AC Variable Frequency Inverter Drives VFD for Screw Feeder 400V
Screw feeders are used in various industries for the metering of
material into a production process. Screw feeder design closely
resembles that of a screw conveyor, but unlike a screw conveyor, a
screw feeder is required to be very precise and accurate. The screw
in a screw feeder is completely filled with material, compared to a
screw conveyor which is typically 40-50% filled. That is part of
the reason the material is accurately discharged when the feeder
screw is rotating at a controlled rate.
Application Challenges
· Fast Response
Capable of accurately regulating material feed.
· Load Detection
Capable of detecting an overload or no material in the screw
situation.
· Speed Range
Be able to provide the required amount of torque throughout the
speed range.
· Trip-less Operation
The product must be capable of continuing to operate after a
momentary power loss or a fault.
Features of G7 matching feeder application
Features | Benefits |
Open Loop and Closed Loop Flux Vector Motor Control | Excellent speed stability and low speed torque production is
possible due to Flux Vector Control technology. |
Overtorque and Undertorque Detection | Both the Overtorque and the Undertorque Detection functions can
sense if there is an overloaded feeder or lack of material. |
PID | Accurate and quick response control of material into the production
process |
Auto-Restart after momentary power loss. | Feeders can quickly restart after fault or momentary power loss. |
Power loss Ride-Through | The material feed is not interrupted during brief power loss. |
Torque Limit | Use of Torque Limit can prevent screw or gear damage due to
excessive torque from foreign material in the load. |
Power range of G7 VFD
Voltage: 400VAC (380VAC – 460VAC)
Power: 22kw/30HP – 1000kw/1250HP
Specification of G7 VFD
Item | Specification |
Input frequency | 50/60Hz |
Output frequency | 0-400Hz |
Overload current | 150% rated current 1min. |
Control mode | Close-loop vector control, sensor-less vector control, V/F control |
Starting torque | 150% 1hz (with PG 0hz) |
Control precision | ±0.2% (With PG ±0.02%) |
Torque precision | ±5% |
Setting frequency resolution | Digital command 0.01hz; analog command 0.03hz/60hz |
Output frequency resolution | 0.01Hz |
Frequency setting signal | -10V~+10V；0~+10V(20kΩ)；4~20mA |
Protection function | Over voltage, under voltage, over load, relay, overheat speed
stall, grounding, instant power cut compensation( within 2 sec for
operation mode. Continue to operate after the power is available),
Charging protection( not to display when the dc voltage of main
circuit is less than 50v) |
Enclosure | IP20 |
Cooling mode | forced air cooling |
Vibration | Less than 0.2g for 20hz |
Ambient temperature / Humidity | -10 Degrees~+40 Degrees / 20~90%Rh (no condensation) |
Tips:
A variable-frequency drive (VFD) is a system for controlling the
rotational speed of an alternating current (AC) electric motor by
controlling the frequency of the electrical power supplied to the
motor. A variable frequency drive is a specific type of
adjustable-speed drive. Variable-frequency drives are also known as
adjustable-frequency drives (AFD), variable-speed drives (VSD), AC
drives, microdrives or inverter drives. Since the voltage is varied
along with frequency, these are sometimes also called VVVF
(variable voltage variable frequency) drives.
