![background image](http://html.mh-extra.com/html/abb/relion-615-series/relion-615-series_technical-manual_2395669.webp)
4.5.7.5
Application
Distributed generation, mainly wind and solar farms, are rapidly increasing due to
liberalized markets (deregulation) and the global trend to use more renewable sources of
energy. These farms are directly connected to grids, and due to their large size may
influence the behavior of the grid. These farms are now required to comply with stringent
grid connection requirement, which was previously mandatory only for high capacity
power plants. These requirements include helping grid in maintaining system stability,
reactive power support, transient recovery and voltage-frequency regulation. These
requirements make it necessary for the wind and solar farms to remain in operation in the
event of network disturbances.
Many grid codes now demand that the distributed generation connected to HV grids must
withstand voltage dips to a certain percentage of nominal voltage (down to 0% in some
cases) and for a specific duration. Such requirements are known as Low-Voltage Ride-
Through (LVRT) or Fault-Ride-Through (FRT) and are described by a voltage versus
time characteristics.
Typical LVRT behavior of a distributed generation can be divided into three areas
according to the variation in voltage over time.
•
At the time of system faults, the magnitude of the voltage may dip to
Voltage level 1
for time defined by
Recovery time 1
. The generating unit has to remain connected to
the network during such condition. This boundary defines area A.
•
Area B defines the linear growth recovery voltage level from
Voltage level 1
to
Voltage level 2
in a time period from
Recovery time 1
to
Recovery time 2
.
•
Area C is the zone where voltage stabilizes.
Voltage level 3
is defined to same value as
Voltage level 2
. The system should remain above this voltage in a time period from
Recovery time 2
to
Recovery time 3
.
The system restores to a normal state and function resets when the voltage is equal or
greater than
Voltage level 4
after
Recovery time 4
time period.
When the voltage at the point of common coupling is above the LVRT curve, the
generation unit must remain connected, and must be disconnected only if the voltage takes
values below the curve.
1MAC059074-MB A
Section 4
Protection functions
615 series ANSI
663
Technical Manual
Содержание Relion 615 series
Страница 1: ... RELION PROTECTION AND CONTROL 615 series ANSI Technical Manual ...
Страница 2: ......
Страница 39: ...Section 17 Glossary 1181 Table of contents 615 series ANSI 33 Technical Manual ...
Страница 40: ...34 ...
Страница 64: ...58 ...
Страница 210: ...3 19 4 Settings Section 3 1MAC059074 MB A Basic functions 204 615 series ANSI Technical Manual ...
Страница 216: ...210 ...
Страница 884: ...878 ...
Страница 1038: ...1032 ...
Страница 1136: ...1130 ...
Страница 1172: ...1166 ...
Страница 1180: ...1174 ...
Страница 1186: ...1180 ...
Страница 1192: ...1186 ...
Страница 1193: ...1187 ...
Страница 1194: ......
Страница 1195: ......