Index PHS designates correspondence to FDPSPDIS or FRPSPDISfunction and index PSD the correspondence to ZMRPSB function.( )tanarc tan³ PSDPHSArgLdArgLd kLdRFwEQUATION1353 V2 EN-US (Equation 92)Consider equation 93,max 25PSDArgLdj= = °EQUATION1354 V1 EN-US (Equation 93)then it is necessary to set the load argument in FDPSPDIS or FRPSPDIS functionto not less than equation 94.( ) ( )tan tan 25arc tan arc tan 37.50.61é ù é ù°³ = = °ê ú ê úë û ë ûPSDPHSArgLdArgLd kLdRFwEQUATION1355 V1 EN-US (Equation 94)It is recommended to set the corresponding resistive reach parameters in reversedirection (RLdOutRv and kLdRRv) to the same values as in forward direction,unless the system operating conditions, which dictate motoring and generatingtypes of oscillations, require different values. This decision must be made on basisof possible system contingency studies especially in cases when the direction oftransmitted power may change fast in short periods of time. It is recommended touse different setting groups for operating conditions, which are changing onlybetween different periods of year (summer, winter).System studies should determine the settings for the hold timer tH. The purpose ofthis timer is to secure continuous output signal from the Power swing detectionfunction (ZMRPSB) during the power swing, even after the transient impedanceleaves ZMRPSB operating characteristic and is expected to return within a certaintime due to continuous swinging. Consider the minimum possible speed of powerswinging in a particular system.The tR1 inhibit timer delays the influence of the detected residual current on theinhibit criteria for ZMRPSB. It prevents operation of the function for shorttransients in the residual current measured by the IED.The tR2 inhibit timer disables the output START signal from ZMRPSB function, ifthe measured impedance remains within ZMRPSB operating area for a time longerthan the set tR2 value. This time delay was usually set to approximately twoseconds in older power-swing devices.Section 7 1MRK 505 393-UEN BImpedance protection142 Line differential protection RED650 2.2 IECApplication manual
