Complete Automation of the Power Plants
Introduction
Automatic voltage regulator device controls the excitation of the ac generators for maintaining constant voltage profile at the terminals, under varying voltage conditions. The maintenance of the constant voltage profile is important as the consumer equipment efficiency is maximum whereas the wear and tear of the equipment at the rated voltage is minimal. In the existing alternator sets driven by petrol or diesel engines, the voltage drop is from 5% to 10% approx. from no load to full load with the conventional excitation control systems.
Salient features
The unit consists of a single phase transformer whose secondary rectified voltage rating selected is a few volts higher than the rated excitation voltage of the alternator at the rated level of loadings. The current rating of the transformer selected is the same as of the excitation windings of the alternator. A full wave rectified control bridge supplies the controlled dc power using SCRs. The firing angle of SCRs is adjusted so that the output voltage remains at a constant level at different levels of loading. The firing angle control unit is an electronic circuit. The function of the electronic circuit is to compare the terminal voltage with a reference voltage and generate an error signal. The amplified error signal is used to shift the synchronised firing pulses appropriately to get the desired results. A small dc supply is required for the operation of the electronic circuit and can be built on the PCB. The ratings of the transformer and of the SCRs are dependent upon the alternator excitation winding specifications.
Prospective Users
Power plants
Type of Technology
Model
Developed by
Dr. S T Bhatti
Department
Center for Energy Studies
For further information please contact
Managing Director
Foundation for Innovation and Technology Transfer (FITT)
Indian Institute of Technology, Delhi
Hauz Khas, New Delhi-110016, INDIA
Tel : 91-011-26597167, 26857762, 26581013, 26597153
Fax : 91-011-26851169
E-mail : drkdpn@gmail.com
