A Publisher for Research Motivation........
Volume 3, Issue 11, November 2015
http://www.ipasj.org/IIJEC/IIJEC.htm
ISSN 2321-5984
1
2
3
1
UG student, JSPM, Tathawade, Pune-33
2
Assistant Professor, JSPM, Tathawade, Pune-33
3
Development Engineer, Savita Machine Tools Pvt. Ltd, Nanded gaon, Pune-41
A
BSTRACT
Variable Frequency Drive(VFD) varies frequency of the input power to motor hereby controlling the speed of the motor.AC voltage input is applied to bridge diode rectifiers that produces a dc output which is then given to the inverter section. The inverter section consists of PWM inverters using IGBT’s. PWM signals is the train of pulses with fixed magnitude and frequency and a varying pulse width. The output of the PWM inverter is given to the 3 Phase Induction Motor. VFD converts a fixed frequency, fixed voltage sine wave power to a variable frequency, variable output voltage used to regulate the speed of the induction motor. Most of the Voltage Source Inverters (VSI) uses pulse width modulation technique because the voltage and current waveform at the output is approximately a sine wave. VFD’s predominantly improves the efficiency and the performance of the induction motor. Speed of the motor is controlled with the help of VFD by keeping the Voltage to
Frequency (V/Hz) ratio constant.
Keywords: VFD, PWM inverter, bridge diode rectifiers, voltage to frequency ratio
1.
I
NTRODUCTION
Variable Frequency Drive (VFD), also known as Variable Speed drive, Micro Drive, or AC drive, is an electronic device that varies the frequency and the speed of AC motors as per the requirements of the loads. Speed control of the
AC/DC motor can be achieved by Variable Speed Drive unit(VSD).AC drive usually squirrel cage ac motors are especially used due to its rugged construction, easy installation and its low cost. VFD converts supply voltage and frequency to required voltage and frequency to drive the motor at desired speed.
2.
L ITERATURE S URVEY
A lot of literature is scanned by us and some of the papers in from of review are presented here. [1]S.Takiyar and
B.K.Chauhan delineated paper on Hybrid method for customized control of Induction Motor. A hybrid method using ladder logic diagram and PWM based VFD.VFD controls Induction motors. This system has an adaptive control for flexible operation. The authors have compared speed torque performance and efficiency of PLC based and inverter based VFD.
[2]The monitoring and control of VFD using PLC and SCADA is presented by Rinchen Geongmit Dorjee et al. VFD was controlled using Programmable Logic Controller (PLC) and Supervisory Control And Data Acquisition (SCADA).
The system also provides Human-Machine Interface so that the entire process can be monitored by human operator.[3]Sagar P.Jain and Dr.Sanjay L.Haridas have put forward VFD for conveyor assembly in automated bottling plant. The PLC used is MicroLogix 1400 and the programming software used is RSLOGIX 500. The communication software used is RS LINX 500.
[4] R. CharletPriya has simulated the design of VFD Induction Motor using seven level inverter developed from modified H-bridge. The inverter is used to provide unipolar or bipolar output voltage switching in seven different switching states. Hence the name seven-level inverter. PWM modulation is used to generate the PWM switching signal.
The design is simulated in PROTEUS SIMULINK software and the simulated results are shown.
[5] Energy conservation using variable frequency drive in pumping application by Mr.Ankur P.Desai et al. In this application, VFD’s are used to save pumping energy. Simplified block diagram of VFD has been outlined. VFD torque speed characteristics are expounded precisely with the help of constant torque area and constant horsepower area modes. The PWM scheme is explained with the help of diagram. The comparison of performance of pumping system with and without VFD is shown in the paper. [6] In Interharmonic-Flicker Curves by Thavatchai Tayjasanant et al. A limit for interharmonics is being proposed in this paper by considering the published limits for voltage flicker. Flicker
Curve is the curve of interharmonic magnitude versus interharmonic frequency. Enhancement is to be done with IEC
Volume 3, Issue 11, November 2015 Page 1

A Publisher for Research Motivation........
Volume 3, Issue 11, November 2015
http://www.ipasj.org/IIJEC/IIJEC.htm
ISSN 2321-5984 flicker meter when it dealt with harmonic caused flickers. In this paper a short preview of each referred paper is given.
The relationship between interharmonic and flicker is determined. Generation of interharmonics from Current Source
Inverter (CSI) VFD is demonstrated and illustrated with an example for precise understanding.
[7] Sanjay N. Huse et al . have presented a case study for water supply system to buildings. The throttling and its consequences are the main concerns considered while designing VFD for the system. The throttling effect can be minimized and the extra power consumption can be saved by the application of the VFD as shown in the paper. The use of the VFD drive provides the significant savings in both cost and GHG emissions. The flowchart for automatic control of motor pumps is also shown in the paper. [8] Robert A. Hanna, discussed the harmonics that are generated in the VFDs. Various source of current and voltage harmonics and their effects are discussed. The presence and analysis of harmonics is explained with the help few cases. The author concludes that the order and magnitudes of the harmonics generated are dependent on drive configuration and system impedance.
3.
C
ONCLUSION
VFDs are mainly used for energy conservation and controlling the speed of AC motors. It is observed that V/F control method is most popular method applied in VFDs. The variable speed of the motor results in better control on the processes. Soft starts to the motors reduce the backlash and increase the equipment life, thus making them cost efficient. The VFDs are being widely used in industries for these benefits.
References
[1].
S Takiyar and B. K. Chauhan, “Hybrid Method for Customized Control of Induction Motor”, International Journal of Computer and Electrical Engineering, Vol. 5, No. 4, pp.350-355, August 2013.
[2].
Rinchen Geongmit Dorjee. “Monitoring and Control of a Variable Frequency Drive Using PLC and SCADA”,
International Journal on Recent and Innovation Trends in Computing and Communication, Volume. 2 Issue. 10, pp-3092-3098, October 2014.
[3].
Sagar P. Jain and Dr. Sanjay L. Haridas, “Energy Efficient Automized Botteling Plant Using Plc And Scada With
Speed Variable Conveyor Assembly”, IOSR Journal of Electronics and Communication Engineering, Volume 9,
Issue 1, Ver. II, PP 09-14, Jan. 2014.
[4].
R. CharletPriya, “Variable Frequency Drive Induction Motor in Air Conditioner Using Seven-Level Inverter”,
International Journal of Advanced Research in Electrical, Electronics and Instrumentation Engineering, Vol. 3,
Special Issue 4, pp-12-19, May 2014.
[5].
Mr.Ankur P. Desai, Mr.Rakesh.J.Motiyani, Dr.Ajitsinh R.Chudasama, “Energy Conservation Using Variable
Frequency Drive in Pumping Application”, In proceedings of International Journal Of Engineering Development
And Research, pp 121-126, January 2014.
[6].
Thavatchai Tayjasanant, Wilsun Xu, “Interharmonic-Flicker Curves”, IEEE Transactions On Power Delivery, Vol.
20, No. 2, pp-1017-1024 April 2005
[7].
Sanjay N. Huse, Ravindra D. Kale, Dr. D.R.Mane, Prof. V.P.Dhote, “Use of the VFD to minimize the throttling effect of the Hostel water supply system by the automation of the system”, International Journal of Scientific &
Engineering Research, Volume 6, Issue 2, pp-92-96, February 2015.
[8].
Robert A. Hanna, “Harmonics and technical barriers in Adjustable Speed Drives”, IEEE Transactions on Industry
Applications, Vol. 25, no. 5, pp. 894-900, September/October 1989.
AUTHOR
Krutika Mokashi is currently pursuing B.E. degree in Electronics & Tele-communication Engineering at J.S.P.M’s Rajarshi Shahu College of Engineering under Savitribai Phule Pune university.
Ms. S.V. Mogre received M.E. in Digital System. Currently working as an Assistant Professor in
J.S.P.M’s Rajarshi Shahu College of Engineering with teaching experience of 7 years.
Kaustubh Kulkarni received B.E. in Electronics & Tele-Communication Engineering from Savitribai
Phule Pune University in 2015. Currently working with Savita Machine Tools Pvt. Ltd. As a
Development Engineer.
Volume 3, Issue 11, November 2015 Page 2