root cause analysis: understand why electronic parts fail in your wind turbine
TRANSCRIPT
q This webinar will be available afterwards at www.windpowerengineering.com & email
q Q&A at the end of the presentation q Hashtag for this webinar: #WindWebinar
Before We Start
Michelle Froese Moderator
Windpower Engineering & Development
John Greulich Director of Sales
PSI Repair Services, Inc.
Aaron Lawson Project Manager
PSI Repair Services, Inc.
Root Cause Analysis: Understand Why Electronic Parts Fail In Your Wind Turbine
#WindWebinar
OUR CAPABILITIES REPAIR
SERVICES ENGINEERING
SERVICES ONLINE
SERVICES SURPLUS SERVICES
• ELECTRONIC • MECHANICAL • BALL SCREW
• RAC® REPAIRABLE ASSET CONTROL
• BUY SURPLUS PARTS • SELL SURPLUS PARTS
• ELECTRONIC DESIGN • MECHANICAL DESIGN • MANUFACTURING • FAILURE ANALYSIS
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• Ford Motor • Bosch • General Motors • Chrysler • Delphi • Hyundai • Denso • Thyssenkrupp • Toyoda • Honda
• EDPR • EDF Renewable Energy • NextEra Energy, Inc. • Iberdrola • Invenergy • MidAmerican Energy
• NavAir • Raytheon • Naval Surface Warfare • Naval Air Warfare • Defense Logistics Agency • Tobyhanna Army Depot • NavSup Weapons Systems • Wyle • DRS
OUR CUSTOMERS AUTOMOTIVE
INDUSTRY WIND ENERGY
INDUSTRY MILITARY
INDUSTRY
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• Texas Instruments • Western Digital • Cypress • IBM • Intel • Freescale • Samsung • Maxim • Seagate
• Triumph • Chromalloy Gas Turbine • Boeing • Honeywell
• Kwikset • Lufkin • Corning • SKF • Black& Decker • Briggs & Stratton • Timken • Honeywell • Alcoa • Eaton
OUR CUSTOMERS SEMICONDUCTOR
INDUSTRY AEROSPACE INDUSTRY
MANUFACTURING INDUSTRY
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WHEN YOU THINK ISP, THINK PSI
• Hydraulic actuators • Hydraulic pump • Proportional valves • Pitch motors • Encoders • Gear boxes – light duty • Transducers
COMPONENT REPAIRS
• Printed circuit board • PLC • Thyristors • MET boards • SCADA • Pitch controls • Monitors and displays
ELECTRONIC REPAIRS
• Current controllers • Anemometers • IGBT banks • Power converters • Inverters
PSI is a leading independent service provider (ISP) to the wind industry. PSI offers component repair and engineering services for these component failures and more:
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The highest-level cause of a problem is called the Root Cause.
WHAT IS: A ROOT CAUSE
ROOT CAUSE
HIGHER-LEVEL CAUSE
FIRST-LEVEL CAUSE
VISIBLE PROBLEM
SYMPTOM
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A Root Cause is “the evil at the bottom” that sets in motion the entire cause-and-effect chain causing the problem(s). Our goal is to permanently eliminate these through design improvements.
Root Cause Examples for Electronics: • Faulty or weak components • External causes, e.g. power issues • Poorly designed circuits, underrated components
WHAT IS: A ROOT CAUSE
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Root Cause Analysis (RCA) is a term that describes techniques and tools used to uncover causes of problems.
WHAT IS: A ROOT CAUSE ANALYSIS
CAUSE
CAUSE
CAUSE
CAUSE
PROBLEM
SYMPTOMS
The symptom is just the Tip of the iceberg!
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Failure Root Cause Edges of Tire Worn Under Inflation
Center of Tire Worn Over Inflation
Knife Stuck in Sidewall You Really Upset Someone!
EXAMPLE: FAILED TIRES
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5 WHYS is a technique used to explore the cause-and-effect relationships underlying a particular problem. The primary goal is to determine the root cause of a problem by repeating the question "WHY?"
TOOLS OF RCA: 5 WHYS?
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BELT BEYOND
LIFE
BELT BROKEN
ALTERNATOR NOT
WORKING
BATTERY DEAD
CAR WON’T START MAINTENANCE
NOT PERFORMED
SCHEDULE PREVENTATIVE MAINTENANCE
TOOLS OF RCA: 5 WHYS?
WHY?
WHY?
WHY?
WHY?
WHY?
ROOT CAUSE CORRECTIVE
ACTION
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Pareto Analysis is a technique used for the selection of a limited number of tasks that produce significant overall effect. It uses the Pareto Principle (also known as the 80/20 rule). Doing 20% of the work can generate 80% of the benefit of doing the entire job.
TOOLS OF RCA: PARETO ANALYSIS OR RED-X
80% RESULTS
20% EFFORT
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= 80% of the failures These are the most critical problems to address.
TOOLS OF RCA: PARETO ANALYSIS OR RED-X
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The Fishbone Diagram identifies many possible causes for an effect or problem. It can be used to structure a brainstorming session. It immediately sorts ideas into useful categories.
Also known as: Ishikawa Diagram Herringbone Diagram Cause-and-Effect Diagram
TOOLS OF RCA: FISHBONE DIAGRAM
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• Extend MTBF (Mean Time Between Failures)
• Save LABOR costs • Prevent turbine DOWNTIME • Less EXPENSIVE than OEM solutions • Avoid major RETROFITS or overhauls • Prevent CATASTROPHIC failures
before they happen
WHY RCA: IS SO CRITICAL TO O&M BUDGETS
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Cumulative Percentage
80%
Majority of Failures Related to IGBT
CASE STUDY: YAW MOTOR MODULE
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Problem: • 35 AMP modules failing
OEM Solution: • Retrofit cabinets with 45 AMP module
PSI Solution: • Upgrade 35 AMP module to 45 AMP
CASE STUDY: YAW MOTOR MODULE
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Issues with OEM Solution: • New unit is wider • Cabinets require modifications • Retrofit labor is costly • Larger units are costly
Result: • Expensive solution
CASE STUDY: YAW MOTOR MODULE
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Upgrades consisting of: • 30 AMP IGBT replaced with 45 AMP device • Recalibrate current sense resistors • This provides additional current handling
for peak energy
CASE STUDY: YAW MOTOR MODULE
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#PartsReplaced
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CASE STUDY: PITCH BATTERY CHARGER
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Testing Data: VA ratings exceeded of all style transformers at nominal input voltage.
CASE STUDY: PITCH BATTERY CHARGER
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Original Design Problems: • High failure rate • Common component failures • Transformer power exceeded • Ambient temperature exceeded
CASE STUDY: PITCH BATTERY CHARGER
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Transformer Failure Analysis: Primary winding failed due to excess power and ambient temperature.
CASE STUDY: PITCH BATTERY CHARGER
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Upgrades Consist of: • Higher power transformer and custom
adapter board • Higher temperature IC’s • Other high failure parts include
electrolytic capacitors replaced on each unit
CASE STUDY: PITCH BATTERY CHARGER
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What happened? The Automatic Lubrication System failed. WHY? The power supply failed. WHY? The power supply has burned components. WHY? The components got too hot. WHY? The power supply produces a lot of heat. WHY? The power supply is an inefficient design. WHY? The power supply is old technology. Solution? Design an efficient power supply!
CASE STUDY: AUTOMATIC LUBRICATION SYSTEM FIVE WHYS?
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• Drop in replacement unit • Custom designed • Higher efficiency = low heat • High reliability • Low cost
CASE STUDY: AUTOMATIC LUBRICATION SYSTEM
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FAILED UNITS
ENVIRONMENT
MATERIALS PEOPLE
Shipping Damage
ESD Damage Low MTBF
Bad Design
Poor Ratings
Power Surges
Low Temp
High Temp
CASE STUDY: RFID TAG READER
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Root Causes of Main Failures: • Component temperature exceeded • Poor antenna design • Poor antenna matching circuit
CASE STUDY: RFID TAG READER
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Poorly Designed OEM Antenna Antenna Redesign and Optimization
Copper Tape Style
Non-Optimized Style
Multiple Designs Simulated and Tested
In-House Prototypes Production Design with Coax Cable
SPICE Simulations
CASE STUDY: RFID TAG READER
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• Custom designed and optimized antenna • Range increased from 2.5cm to 5cm • Higher temperature components • Coax cable to antenna • Brighter LEDs • Over 1,000 field installations
CASE STUDY: RFID TAG READER
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What did the customer like most about the new design? • Increased range? • Longer life? • NO?
Brighter LEDs can be seen more easily
Original LEDs
CASE STUDY: RFID TAG READER
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WHY? OLD TECHNOLOGY
TRANSISTORS WHY?
POOR QUALITY CAPS
WHY? CAP ESR TOO HIGH
WHY? TRANSISTORS
GENERATE TOO MUCH HEAT
WHY? CAPS LEAKED AND SHORTED TRACES
WHY? TEMPERATURE WAS
EXCEEDED
WHY? IT HAS BURNED
CAPS
WHY? THE PCB IS BURNED
WHAT HAPPENED? PITCH DRIVE FAILED
WHY? AMBIENT TEMP GETS TOO HIGH
5 WHYS? Multiple Paths and
Multiple Root Causes
CASE STUDY: PITCH MOTOR DRIVE
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Problems with original design: • Extremely short life: <2 years in most cases • Catastrophic failures – Many units non-repairable • Units up tower in hub – Expensive to replace • Poorly rated capacitors and transistors • Inefficient design generates excess heat • Damaged threads on ground lug hole
CASE STUDY: PITCH MOTOR DRIVE
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New Design Features: • Higher efficiency: 25ºC cooler than OEM • Allows repair of catastrophic failures • FETs with lower on resistance • Capacitors handle higher ripple current • Thicker copper traces on PCB • Over 3,000 field installations • MTBF reduced by over 80%
CASE STUDY: PITCH MOTOR DRIVE
Steel Inserts create more durable ground lug threads.
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CASE STUDY: CURRENT CONTROLLER
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Pareto Analysis: Large variation in failures
VRCC Rotor Current Controller
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• Component rotates with generator • High vibration environment • Short MTBF • High ambient temperatures
CASE STUDY: CURRENT CONTROLLER
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Original Design Problems: • Broken solder joints on capacitors • High vibration during operation • DC-DC converter failures • Rotating component is poorly balanced
CASE STUDY: CURRENT CONTROLLER
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Upgrades: • Tab style mechanical connections on
snubber capacitors • Through hole solder joints eliminated • Resistant to damage from vibration • Repaired units balanced with custom,
mechanically secured weights. • Improved DC-DC converters
New PSI Snubber Board Design
CASE STUDY: CURRENT CONTROLLER
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WHEN YOU THINK ISP, THINK PSI To learn more about Wind Energy Life Cycle Solutions, visit http://info.psi-repair.com/wind-root-cause-analysis, or call John Greulich at 734-853-5360.
Questions? Root Cause Analysis: Understand Why Electronic Parts Fail In Your Wind Turbine
John Greulich Director of Sales
PSI Repair Services, Inc. [email protected]
Aaron Lawson Project Manager
PSI Repair Services, Inc. [email protected]
Michelle Froese Moderator
Windpower Engineering [email protected]