Hybrid Vehicle ISG Regenerative Power Control

Solution Overview

Problem

Conventional methods for hybrid vehicles fail to effectively manage regenerative electric power during coasting, leading to battery overcharging and reduced drivability when the battery is fully charged, as they either perform fuel-cut control or consume power by unwanted operation of the air conditioner or heater.

Innovation Solution

A method and system that control charging and discharging by switching to a regenerative braking mode when coasting, determining the battery's state of charge, and using the integrated starter-generator to consume regenerative electric power, with the engine clutch open, allowing the ISG to operate based on engine speed and friction torque maps.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If regenerative braking is performed to charge the battery during coasting, then regenerative electric power is collected, but the battery cannot be charged when it is in a fully charged state or over-temperature state

Engineering Contradiction:
Core Design Contradiction:
Use of energy by moving objectVSReliability

Solution Approach 1:

The system allows the ISG to consume the regenerative electric power generated by the motor during coasting, making the system self-sufficient by utilizing its own generated power for auxiliary operations rather than requiring external power sources or waste disposal mechanisms

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The control system dynamically adjusts the operating parameters of the ISG based on the battery's state of charge and temperature conditions, enabling flexible power consumption that adapts to real-time battery status and coasting conditions

Inventive Principle:
Principle #35Parameter changes

2Ease of operation

If fuel-cut control is performed using engine friction torque during coasting, then drivability is maintained, but the friction torque cannot be varied and drivability rapidly deteriorates when transmission gear shifts

Engineering Contradiction:
Core Design Contradiction:
Ease of operationVSAdaptability or versatility

Solution Approach 1:

The system replaces the mechanical friction torque control of the engine with electrical torque control of the ISG, allowing for precise and variable torque adjustment through electrical means rather than mechanical constraints

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The ISG provides dynamically adjustable torque that can be continuously varied based on driving conditions, unlike the fixed friction torque of fuel-cut control, enabling smooth adaptation during transmission gear shifts and maintaining consistent drivability

Inventive Principle:
Principle #15Dynamics

3Use of energy by moving object

If regenerative electric power is consumed by air conditioner or heater, then power is utilized, but temperature in the hybrid vehicle changes unwantedly

Engineering Contradiction:
Core Design Contradiction:
Use of energy by moving objectVSTemperature

Solution Approach 1:

The control system incorporates feedback mechanisms that monitor vehicle operating conditions and battery status, using this information to intelligently control the operation of auxiliary devices and maintain comfortable temperature conditions while utilizing regenerative power

Inventive Principle:
Principle #23Feedback

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 approach protects the battery and enhances drivability by efficiently consuming regenerative power while coasting, preventing battery overcharging and maintaining consistent drivability by utilizing regenerative power through the ISG according to the battery's state of charge.

Implementation Method 1

the motor 20 of the hybrid vehicle generally operates as a generator for collecting the inertia energy during the regenerative braking (RB) mode

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 2

power from an internal combustion engine and power from a battery

Methodology Applied
Scientific EffectElectrical energy storage: Battery (electricity)

Data Source

PatentUS9096221B2Method and system for controlling charging and discharging for a hybrid vehicle
Publication Date: 2015.08.04
  • US9096221B2 patent drawing
  • US9096221B2 patent drawing
  • US9096221B2 patent drawing

AI summary

A method and system for controlling charging and discharging for a hybrid vehicle that may consume regenerative electric power collected by a motor through regenerative braking while coasting the hybrid vehicle when operating an integrated starter-generator (ISG) according to a state of charge (SOC) of a battery. The method of controlling charging and discharging for a hybrid vehicle which includes a motor operated by power of a battery and an ISG configured to start an engine or generate electric power by torque of the engine includes: changing a running mode of the hybrid vehicle to a regenerative braking mode when the hybrid vehicle is coasting, controlling the motor to generate electric power in the regenerative braking mode, determining whether an SOC of the battery is a charge limiting state, and operating the ISG by electric power generated by the motor when the SOC of the battery is the charge limiting state.