Hydraulic Pitch Force Control for Wind Turbines

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Solution Overview

Problem

Hydraulic pitch systems in wind turbines often exceed their capability during high wind or turbulent conditions, leading to potential shutdowns due to insufficient hydraulic oil pressure or leakage, which can disrupt energy production.

Innovation Solution

A method to control the hydraulic pitch force system by reducing or suspending pitch-based activities when hydraulic system parameters, such as oil pressure or leakage, fall outside a predetermined range, allowing the system to operate in a reduced mode and maintain energy production.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If the hydraulic pitch system operates under full load conditions or turbulent conditions, then the pitch system is used more to control blade pitch angle, but the requirements to the pitch system exceed its capability leading to insufficient hydraulic oil pressure

Engineering Contradiction:

Improvepitch system capabilityVSAvoidhydraulic oil pressure

Core Design Contradiction:

Adaptability or versatilityVSReliability

Solution Approach 1:

The system dynamically adjusts the pitch control mode based on real-time monitoring of hydraulic oil pressure. When pressure drops below a threshold during full load or turbulent conditions, the system automatically transitions from normal pitch control to a reduced mode, suspending pitch-based structural load reduction activities to maintain adequate pressure levels and prevent shutdown.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The system changes the operational parameters of the pitch system by suspending certain pitch activities when hydraulic oil pressure falls outside the acceptable range. This parameter change allows the system to continue operating in a limited capacity rather than shutting down completely, maintaining energy production while preserving the hydraulic system.

Inventive Principle:

Principle #35Parameter changes

2Productivity

If the hydraulic pitch system experiences leakage, then the system continues to operate, but the operational period is limited until repairs can be made

Engineering Contradiction:

Improveenergy productionVSAvoidoperational period

Core Design Contradiction:

ProductivityVSDuration of action of moving object

Solution Approach 1:

The system implements continuous feedback monitoring of hydraulic system parameters including oil pressure levels. When leakage is detected through pressure drop monitoring, the system provides feedback to the control unit which then activates the reduced mode, extending the operational period by adjusting pitch activities to match the reduced hydraulic capacity.

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

Instead of completely suspending pitch control functions when leakage occurs, the system applies partial action by maintaining essential pitch control while suspending only the pitch-based structural load reduction activities. This allows the wind turbine to continue generating energy at reduced capacity rather than shutting down completely.

Inventive Principle:

Principle #16Partial or excessive action

3Reliability

If pitch based activities are reduced or suspended, then hydraulic oil pressure is maintained, but structural load reduction capability is compromised

Engineering Contradiction:

Improvehydraulic oil pressureVSAvoidstructural loads

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The system extracts and separates the essential pitch control function from the pitch-based structural load reduction activity. When hydraulic pressure is insufficient, the system maintains the core pitch control capability while suspending only the load reduction enhancement features, allowing continued operation with basic pitch control functionality.

Inventive Principle:

Principle #2Taking out (Extraction)

Data Source

PatentUS10920747B2Method for controlling hydraulic pitch force system

Publication Date: 2021.02.16 VESTAS WIND SYSTEMS AS

AI summary

There is provided a method for controlling a hydraulic pitch force system (220) so as to reduce or eliminate a decrease in hydraulic oil pressure (241) if a hydraulic system parameter value is outside a hydraulic system parameter range, the method comprising: Obtaining (690) the hydraulic system parameter value, and operating the hydraulic pitch force system (220) according to a reduced mode (692) if the hydraulic system parameter value is outside the hydraulic system parameter range, wherein in the reduced mode one or more pitch based activities are reduced (694) or suspended. An advantage thereof may be that it enables keeping the wind turbine in production in certain instances rather than shutting down the wind turbine. In aspects, there is furthermore presented a computer program product, a pitch control system (250) and a wind turbine (100).