ST MicroelectronicsSolar DiodesSolar MPPT Booster

Available from Available from

Avnet Electronics MarketingAvnet Electronics Marketing

www.avnetexpress.comwww.avnetexpress.com

Boosting solar energy conversion

At junction box or panel level cool bypass switch At photovoltaic array level solar energy booster

Load

Inverter

MeterAC grid

Photovoltaicarray

Junction box

Improving solar energy conversion

More efficient solar energy conversion

New approach to renewable energy based 100% on ST’s proprietaryIPs and technologies for:

At junction-box level Minimized power dissipation and leakage currents Improved reliability and maximized lifetime

At photovoltaic-panel array level Minimized shadowing impact on power generation Minimized panel mismatch Improved inverter efficiency Panel diagnosis using remote monitoring and control functions

System in package Embedded power MOSFET Very low forward-voltage drop Very low reverse leakage current

Key features

Main benefits

Cooler than Schottky diodes Low power dissipation Longer lifetime Higher reliability

(1) CBS available in different packages

TO-220

D2PAKTO-220 AC

MLPD 5x6(1)

(2)

(2) CBS in MLPD package: very low profile (less than 1mm) to laminate device directly on the panel

Cool bypass switch (CBS)

CBS versus standard Schottky diodes

PV panel

+-

Junction box

Hot spot

StandardSchottky diode

Cathode

Anode

Cool bypassswitch

Cathode

Anode

Cool bypass switch (CBS)

CBS vs standard Schottky diodes: power dissipation in forward biasing

StandardSchottky diode

Note: acquisitions made at steady state

Cool bypassswitch

Biasing Current [A]

0

1

2

3

4

5

1 2 3 4 5 6 7 8 9 10

Po

we

r D

iss

ipa

tio

n [

W]

Cool bypass switch (CBS)

CBS vs standard Schottky diodes: leakage current in reverse polarity

Note: acquisitions made at steady state

Cool bypassswitch

StandardSchottky diode

0.001

0.01

0.1

1

10

100

1000

5 10 15 20 25 30 35 40

Reverse Voltage [V]

Le

aka

ge

Cu

rre

nt

[mA

] 125 °C

115 °C

105 °C

95 °C

85 °C

Cool bypass switch (CBS)

CBS versus standard Schottky diodes: heat dissipation compared at ambient temperature, without dissipation tools

StandardSchottky diode

Note: acquisitions made at steady state

5 A 6 A

7 A 8 A

Cool bypassswitch

StandardSchottky diode

Cool bypassswitch

Cool bypass switch (CBS)

Removes need for centralized power conversion, moving part of the electronics from the inverter to the panel

Solar energy boosterStandard PV panel

Antiislanding

DC-ACconverter

DC-DCconverter

MPPT inverter anti-islanding control control control

Inverter basic architecture

+-

electronic parts centralized at inverter level

+

-

Boost+MPPT

Boost+MPPT

Boost+MPPT

distributed architecture DC-DC and MPPT at single cell-string level

Solar energy booster

Monolithic power converter embedded in the panel Breakthrough device allows distributed architecture:

one or more power converters integrated on the panel MPPT implemented at single cell-string level

Key features

Main benefits

MPPT computed for each cell string Maximized power extracted from a single cell string Boosted overall efficiency of the photovoltaic system

Maximum power point tracker (MPPT) algorithm Maximizes solar DC power from the PV panels under any temperature and radiation

conditions (shadowing, panel performance mismatch, thermal gradient, etc.) Tracks power-output changes from the PV modules and maintains continuous grid

connectivity

Solar energy booster demonstration board

Panel diagnostics using remote monitoring and control function

Solar energy booster

Improving photovoltaic technology

Main benefits

Cool bypass switch Solar energy booster

Reduced power dissipation

Cooler device

Smaller and lighter junction box

Higher reliability

Longer lifetime

Maximized efficiency of the photovoltaic system

Extra energy production

Higher reliability: fewer devices, lower failure rate

Panel diagnostics: remote monitoring and control