SPI-PPT-Agopian intropptx v4...1. R&D processes (Lean and agile) 2. Rigorous testing program for the whole inverter 3. Sub-assemblies tested ‒ Fans, power stacks, breakers, contactors,

MTBF Matchup!! A Town Hall Discussion of Inverter Technology

9/15/16 1

Tale of the Tape! Our Panel of Speakers

9/15/16 2

RicardoEspinosaSeniorProgramManagerYaskawa–[email protected]

CiaranFoxVicePresident,[email protected]

15yearsofexperience

JaniKangasProductLineManagerABBProductGroupSolar,[email protected]


Whom Am I?

9/15/16 3 MTBF Matchup!!

A Town Hall Discussion of Inverter Technology

10pointstoanyonethatcannamethemakeandmodelofthisinverter

Rules of the Matchup!

!  2 Rounds of Topic Talk by Panel Members ! Q&A from the audience each Round !  Finale Round – Last words from the Panel !  Final Q&A, time permitting ! No KO’s and the Moderator calls the Matchup

9/15/16 MTBF Matchup!!

A Town Hall Discussion of Inverter Technology 4

What this is NOT!

! One company versus another ! One topology versus another ! One size fits all ! All the answers!



MTBF???

! What does this mean? ! Why is this important to you? ! Are there other metrics? HALT? ALT? MTTR? ! What is “Reliability?”



MTBF Simplified Round 1

9/15/16 7

MeanTimeBetweenFailures

IMPACTOFINVERTERCONFIGURATIONONPVSYSTEMRELIABILITYANDENERGYPRODUCTIONAleksandarPregelj,MiroslavBegovicandAjeetRohatgi,SchoolofElectricalandComputerEngineering,GeorgiaInsFtuteofTechnology


MTBF is a calculation. What’s important is what leads to it… ! Research, Design, and Development ! Reliability Process ! Quality Procedures !  Testing Protocols !  In Service Data

9/15/16 8

Mul7ProngApproach


End of Round 1 - Q&A



What is the Bathtub Curve? Round 2

9/15/16 10

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Constant Hazard rate

Wearout segment

Infant Mortality or Early Life

Time (years) MTBF Matchup!!


9/15/16 11

HASS


Stress Tests

HALT (Highly Accelerated Life Testing) HALT is a stress testing method used to determine the operating and destruct

limits of a design ALT (Accelerated Life Testing) ALT is the process of testing a product by subjecting it to conditions in excess

of its normal service parameters

HASS (Highly Accelerated Stress Screen) HASS testing is an accelerated reliability screen that can be done in production

and can reveal latent flaws



End of Round 2 - Q&A



Finale Round - Panel Talk



! Ricardo! Ciaran

! Jani

www.solectria.com

SIMPLIFYING SOLAR

© 2015 Yaskawa – Solectria Solar / Company Confidential

PV Inverter Designed-in and Verified Reliability How does Yaskawa “design-in” reliability and verify reliability during the product development process ?

1)  Reliability requirements management

2)  Software reliability process (UL1998, MISRA C, CERT C, Polyspace, Software Stress Testing and (PIL)Processor in the Loop testing)

3)  Hardware reliability process •  Careful selection of components •  Derating components to increase design margins •  Stress Tests (HALT, ALT, HASS, etc.)

Requirements and Concept Phases

Prototype Phase

Design Validation/Verification Phase

www.solectria.com

SIMPLIFYING SOLAR


Reliability Requirements Management

Yaskawa integrates reliability and validation tracking with requirements management to ensure that all requirements have full traceability to testing activities

www.solectria.com

SIMPLIFYING SOLAR


Software Reliability Process •  Yaskawa has Software best practices which embrace:

o  UL 1998 "  Potential failure modes with microprocessor based control and safety controls are

systematically tested through life of the product

"  MISRA C/C++ "  CERT C (programming for security and reliability) "  Processor in the Loop (PIL) software test "  Static code Analysis: Polyspace

www.solectria.com

SIMPLIFYING SOLAR


PV Inverter Designed-in Reliability •  Hardware reliability during prototype phase

o  Careful selection of components "  Yaskawa independently validates every component in our own labs (connectors, magnetics, switching devices,

switches, etc.) "  Derate components to increase design margins

Yaskawa has derating guidelines for all components: Running a component well below their max ratings: Example Operating an 800V Film capacitor at 600Vor Example Operating a resistor at 50% of it’s max rated power

Careful selection and application components: Film Capacitors vs. Electrolytic (same capacitance and voltage) Identical cap bank composed of 600V capacitors Electrolytic Capacitors MTBF = 2.7 million hrs Useful Life 10-15 yrs Film Capacitor MTBF = 2.6 million hrs Useful Life 20-30 yrs

Testing components for the all environmental situations Example: Opto-couplers. 25ºC MTBF = 129 million hrs (FIT 7.75) 60ºC MTBF = 5.38 million hrs (FIT 186) That’s 24 times reduction in MTBF 60ºC vs. 25ºC!!! (ALL MTBF calculations via Telcordia Standard)

| © 2016 Enphase Energy, Inc.|CONFIDENTIAL 19

What is the Bathtub Curve?

0

0.1

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Inst

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Constant Hazard rate

Wearout segment

Infant Mortality or Early Life

Time (years)

Mean Time Between Failure (MTBF =1/FIT) x conversion factor


What does design-in quality approach mean?

The cycle of quality is aligned and coordinated, for example, in design this means: •  Clear reliability requirements •  Component selection •  Component verification •  Component use •  Rigorous thermal design

Industry Leading Quality

Design Engineering

Test Product Verification

Field Product Management

Manufacturing Operations


What does comprehensive qualification program mean? Long-term testing above IEC standards •  Learn from module partners (IEC 61215) •  Adapt to Field Knowledge/Experience

•  Maximum power, in-situ testing with real-time feedback, increased sample size as you improve, 1M POH before product release

•  Augmented IEC61215 p10.11 Thermal Cycling •  850C to -400C, 600 cycles

•  Augmented IEC61215 p10.13 Damp-Heat •  850C /85% RH, 1500 hours

HIGH CAPACITY ENVIRONMENT STRESS CHAMBERS – High sample size


Critical aspects to consider in inverter design choice

•  Assess the quality program of inverter/module company •  Design-in quality approach •  Comprehensive development qualification program •  Real-time field feedback, data synthesis, and action-oriented

•  Minimize single points of failure through distributed architecture

•  Future proof by remote updating capability

Let’s Achieve Part-Per Million Failure Rates…

500,000+ Systems – 100+ Countries – 2TB+ Data/day Annual Temperature Experience

© ABB Slide 23

Reliable R&D processes and products 1/3

© ABB Group September 15, 2016 | Slide 23

Customer requirements

Technical requirements

Technical specifications

Component specifications

Component testing

Unit testing

System testing

Integration testing

Ongoing Reliability programs

© ABB Slide 24


Central inverter testing dilemma: large physical size can make testing more complex. 1.  R&D processes (Lean and agile) 2.  Rigorous testing program for the whole inverter 3.  Sub-assemblies tested ‒  Fans, power stacks, breakers, contactors, PCBAs

4.  Supplier involvement 5.  Reliability tests (HALT, ALT) 6.  Key performance and component simulations 7.  Reliability calculations (FMEA, MTBF) 8.  Ongoing Reliability programs (ORT) 9.  Automated software testing 10.  Utilized field data and experience in design 11.  Utilized common components and platforms with other products

© ABB Group September 15, 2016 | Slide 24

© ABB | Slide 25 September 15, 2016


Reliability is not a number – it is hard work with right development principles

•  Requirement management •  Take benefit of changing requirements

•  Agile working principles/processes •  Learn and respect

•  Project management •  Builds, scrum, Kanban, multi level

project planning •  Develop competences

•  Simulations, calculations, automated testing

Learning and agility Process principles

Final Q&A



How Did We Do?

!  Like us, or don’t like us ! Matchup for 2017? ! We need to hear from you!



Documents

SPI-PPT-Agopian intropptx v4...1. R&D processes (Lean and agile) 2. Rigorous testing program for the whole inverter 3. Sub-assemblies tested ‒ Fans, power stacks, breakers, contactors,