0 Confidential String inverters for commercial PV applications David Smith, November 2013.

1 Confidential

String inverters for commercial PV

applicationsDavid Smith, November 2013

2 Confidential

Commercial PV projects: Main Drivers

Energy Harvesting

Product Reliability

Simple Installation & Maintenance

Product Flexibility

3 Confidential

String Application - Considerations

• High design flexibility for a wide range of applications

• Ease of installation• BoS Integration (DC combiner)

PRO

• No Panel level MPPT• No panel level monitoring

CONS

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Double MPPT with High-Speed algorithm

String : optimizing energy harvestingDouble MPPT & Scanning Function

Different MPPs to be managed separately for a better energy harvesting

Real “equal & independent MPPTs” for a unique flexibility in designing your own PV field

High Dynamic Efficiency: less than 2 seconds to find the MPP

HarvestingFlexibility

MPPT Scanning Function

Voltage

Power

0 Voc

Real Pmax False Targets

Vmin

Mpp1 Mpp2

Running a preliminary scanning function all over the input voltage range considerably increases the MPPT algortithm’s effectiveness

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String: design flexibility and efficiency

Longer strings = benefits with high-Voc PV modules.

HarvestingFlexibility

Flat efficiency curve

Inverter’s efficiency stays at very high levels on a wide range of Vdc and Pac values. This feature gives you a unique design flexibility for your PV plant

Wide input voltage range andFlat efficiency curve

Operating DC input voltage up to 970V

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String: keeping an eye on reliability

Electrolyte-free technology, no fans and IP65 enclosure

No electrolytic capacitors and fans

Removing two of the main causes of

failures = reliability TRIO = 10 year

warranty

IP65 enclosurewith rear heatsink

The rear heatsink allows performing an

easy maintenance from the front of the

inverter

Reliability Installation & Maintenance

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String: making everything easier

Ease of installation & Maintenance Installation & Maintenance

Installer-friendly wall connection

system

The inverter’s wall connection system has been

designed so that you’ll be able to install your own

product just performing a few easy on-site actions.

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DC – AC Switch

Compliant with ECA/MCS Guide to the Installation of PV

2.1.12.2 Switch Disconnector2.1.12.3 Array Switch Disconnector

Reducing Balance of System Costs

String Fuse Protection

Compliant with ECA/MCS Guide to the Installation of PV

2.1.10 String Fuses2.1.10.1 String fuse Selection

Surge Protection

Compliant with ECA/MCS Guide to the Installation of PV

2.2.6 Surge Protection Measures

Installation & Maintenance

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String: Grid Management

Smart Grid ready

Inverter contributes to grid stability and

control to increase grid quality

Capability to select Active power reduction and

Reactive power regulation

= Smart grid ready

Frequency control

Voltage Control

Power Factor Management

Flexibility

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Class II ProtectionAC + DC Switch

String level monitoring

Basic version

-S2 version

-S2F version

-S2X version

A closer look at TRIOCompactness &

FlexibilityInstallation & Maintenance

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Why Use TRIO?

• High efficiency• Wide input voltage range (up to 1000V)• Double Independent MPPTs• Fast and precise MPP tracking algorithm

High energy harvesting

• Natural Convection Cooling• Electrolyte free (no electrolytic capacitors)• IP65 environmental protection rating

High reliability

• Detachable Wiring Box• Graphic displayFast installation

• Graphic display• Remote connectionEasy to use

• Wide input voltage range (up to 1000V)• 4 different options for the wiring box• 20.0 and 27.6 kW models

Flexible PV plant planning

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Hardware

Balance of System cost reductions - <50kW

~30% reduction in comparison of Inverter(s) + BOS for 20kW-50kW systems.

+ 10 year standard warranty for TRIO

Installation + O+M Install cost reduction - Integral DC + AC Isolator, Fuse combiners + OVP

OPEX (Reduced Maintenance) - Inverter can be replaced simply without qualified staff.

String level monitoring = Preventative O+M

£/W Price

Lower Cost/W

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Lost Energy Detection Improves Performance

• Commercial rooftop system

• 4 years operation with Inverter-level only monitoring.

• Converted to string level monitoring

Before

After

67% PR

82% PR

Harvesting

14 Confidential

• Location: Burgess Hill, Sussex, UK

• Installed: Spring 2012

• Inverters:

• TRIO-20.0-TL-OUTD-S2X• TRIO-27.6-TL-OUTD-S2X

50kWp Roof example

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• Location: Bridgewater, Somerset, UK

• Installed: Summer 2013

• Inverters:

• TRIO-20.0-TL-OUTD-S2X• TRIO-27.6-TL-OUTD-S2X

1MWp Roof Project

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• Location: Crewe, Staffordshire , UK

• Installed: Spring 2013

• Inverters:

• TRIO-20.0-TL-OUTD-S2X• TRIO-27.6-TL-OUTD-S2X

5MWp Roof Project

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