Basler DECS-250 Instruction Manual

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Contents

Basler DECS-250 Instruction Manual Manual pdf 37 page image

Operation with Paralleled GeneratorsBESTCOMSPlus® Navigation Path: Settings Explorer, Operating Settings, Parallel/LineDropCompensationHMI Navigation Path: Settings, Operating Settings, Parallel/LineDrop CompensationThe DECS-250 can be used to control the excitation level of two or more generators operating in parallelso that the generators share the reactive load. The DECS-250 can employ either droop compensation orcross-current compensation (reactive differential) schemes for reactive load sharing. A separate loadsharing function enables each machine to share the load proportionally without incurring a voltage andfrequency droop.Paralleled generator settings are illustrated in Figure 19 and described in the following paragraphs.Reactive Droop CompensationDroop compensation serves as a method of controlling reactive current when the generator is connectedin parallel with another energy source. When droop compensation is enabledA, the generator voltage isadjusted in proportion to the measured generator reactive power. The reactive droop compensationsettingBis expressed as a percentage of the generator rated terminal voltage.NoteFor droop compensation to operate, the PARALLEL_EN_LM logicblock must be set true in BESTlogicPlus programmable logic.Cross-Current CompensationCross-current compensation (reactive differential) mode serves as a method of connecting multiplegenerators in parallel to share reactive load. When reactive load is shared properly, no current is fed intothe DECS-250 cross-current compensation input. Improper sharing of reactive load causes a differentialcurrent to be fed into the cross-current compensation input. When cross-current compensation isenabledC, this input causes the DECS-250 to respond with the proper level of regulation. The response ofthe DECS-250 is controlled by the cross-current compensation gain settingDwhich is expressed as apercentage of the system nominal CT setting.Application information about cross-current compensation is available in the Voltage and Current Sensingsection of this manual.Network Load SharingIn a multiple-generator application, the load sharing function ensures equal generator reactive-powersharing. It operates in a similar manner to cross-current compensation but without the external hardwarerequirements and distance limitations. Instead of sharing load based on the CT ratio, load is shared on aper-unit basis calculated from the generator rated data. Sharing of load information between DECS-250controllers is accomplished through the Ethernet port of each DECS-250 communicating over a peer-to-peer network dedicated for the load sharing function. Each DECS-250 measures the reactive current of itsassociated generator and broadcasts its measurement to all other DECS-250 controllers on the network.Each DECS-250 compares its level of reactive current to the sum of all measured currents and adjusts itsexcitation level accordingly.Network load sharing implements a fading droop function based on the droop setting, washout filter gain,and washout filter time constant. During transients, load sharing will droop according to the drooppercentage and washout filter gain settings. The droop characteristic will fade with a time constantaccording to the washout filter time constant.A Load Share ID setting identifies the DECS-250 as a load sharing unit in the network. Checking a LoadSharing Unit number box allows any DECS-250 load sharing units on the network with that Load Share IDnumber to share load with the currently connected DECS-250. It is not necessary for the Load Share ID tobe unique for each unit. This allows for load sharing units to be grouped.CALL US TODAY1-888-POWER-58REQUEST A QUOTEparts@genpowerusa.comSHOP ONLINEwww.genpowerusa.comCALL US TODAY1-888-POWER-58REQUEST A QUOTEparts@genpowerusa.comSHOP ONLINEwww.genpowerusa.com