Basler Electric DECS-250N - Manual (Page 206)

190 9440500990 Rev D
Testing DECS-250N
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OelOutput: OEL Controller Output
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OelRef
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OelState
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PF: Power Factor
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PositionInd: Position Indication {pu}
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Post: Post-Limit Output {pu}
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POut: Final PSS Output {pu}
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Prelim: Pre-Limit Output {pu}
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PsskW: PSS Electric Power {pu}
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Ptest: Time Response Signal {pu}
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SclOutput: SCL Controller Output
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SclRef
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SclPfRef
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SclState
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Synth: Synthsized Speed {pu}
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TermF: Terminal Frequency Deviation
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Test: Frequency Response Signal {pu}
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Tflt1: Torsional Filter #1 {pu}
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TrnOp: Internal State {pu}
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UelOutput: UEL Controller Output
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UelRef
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UelState
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V1: Positive Sequence Voltage {pu}
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V2: Negative Sequence Voltage {pu}
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Vab: PhA-PhB L-L Voltage {pu}
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Var/PfErr
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Var/PfOut
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Var/PfState
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VarLimOutput: Var Limiter Output
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VarLimRef
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VarLimState
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Vaux: Aux Voltage Input {pu}
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Vavg: Ave L-L Voltage {pu}
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Vbc: PhB-PhC L-L Voltage {pu}
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Vbus: Bus Voltage {pu}
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Vca: PhC-PhA L-L Voltage {pu}
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Vfd: Field Voltage {pu}
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Vtmag: PSS Term Voltage
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WashP: Washed Out Power
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WashW: Washed Out Speed {pu}
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x10: Mechanical Power LP #3
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x11: Mechanical Power LP #4
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x15: Lead-Lag #1 {pu}
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x16: Lead-Lag #2 {pu}
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x17: Lead-Lag #3 {pu}
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x2: Speed HP #1
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x29: Torsional Filter #2 {pu}
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x31: Lead-Lag #4 {pu}
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x5: Power HP #1 {pu}
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x7: Mechanical Power {pu}
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x8: Mechanical Power LP #1
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x9: Mechanical Power LP #2
Frequency Response
Read-only frequency response fields indicate the magnitude response, phase response, and test signal
frequency. The magnitude response and phase response corresponds to the test signal previously
applied. The test frequency value reflects the frequency of the test signal currently being applied.
Caution
Exercise caution when performing frequency response testing on a
generator connected to the grid. Frequencies that are close to the
resonant frequency of the machine or neighboring machines are to be
avoided. Frequencies above 3 Hz may correspond to the lowest shaft
torsional frequencies of a generator. A torsional profile for the machine
should be obtained from the manufacturer and consulted before
conducting any frequency response tests.
Time Response
Tests should be performed at various load levels to confirm that the input signals are calculated or
measured correctly. Since the PSS function uses compensated terminal frequency in place of speed, the
derived mechanical power signal should be examined carefully to ensure that it does not contain any
components at the electromechanical oscillation frequencies. If such components are present, it indicates
that the frequency compensation is less than ideal, or that the machine inertia value is incorrect.
PSS test signal configuration settings are provided on the Time Response screen shown in Figure 161.
Click the RTM Analysis screen’s Time Response button to access this screen.