Westinghouse HKB Series Instructions Manual

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The high-speed
mission lines is
good system
protection is provided by th� method known as
differential
the two ends
termine whether
section or external
This assures simultaneous
breakers, which is desirable from the
points of stability,
quick reclosing,
ment. For many lines, carrier relaying is the
most practical
paring the conditions
line.
HKB
The type
uses a single
only )
at each
section to detect and determine the
of faults. It compares
channel the phase angle between
the two ends of a line section
whether
an internal or external fault exists.
A positive, negative and
rent filter is used
voltage from the
and this voltage is utilized to energize fault
detectors and to
alternate half cycle
frequency ) of carrier energy from both ends of
the line section.
The carrier signal from each end is received
at the opposite
rectified, and
sition of the
sequence filter.
in the grid circuit of a
NEW INFORMATION
O P E R
INSTRUCTIONS
TYPE HKB CARRIER BELAYING
INTRODUCTION
clearing of faults on trans­
recognized as necessary for
operation. The best
relaying in which conditions at
of the line are compared to de­
the fault is in
to the protected "' zone.
tripping
continuity of
and minimum damage to equip­
and reliable medium
at the two ends of the
system of carrier protection
( on current
relay
operating
end of the transmission line
a
over carrier
currents
to
zero sequence cur­
to obtain a single-phase
three-phase line currents,
control the transmission of
( at the
blocks
end of the line where it is
compared with the phase po­
output voltage of
This compRrison takes
vacu�m tube which is
A T O N
so biased
there is no filter or carrier
control grid.
carrier voltages is such that no current flows
overall
in the vacuum
external
the line �urrents
two ends.
the line
rents at the two ends or the line
phase, plate
of the
half-cycles
stand­
This plate current flows through a transformer
service,
primary winding, and the a-c voltage developed
on the secondary
supplied
for com­
trip circuit.
secondary is sufficient to trip
an internal fault.
vides simultaneous
line section for
tings of the relay.
on line current
location
tripping on power swing
pilot
conditions
at
appear to the relays as "·n external fault.
determine
tripping is desired on
condition, auxiliary
this purpose.
fed from one end only, tripping will occur
the terminal
flowing into the line section.
COMPONENTS OF COMPLETE
power
An outline
terminal
follows:
One type HKB
l.
the local sequence
place start the transmlssion
control the operating element
O F S C H
that no plate current
voltage on its
The polarity of the filter and
tube plate circuit
to the protected line
are exactly in phase at the
For an internal fault with the cur­
current will flow
of the line current frequency.
side is rectified
to a relay whose contact is in the
The voltage in the
This arrangement thus pro­
tripping over the entire
all faults within the
As this system
only, it is not
or out-of-synchronism
since the circulating
an out-of-synchronism
relays must be added for
For an internal fault on a line
through which fault current is
EQUIPMENT
of the equipment used
of a transmission line section is as
relay which
filter, fault detectors
of
EFFECTIVE 7-47
I. L. 41-600.3
E M E
flows when
for a fault
section when
180°
out-of­
on alternate
and
transformer
the relay for
set­
operates
sub j ect
to
currents
If
at
at each
includes the
to
carrier and
( tripping