Electric Machine Damping for Transmission Slack State

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

In transmission systems, especially during load changes, a loose condition can arise due to production-related play, leading to a lack of frictional connection between input and output shafts, resulting in undesirable sudden transitions and torque overshoots, particularly at the end of the slack interval.

Innovation Solution

A method and device that differentiate the influence on an electric machine based on the speed of the input and output shafts to determine the loose state, allowing for quick passage through the slack state while minimizing impacts at the end, by dividing the slack state into two angular ranges with varying damping levels, weak damping at the beginning and strong damping at the end.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If the transmission operates with production-related play, then the transmission can be manufactured with standard tolerances, but a loose condition arises during load changes causing sudden transitions and torque overshoots

Engineering Contradiction:
Improvemanufacturing toleranceVSAvoidtorque transmission stability
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The control system dynamically adjusts the damping characteristics of the electric machine based on the real-time angular position within the slack interval. By transitioning from weak damping at the beginning to strong damping at the end of the slack interval, the system adapts to changing mechanical conditions, resolving the contradiction between manufacturing tolerances and torque stability.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The invention changes the damping parameter of the electric machine control system as a function of the angular position during the slack interval. This parameter change allows the system to tolerate manufacturing play while preventing harmful torque overshoots, as the damping strength is optimized for each phase of the slack interval passage.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If strong damping is applied throughout the entire slack interval, then torque overshoots are suppressed, but the passage through the slack state takes longer

Engineering Contradiction:
Improvetorque overshoot suppressionVSAvoidslack interval duration
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The slack interval is segmented into two distinct angular ranges: a first range where weak damping is applied to allow quick passage, and a second range where strong damping is applied to suppress torque overshoots. This segmentation resolves the contradiction by applying appropriate damping strength to each phase of the slack interval passage.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The damping characteristic is made dynamic rather than static, transitioning from weak to strong damping based on the angular position within the slack interval. This dynamic adjustment optimizes both the speed of passage and the suppression of harmful effects.

Inventive Principle:
Principle #15Dynamics

3Loss of time

If weak damping is applied throughout the entire slack interval, then the passage through the slack state is quick, but sudden transitions and torque overshoots occur at the end

Engineering Contradiction:
Improveslack interval durationVSAvoidtorque overshoot
Core Design Contradiction:
Loss of timeVSObject-generated harmful factors

Solution Approach 1:

The slack interval is divided into two angular ranges with different damping strategies. The first range uses weak damping for rapid passage, while the second range uses strong damping to eliminate harmful torque overshoots, thus resolving the contradiction between speed and harm suppression.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The control system prepares for the upcoming harmful effects by maintaining weak damping initially for speed, then transitions to strong damping in advance of the expected torque overshoot region, preventing the harmful effects before they fully manifest.

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 approach effectively compensates for unwanted sudden transitions and torque overshoots, ensuring a smooth passage through the slack state and preventing abrupt transitions at the end, thereby enhancing the operational stability of the transmission system.

Implementation Method 1

the electric machine is influenced differently... the electric machine is operated as a motor and as a generator

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Data Source

PatentEP2410310B1Method and device for operating an electric machine coupled with a drive
Publication Date: 2013.06.26 GE ENERGY POWER CONVERSION GMBH
  • EP2410310B1 patent drawingFigure 1
  • EP2410310B1 patent drawingFigure 2a~2c

AI summary

The method involves determining a loose condition of a gear (11) according to a speed (n1) of an input shaft (11a) and the speed (n2) of an output shaft (11b) of the gear. The input shaft and the output shaft are not connected in a force-fit manner. Different loose states of an electric machine (12) are divided into two angular regions, during which the electric machine is affected in different manner. An independent claim is also included for an apparatus for operating an electric machine coupled with a gear.