Eaton Cooper Power Series Installation, Operation And Maintenance Manual

Also see for COOPER POWER SERIES: Installation and operation instructions Installation instructions Installation instructions Installation and operation instructions Operation instructions

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Eaton Cooper Power Series Installation, Operation And Maintenance Manual Manual pdf 143 page image

DeltaCalc featureThe CL-7 Multi-Phase (MP) control opens up newapplications unavailable with individual single-phase controls.The single control now has access to the metering andphasor information from all connected voltage regulators.This measured data can be used to calculate meteringvalues unavailable on single-phase connected controls,without the addition of external metering transformers.DeltaCalc settingsThe DeltaCalc settings are accessible using the controlHMI or through ProView NXG software. Since DeltaCalcis available only on the CL-7 MP control, the settings areassociated with the other control multi-phase settings.Through the control HMI, FC 212 is used to select theDeltaCalc Mode. When the DeltaCalc feature is enabled,the control will determine whether the control is connectedto an open or closed delta configured system based uponthe number of VRs Configured (FC 202) and the SystemConfiguration setting (FC 41). There are three options for theDeltaCalc parameter (Off, Basic, and Advanced), which areexplained below.DeltaCalc settings for open deltaFor open delta configured systems, the DeltaCalc settingparameter of Off will result in traditional independentregulation of phases A and C without consideration of phaseB voltages. The parameter settings of Basic and Advancedboth result in the same voltage regulator operations asdescribed in the next section.Open delta voltage regulationAs an example, Figure 43 shows the connection of twoType B voltage regulators connected in an open deltaconfiguration. Similar operations as described here will alsooccur when DeltaCalc is applied to Type A regulators. It isclear in the figure that voltages are known between phase Aand phase B. The voltages are also known between phase Cand phase B. The load voltages are measured using controlwindings (S2 to G); the source voltages are determined withthe addition of measured voltages between S4 and G or asource voltage calculation.Figure 43 Two type B regulator connected in an open-deltaWhat would not traditionally be known when regulators areconnected in open delta is the voltages between phasesA and C. The DeltaCalc feature uses the known values andphasor math to calculate the phase A to C voltage. With thisinformation, the control will make decisions about operatingthe voltage regulators to regulate the A to C voltage.When a determination has been made that regulationis needed for A to C, the control will determine whichconnected voltage regulator is best able to affect regulation.The operation will then occur on one of the voltageregulators to bring the A to C voltage back into band. TheMP control settings for VR3 (set voltage, bandwidth, timedelay, LDC resistance, and LDC reactance) will be used forA to C regulation.Open delta load ampsWith the open-delta systems there has been no method ofmeasuring the load current of the open phase. Using theDeltaCalc feature, the open phase load current is calculatedbased upon the known measured values of the adjacentphases.Close delta voltage regulationFigure 44 shows the connection of two Type B voltageregulators connected in a closed delta configuration. Thisfigure is being used to illustrate how the DeltaCalc featureoperates when applied to voltage regulators connected in aclosed delta configuration. Similar operations as describedhere will also occur when DeltaCalc is applied to Type Aregulators.For closed delta connected regulators, without theDeltaCalc feature, reverse power regulation has presenteda problem. Figure 44 illustrates the problem. It can be seenin the figure that reverse regulation requires the control tohave knowledge of the voltages between the adjacent S137INSTALLATION, OPERATION, AND MAINTENANCE INSTRUCTIONS MN225003EN April 2018CL-7 Voltage Regulator Control