A variable frequency drive is a device for Ac motor drive. With the special topology, controls speed and torque by varying the frequency of input power supply.It will control the motor start very smoothly.Vsd can be used in application ranging from small fan, pump applications to larger compressor, convey and so on.
Variable frequency drive is used in a drive system consisting of Ac motor, drive controller and operate interface.Ac motor is usually three phase or single phase asynchronous and synchronous motor. The controller including three parts, a rectifier bridge converter, a direct current link, and a three phase inverter unit. Voltage-source type vfd is the most common in far. The rectifier converter is configured as triple phase six pulse, full wave diode bridge.Dc link consists of capacitors to smooth the Dc output ripple and provides a stiff input to the inverter.The control mode of vfd mostly including V/F, SPWM, SVPWM.
Many fix-ed speed motor load applications connect directly to three phase power supply can save energy by using vfd. As fix-ed loads subject the motor to a high starting torque and current surges that are up to 8-10 times the full-load current. Ac drives could gradually ramp the motor up to the rated speed to lessen the mechanical and electrical stress, reducing the repair cost and larger the life of motor and driven equipment.The current about 1.2 times of the motor rated speed, rapidly lower the inrush current.
Process control and energy conversation are the main reasons for using frequency drives. Such as using in the pump. When adjusted speed drives are used, the pumps operates continuously at a speed that increase as the wet well level increase,which matches the outflow of the average inflow.
Xi’an Noker Electric is committed to providing customers with complete motor starting control solutions, you have any motor starting problems, please feel free to contact us. We will provide you with system solutions.
Post time: Apr-15-2023