V/F Control VFD
Variable frequency drive (VFD), the V/F control method used in large part determines a motor’s efficiency and performance in an application. Once engineers and designers understand the advantages, disadvantages of each control method and given specifications, the choice of the right one is used for any application will become simple.
VFD control methods focuses on V/F control. There are four primary types of motor control methods for induction motors connected to VFDs: V/f (volts-per-hertz), V/f with encoder, open-loop vector, and closed-loop vector. These methods all use pulse-width modulation (PWM), a technique that different width of a fixed signal by modulating pulse duration to create a variable analog signal.
Different V/f modes allow VFD to control several different applications while maintaining the best performance. A constant torque mode is a straight line that results in a constant V/f ratio to provide a constant motor torque across the entire speed range. The V/F control mode has a lower voltages to prevent the motor from being saturation at lower speeds . V/F mode defines a voltage frequency ratio for the motor and frequency conversion can only have a V/F mode programming. V/F mode or curve, determines what is output voltage to the motor based on a given speed reference frequency.
V/F Control VVVF AC Drive
Wide range of application: It is suitable for the V/F control of asynchronous motor and synchronous motor.
Excellent property: SVC, start torque and multiple brake torque model are without braking resistor can achieve rapid flux braking mode.
Special AC Drive for Ball Mill
Soft start: starting current faster 3-5 times than normal drive.
Speed control: PLC grind time, milling time and automatic stop.
Item: AC-DC-AC AC drive
High Performance Universal VFD
Advanced Vector Control Algorithm: Vector mode 0 control.
Overload capacity: Type G：150% rated current 60/s Type P：110% rated current 60/s.
Multi speed control：Simple PLC, PID module and pulse counting control.
Input Voltage: 220Va
High/Low Frequency Integration Frequency Inverter
Analog input: One analog input terminal AI1, support 0~10V voltage or 0 ~ 20mA current input.
Analog output: One analog output terminal AO, support 0~10V voltage or 0 ~ 20mA current output.
AC Drive for Construction Elevator
Overload Design: Strong overload capability, 150% rate current 60/s, 180% rate current 3/s.
Optimized speed loop: The speed loop applies variable ratio and Integral gain control.
Forced deceleration process: prevent shock in up/down running;