Linear Motor Power-Feeding Switching Compensation

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Solution Overview

Problem

Linear motor systems for long-distance applications are costly due to the increased number of armature coil units required, and they experience switching shock during power-feeding target changes.

Innovation Solution

A linear motor system with a stator and mover featuring spaced armature coil units and a controller that sequentially selects and compensates power-feeding targets, performing computations for power-feeding control based on speed commands and incorporating a power-feeding-switching compensation function to minimize switching shock.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Length of stationary object

If the number of armature coil units is increased to achieve long-distance movement, then the movement distance is extended, but the system cost increases due to more wiring lines and components

Engineering Contradiction:
Improvemovement distanceVSAvoidsystem cost
Core Design Contradiction:
Length of stationary objectVSDevice complexity

Solution Approach 1:

The stator is divided into multiple independent armature coil units that are spaced apart at specific intervals rather than continuously arranged. This segmentation allows the system to achieve long-distance movement capability while reducing the total number of coil units and associated wiring, thereby lowering system cost.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The controller performs switching compensation computation in advance when switching between armature coil units. By calculating the compensation value before the actual switching occurs, the system prepares the necessary adjustments to maintain stable motor operation during transitions, reducing switching shock without requiring additional hardware.

Inventive Principle:
Principle #10Preliminary action

2Productivity

If power-feeding target is switched between armature coil units, then the mover can be driven along the movement path, but switching shock occurs during the transition

Engineering Contradiction:
Improvemover driving capabilityVSAvoidswitching shock
Core Design Contradiction:
ProductivityVSObject-generated harmful factors

Solution Approach 1:

The controller performs switching compensation computation in advance when switching between armature coil units. By calculating the compensation value before the actual switching occurs, the system prepares the necessary adjustments to maintain stable motor operation during transitions, reducing switching shock without requiring additional hardware.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system uses feedback from the mover's present position to determine when switching between armature coil units is necessary and to calculate the appropriate compensation values. This feedback mechanism allows the controller to adjust power feeding dynamically, maintaining smooth operation during transitions between different coil units.

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

The system reduces costs by minimizing the number of wiring lines and effectively suppresses switching shock, enabling stable and efficient movement over long distances.

Implementation Method 1

a mover arranged so as to oppose the stator and includes a permanent magnet

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 2

Each armature coil unit is provided with a corresponding power converter. The controller switches the target power converter in accordance with the present position of the mover, and supplies driving power from the target power converter to the armature coil unit corresponding to the present position of the mover. In this way, thrust is produced and consequently the mover is moved.

Methodology Applied
Scientific EffectLorentz force: Lorentz Force

Data Source

PatentUS9379649B2Linear motor system
Publication Date: 2016.06.28 YASKAWA DENKI KK

AI summary

A linear motor system includes a stator, a mover, and a controller. The stator includes a plurality of armature coil units arranged so as to be spaced apart from one another at certain intervals. The mover includes a permanent magnet. The controller is configured to sequentially select, as a power-feeding target, an armature coil unit opposing the mover from among the plurality of armature coil units, perform, for the power-feeding target, computation for power-feeding control on the basis of a speed command, and sequentially feed power to the armature coil unit. The controller includes a power-feeding-switching compensation function of performing switching compensation when the power-feeding target is switched to a next armature coil unit.