FUNCTION CHARACTERISTICS
223
— Overvoltage - 59
Preface
Two operation thresholds, independently adjustable (U>, U>>) with adjustable delay (t
U
>, t
U
>>).
The first one may be programmed with definite or inverse time, while the second threshold operates
with definite time characteristic.
Each threshold may be separately enabled or disabled.
The first threshold trip (U>) may be inhibited by start of the second threshold (U>>).
Operation and settings
The fundamental frequency of a selectable voltages, phase to ground (U
L1
, U
L2
, U
L3
) or phase-to-pha-
se voltages (U
12
, U
23
, U
31
) are employed:
Each of three voltages is compared with the setting values (U>, U>>). The start and trip logic may
be selected OR or AND.
With OR selection, a start is issued when at least one of the three voltages overcomes the adju-
stable threshold (START); after expiry of the associated operate time (t
U
>, t
U
>>) a trip command is
issued; if instead the voltages drops below the threshold, the element is restored.
With AND selection, a start is issued when all the three voltages overcomes the adjustable thre-
shold; after expiry of the associated operate time (t
U
>, t
U
>>) a trip command is issued; if instead the
voltage drops below the threshold, the element is restored.
The first threshold (U>) may be programmed with definite or inverse time according the following
characteristic curve:
t=0.5 t
U
>
inv
/ [(U/U>
inv
) - 1]
Where:
t
: operate time
U>
inv
: threshold setting
t
U>inv
: operate time setting
For the inverse time characteristic, following data applies:
• The operate time setting is referred to an input voltage equal to 1.5 of the pickup value.
• Asymptotic reference value (minimum pickup value): 1.1 U>
inv
• Minimum operate time: 0.1 s
• Range where the equation is valid: 1.1 ≤ U/U>
inv
≤ 4
• If U>
inv
pickup ≥ 0.5 U
n
, the upper limit is 2 U
n
.
The first overvoltage element can be programmed with definite or inverse time characteristic by
setting the U>Curve parameter (
DEFINITE,INVERSE) available inside the Set \ Profile A (or B) \
Overvoltage-59 \ U> Element \ Setpoints menu.
Each element can be enabled or disabled by setting ON or OFF the
U>Enable parameter inside
the Set \ Profile A (or B) \ Overvoltage-59 \ U> Element \ Setpoints menu and/or the State parameter
inside the Set\Profile A (or B) \ Overvoltage-59 \ U>> Element \ Definite time.
The voltage measurement type (Phase-to-phase or phase-to-neutral) and the operating logic (AND
or OR), is adjustable inside the Set \ Profile A (or B) \ Overvoltage-59 \ Common configuration menu
by means the
Utype59parameter; the allowed setting are Uph-ph (phase-to-phase) or Uph-n
(phase-to-neutral).
The corresponding unit are p.u. U
n
for Uph-ph setting and p.u. E
n
for Uph-n setting.
12
L1
L2
23
=|U
L2
-U
L3
31
=|U
L2
-U
L1
|
t-int-F59.ai
U
U>>
t
U
>
t
U
>>
U>
t
General operation time characteristic for the overvoltage elements - 59
TRIP
XMR-D EQUIPMENT MANUAL
Ed. 2.9 - 02/2021
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