ABB REU615, Product Manual, Page: 8 / 60

GUID-DCA293F5-58D2-4CE8-9602-842A6498F9ED V2 EN
Figure 2. Protection function overview of standard configuration B
4. Application
Standard configuration A
The A configuration of REU615 is intended to be
used in medium voltage switchgear, supplied with
a dedicated voltage measurement cubicle. The A
configuration of REU615 provides busbar
overvoltage and undervoltage supervision,
network residual overvoltage supervision and
frequency supervision. REU615 offers the
functionality needed to provide load shedding or
generation rejection to enhance network stability.
In generator and motor applications REU615
provides supplementary protection by detecting
any deviation from the permitted frequency and
voltage values. An integrated synchro-check
function ensures a synchronized connection of
the equipment into the network. In distribution
networks containing distributed power generation
REU615 can be used for loss-of-mains (LOM)
protection for single power generating units.
Standard configuration B
The B configuration of REU615 including voltage
regulation is intended for automatic and manual
voltage regulation of power transformers
equipped with motor driven on-load tap-
changers. In small substations with a single
power transformer, REU615 can be used for load-
side voltage regulation. For substations with two
or more power transformers operating in parallel
three alternative voltage regulation principles are
available, i.e. the master/follower principle, the
negative reactance principle (NRP) and the
minimizing circulating current (MCC) principle.
Voltage Protection and Control 1MRS757058 D
REU615
Product version: 4.0
8 ABB