ABB PVS800 Handbuch Seite 8

4
Grid monitoring for voltage and frequency
The PVS800 can monitor grid conditions (voltage and frequency) with internal measurements or with
an external grid monitoring device (usually a grid monitoring relay). Depending on the installation
country, an external third party -certified relay may be needed.
Grid monitoring relay (+Q969/+Q974)
An output of the grid monitoring relay (option +Q969/+Q974) is signal that informs whether the grid is
OK. The grid monitoring signal is connected to the RDIO-01 module installed on RDCU A41. See the
hardware manual for connection details. A usage mode of the external grid monitoring can be
selected from parameter
Internal grid monitoring
The internal grid monitoring is based on three-phase voltage measurements via a NAMU
measurement board. A positive sequence of the grid voltage
frequency (02.18 GRID
compared against protection limits to see if the grid is OK. The internal grid monitoring has three
operation modes: alarm (the inverter continues to run with a grid monitoring alarm), fault (the inverter
stops with a grid monitoring fault) and none (the internal grid monitoring is disabled).
The internal grid monitoring has two adjustable settings for under voltage, over voltage, under
frequency and over frequency. Each of these settings has its own adjustable time delay (ie, how long
time the grid must be in an abnormal condition before the inverter reacts). Settings for the internal
grid monitoring can be found from parameter group
Settings
•
Parameters 39.06 GRIDMON SUPV
•
Parameter group
Diagnostics
•
Signals 01.11 MAINS
•
Alarms AC OVERVOLT
UNDERFREQ (31A3)
•
Faults AC OVERVOLT
UNDERFREQ (3142)
Update notice
39.06 GRIDMON SUPV
FREQUENCY) are calculated from measurements. These values are
MODE,
44 GRID MONITORING
VOLTAGE, 02.18 GRID FREQUENCY
(31A0), AC UNDERVOLT
(3110), AC UNDERVOLT
MODE.
(01.11 MAINS
44 GRID MONITORING.
39.07 GRIDMON RESTR DLY
(31A1), AC OVERFREQ
(3120), AC OVERFREQ
VOLTAGE) and a grid
(31A2), AC
(3141), AC