User manual

Page 81
EA Elektro-Automatik GmbH
Helmholtzstr. 31-33 • 41747 Viersen
Germany
Fon: +49 2162 / 3785-0
Fax: +49 2162 / 16230
www.elektroautomatik.de
[e-mail]
PSI 9000 2U Series
3.10.3 Two quadrant operation (2QO)
3.10.3.1 Introduction
This way of operating refers to the use of a source, in this case a power supply
of this series PSI 9000 2U, and a sink, for example a series ELR 9000 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 or
nal test
The user can decide whether the system is operated manually or the power
supply only as the dominant unit or both devices should be controlled by PC.
We recommend to focous on the power supply, which is intended to control the
load’s behaviour regarding voltage and current via the Share Bus connection.
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 maximum approved limits for the application should be set
in the power supply. This can be done via the interface. The
electronic load should preferably be in operating mode CV. The
load will then, using the Share Bus, control the output voltage
of the power supply.
Typical applications:
• Fuel cells
• Capacitor tests
• Motor driven applications
• Electronic tests where a high dynamic discharge is required.
3.10.3.2 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:
1 e-load and 1 power supply, plus 1 test object (E.U.T).
This is he most common conguration for 2QO.
The nominal values for U and I of the two devices should
match, but at least the voltage. For example, an ELR 9080-
170 and PSI 9080-120 2U would match. The system is con-
trolled by the power supply unit, which has to be set to be
“Master” in the setup menu, even though there is no master-
slave operation running.
E.U.T
E-LOAD PSU 1
PSU n
Master-Slave
SB
Share-Bus
Conguration B:
1 e-load and multiple power supplies, plus 1 test object
(E.U.T).
For adapting the total power of the power supply device to
the possibly higher input power of the load, the power sup-
plies are connected via Master-Slave and the load’s current is
shared across the power supplies when wiring the Share bus
to gain a balanced load distribution. The digital master-slave
bus can be wired if installed on the power supply units. One
PSU, preferable PSU 1, has to be set to Master for the Share
bus connection, no matter if MS operation via the digital MS
bus used or not.