- The PEMS Advantages Hardware :
PEMS runs on 64-Bit PC, supplemented by a variety of
user interface and IED communications equipment. It can support Ethernet TCP/IP Network. Based on Networking, PEMS can
be expanded and/or customized as needs required.
- Software :
PEMS is based on Windows 98, Windows NT 4.0 (include Chinese version) or later.
- Functions :
- Data Acquisition
- Data Processing
- Supervisory Control Alarm
- Data Acquisition :
Data acquisition is provide through an integrated combination
of hardware and software in the IEDs, the PEMS Front-end Processor, and the CPU (PC). The four major types of power system
information are scanning from IEDs: Power Values (V, A, W, A Var, PF, VA, F), Energy Values (WH, VarH), Status, and
- Data Processing :
When PEMS places information into its database, it performs the following basic processing functions : Data Quality / Limit Checking,
Analog Value / Status Processing, and special Calcultion Processing.
- Supervisory Controls :
Operators can issue two types of supervisory controls. One type of control affects the way PEMS processes and displays data. For
example, a user can :
- Inhibit or enable alarms pertaining to a device.
- Place or remove tags on points.
- The other type of control causes a change in the power system causing a breaker to trip or close, for example. Specifically, PEMS supports the following controls :
- TRIP / CLOSE (OFF / ON; AUTO / MANUAL; STOP / START; etc.)
- RAISE / LOWER (single-step after initiation ... e.g., jogging of a gate or tap changer)
- Alarm (Displaying, Logging, and Printing) :
As noted, PEMS issues alarms to alert operator to unusual conditions. The PEMS presents alarm information in the following displays :
- Real Time Alarm : An Alarm Summary only displays current alarms.
- Historical Alarm : An Alarm / Event Summary displays include the occurrence of the alarm, and the time the alarm condition returned to normal; and the
occurrence of the event. An event is defined as a data value is changed either by the operator or the system.
- In addition to displaying Alarm / Event, PEMS allows alarm / event to be logged to the computer's hard disk, to be printed to the Event Printer.
- Trends :
The PEMS has the capability of displaying / printing trend charts of database. Charts have the appearance of graph paper with
the time values moving from right to left. The operator can specify the time span, value range, location of time stamps,
location of value stamps, and number of pens (up to 4). There are two types of Trend, Real-Time Trending and Historical Trending.
The difference is the data of real-time trend are stored in computer's memory only, but the data of historical trend are stored
in computer's hard disk. So, the data of real-time trend will be lossed after PEMS restart.
- Reports :
The PEMS has the capability of displaying, printing, and logging two types of Report, the Periodic Reports and sequence of Event (SOE)
Report. The Periodic Reports include the hourly, daily, and monthly reports; and based on manually entered data, telemetered
data, and data developed from the integration of instantaneous telemetered and program-calculated values.All basic data for the
periodic reports is available for the operator to review and modify at any time via console display. The periodic reports can be
printed automatically after the period of time encompassed by report, or manually based on the operator request. The SOE report
can be printed / logged antomatically when the SOE's Buffer is approaching capacity; or on demand by the operator.
- ON-Line PEMS (Run-Time Version & Development Version) :
- Data Acquisition
- Data Processing
- Supervisory Control
- Alarm Display and Logging
- Periodic Collection and Report
- Trend Display
- User Program Interface
- Man Machine Interface
- OFF-Line PEMS (Development Version only)
- Data Base Management
- On Line Display Generator
- System Configuration Control
- Report Creation Control
- Trend Configuration Control
- User Program Interface Control