Suzlon Energy GmbH

The Use of Simpack in Wind Turbine Development

Florian Stache Suzlon Product Development Hamburg, 26.09.2012

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Suzlon Energy GmbH Introduction

• Increasing market requirements in terms of wind turbine reliability as well as long term field feedback ask for more detailed investigations in the design practice for the subsystems of a wind turbine (i.e. Pitch, Yaw, drive train…)

• Load assumptions for subsystems are often based on global load simulation models without considering the subsystem behavior itself (i.e. blade actuator model in Flex5 or GH Bladed)

• Influence of subsystem on global loads is for some Design Load Cases insufficient (i.e. Pitch overload, Yaw slippage…)

SIMPACK is therefore increasingly used at SUZLON

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Suzlon Energy GmbH Overview

• Subsystem load simulation

• Global load models

• Integration of SIMPACK into the new product development process

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Suzlon Energy GmbH Subsystem load simulation

Global WTG behavior

Subsystem behavior

Post Processing (same for global and subsystem)

• Apply global load results in form of time series on detailed subsystem models (similar to substructuring in FEA)

• Applicable if the subsystem has no influence on the global loads and only target is to obtain more precise subsystem loads

Validated load simulation (Flex5)

• detailed model in SIMPACK

• test bench validation

• LDD • RFC • MinMax

Suzlon Energy GmbH Pitch system load simulation

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pitch angle from FLEX5

blade position or position sensor feedback

motor speed

motor torque

detailed motor and inverter

model

Pitch Inverter controler (position and speed control)

Blade bearing friction model

Blade root bending moment from Flex5

MATSIM or user routine

Suzlon Energy GmbH Pitch system load simulation

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Suzlon Energy GmbH Pitch system loads post processing • Rainflow count results are showing a very much different behavior when

comparing to the very simple Flex5 pitch model

• Opens new design verification methods:

– Analysis of tooth forces at critical operating point

• Enables optimization of pitch system behavior (i.e. blade positioning control)

• Global load requirements verification in terms of positioning accuracy and time constants

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Suzlon Energy GmbH Drive train simulation

• Use for internal resonance analysis as well as for certification

• Identification of potential vibration and tonality issues during the turbine design process or in RCA

• Challenges:

Accuracy in higher frequency ranges

Verification through measurements

Agreement with Gearbox supplier on model/input sharing

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Suzlon Energy GmbH Drive train model

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Gear pair with simple spring/damper element

or FE-225

Flexible mainframe using ANSYS interface

Flexible blades imported from Flex5

Suzlon Energy GmbH Typical results using modal analysis

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Suzlon Energy GmbH Global loads

• SIMPACK to be used when the limits of Flex5 is reached

Requirements for additional dof (advanced blade models)

Interaction of global loads with a subsystem (Pitch, Yaw, Drive Train)

At the moment used only in dedicated load cases because of license costs, computation time and stable existing process using Flex5

• Ability to migrate Flex5 model to SIMPACK

• Subsystem component database for enhancement of Flex5-like model

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Identify critical DLC from FLex5

results

Migrate to SPCK and enhance

with subsystem details

Simulate DLC in SPCK

Compare result to Flex5 and substitute

Suzlon Energy GmbH Global load model

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Flex5 like turbine model (same dof)

• Aerodynamic routine taken from Flex5 including wind fields and all features (i.e. dyn. Stall)

• Pitch and torque control using Matlab dll generated with MATSIM target

Suzlon Energy GmbH Model verification

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• An extensive model validation was carried out through comparison to Flex5

• Step by step switching on the dofs and aerodynamic features

• Small differences due to some differences in structural modeling approach are remaining but explained and almost negligible

Suzlon Energy GmbH

Extension to yaw system

14 Factory testbench

SPCK yaw-model

Subsystem Verification

Flex5 Model

SPCK WT-model

WT model Verification

Utilization of advanced model

results

Integrated yaw in WT

model

Suzlon Energy GmbH

Integration of drive train into full turbine model

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• Simulation of dedicated load cases (LVRT, short circuit)

• Electrical system model from Simulink • Used for run up and frequency sweep

Suzlon Energy GmbH Component database / configuration management

• Automatic model transfer from flex5 to SIMPACK

• quick model implementation of components/subsystems from database

– Gearbox variants or from different supplier

– Coupling

– Pitch system

– Yaw system

– Structural components (i.e. mainframe) as SID files

• Well defined interfacing points for model integration

• Turbine configurator and automatic model generation for plug-and-play

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Suzlon Energy GmbH Model migration

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DLC generator

FLEX5

Load analyser

SIMPACK

FLX2SPCK

Suzlon Energy GmbH Summary

• SIMPACK is integrated into our simulation environment with pre-defined parameterized model topologies in order to enable load simulation engineers concentrate on product optimization

• Challenges:

– Validation of detailed models

– Improvements in strength analysis methods to enable optimal use of these new results

– Computation time

– Licensing for parallel computation

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Suzlon Energy GmbH

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Suzlon Energy GmbH

Thank You