GE Multilin G60 Generator Management Relay 5-1955 SETTINGS 5.8 TRANSDUCER INPUTS/OUTPUTS5The relay checks the driving signal (x in equations below) for the minimum and maximum limits, and subsequently re-scales so the limits defined as MIN VAL and MAX VAL match the output range of the hardware defined as RANGE. The follow-ing equation is applied:(EQ 5.44)where: x is a driving signal specified by the SOURCE settingI min and Imax are defined by the RANGE settingk is a scaling constant calculated as:(EQ 5.45)The feature is intentionally inhibited if the MAX VAL and MIN VAL settings are entered incorrectly, e.g. when MAX VAL – MINVAL < 0.1 pu. The resulting characteristic is illustrated in the following figure.Figure 5–115: DCMA OUTPUT CHARACTERISTICThe dcmA output settings are described below.• DCMA OUTPUT H1 SOURCE: This setting specifies an internal analog value to drive the analog output. Actual values(FlexAnalog parameters) such as power, current amplitude, voltage amplitude, power factor, etc. can be configured assources driving dcmA outputs. Refer to Appendix A for a complete list of FlexAnalog parameters.• DCMA OUTPUT H1 RANGE: This setting allows selection of the output range. Each dcmA channel may be set inde-pendently to work with different ranges. The three most commonly used output ranges are available.• DCMA OUTPUT H1 MIN VAL: This setting allows setting the minimum limit for the signal that drives the output. Thissetting is used to control the mapping between an internal analog value and the output current (see the followingexamples). The setting is entered in per-unit values. The base units are defined in the same manner as the FlexEle-ment™ base units.• DCMA OUTPUT H1 MAX VAL: This setting allows setting the maximum limit for the signal that drives the output. Thissetting is used to control the mapping between an internal analog value and the output current (see the followingexamples). The setting is entered in per-unit values. The base units are defined in the same manner as the FlexEle-ment™ base units.The DCMA OUTPUT H1 MIN VAL and DCMA OUTPUT H1 MAX VAL settings are ignored for power factor base units (i.e. ifthe DCMA OUTPUT H1 SOURCE is set to FlexAnalog value based on power factor measurement).Three application examples are described below.I outI min if x MIN VAL<I max if x MAX VAL>k x MIN VAL–( ) I min+ otherwise⎩⎪⎨⎪⎧=k I max I min–MAX VAL MIN VAL–-------------------------------------------------=842739A1.CDRDRIVING SIGNALOUTPUT CURRENTMIN VALI minI maxMAX VALNOTE
