Editor | On 15, Jun 2005

Authors
Isak Bukhman, TRIZ Master, Chief Methodology Specialist, Invention Machine Stephen Brown, Vice President Strategic Marketing, Invention Machine Corp.

Abstract
Given the fast growing population and the ever increasing consumption of resources it is imperative that breakthrough innovations make alternative energy sources more commercially viable. Wind turbines represent an attractive source of sustainable and environmentally friendly energy. World wind energy capacity has been doubling every three years during the last decade and growth rates in the last two years have been even faster. Yet the technology still needs a higher profile and greater efficiency.

Using the improvement of Wind Turbine Development as a case study, this presentation focuses on a proven and repeatable process that overcomes common TRIZ deployment challenges by showing a workflow and methodology for how to get started working on a problem with TRIZ, how to compliment TRIZ with Value Methodologies for problem identification, and how to leverage internal and external knowledge sources to accelerate concept identification.

Introduction – Wind Turbine Development
The potential for wind energy production is yet to be realized, but holds great promise for as a renewable and environmentally friendly source of energy.
* Wind power is expected to grow at an annual rate of 20 % resulting in a total of about 40 000 MW of installed capacity around the world by 2004.
* According to recent study “Wind Force 10” wind power could generate 10 % of global electricity by 2020, and create 1,7 million jobs at the same time.
* International installation of 1,2 million MW of wind capacity by 2020 would generate more electricity than the entire continent of Europe consumes today.
* Total wind energy potential in the world is 53 trillion kWh, 17 times higher than the Wind Force 10 goal.
* According to the study the cost of generating electricity with wind turbines is expected to drop to 2.5 US cents/kWh by 2020, compared to the current 4.7 US cents/kWh.

*Environmental benefits of the 10 % target would be enormous – savings of 69 million tones of CO2 in 2005, 267 millions tons in 2010 and 1780 million tones in 2020.

The potential for TRIZ as a high-value problem solving methodology has also yet to be fully realized, especially in combination with Value Engineering and a fund of targeted informational resources. But with an effective roadmap to guide the practitioner, the benefits of combining and deploying these discrete resources and methodologies are readily attainable. This paper describes such a roadmap and thereby provides a repeatable process for improving not only sustainable wind energy generation, but a method for improving virtually any technical system.

Project Description & Initial Situation

We have selected Three-Blades Turbine as a base Turbine design for our research project. The Three- Blade Turbine is most common, sometimes known as a Danish Concept. These three-bladed wind turbines are operated “upwind,” with the blades facing into the wind. Wind turbine works the opposite of a fan. Instead of using electricity to make wind, a turbine uses wind to make electricity. The wind turns the blades, which spin a shaft, which connects to a generator and makes electricity. The electricity is sent through transmission and distribution lines to a substation, then on to homes, business and schools.

Identify and define the component structure of the wind turbine

Identify trends of past and present R&D efforts that have contributed to current utilityscale turbine technology

• Improvements in the aerodynamics of wind turbine blades, resulting in higher capacity factors and an increase in the watts per square meter of swept area performance factor.
• Development of variable speed generators to improve conversion of wind power to electricity over a range of wind speeds.
• Development of gearless turbines that reduce the on going operating cost of the turbine.
• The general trend is toward wind turbines with maximum power output of 1 MW or more. European firms — such as Danish companies Vestas and NEG Micon — currently have more than 10 turbine designs in the megawatt range with commercial sales.
• Wind turbine manufacturers optimize machines to deliver electricity at the lowest possible cost per kilowatt-hour (kWh) of energy.
• Development of lighter tower structures. A by-product of advances in aerodynamics and in generator design is reduction or better distribution of the stresses and strains in the wind turbine. Lighter tower structures, which are also less expensive because of material cost savings, may be used because of such advances.
• Smart controls and power electronics have enabled remote operation and monitoring of wind turbines. Some systems enable remote corrective action in response to system operational problems. The cost of such components has decreased. Turbine designs where power electronics are needed to maintain power quality also have benefited from a reduction in component costs.

System Functional Analysis
A functional model of the system is nessesary to obtain a proper understanding of system
behavior. Each component and function must be defined.

Advanced function analysis allows us to define parameters of functions, their actual and required values, and their dependencies.

The completed full function model will document the system sufficiently to enable the recognition of problematic areas in the system. Additionally, the documented model permits an in depth automated evaluation from a Value Engineering perspective.

Use a matrix to provide a checkpoint confirmation that all functions are identified.

Model Data Device Diagnostic: Component Parameters and rating help define strategies for subsequent changes or simplifications of the system configuration. A variety of criteria can be evaluated in order to select strategies that best align with the project goals.

Design Simplification Strategy – Trimming Method

* Improves product/process by eliminating low value (problematic) components and redistribution their useful functions between other components.
* Simplifies and reduces the cost of user product/process, while preserving the essential functionality.
* The design variants that results from Trimming will generate different problem statements, if solved, can lead to highly innovative solutions.

Wind Turbine -> trimming scenario results
1. Low-speed shaft, Gear box, High speed shaft, Wind wane, Wind direction data, Pitch (mechanism) were trimmed.
2. Stator of AC Generator connects Hub.
3. Hub rotates Stator of AC Generator

Pre-Problem Selection
We have selected one problem (pre-problem) for the next stage of the project: The value of the torque parameter, which describes the effect of the action push (rotate) by the wind (wind energy) on the Blades (three), is 2000 Nm. The required value of this parameter is 4000 Nm to provide to increase efficiency of blades. The problem is: How to increase the torque of the Blade?

Conclusion – Best Solutions
In total, 6 concepts were ranked as high level available solutions, having the ranking equal or higher than 10, including:

This repeatable process overcomes common TRIZ deployment challenges by showing a workflow and methodology for how to get started working on a problem with TRIZ, how to compliment TRIZ with Value Methodologies for problem identification, and how to leverage internal and external knowledge sources to accelerate concept identification.

About the Authors:
Isak Bukhman, TRIZ Master, Chief Methodology Specialist, Invention Machine Isak has spent 7 years at IMC and currently serves as their Chief Methodology Specialist. He is a TRIZ Master, Value Methodology (VM), and 6Sigma certified specialist with more then 20-year practice in the product/process development and manufacturing areas. He guided development of innovation projects for several world leading companies such as Philips, Mattel/Fisher-Price, Microsoft, Shell, Samsung, LG, POSCO, Masco, Medtronic, Xinetics, Henkel, etc.

He also directed a team of more than 100 scientists, experts, developers, and animators that designed and developed about 8000 detailed description and running movies of scientific and engineering effects. He created the unique functional/parametric classification system for the scientific/engineering knowledge database and developed the Control & Connect Modes for new knowledge creation by linking effects. He has delivered numerous basic and advanced seminars (some together with Genrich Altshuller), and educated and trained more than 600 Managers, Engineers, and Researchers in TRIZ/Value Methodology, and in Product/Process Evolution and Development.

T: 617-305-9250 ext. 374 M: 617-407-2202 ibukhman@invention-machine.com Stephen Brown, Vice President Strategic Marketing, Invention Machine Corp., Steve is responsible for product marketing activities including the positioning and future evolution of the company’s market strategy. Prior to Invention Machine, he spent 10 years at Vality Technology, the industry’s leading supplier of data quality software for the ERP, CRM, and business intelligence markets where he served as Vice President of Product Strategy until its acquisition by Ascential Software in April 2002. At Ascential, he served as Executive Director, leading Product Management and Marketing functions for Ascential’s suite of data-integration products. Previously Steve had served 20 years in technology management and development capacities at Legent Corporation, Cullinet Software and Honeywell. He is a graduate of Harvard University.

T: 617-305-9250 ext. 363 sbrown@invention-machine.com
Invention Machine Corporation.
133 Portland Street, Boston, MA 02114
Main: 617-305-9250 Fax: 617-305-9255
www.invention-machine.com

Wind Turbine Components

Anemometer:

Measures the wind speed and transmits wind speed data to the controller. These are attached to the back of the nacelle. A 3-cup anemometer spins to measure the wind speed.

(Rotor) Blades:
Wind turbine blades act similar to an airplane’s wing or a boat’s sail. When air travels over the curved blade, a low-pressure area is created on the concave side of the blade (referred to as Bernoulli’s effect) creating pressure. This pressure pushes against the blade, causing the rotational mechanical energy that drives the low speed shaft connected to the hub.

The rotor blades are the elements of the turbine that capture the wind energy and covert it into a rotational form. The profile and shape of the blade is designed for maximum efficiency and minimum noise. The turbine blades are made of fiberglass. Using stronger and more lightweight materials has allowed manufacturers to create larger blades, increasing the capacity of the turbines.

Wind Turbine Components (con.)
Brake:

A disc brake which can be applied mechanically, electrically, or hydraulically to stop the rotor in emergencies. The mechanical brake is a physical brake, similar to a disc brake on the wheel of a car, connected to the high-speed shaft. It is used for servicing the equipment to ensure that no components start to rotate, endangering the repair worker. This is used to stop the blades rotating in gale force winds or for maintenance purposes. It is hydraulically operated using the same principles as found in a car’s disc brakes.

Wind Turbine Components (con.)
(Electronic) Controller:

The controller starts up the machine at wind speeds of about 8 to 16 miles per hour (mph) and shuts off the machine at about 65 mph. Turbines cannot operate at wind speeds above about 65 mph because their generators could overheat. The controller is a computer system that monitors and controls various aspects of the turbine. It has the ability to shut down the turbine if a fault occurs. Continuously monitors the condition of the wind turbine. Controls pitch and yaw mechanisms. In case of any malfunction (e.g., overheating of the gearbox or the generator), it automatically stops the wind turbine and may also be designed to signal the turbine operator’s computer via a modem link. Brake:

Wind Turbine Components (con.)

Cooling system:
The cooling system is used to ensure that the components do not overheat and cause damage to themselves or any other component. A typical cooling system is either an electrical fan or a radiator system.

Gear box:
Gears connect the low-speed shaft to the high-speed shaft and increase (transform) the rotational speeds from about 30 to 60 rotations per minute (rpm) to about 1200 to 1500 rpm and drives the generator. Connects to the low-speed shaft and turns the high-speed shaft at a ratio several times (approximately 50 for a 600 kW turbine) faster than the low-speed shaft.

Almost all wind turbines (except, Variable Speed Gearless Wind Turbine) contain gearboxes, which convert the slow rotation of the shaft into the high speed required to generate electricity. The gear box is a costly (and heavy) part of the wind turbine and engineers are exploring “direct-drive” generators that operate at lower rotational speeds and don’t need gear boxes.

Wind Turbine Components (con.)
Generator:
The generator is connected to the high-speed shaft and is the component of the system that converts the rotational energy of the shaft into an electrical output. Usually an off-the-shelf induction generator that produces 60-cycle AC electricity. The generator (3-phase, 690 volt) is driven by the high-speed shaft and also turns at 1,500 rpm, supplying electricity through a low voltage transformer to a high voltage transmission transformer and into Country Energy’s distribution grid. In recent years, wind power has become very competitive in electrical cost production due to increased efficiencies and the increased size of the generators, with typical outputs over 500kW for newer, utility-scale systems. Usually an induction generator or asynchronous generator with a maximum electric power of 500 to 1,500 kilowatts (kW) on a modern wind turbine.

High-speed shaft:
Drives the electrical generator by rotating at approximately 1,500 revolutions per minute (RPM).

Wind Turbine Components (con.)
Hub:
For propeller-driven turbines hub is the connection point for the rotor blades and the low speed shaft. Hub captures the wind and transfers its power to the rotor. Attaches the rotor to the low-speed shaft of the wind turbine. The hub is made of cast iron and connects the turbine’s blades to the main shaft. When the wind blows, the blades and hub rotate at 28 revolutions per minute (rpm). The hub and blades together weigh 8.5 tones.

Low-speed shaft:
The rotor turns the low-speed shaft at about 30 to 60 rotations per minute. Connects the rotor hub to the gearbox. Low-speed shaft is connected with large gear (ones is a component of the gearbox) and transmits rotation to it.

Wind Turbine Components (con.)
Nacelle:
The case or housing (from steel and/or fiberglass…), which is mounted on the tower and includes (encapsulates, supports, protects, covers) the gear box, low- and highspeed shafts, electrical generator, yaw system, hydraulics, controller, and brake. The nacelle can move though 360° and is turned into the wind using “yaw” motors that are controlled by the wind vane. The nacelle and equipment weigh 19 tones.

Pitch (Mechanism):
Blades are turned, or pitched, out of the wind to keep the rotor from turning in winds that are too high or too low to produce electricity. Vestas company -> Pitch control is achieved by feathering the blades.

Rotor:
The blades and the hub together are called the rotor and it rotates a low-speed shaft.

Wind Turbine Components (con.)
Tower:
Because wind speed increases with height, taller towers (it is advantageous) enable turbines to capture more energy and generate more electricity. The tower is used to support (carries) the nacelle and rotor blades (rotor).

Wind vane:
Measures wind direction and communicates with the yaw drive to orient the turbine properly with respect to the wind. Measures the direction of the wind while sending signals to the controller to start or stop the turbine.

Yaw drive:
Upwind turbines face into the wind; the yaw drive is used to keep the rotor facing into the wind as the wind direction changes. These are controlled by the information from the wind vane and ensure that the nacelle is always facing into the wind. Downwind turbines don’t require a yaw drive, the wind blows the rotor downwind.

Yaw motor:
Powers the yaw drive.

Trends of the R&D efforts that have contributed to current utility-scale turbine technology
• Improvements in the aerodynamics of wind turbine blades, resulting in higher capacity factors and an increase in the watts per square meter of swept area performance factor.
• Development of variable speed generators to improve conversion of wind power to electricity over a range of wind speeds.
• Development of gearless turbines that reduce the on going operating cost of the turbine.
• The general trend is toward wind turbines with maximum power output of 1 MW or more. European firms — such as Danish companies Vestas and NEG Micon — currently have more than 10 turbine designs in the megawatt range with commercial sales.

Trends of the R&D efforts that have contributed to current utility-scale turbine technology (con.)
• Wind turbine manufacturers optimize machines to deliver electricity at the lowest possible cost per kilowatt-hour (kWh) of energy.
• Development of lighter tower structures. A by-product of advances in aerodynamics and in generator design is reduction or better distribution of the stresses and strains in the wind turbine. Lighter tower structures, which are also less expensive because of material cost savings, may be used because of such advances.
• Smart controls and power electronics have enabled remote operation and monitoring of wind turbines. Some systems enable remote corrective action in response to system operational problems. The cost of such components has decreased. Turbine designs where power electronics are needed to maintain power quality also have benefited from a reduction in component costs.

WIND ENERGY PRODUCTION POTENTIAL
– Wind power is expected to grow at an annual rate of 20 % resulting in a total of about 40 000 MW of installed capacity around the world by 2004.
– According to recent study “Wind Force 10” wind power could generate 10 % of global electricity by 2020, and create 1,7 million jobs at the same time.
– International installation of 1,2 million MW of wind capacity by 2020 would generate more electricity than the entire continent of Europe consumes today.

WIND ENERGY PRODUCTION POTENTIAL (con.)
– Total wind energy potential in the world is 53 trillion kWh, 17 times higher than the Wind Force 10 goal.
– According to the study the cost of generating electricity with wind turbines is expected to drop to 2.5 US cents/kWh by 2020, compared to the current 4.7 US cents/kWh.
– Environmental benefits of the 10 % target would be enormous – savings of 69 million tones of CO2 in 2005, 267 millions tons in 2010 and 1780 million tones in 2020.

Design Simplification Strategy – Trimming Method
Radical product/process changes
– Improves product/process by eliminating low value (problematic) components and redistribution their useful functions between other components.
– Trimming Method simplifies and reduces the cost of user product/process, while preserving the essential functionality.
– The design variants that results from Trimming will generate different problem statements, if solved, can lead to highly innovative solutions. Benefits:

This repeatable process overcomes common TRIZ deployment challenges by showing a workflow and methodology for how to get started working on a problem with TRIZ, how to complement TRIZ with Value Methodologies for problem identification, and how to leverage internal and external knowledge sources to accelerate concept identification.