Close Loop Vector Variable Speed Frequency Inverter

Closed-loop vector control uses a vector algorithm to determine output voltage, similar to the open-loop control. The difference of the key is that closed-loop vector uses an encoder. Encoder feedback, paired with the vector control, means 100% of the motor’s rated torque is available at 0 rpm. This is a selling point for apps required to hold a load without moving, such as elevators, textile, hoists, crane, cables, ceramics and building automation.

Encoder feedback allows for speed responses over 50 Hz and speed control ranges of 1:1500, the highest of all the control methods. Closed-loop control can also run a motor in torque-control mode. Torque control lets the VFD control motor torque rather than motor speed. This is needed in any application where torque is more important than speed. Winders, rewinders, capping, and web applications are good examples of where torque control is used.

SD300 Series close loop vector variable speed frequency inverterfeatures and functions:

 Closed-loop vector support multiple encoders: Differential encoder, Open collector encoder, UVW encoder, Resolver encoder.

1.  Multi-motor switch, Dual-motor switch enables two separate motors, free switching in the independent control mode.

2.  Virtual IO function. It can set 5 groups virtual DI/DO，virtual DI terminal state can be directly given by the function code or bind the corresponding virtual DO function. Implement AI1 beyond the upper and lower limit frequency and AC Drive suggests fault Err 27

3. Motor overheating protection: selec input and output expansion card, analog input AI3 can accept motor temperature sensor input (PT100, PT1000),when the motor temperature exceeds the warning value, the AC Drive output pulse signal

suggest overheating, when the motor temperature is higher than the overheating protection value, the AC Drive fault output will protect the motor properly.

4. Flexible and practical analog input / output ports

Each analog input (AI1 ~ AI3) can be set separately four points curve and flexible.  AI1 ~ AI3 enable factory calibration or user-site calibration of linear curve, after correction accuracy arrive 20mV. AO enable factory calibration or user-site calibration curve linear zero drift and gain, after correction accuracy arrive 20mV.  AI1 ~ AI3 can be used as DI. AI3 is isolate input port, it can be used as PT100 , PT1000 or 0 + 10 v input port.