Elevator Linear Motor Mover Position Control

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

High-rise elevators face challenges with the weight of hoist ropes and tilting issues due to the need for additional windings to maintain levitation and stabilize the mover relative to the stator, leading to uncomfortable vibrations for passengers.

Innovation Solution

An electric linear motor design with at least two stators on opposite sides and two units of electromagnetic components, including windings and permanent magnets, arranged to control the mover's position and tilting by independently controlling the d-axis component of currents injected into the windings, eliminating the need for additional windings for levitation and tilting control.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If additional windings are added to maintain levitation and stabilize the mover, then the mover position control is improved, but the device complexity and manufacturing cost increase

Engineering Contradiction:
Improvemover position controlVSAvoidwinding structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent makes the traction windings perform multiple functions: they generate both the traction force for moving the elevator car and the levitation force for maintaining the air gap. By controlling the d-axis and q-axis current components independently, the same winding system achieves both propulsion and levitation, eliminating the need for separate winding sets and reducing overall system complexity

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent combines the previously separate traction windings and levitation windings into a single integrated winding system. The mover contains one set of windings that serves dual purposes, with independent control of current components allowing simultaneous achievement of traction and levitation functions, thereby simplifying the device structure

Inventive Principle:
Principle #5Merging (Combining)

2Stability of the object's composition

If additional windings are added for levitation control, then the mover stability is improved, but the manufacturing precision requirements increase

Engineering Contradiction:
Improvemover stabilityVSAvoidwinding arrangement
Core Design Contradiction:
Stability of the object's compositionVSManufacturing precision

Solution Approach 1:

The patent makes the traction windings perform multiple functions: they generate both the traction force for moving the elevator car and the levitation force for maintaining the air gap. By controlling the d-axis and q-axis current components independently, the same winding system achieves both propulsion and levitation, eliminating the need for separate winding sets and reducing overall system complexity

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent changes the control parameters by independently regulating the d-axis and q-axis current components. This allows dynamic adjustment of the magnetic field to achieve both traction and levitation effects, maintaining mover stability without requiring additional windings or higher manufacturing precision

Inventive Principle:
Principle #35Parameter changes

3Reliability

If additional windings are added for tilting control, then the mover position control is improved, but the device complexity increases

Engineering Contradiction:
Improvemover position controlVSAvoidelectromagnetic components
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent makes the traction windings perform multiple functions: they generate both the traction force for moving the elevator car and the levitation force for maintaining the air gap. By controlling the d-axis and q-axis current components independently, the same winding system achieves both propulsion and levitation, eliminating the need for separate winding sets and reducing overall system complexity

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent introduces dynamic control of the winding currents through independent d-axis and q-axis component regulation. This dynamic control enables the system to adaptively adjust magnetic field distribution to achieve traction, levitation, and tilting correction functions, improving position control without adding static structural complexity

Inventive Principle:
Principle #15Dynamics

4Force

If traditional linear motor design is used with windings on stator, then the motor can generate sufficient force, but the winding material consumption increases significantly

Engineering Contradiction:
Improvemotor forceVSAvoidwinding material
Core Design Contradiction:
ForceVSLoss of substance

Solution Approach 1:

The patent inverts the traditional linear motor design by placing the windings on the mover instead of on the stator. The stator contains only permanent magnets, while the mover contains the controllable windings. This inversion reduces the length of windings required since the windings move with the car rather than spanning the entire shaft length, significantly reducing material consumption while maintaining force generation capability

Inventive Principle:
Principle #13The other way round (Inversion)

Solution Approach 2:

The patent segments the magnetic field generation functions: permanent magnets on the stator provide the base magnetic field, while controllable windings on the mover provide the variable component. This segmentation allows force generation with reduced winding material since only the moving portion requires controllable windings, not the entire stator length

Inventive Principle:
Principle #1Segmentation

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 effectively controls the levitation and tilting of the mover along the stator beam, reducing the need for additional windings and minimizing vibrations, thereby enhancing passenger comfort and operational efficiency.

Implementation Method 1

The rotor, or 'mover', typically comprises permanent magnets, magnetic fields of which, when being in electromagnetic engagement with the 'traveling' magnetic field of the stator, causes the rotor to move along the linear stator

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 2

magnetic fields of which, when being in electromagnetic engagement with the 'traveling' magnetic field of the stator, causes the rotor to move

Methodology Applied
Scientific EffectLorentz force: Lorentz Force

Implementation Method 3

controlling the d-axis component of currents injected to the windings, respectively and independently of each other, for controlling the movement and the tilting of the mover

Methodology Applied
Scientific EffectElectromagnetic force control: Lorentz Force

Data Source

PatentEP3373428B1Electric linear motor for an elevator and method for controlling thereof
Publication Date: 2022.07.13 KONE OYJ
  • EP3373428B1 patent drawingFigure 1~5
  • EP3373428B1 patent drawingFigure 6~7B
  • EP3373428B1 patent drawingFigure 7C

AI summary

An electric linear motor (125) for an elevator (100) and a method for controlling the operation thereof are presented. The electric linear motor (125) comprises at least one stator beam (130) and at least one mover (160), wherein said at least one stator beam (130) comprises at least two stators (301, 302; 303, 304) on opposite sides of the stator beam (130), and the at least one mover (160) is in electromagnetic engagement with said at least two stators (301, 302; 303, 304) and configured to be moved relative to said stator beam (130). Said at least one mover (160) comprises at least two units of electromagnetic components (311, 312; 313, 314) arranged on opposite sides of the stator beam (130) to face said at least two stators (301, 302; 303, 304) for controlling the movement and the position of the mover (160) with respect to said stator beam (130).