Basler BE1-25A Instruction Manual - Introduction
BE1-25A
INTRODUCTION
2
The BE1-25A automatic synchronizer initiates closure
of the generator circuit breaker when voltage magnitude,
slip frequency, and phase difference are within preset
limits. This capability minimizes system transients that
can result from differences in speed, voltage level, or
phase angle at the instant of the breaker closure -
transients that can damage the breaker and generating
system.
The BE1-25A has the ability to operate over a wide
range of slip frequencies. This allows it to be used on
virtually any type of prime mover, from very slow-
responding, high inertia, hydroturbines to fast-respond-
ing gas turbines and diesel engines.
To ensure that the circuit breaker closes when the
proper phase relationship exists between the oncoming
generator and the station bus, the BE1-25A calculates
an advance angle based upon the preset circuit breaker
closing time and the measured slip frequency (F
S
) (See
Figure 1). It delivers the breaker close signal ahead of
system co-incidence so that actual closure of the
breaker contacts occurs when the phase angle between
the generator and the bus voltage is at, or very close to,
zero.
Figure 1 - Slip, advance angle, and breaker closing
time
40°
30°
20°
10°
AD
V
A
N
C
E AN
G
L
E (
D
EG
R
EES
)
CIRCUIT BREAKER CLOSING TIME (SECONDS)
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0
F S
=
0.50 H
z
F S
=
0.30 H
z
F S
=
0.20 H
z
F S
= 0.15 H
z
F S
= 0.1 H
z
FS = 0.005 to 0.01 Hz
FS =
0.05 H
z
Assurance of picking up load upon synchronizing can
be achieved by closing a contact connected to the
GF>BF (generator frequency greater than bus fre-
quency) terminals at the rear of the unit.
Likewise, closing a contact connected to the GV>BV
terminals will ensure that circuit breaker closing will
only occur if the generator voltage is greater than the
bus voltage. This feature is only available if Voltage
Acceptance options are included.
Optional modules may be used to provide correction
signals to the generator for automatic synchronizing.
The system dynamics of hydro-electric facilities
require close control of the speed (frequency) correc-
tion signals. Optional control features are available to
supply correction pulses whose duration is adjustable
or vary in proportion to slip frequency.