Application Scope - Siemens SIPROTEC 4 7VE61 Manual

Introduction

1.2 Application Scope

1.2 Application Scope
The digital paralleling devices 7VE61 and 7VE63 of the SIPROTEC 4 family are multifunctional compact
devices, which may be used for parallel switching systems and generators. Its technical version warrants a
high security during parallel switching. This can be reached by means of the 1
nique in device 7VE61 or the two-channel measurement technique in 7VE63 and a special hardware design.
Additionally, numerous monitoring functions serve as support.
Except for the synchronizing functions, in the devices 7VE61 and 7VE63 are available optional voltages and
frequency functions. Thus, the devices can be used for the protection function and for network decoupling
tasks.
The devices are recommended for the different applications:
7VE61:
•
Synchrocheck monitoring for systems and manual synchronization. In this option a total of 3 synchron-
izers can parallel operate.
•
Parallel switching for systems
•
Systems Disconnection and Automatic Re-synchronization
•
Automatic synchronization of small to medium generators.
7VE63:
•
Operation with increased safety requirements through a two-channel feature
•
Parallel switching for high-voltage and extra high-voltage systems
•
Automatic synchronization of large generators
•
Operation of several synchronizers by a device (up to 8 are possible)
•
Visualization of the condition system through a graphic display and local control.
Synchronization Functions
The devices recognize automatically the operating conditions and react depending on the pre-settings.
•
In the operation mode "Synchrocheck" will be checked the validity of a restart according to different
considerations.
•
In the operation mode "Switching Synchronous Systems" will be determined the frequency difference
with high accuracy. The connection will take place if the difference frequency is for a long time near to 0.
•
If asynchronous conditions are available as in the case of synchronization for generators and systems,
thus the speed can bring near automatically at the system frequency and the generator voltage at the
system voltage. A considering factor of the circuit breaker closing time is that the generator will be
switched to a point of synchronism.
•
A very high security for recognition of a de-energized line or bus is achieved via the multi-voltage circuit
and the multiple inquiries of the voltage. As a result, a connection of the network is trouble-free reestab-
lished.
Protection and Automation Functions
Except for the synchronizing functions, in the devices 7VE61 and 7VE63 are available optional voltages and
frequency functions. Thus, the devices can be used for the protection function and for network decoupling
tasks.
The devices include the following basic functions:
•
Overvoltage protection U>
•
Undervoltage protection U<
•
Overfrequency f>
•
Underfrequency protection f<
•
Rate-of-frequency df/dt>; –df/dt<
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1 / channel measurement tech-
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SIPROTEC 4, 7VE61 and 7VE63, Manual
C53000-G1176-C163-3, Edition 10.2017