ABB The new GAF range, the world‘s first block contactors with ratings up to 2000 A for 1000 V DC

The GAF contactor’s ability to break DC up to 2000 A at a voltage

up to 1000 V derives from the use of permanent magnets in the

arc packages. The magnets enable the contactor to extinguish the

powerful electrical arcs that arise between the contact surfaces

when breaking DC. Normal AF contactors can break DC up to

some extent but since they lack the permanent magnets they

will not be able to break DC as a corresponding GAF contactor.

Applications – solar

What is PV power?

Photovoltaic (PV) power is a renewable energy source converting

sunlight directly into electrical energy using PV cells. Large PV

systems often consist of following main components:

• PV cells (combined to strings, generating the power).

•  Inverter (one or several, converting the generated DC voltage

into AC 50Hz or 60Hz, also including devices for switching,

protection and control).

•  Combiners (junction boxes, including switching devices, with

several cables on input and one cable on output).

• Trackers (mechanical structure to move the angle of PV cells

to follow the sun, increasing system efficiency, also including

motors, PLC, communication, protection).

• Switching devices and protection devices (to change PV

string configuration, protect from over currents, surge

voltages and earth faults etc.).

• Distribution transformer (transforming low voltage to high

voltage, as grid connection often is done on high voltage level).

What is the future of PV power?

Solar energy is today the fastest growing segment in renewable

energy and is believed to be one of the major energy sources in

the future.

Factors that vouch for a bright future of solar energy:

• Growing climate awareness brings more focus on renewable energy.

• Continuously higher legislative demands on increasing the share of green energy.

• Intense research and development of the PV technology in

order to make it more efficient and easier to produce.

Decreased production costs due to higher volumes and

improved production technique make it possible to pro-

duce low cost PV cells which in turn will expand the market.

Why is DC contactors needed?

PV plants contain some major application for DC swit

ching, since the electricity produced by the PV panels is DC.

Depending on application requirements, different products can

be used for switching. Contactors are typically selected for app

lications with the need for remote control and switching at least

once per day.