FC 300 Design GuideIntroduction to FC 300The motor is supplied with variable voltage / current and frequency, which enables infinitely variable speedcontrol of three-phased, standard AC motors and permanent magnet synchronous motors." FC 300 ControlsThe adjustable frequency drive is capable of controlling either the speed or the torque on themotor shaft. Setting par. 1-00 determines the type of control.Speed control:There are two types of speed control:ï Speed open loop control which does not require any feedback (sensorless).ï Speed closed-loop control in the form of PID control that requires speed feedback to an input. Properlyoptimized speed closed-loop control will have higher accuracy than speed open loop control.Selects which input to use as speed PID feedback in par. 7-00.Torque control (FC 302 only):Torque control is part of the motor control and correct settings of motor parameters arevery important. The accuracy and settling time of the torque control are determined fromFlux w motor feedb (par. 1-01 Motor Control Principle).ï Flux sensorless offers superior performance in all four quadrants at motor frequencies above 10 Hz.ï Flux with encoder feedback offers superior performance in all four quadrants and at all motor speeds.Speed / torque reference:The reference to these controls can either be a single reference or the sum of various references includingrelatively scaled references. The handling of references is explained in detail later in this section.17MG.33.B6.22 - VLT is a registered Danfoss trademark
