Historical data: where the data source is
BaxEnergy ESP Historical Database, which
contains all the aggregated data coming from the
power plants (at five or ten minutes, depending
on the plant technology).
The Alarms Server is able to monitor parts of a
process that may require operator attention when
defined threshold are reached, e.g. safety limits of
equipment, event detection, abnormal situation and
similar. It also can be used to collect and record
alarms for audits or used in correlation with other
historical data.
Once events are generated, they can be sent to an
Alarm Client, which can be integrated in other
applications (in this case inside a Sentinel agent
called Alarms Server Agent), and these events are
automatically stored into an Alarms History database.
Once defined, the alarms in the system are
automatically generated, based on the operating
conditions and actions performed in the process plant,
so they provide advisory information to help
operators focus on important alarm information and
take correct, quick actions.
3.3 Alarms Configurator
The Alarms Server is a Windows Service that reads
from a configuration module named Alarms
Configurator. Thanks to this module, the end-user
can edit the configuration of the alarms. The Alarms
Configurator is a desktop application which is
responsible of the real-time data configuration and
alarms definition. Alarms can be created and
configured in the Alarm tab located in the right panel
of the window. The main elements of this tab are:
• Alarm Groups, represent common alarms or alarm
grouped by RES technology (e.g. wind,
photovoltaic, or based on user defined criteria), a
set of alarms that shares the same execution
settings;
• Areas, can be refer to specific alarms categories
(as environmental, measurements, status);
• Symbols, items created in order to configure
alarms for particular groups of devices. A sort of
devices subset, which replicates the rule of an
alarm over a set of multiple devices.
In order to specify a value for a certain Sentinel
host property you have to set a field of the Alarms
Configurator called condition, which represents the
scalar value that will be monitored. This one
represents a generic expression, which make use of
IronPython, an open-source implementation of the
Python programming language which is tightly
integrated with the .NET framework in order to use
Python code easily (Ironpython, 2019), and a specific
syntax to evaluate the input string and if it’s an
historical alarm this one will be stored in a database.
3.4 Creating New Alarm Sentinel Hosts
In order to create a Sentinel host property alarm, first
you have to create an Alarm Group, then the
following steps can be carried out:
• Specify Alarm name, e.g.
“WindowsServicesAlarm”;
• Check if this alarm is Historical or not
• Check if this alarm is Active or not
• Insert the condition (syntax is shown below)
• Chose the Alarm type
• Additionally, you can specify other properties.
The condition syntax is expressed as:
{SentinelServer#hostProject.hostName |
hostProperty}
It is also possible to control more than one property
associated to the same host by using and/or operators.
The current syntax does not allow to specify more
than one host in a single alarm because you have to
specify also the Alarm identifier which represents the
name of a single host.
Considering Alarm types, which indicates the
type of condition that triggers the alarm, the following
values can be distinguished:
Hi, HiHi: the alarm triggers if the value in the
condition field is over a selected threshold. Hi
and HiHi represent two different levels of
severity.
Low, LowLow: the alarm triggers if the value in
the condition field is under a selected threshold.
Low and LowLow represent two different levels
of severity.
Digital: the alarm triggers if the value in the
condition field is true (in this case you don’t have
to insert a threshold).
User Input: the status of the alarm is set by an
external process.
Rate of Change (RoC) Analog: the alarm triggers
if the number of changes of condition field (ΔV)
exceeded the limit in a given time frame (ΔT).
Sequence Digital: the script that is called by the
condition field has the responsibility to manage
the status transitions of the alarm, through the
property “alarmState”. It is also possible to store
variable to maintain the status of the script in a
specific memory area that is hold between
different executions.
Rate of Change (RoC) Digital: the alarm triggers
if the condition field occurs in a True value for a
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