Switched Reluctance Motor H-Bridge for Battery Charging

Solution Overview

Problem

Existing battery charging circuits for hybrid electric vehicles require additional components beyond motor control electronics, leading to increased cost and weight, and suffer from reduced power factor due to large AC line current peaks, limiting power draw from the AC input.

Innovation Solution

Incorporating two or more semiconductor H-bridges with the windings of an electromagnetic machine, where each line of an AC electric source is connected to a switching node of the H-bridge, allowing the motor control circuit elements to draw power factor corrected currents, thereby integrating motor control and battery charging functions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If additional components are added to motor control electronics to implement battery charging function, then battery charging capability is achieved, but device complexity and cost increase

Engineering Contradiction:

Improvebattery charging capabilityVSAvoiddevice complexity

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The motor control electronics are designed to perform both motor control and battery charging functions using the same semiconductor H-bridge circuitry. The H-bridge switches and associated components serve dual purposes: controlling motor phases during propulsion and implementing battery charging during regenerative braking or vehicle operation, thereby achieving multi-functionality without adding redundant components

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The battery charging circuit is merged with the motor control electronics by integrating the charging function into the existing H-bridge circuitry. The same power switches, diodes, and control logic are utilized for both motor drive and battery charging operations, combining previously separate functions into a unified system that reduces overall device complexity

Inventive Principle:

Principle #5Merging (Combining)

2Adaptability or versatility

If additional components are added to motor control electronics to implement battery charging function, then battery charging capability is achieved, but weight increases

Engineering Contradiction:

Improvebattery charging capabilityVSAvoidweight

Core Design Contradiction:

Adaptability or versatilityVSWeight of stationary object

Solution Approach 1:

The motor control electronics are designed to perform both motor control and battery charging functions using the same semiconductor H-bridge circuitry. The H-bridge switches and associated components serve dual purposes: controlling motor phases during propulsion and implementing battery charging during regenerative braking or vehicle operation, thereby achieving multi-functionality without adding redundant components

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The battery charging circuit is merged with the motor control electronics by integrating the charging function into the existing H-bridge circuitry. The same power switches, diodes, and control logic are utilized for both motor drive and battery charging operations, combining previously separate functions into a unified system that reduces overall device complexity

Inventive Principle:

Principle #5Merging (Combining)

3Object-generated harmful factors

If boost circuit is employed to force AC input currents to unity power factor, then power factor is improved, but device complexity increases

Engineering Contradiction:

Improvepower factorVSAvoiddevice complexity

Core Design Contradiction:

Object-generated harmful factorsVSDevice complexity

Solution Approach 1:

The motor control electronics are designed to perform both motor control and battery charging functions using the same semiconductor H-bridge circuitry. The H-bridge switches and associated components serve dual purposes: controlling motor phases during propulsion and implementing battery charging during regenerative braking or vehicle operation, thereby achieving multi-functionality without adding redundant components

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The motor control electronics inherently provide power factor correction as a byproduct of its normal operation. The controlled switching of the H-bridge during motor control already shapes the AC input current waveform, and this same switching action simultaneously achieves power factor correction without requiring a separate boost circuit or additional power factor correction components

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

This solution eliminates redundant components, reduces cost and weight, and achieves unity power factor, enhancing the efficiency of power draw from the AC source for battery charging.

Implementation Method 1

can be controlled to draw power factor corrected currents from the AC source

Methodology Applied

Scientific EffectPower factor correction:

Implementation Method 2

with the windings of an electromagnetic machine connected across the H-bridges

Methodology Applied

Scientific EffectElectromagnetic induction: Electromagnetic Induction

Data Source

PatentUS8466652B2Method and apparatus for generating a charging circuit

Publication Date: 2013.06.18 ARVINMERITOR TECHNOLOGY LLC

AI summary

This invention utilizes the power electronics of a switched reluctance motor controller and the phase windings of a switched reluctance motor to make up a single stage boost converter capable of charging a battery with power factor correction (PFC) in the AC line.