TDK-Lambda ZERO-UP 200W User Manual

Contents

TDK-Lambda ZERO-UP 200W User Manual Manual pdf 39 page image

4.4.13 Auto Parallel Operation4.While operating in CV mode, the master unit regulates the output voltage and the slave units operateas controlled current source, following the master output current. It is recommended to design thepower system so that each unit will supply up to 95% of it’s current rating, because of an imbalancewhich may be caused by cabling and connections voltage drop.The master unit OVP should be adjusted to the desired OVP level. TheOVP of the slave units should be adjusted higher than the Master OVP. When the master unit shutsdown, it programs the slave units to zero output voltage. If a slave unit shuts down (when it’s OVP isset lower than the master output voltage), only that unit will shut down and remaining slave unitswill supply all the load current.At auto-parallel mode, power supplies can be connected in local or remotesensing. Refer Fig. 4-9, 4-10 & 4-11 for typical connections of paralleled power supplies. The figurebelow shows connection of two units, however the same connection method applies for up to 5 units.5. Over Voltage Protection:6. Connection to the Load:Fig. 4-9: Auto-parallel with local sensing(ZUP rear panel view)- V- V+V+VLOADMASTERPOWERSUPPLYSLAVEPOWERSUPPLY+_- LS- LS- S- S221414111313+LS+LS+S+SOn/OffOn/OffCOMCOMPPVRFVVRFVVCVPVCVPVRFIVRFIVCCPVCCPRCVPRCVPTo other slavesRCCPRCCPNOTEWith local sensing it is important to minimize the wire length and resistance. Also the wiresresistance should be as close as possible to achieve current balance between power supplies.1.Up to five units of the same rating can be connected in an auto-parallel combination to provide up tofive times the output current capability. One of the power supplies operates as a master and theremaining units as slaves. The slave units are analog programmed by the master unit. At remoteoperation, only the master unit can be programmed by the computer while the slave units may beconnected to the computer for actual voltage and current readback only.2. Foldback protection if desired, may only be used with the master unit. When the master unit shutsdown it programs the slave units to zero output voltage.3. Setting the voltage and current:The output voltage of the slave units should be programmed higher than the output and the master toavoid interference with the master CV control. Output voltage of the master should be programmedto the desired voltage, and the current limit to the desired load current divided by the number ofparallel units. During operation, the master unit operates at CV mode and the slave units at CC mode.Output GoodOutput Good