Commissioning The Frequency-Time Monitoring - Siemens SINAMICS S120 System Manual

Notes
● The times in p5553[x] must be entered in ascending order.
For example, for simply parameterizing steps, the same consecutive times are
permissible.
● The time in p5553[9] defines the maximum duration of a fault ride through and must
therefore always be defined.
Fault F6851 is output if the voltage does not return to the tolerance band within this time.
If not all of the interpolation points are required, then the interpolation points before point
p5553[9] can be assigned the same voltage values.
7.8.3

Commissioning the frequency-time monitoring

Activating
The frequency-time monitoring is activated using p5540.7 = 1. The simple threshold
monitoring that is otherwise active is deactivated using p5544.
Response when grid faults occur
● The start of a grid fault is identified as soon as the frequency lies above threshold
p5555[0] or below threshold p5555[1].
● The grid fault has ended as soon as the frequency lies below threshold (p5555[0] -
p5555[2]) or above threshold (p5555[1] + p5555[2]).
● Both frequency characteristics are monitored during a grid fault.
– When the HFRT curve is exceeded (frequency increases), then the system is shut
– When the LFRT curve is fallen below (frequency dip), then the system is shut down
● If the frequency does not return within the parameterized fault duration p5556[9] or
p5558[9] then the system is shut down and fault F6851 is output. Taking into account the
selected hysteresis p5555[2], the lower limit of the tolerance range is (p5555[0] -
p5555[2]), the upper threshold is obtained according to the sum p5555[1] + p5555[2].
Grid infeed
System Manual, 04/2015, A5E03347436A
down without delay and fault F6851 is output.
without delay and fault F6851 is output.
7.8 Commissioning of dynamic grid support
Commissioning
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