Frequency Inverter DF51... - Moeller.com.tr

Setting parameters04/07 AWB8230-1541GBA072aWA077x (–1)+ (–)– (+)A071PA073I+++A078A004A061A062cA075DbX2324C005 ... C0015 43 2 1...Figure 139: Block diagram, PID control (cont. from fig. 138)a w = reference value channelb x = actual value channel (process variable PV)c Manipulated variable (output frequency)hhPID control is superimposed on the frequency inverterfunction. You should therefore set all of the frequencyinverter’s drive-related parameters, such as maximumoutput frequency (motor speed), acceleration anddeceleration ramps (mechanical load, belts). <strong>Frequency</strong>inverter and motor are process-integrated actuators. Theoutput frequency to the motor (which determines thespeed) is specified as manipulated variable from the PIDcontroller.When PID control is enabled, the reference and actualvalues be<strong>com</strong>e process variables and are automaticallyconverted into percentages. The specified reference value(0…100 %) corresponds with, for example, a volumeflow rate (0…50 m 3 /h). The process variable is thereading (m 3 /h) from a sensor and is again evaluated as apercentage (0…100 %). If this process data is to beoutput as a physical unit (m 3 /h) you can set theconversion with PNU A075 (a section “Display factor(PNU A075)”, page 130).128