Siemens 6MD85 Manual page 369

Stage Type
Synchronous/asynchronous stage
Configuration of the Voltages V1 (Reference Side) and V2
The voltages V1 and V2 are established via the connection of the measuring points to the interface of the
function groups (refer to chapter
interface Voltage is the reference side 1 with the reference voltage V1. The measuring point connected to the
interface Sync. voltage is the side 2 with V2. The definition of the Delta parameters that can be derived from
this is also described in chapter
Parameter: Min. operating limit Vmin, Max. operat. limit Vmax
•
Recommended setting value (_:5071:101) Min. operating limit Vmin = 90 V
•
Recommended setting value (_:5071:102) Max. operat. limit Vmax = 110 V
The values define the voltage operating range of the synchronization stage. A normal setting is approx. ±10 %
of the rated voltage.
NOTE
i
i
All voltages connected according to the parameterized measuring-point connection type are subjected to
the appropriate Vmin/Vmax test. Therefore, connected phase-to-ground voltages are multiplied by √3 as
the threshold values with reference to the rated voltage (phase-to-phase voltage) must be set.
SIPROTEC 5, High-Voltage Bay Controller, Manual
C53000-G5040-C015-9, Edition 11.2017
Application
Select this type of stage if it is necessary to differentiate between
synchronous and asynchronous systems, depending on the switch posi-
tion.
If galvanically coupled systems are switched in parallel, synchronous
systems are present. A typical characteristic for synchronous systems is
equality of frequency (Δf ≈ 0). In this state, the conditions Δα and ΔV
are checked.
If the systems are galvanically isolated, asynchronous systems can be
present. At the same time, compliance with the voltage difference ΔV
and frequency difference Δf conditions is checked. The time of the
direct close command is calculated taking into account the angle differ-
ence Δα and the closing time of the circuit breaker. The time of the
direct close command is calculated so that the voltages are equal at the
moment of pole contact of the circuit breaker (ΔV ≈ 0, Δα ≈ 0).
6.4.3 Connection and Definition). The measuring point connected to the
6.4.3 Connection and Definition.
Control Functions
6.4 Synchronization Function
369