Inverter Circuit Pulse-Activation for Powertrain Synchronization

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Solution Overview

Problem

Existing electrified powertrain systems face challenges in efficiently managing energy consumption and responsiveness, particularly in high-speed vehicle operations where electric machines can enter uncontrolled generating modes, leading to excessive current flow and potential battery overcharging.

Innovation Solution

A powertrain system with a motor disconnect clutch and a method for controlling the electric machine's speed, involving deactivation and pulse-activation of the inverter circuit to synchronize with the driveline speed before activating the clutch, thereby preventing uncontrolled generating modes and optimizing energy use.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If the electric machine is continuously operated at high speed, then the vehicle maintains high-speed operation capability, but the electric machine enters uncontrolled generating mode causing excessive current flow and battery overcharging

Engineering Contradiction:

Improvevehicle speedVSAvoidelectric machine control stability

Core Design Contradiction:

SpeedVSReliability

Solution Approach 1:

The inverter circuit is deactivated during high-speed operation to prevent uncontrolled generating mode, and periodically pulse-activated to maintain minimum motor speed. This periodic control approach allows the vehicle to maintain high-speed capability while preventing the electric machine from entering harmful generating modes that cause excessive current flow and battery overcharging.

Inventive Principle:

Principle #19Periodic action

2Loss of time

If the motor disconnect clutch is activated immediately during deceleration, then the clutch engagement is quick, but the synchronization delay causes motor noise and potential damage

Engineering Contradiction:

Improvesynchronization delay timeVSAvoidmotor noise

Core Design Contradiction:

Loss of timeVSObject-affected harmful factors

Solution Approach 1:

The control system pulse-activates the inverter circuit before clutch engagement to pre-synchronize the motor speed with the driveline speed. This preliminary action reduces the synchronization delay and prevents motor noise during clutch engagement, ensuring smooth transition without harmful mechanical shocks or excessive noise.

Inventive Principle:

Principle #10Preliminary action

3Productivity

If the inverter circuit remains activated during high-speed operation, then the electric machine can respond quickly to torque demands, but energy consumption increases and battery overcharging occurs

Engineering Contradiction:

Improvetorque response capabilityVSAvoidenergy consumption

Core Design Contradiction:

ProductivityVSUse of energy by moving object

Solution Approach 1:

The inverter circuit is deactivated during high-speed operation to reduce energy consumption and prevent battery overcharging, while being periodically pulse-activated to maintain minimum motor speed and preserve torque response capability when needed. This periodic control strategy optimizes the balance between productivity and energy efficiency.

Inventive Principle:

Principle #19Periodic action

4Speed

If the motor speed is not controlled during clutch disengagement, then the system response is fast, but the electric machine enters uncontrolled generating mode causing excessive current flow

Engineering Contradiction:

Improveclutch disengagement speedVSAvoidexcessive current flow

Core Design Contradiction:

SpeedVSLoss of energy

Solution Approach 1:

The control system decreases motor speed to a minimum inactive speed threshold before deactivating the inverter circuit and disengaging the clutch. This preliminary speed control prevents the electric machine from entering uncontrolled generating mode during clutch disengagement, avoiding excessive current flow and energy loss while maintaining fast system response.

Inventive Principle:

Principle #10Preliminary action

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 reduces synchronization delay times, mitigates motor noise, and ensures efficient energy management by preventing excessive current flow and battery overcharging, enhancing the overall performance and longevity of the powertrain system.

Implementation Method 1

Electric machines, e.g., multi-phase electric motor/generators have stator windings that are energized by alternating current from inverter modules

Methodology Applied

Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 2

The electric machine may be employed as a regenerative brake to a vehicle driveline

Methodology Applied

Scientific EffectElectromagnetic induction: Electromagnetic Induction

Data Source

PatentUS9517706B2Method and apparatus for controlling an electrified powertrain system of a vehicle

Publication Date: 2016.12.13 GM GLOBAL TECHNOLOGY OPERATIONS LLC

AI summary

A method for controlling a powertrain system includes deactivating a motor disconnect clutch during vehicle operation. Motor speed is decreased to a first inactive speed threshold and an inverter circuit is controlled to an inactive state while monitoring the motor speed. The inverter circuit is deactivated, and when the motor speed decreases to a second inactive speed threshold, the inverter circuit is pulse-activated to operate the electric machine to increase motor speed to the first inactive speed threshold, and then deactivated. The inverter circuit is activated to increase the motor speed to synchronize with speed of the driveline prior to activating the motor disconnect clutch.