What is the difference between open loop and closed loop VFD?
A. Open loop VFD uses sensorless vector control, while closed loop VFD uses sensor-based vector control
B. Open loop VFD uses sensor-based vector control, while closed loop VFD uses sensorless vector control
C. Open loop VFD uses scalar control, while closed loop VFD uses vector control
D. Open loop VFD uses vector control, while closed loop VFD uses scalar control
Answer:A
What is the difference between open loop and closed loop VFD?
A. Open loop VFD uses sensorless vector control, while closed loop VFD uses sensor-based vector control B. Open loop VFD uses sensor-based vector control, while closed loop VFD uses sensorless vector control C. Open loop VFD uses scalar control, while closed loop VFD uses vector control D. Open loop VFD uses vector control, while closed loop VFD uses scalar control
Explanation: In an open loop VFD, the control algorithm does not use any feedback from the motor, and instead relies on the VFD’s internal model of the motor to control the speed and torque. This is known as sensorless vector control. In a closed loop VFD, the control algorithm uses feedback from sensors on the motor to adjust the control signals sent to the motor. This is known as sensor-based vector control. Closed-loop VFDs are generally more precise and efficient than open-loop.