68 Frequency Converters Basic features: • Voltage vector control in relation to steady-state characteristic values (static) Typical shaft output: • Speed setting range 1:100 • Speed accuracy (steady state) ± 0.5% of rated frequency • Acceleration torque 80-130% of rated torque • Speed change response time 50-300 ms • Torque change response time 20-50 ms 2.7.3.2 Space Vector (Closed Loop) For the closed loop space vector method, an encoder or other device to detect the motor speed or position is required. It is the control software, the resolution on the feedback input and encoder’s resolution that determines the accuracy of motor control. Typical shaft output: • Speed setting range 1 :
1000 – 10,000 • Speed accuracy (steady state) Depends on resolution of feedback component used • Acceleration torque 80 – 130% of rated torque • Speed change response time 50 – 300 ms • Torque change response time 20 – 50 ms