Environmental Engineering Reference
In-Depth Information
Start up
When starting is commanded the turbine runs up on no-load, driven by the wind,
until the speed has reached a suitable waiting state.
Waiting
In waiting state all components are in stand-bye. The electrical system is not con-
nected
to
the
POC.
Conditions
of
switch-off
on
error
and
shut
down
are
checked.
Run-up
In case of sufficient wind velocity the speed is brought to a suitable value, where
after checking of generator and converter state, the electrical system is connected to
the grid.
Load run
In part-load operation the system supplies power dependent on speed, usually under
control on the electrical side. When reaching full load the pitch control becomes ac-
tive. Overload operation within a limited interval is possible, as long as the thermal
state of the system components permits.
Retardation
Retardation to a waiting state must be possible from any load or run-up operation.
Blades can be brought in feathering direction, and electrical system can be discon-
nected.
Shut-down
Bringing the system to standstill must be possible from any operational state.
Disconnect on fault
Disconnection under fault condition is performed as a shut-down, but may be using
steeper set-value ramps.
Disconnect on emergency
An emergency shut-down can be tripped either by the operation management or by
the safety-system. Braking systems are used to decelerate as fast as possible. Any
new start-up requires clearance by operator.
6.4.3 Grid Fault Reaction
In case of short-circuit a disconnection under fault should be made to prevent detri-
mental effects of the large currents on the electrical system. On the other hand the
loss of load gives rise to turbine acceleration which must be limited by action of the
pitch control. Similarly, when a short break happens in the grid, the normal action
is to disconnect the system.
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