VLT ® 2000 Series Description of parameters I I 119 FF factor (FEED FWD FACTR) Value: 0 - 500% ✭ 100% 121 Proportional gain (PROPRT /L GAIN) Value: 0.01 - 10.00 ✭ 0.01 Function: This parameter is used in connection with a PI controller. The FF factor sends a large or small part of the reference signal around the PI controller so that the PI controller only affects part of the control signal. Any change of the setpoint will therefore directly affect the motor speed. The FF factor gives high dynamics at changes of the setpoint and less overswing. Function: The proportional gain indicates how many times the deviation (between feedback signal and setpoint) must be amplified. Description:
Fast regulation is obtained when amplification is high. The value can be too high, and then the process may become unstable. Description: You can choose the required percentage value in the interval f MIN - f MAX. Choose a value above 100% if the setpoint variations are only minor. I 122 Integral time (INTEGRAL TIME) Value: 0.01 - 7200 sec. ✭ (OFF) Function: The integral time determines how long the PI control- ler takes to regulate the signal. The integral time will delay/dampen the signal. I 120 Controller range (CONTRL RANGE) Value: 0 - ✭ 100% Function: The controller range (band width) limits the output from the PI controller as a percentage of f MAX. Description:
Fast regulation is obtained when the integral time is short. The value can be too short, making the process unstable. When the integral time is long regulation is slow. “Off” means that the function is not active. Description: You can choose a percentage value of f MAX . If the controller range is reduced the speed variations will be lower during adjustment. I 125 FB-factor (FEEDBACK SCALE) Value: 0 - 500% ✭ 100% Warning: The output frequency is limited by 0.9 x f MIN and 1.1 x f MAX no matter what the band width setting is. The controller can therefore be active without affecting the output frequency. When the PI controller is active the output frequency can exceed f MAX by 10%. Function:
The FB factor is used if the transmitter cannot be selected optimally to the scaling range of the input signals. Description: This parameter is only used if the feedback signal in parameter 114 is not of a suitable level. If you choose 100% the feedback signal is not changed. ✭ = Factory setting. Text in ( ) = Display text. The figures in [ ] are used in bus communication. 66 MG.20.B6.02 – VLT is a registered Danfoss trademark