User manual

Page 79
EA Elektro-Automatik GmbH
Helmholtzstr. 31-37 • 41747 Viersen
Germany
Fon: +49 2162 / 3785-0
Fax: +49 2162 / 16230
www.elektroautomatik.de
[e-mail]
EL 9000 B HP Series
3.11.3 Two quadrants operation (2QO)
3.11.3.1 Introduction
This kind of operation refers to the use of a source, in this case a power supply
from a compatible series (see section „1.9.9. “Share” connector“) and a sink,
in this case a series EL 9000 B HP electronic load. The source and the sink
function alternately in order to test a device, such as a battery, by deliberate
charging and discharging as part of a functional test, or a motor by clipping
excess energy with the sink.
The user can decide either to operate the system manually or only the power
supply device as the driving unit or to control both devices by PC. It is recom-
mended to focus on the power supply, which is intended to control the load
via the Share Bus connection. The two quadrant operation is only suitable for
constant voltage operation (CV).
Clarication:
U+
U-
I+
I-
III
III
IV
A combination of source and sink can only map the quadrants
I+II.Thismeansthatonlypositivevoltagesarepossible.The
positive current is generated by the source or application and
thenegativecurrentowsintotheload.
The set values for current and power of the load need to be set
to match the application’s requirements. This can be done manu-
ally or via any interface. The power supply has to be operating
in mode CV. Only then it will control the input voltage of the load
using the Share Bus.
Typical applications:
• Fuel cells
• Capacitor tests
• Motor driven applications
• Electronic tests where a high dynamic discharge is required.
3.11.3.2 Connecting devices to a 2QO
There are a number of possibilities to connect source(s) and sink(s) to make a 2QO:
Share-Bus
E.U.T
E-LOAD PSU
Conguration A:
1x e-load and 1x power supply, plus 1x test object (E.U.T).
Thisisthemostcommoncongurationfor2QO.Thenominal
values for U,I and P of the two devices should match, such
as EL 9080-170 B HP and PSI 9080-170 3U. The system is
controlled by the power supply, which has to be set to “Master”
in the setup menu, even if there is no master-slave operation
running.
E.U.T
E-LOAD 1
PSU 1
Master
PSU nE-LOAD n
Master-Slave
Share-Bus
Master-Slave
Conguration B:
Multiple e-loads and multiple power supplies for increased total
performance, plus 1 test object (E.U.T).
The combination of load units and power supply units each
create a block, a system with certain power. Here it is also
necessary to match the nominal values of the two systems,
like the 80 V DC input of the loads to a max. 80 V DC output
of the power supplies. The max. number of 10 units cannot
be exceeded. Regarding the Share bus connection, all e-load
units have to be slaves, while one of the PSUs has to be set
as master.
Incasethedigitalmaster-slavebus,wherefeatured,isalsoconnected,oneloadunitwillbedenedasmaster
for the MS system of load, but still has to be slave on the Share bus, which is activated with parameter “PSI/EL
system” in the setup menu.