4.3 SENSITIVE POWER LOGICSensP 1 Trip AV00902SensP 1 Start AP1 Poledead InhEnabledVTS Slow Block&&Aph Sens PowerEnabledSens P 1 FunctionOver& 1Reverse1Low ForwardDisabledSens P >1 SettingSens P <1 SettingSens -P>1SettingSens P 1 DelayDTNote: This diagram does not show all stages . Other stages follow similar principles.It also does not show all phases . Other phases follow similar principles.Aph Sen WattsAph Sen WattsAph Sen WattsFigure 139: Sensitive Power logic diagram4.4 APPLICATION NOTES4.4.1 SENSITIVE POWER CALCULATIONInput QuantitiesSensitive power is calculated from the A-phase-neutral voltage and the A-phase sensitive current input.The calculation for active power with the correction angle is:P I VA AS A C= −cos( )ϕ θwhere:● PA = sensitive power● VA = A-phase voltage● IAS = A-phase sensitive current● Φ= the angle of IAS with respect to VA● θC = the CT correction angleCalculations within the device are based upon quadrature components obtained from the Fourier analysis of theinput signals. The quadrature values for VA and IAS are used for the sensitive power calculation as shown:P14x Chapter 12 - Power Protection FunctionsP14xEd1-TM-EN-1 267
