4. Application
RET620 has been designed to be the main protection for two-
winding power transformers and power generator-transformer
blocks. RET620 also includes an optional voltage regulation
function.
RET620 can be used with either single- or double-busbar
configurations with either one or two breakers, and with
numerous switching device configurations. It supports a
substantial number of both manually and motor-operated
disconnectors and earthing switches, and it is capable of
running large configurations. The number of controllable
devices depends on the number of inputs and outputs left
free from other application needs. The number of available I/
Os can be increased with the RIO600 Remote I/O device.
RET620 offers extensive possibilities to tailor the
configurations to end application requirements. The tool suite
for all Relion IEDs is Protection and control IED manager
PCM600, which contains all the necessary tools for
configuring the device, including functionality,
parameterization, the HMI and communication.
RET620 provides both transformer protection and control and
voltage regulator control at the same time. Voltage regulation
capability is targeted for automatic and manual voltage
regulation of power transformers equipped with a motor-
driven on-load tap changer. An automatic voltage regulation
can be applied both with a single transformer as well as with
up to four transformers running in parallel. The IED also
supports both traditional resistor connection-based and
numerically calculated high-impedance earth-fault protection.
To further improve the arc fault protection and minimize the
effects of an arc fault, the 620 series IEDs ordered with the
arc fault protection option can be equipped with an I/O card
featuring high-speed outputs.
Io HV
Io LV
3I HV
3I LV
3U
U
12
U
12b
Uo
RTD
RET620
Example conf.
ANSI
IEC
N
25
50L/50NL
50P/51P
51P/51N
67/67N
84M
87T
90V
MAP
49T
87NH
87NL
87NH
87NL
SYNC
ARC
3I>>>
3I/Io
3I
→
/Io
→
TPOSM
3dI>T
COLTC
MAP
3Ith>T
dIoHi>
dIoLo>
dIoHi>
dIoLo>
HV
side
LV
side
GUID-A758C254-7907-4965-9389-113BCBD77B75 V1 EN
Figure 2.
The protection of HV/MV, or an MV/MV transformer with low-impedance EF on both sides of trafo
Transformer Protection and Control
1MRS757846 A
RET620
Product version: 2.0
10
ABB