvoidweight

Core Design Contradiction:

Adaptability or versatilityVSWeight of moving object

Solution Approach 1:

The patent combines the DC-DC converter function with the motor controller by integrating the buck converter circuit into the existing motor controller hardware. The field coil and armature coil of the motor are utilized as inductors in the buck converter circuit, allowing the motor controller to perform both motor control and voltage conversion functions simultaneously, thereby eliminating the need for a separate DC-DC converter and reducing overall system weight.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The motor controller is designed to perform multiple functions: it controls the motor operation and simultaneously acts as a DC-DC converter for charging batteries with different voltages. The buck converter circuit within the motor controller can convert the high voltage from the first battery to the lower voltage required by the second battery, enabling the single device to serve dual purposes and eliminate redundant components.

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Adaptability or versatility

If a separate DC-DC converter is used to charge batteries with different voltages, then charging capability is improved, but internal space is reduced

Engineering Contradiction:

Improvecharging capabilityVSAvoidinternal space

Core Design Contradiction:

Adaptability or versatilityVSVolume of moving object

Solution Approach 1:

The patent combines the DC-DC converter function with the motor controller by integrating the buck converter circuit into the existing motor controller hardware. The field coil and armature coil of the motor are utilized as inductors in the buck converter circuit, allowing the motor controller to perform both motor control and voltage conversion functions simultaneously, thereby eliminating the need for a separate DC-DC converter and reducing overall system weight.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The motor controller is designed to perform multiple functions: it controls the motor operation and simultaneously acts as a DC-DC converter for charging batteries with different voltages. The buck converter circuit within the motor controller can convert the high voltage from the first battery to the lower voltage required by the second battery, enabling the single device to serve dual purposes and eliminate redundant components.

Inventive Principle:

Principle #6Universality (Multi-functionality)

3Loss of energy

If the engine is not driven, then fuel consumption is reduced, but battery charging capability is lost

Engineering Contradiction:

Improvefuel consumptionVSAvoidbattery charging capability

Core Design Contradiction:

Loss of energyVSAdaptability or versatility

Solution Approach 1:

The system enables the first battery to charge the second battery directly through the buck converter circuit integrated in the motor controller, without requiring external energy sources or engine operation. This self-service charging mechanism allows the vehicle to maintain battery charging capability even when the engine is not running, thereby reducing fuel consumption while preserving adaptability.

Inventive Principle:

Principle #25Self-service

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 efficient and space-effective charging of multiple batteries with different voltages without a separate converter, reducing weight and volume, and allowing emergency charging without engine operation.

Implementation Method 1

a motor controller which includes a buck converter circuit configured to convert a voltage of the first battery into a voltage for charging the second battery

Methodology Applied

Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 2

an inverter circuit connected to the armature coil

Methodology Applied

Scientific EffectElectromagnetic conversion: Electromagnetic Induction

Data Source

PatentUS9889753B2Driving apparatus for electric vehicle

Publication Date: 2018.02.13 LG MAGNA E POWERTRAIN CO LTD

AI summary

A driving apparatus for an electric vehicle is provided. The driving apparatus for the electric vehicle can charge the other batteries using a charging voltage of any one battery in a state in which an engine is not driven, control a voltage generated by an integrated starter generator (ISG), selectively charge a plurality of batteries having different charging voltages without using a separate converter, and reduce a weight and volume thereof.