variable frequency drive (vfd) installation
DESCRIPTION
VFD need VFD operation VFD installation VFD- Variable Frequency DriveTRANSCRIPT
Study of VFD Installations
Basics Construction of VFD Inside the VFD there are 4 major sections:
rectifier (AC/DC Converter), intermediate circuit (DC Link), inverter (DC/AC Converter) and control/regulation (for interface)
Working of VFD The operation of the drive is as follows :
Power first goes into the rectifier, where the 3-phase AC is converted into a rippling DC voltage. The intermediate circuits then smoothes and holds the DC Voltage at a constant level or energy source for the inverter. The last section, the inverter, uses the DC voltage to pulse the motor with varying levels of voltage and current depending upon the control circuit.
The control section uses the frequency, voltage and phase angle to control the inverter.
Function of VFDVFD is a system for controlling the rotational speed of
a motor by controlling the frequency of the electrical power supplied to the motor
Variable speed drives gradually ramp the motor up to operating speed to lessen mechanical and electrical stress, reducing maintenance and repair costs, and extending the life of the motor and the driven equipment
Variable-frequency motors on fans save energy by allowing the volume of air moved to match the system demand. By using VFDs the system can maintain a constant level or pressure without continuously cycling the pump or fan on and off. This allows for a better system control of a level or pressure, instead of cycling between a wide differential
How to analyze the necessity for VFD at a location
We check for the pump valves that are throttledIf the valve is 30-40 % throttle (closed), then it
indicates that flow required is lessIn such a case VFD can be installed, the valve
can be opened fully and fluid’s speed and flow can be controlled
For example : Back water pump 2 at PM-1, was running at 1400 rpm taking 22 kW before installation of VFD. But after VFD installation, it consumes 12 kW while operating at 1100 rpm.
VFDs in Drive Room
VFD SHIFTING WORK IN PROGRESS VFD IN LINE
Wiring Diagram of Fan Pump Motor
VFD in Drive Room
How VFD works at these locations
VFDs are installed at Fan Pump motors.Fan pump motor responsible for providing stock to
the Head BoxHead Box requires a control of either head or level Control of a level or pressure in Head Box is done
by VFDA reference signal is fed to the VFD and using a
comparator, an error signal is generated based on the deviation of current value from the reference value. The controller in the VFD, then, increases/decreases the speed based on the signals generated
4-20 mA
IP- Current to Pressure Converter
SP- Set Point
PV- Process Value
PCV- Pneumatic Control Valve
LIC- Level Indicating Controller
VFD- Variable Frequency Drive
LT- Level Transmitter
PT- Pressure Transmitter
0.2 To 1 kg/cm2Air Supply 1.4 kg/cm2
Fan Pump
VFDVFD
Head box
IP
PTPT
PIC
LTLT
LIC
LP
HP
Inlet Pulp
PCV
Air DrainSP
4-20 mA
PV
Air from Air Receiver
Head Box Pressure and Level Control
Tender EndDrive End
Major Considerations while installing a VFD
Motor SpecificationsVFD SpecificationsVFD input/output currentCable SizeStarting parameters
Motor name plateReference speedOverload current settingOperating option
(keypad/remote)V/f ratio control
Conclusive advantages of using a VFD
Energy SavingsBetter Process ControlReduced MaintenanceHigher System
EfficiencyRemote Mounting
Thank You