General Description - Leroy-Somer Nidec R180 Installation And Maintenance Manual

Electric Power Generation

1 - GENERAL DESCRIPTION

The R180 is a fully solid- state automatic
voltage regulator (AVR) which is used for
excitation of a brushless alternator powered
by a Permanent- Magnet (PMG) exciter or
by auxiliary windings.
The alternator voltage between phases V- W
is sampled, processed and converted to a
direct current value. This signal is compared
to the reference value which is internally
generated depending upon the voltage
setting. The comparison is made by a PID
controller, which controls the alternator
excitation. The power circuit uses a pulse
width modulated (PWM) IGBT circuit to
adjust the field current, which gives a good
dynamic/transient response.
It takes a 1 and 5A signal from a droop
current transformer in U phase to give a
voltage droop which allows the alternator to
operate in parallel.
The R180 has an accessory input, which
can be used as a remote potentiometer
terminal when connected to a 1 KΩ
potentiometer or takes ± 4.5V DC in order to
change the terminal voltage.
It has an under frequency voltage roll- off
function to prevent alternator overfluxing in
the event of underspeed operation. The
AVR has a potentiometer for setting the
knee- point for under frequency roll- off and
a 50Hz/60Hz selection jumper. This jumper
makes it easy to select the AVR frequency
for a 50Hz/60Hz alternator.
4
Installation and maintenance
R180
AVR
The AVR output is limited to 6A. This limiter
is delayed type so that it does not interfere
with field forcing. In the event of loss of the
sensing input, the AVR provides 9A DC
excitation current for 5 seconds and
reduces the excitation current.
The R180 is triggered from the alternator
remanent voltage.
5599 en - 2020.07 / f