Wind Turbine Split Power References for Damping Without Grid Flicker

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Modern wind turbines face limitations in power control due to grid requirements, where power fluctuations caused by control systems risk being passed to the grid, and the need to emulate a synchronous generator disrupts turbine control, limiting effectiveness.

Innovation Solution

A method and system that generate distinct turbine and grid control reference signals to decouple power generation from grid transfer, allowing for independent control of energy production and distribution, using a machine side and line side unit within a power or torque control system, with optional battery storage and resistor dumping to manage energy differences.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a single power reference signal is used to control both turbine operation and grid power transfer, then the control system is simple, but power fluctuations from damping control are passed to the grid and the extent of power variation is limited

Engineering Contradiction:

Improvecontrol system structureVSAvoideffectiveness of damping control

Core Design Contradiction:

Device complexityVSReliability

Solution Approach 1:

The single power reference signal is segmented into two separate reference signals: a turbine control reference signal for the machine side unit and a grid control reference signal for the line side unit. This segmentation allows independent optimization of turbine damping control and grid power transfer, resolving the contradiction between control simplicity and damping effectiveness.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The damping control function is extracted from the grid power transfer control. The turbine control reference signal includes damping components that are applied only to the machine side unit, while the grid control reference signal maintains stable power transfer to the grid. This extraction allows damping control to operate effectively without passing fluctuations to the grid.

Inventive Principle:

Principle #2Taking out (Extraction)

2Reliability

If the turbine control system applies large power variations for damping, then damping effectiveness is improved, but power fluctuations are passed to the grid causing flicker

Engineering Contradiction:

Improvedamping effectivenessVSAvoidgrid flicker

Core Design Contradiction:

ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The control system segments power variations into two paths: damping-related power variations are applied through the machine side unit to the turbine, while grid-related power transfer is controlled separately through the line side unit. This segmentation allows large power variations for damping without passing them to the grid, eliminating flicker while maintaining damping effectiveness.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The machine side unit acts as an intermediary that absorbs damping control actions. The turbine control reference signal with damping components is applied to the machine side unit, which handles the power variations locally. The line side unit then provides stable power transfer to the grid, preventing flicker while allowing effective damping control.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Adaptability or versatility

If a virtual synchronous machine concept is implemented to meet grid requirements, then grid compliance is improved, but the direct link disrupts turbine control systems

Engineering Contradiction:

Improvegrid complianceVSAvoidturbine control system

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The control system is segmented into two independent control paths: one for turbine operation (machine side unit) and one for grid compliance (line side unit). The turbine control reference signal handles turbine-specific requirements including damping, while the grid control reference signal handles grid compliance requirements. This segmentation allows virtual synchronous machine functionality to be implemented without disrupting turbine control.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The virtual synchronous machine functionality is extracted and implemented only in the line side unit for grid power transfer. The turbine control reference signal remains independent and focuses solely on turbine operation. This extraction allows grid compliance requirements to be met without the direct link of virtual synchronous machine disrupting the turbine control system.

Inventive Principle:

Principle #2Taking out (Extraction)

Data Source

PatentUS11811354B2Control of a wind turbine using split power reference signals

Publication Date: 2023.11.07 VESTAS WIND SYSTEMS AS

AI summary

A method of controlling a wind turbine connected to an electrical grid is provided. The method comprises generating a turbine control reference signal and a grid control reference signal. The turbine control reference signal is provided to a machine side unit of a power or torque control system of the turbine to control the amount of energy generated by the turbine. The grid control reference signal is provided to a line side unit of the power or torque control system to control the amount of energy transferred to the electrical grid based on the grid control reference signal.