Voltage Limiting Unit Heating in Wind Turbines

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Solution Overview

Problem

Wind turbine facilities face challenges in efficiently utilizing existing components for heating, particularly during low voltage ride-throughs, where the voltage limiting unit's thermal capacity is maximized, and there is a need to protect equipment from cold and humidity without additional heating systems.

Innovation Solution

The voltage limiting unit, comprising a resistor and semiconductor switch, is controlled to generate heat according to predefined settings for ambient heating, utilizing existing components to maintain temperature and prevent condensation, and can switch to a protection mode during low voltage ride-throughs, leveraging thermal convection for heat distribution within the wind turbine tower.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the voltage limiting unit is designed with huge thermal capacity to absorb full power during low voltage ride through, then the reliability of the wind turbine facility is improved, but the device complexity and cost increase

Engineering Contradiction:
ImprovereliabilityVSAvoiddevice complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The voltage limiting unit is designed to perform dual functions: limiting voltage during low voltage ride through events and providing ambient heating during normal operation. The resistor element that dissipates electrical energy as heat during voltage limiting is utilized as a heating source for the wind turbine facility interior, eliminating the need for separate heating systems and reducing overall device complexity

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

Solution Approach 2:

The voltage limiting unit serves itself by using the heat generated during its protective function to provide beneficial heating during normal operation. The system automatically transitions between protection mode and heating mode based on operational conditions, with the controller managing the semiconductor switch to enable the resistor to function as a controlled heating element when full power absorption is not required

Inventive Principle:
Principle #25Self-service

2Reliability

If the voltage limiting unit is designed with huge thermal capacity to absorb full power during low voltage ride through, then the reliability of the wind turbine facility is improved, but the manufacturing cost increases

Engineering Contradiction:
ImprovereliabilityVSAvoidmanufacturing cost
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The voltage limiting unit is designed to perform dual functions: limiting voltage during low voltage ride through events and providing ambient heating during normal operation. The resistor element that dissipates electrical energy as heat during voltage limiting is utilized as a heating source for the wind turbine facility interior, eliminating the need for separate heating systems and reducing overall device complexity

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

Solution Approach 2:

The voltage limiting unit serves itself by using the heat generated during its protective function to provide beneficial heating during normal operation. The system automatically transitions between protection mode and heating mode based on operational conditions, with the controller managing the semiconductor switch to enable the resistor to function as a controlled heating element when full power absorption is not required

Inventive Principle:
Principle #25Self-service

3Object-affected harmful factors

If a separate heating system is installed to prevent freezing and condensation, then the protection of equipment from cold and humidity is improved, but the device complexity and cost increase

Engineering Contradiction:
Improveprotection from cold and humidityVSAvoiddevice complexity
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The voltage limiting unit is designed to perform dual functions: limiting voltage during low voltage ride through events and providing ambient heating during normal operation. The resistor element that dissipates electrical energy as heat during voltage limiting is utilized as a heating source for the wind turbine facility interior, eliminating the need for separate heating systems and reducing overall device complexity

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

Solution Approach 2:

The voltage limiting unit serves itself by using the heat generated during its protective function to provide beneficial heating during normal operation. The system automatically transitions between protection mode and heating mode based on operational conditions, with the controller managing the semiconductor switch to enable the resistor to function as a controlled heating element when full power absorption is not required

Inventive Principle:
Principle #25Self-service

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 method allows for efficient ambient heating of wind turbine facilities using existing components, maintaining optimal temperatures and preventing freezing or condensation, while also providing protection during low voltage events without the need for additional heating systems, thus extending the operational lifespan of equipment.

Implementation Method 1

The voltage limiting unit comprises a resistor, which may be electrically connected to the DC link for converting electrical energy from the DC link irreversibly to thermal energy (i.e. heat) which may be radiated to the environment

Methodology Applied
Scientific EffectJoule heating: Joule Heating

Implementation Method 2

heating air inside the wind turbine facility with heat generated by a voltage limiting unit

Methodology Applied
Scientific EffectThermal convection: Convection

Data Source

PatentEP3411594B1Heating of a wind turbine facility
Publication Date: 2021.03.31 ABB (SCHWEIZ) AG
  • EP3411594B1 patent drawingFigure 1~2
  • EP3411594B1 patent drawingFigure 3~4

AI summary

A method for heating a wind turbine facility (42) comprises: charging a DC link (24) of an electrical converter (10) connected with a wind turbine (14) of the wind turbine facility (42); heating air inside the wind turbine facility (42) with heat generated by a voltage limiting unit (28) interconnected with the DC link (24), which comprises a resistor (30) adapted for dissipating electrical energy into heat for reducing a voltage in the DC link (24), when the voltage is above a threshold voltage; wherein the voltage limiting unit (28) is controlled, such that the voltage limiting unit (28) generates heat according to settings defined in a controller (34) of the voltage limiting unit (28). The heating settings are changed based upon commands from a user interface (64). Furthermore, the DC link (24) is charged by a grid side converter (20) of the wind turbine facility (42) with power from an electrical grid (16).