Electronics & Communication
Technologies
-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
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
