User Manual

Page 77
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 3U Series
Share-
Bus
E.U.T
E-LOAD 1 PSU 1
PSU nE-LOAD n
Master-Slave
Master-Slave
Conguration C:
Multiple e-loads and Multiple power supplies, plus 1 test
object (E.U.T), for raising the total performance.
The load combination and the power supply combination
createineachcaseatotalsystemwithadenedpower.Itis
necessary also here to match the nominal values of the two
systems. i.e an 80 V DC output of the loads to a max. 80 V
DC output of the power supplies.
3.9.3.3 Application example:
Charginganddischargingabattery,24V/400Ah,usingthewiringexampleincongurationA.
• Power supply PSI 9080-170 3U set to: Imax = 50 A, Pmax = 5000 W
• Electronic load ELR 9080-170 set to: Imax = 100 A, Pmax = 3500 W, U = 0 V or any other minimum value to
which the battery shall be discharged to
• Assumption: battery has a voltage of 26 V at test start
1. Discharge of the battery to 24 V
Requirements: Voltage on the power supply set to 24 V, DC output of power supply and DC input of load activated
Reaction: the e-load will load the battery with a maximum of 100 A in order to discharge it to 24 V. The power
supplies no current at this moment, because the battery voltage is still higher than what is adjusted on the power
supply. The load will gradually reduce the input current in order to maintain the battery voltage at 24 V. Once the
battery voltage has reached 24 V with a discharge current of approx. 0 A, the voltage will be maintained at this
level by charging from the power supply.
2. Charging the battery to 27 V
Requirements: Voltage on the power supply set to 27 V
Reaction: the power supply will charge the battery with a maximum current of 50 A, which will gradually reduce with
increasing voltage as a reaction to the changing internal resistance of the battery. The load absorbs no current at
this charging phase, because it is controlled via the Share bus to set 27 V, which is still higher than the actual bat-
tery voltage. When reaching 27 V, the power supply will deliver only the current needed to maintain battery voltage.