Hoisting Winch Power Adaptation via Voltage Feedback

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Solution Overview

Problem

Tower cranes equipped with lifting winches face challenges when the electrical power supply is temporary, precarious, or insufficient, limiting the use of lifting devices on construction sites due to the need for high power and expensive generators.

Innovation Solution

A method to adapt the power of the lifting winch by measuring the electrical supply voltage and applying a power coefficient greater than one when the voltage exceeds a predefined value, using frequency converters to increase the mechanical power of the winch automatically, allowing maximum utilization of the available power without user intervention.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If the winch is designed with high power to handle maximum loads, then the lifting capacity is improved, but the requirement for high-power electrical supply and expensive generators increases

Engineering Contradiction:
Improvewinch powerVSAvoidelectrical supply complexity
Core Design Contradiction:
PowerVSDevice complexity

Solution Approach 1:

The winch power is made dynamic and adaptable through frequency converter control. The system automatically adjusts the winch power level based on real-time voltage measurements from the electrical network, transitioning from a fixed high-power design to a variable power system that matches available electrical capacity.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system changes the operational parameters of the winch by modifying the frequency and voltage supply through frequency converters. When network voltage is sufficient, the winch operates at higher power; when voltage is limited, the system automatically reduces power consumption to match the available electrical capacity.

Inventive Principle:
Principle #35Parameter changes

2Productivity

If the winch operates at high power continuously, then the productivity is improved, but the adaptability to insufficient electrical networks deteriorates

Engineering Contradiction:
Improvelifting operations efficiencyVSAvoidadaptability to electrical network
Core Design Contradiction:
ProductivityVSAdaptability or versatility

Solution Approach 1:

The system implements feedback control by continuously measuring the actual voltage from the electrical network and using this information to adjust the winch power output. The frequency converter receives voltage feedback and automatically modifies the motor supply to match the available electrical capacity, ensuring the winch operates efficiently within network limitations.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The winch power is made dynamic and adaptable through frequency converter control. The system automatically adjusts the winch power level based on real-time voltage measurements from the electrical network, transitioning from a fixed high-power design to a variable power system that matches available electrical capacity.

Inventive Principle:
Principle #15Dynamics

3Power

If a powerful electrical generator is used to ensure sufficient power, then the power availability is improved, but the cost and complexity of the site infrastructure increases

Engineering Contradiction:
Improveelectrical power availabilityVSAvoidsite infrastructure complexity
Core Design Contradiction:
PowerVSDevice complexity

Solution Approach 1:

The winch system performs self-adjustment by automatically measuring network voltage and modifying its own power consumption accordingly. This self-service capability eliminates the need for expensive external power infrastructure modifications, as the system adapts to existing network conditions without requiring additional generators or infrastructure upgrades.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The system changes the operational parameters of the winch by modifying the frequency and voltage supply through frequency converters. When network voltage is sufficient, the winch operates at higher power; when voltage is limited, the system automatically reduces power consumption to match the available electrical capacity.

Inventive Principle:
Principle #35Parameter changes

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

Enables efficient use of the electrical distribution network by automatically increasing the winch's power when possible, ensuring continuous operation of tower cranes by exploiting surplus power, thereby enhancing site progress without additional costs or manual adjustments.

Implementation Method 1

the electric motors of the lifting winches of tower cranes have been controlled by frequency converters, to obtain a continuous variation of the speed of the winch

Methodology Applied
Scientific EffectFrequency conversion:

Implementation Method 2

Tower cranes are equipped with winches, driven by electric motors, to lift loads

Methodology Applied
Scientific EffectElectromagnetic conversion: Electromagnetic Induction

Data Source

PatentEP2261165B1Method for adapting the power of a hoisting winch
Publication Date: 2012.05.30 MANITOWOC CRANE GROUP FRANCE
  • EP2261165B1 patent drawingFigure 1
  • EP2261165B1 patent drawingFigure 2

AI summary

The method involves weighing a load (4) to be lifted during an initial lifting phase of the load, and measuring voltage (V) of an electrical power supply network (8) during the initial lifting phase of the load. A power coefficient equal to one is defined if the measured voltage is between a nominal voltage and an advance nominal voltage of predetermined value. A power coefficient greater than one is defined if the measured voltage is greater than the advance nominal voltage. The defined power coefficient is intervened to increase power of a hoisting winch (6).