XA/21™ EMS - Energy Management Systems

Digital Energy

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XA/21

™

EMS

Energy Management Systems

Energy Management Systems to meet the challenges of today’s

smart grid environment

Electric utilities are faced with many challenges imposed by today’s Smart Grid. High penetration of bulk

renewables, demand response options, aging assets and an aging workforce, coupled with increased

operating and maintenance costs, security, increased integration with external systems and increased

data processing requirements contribute to the needs of today’s advanced Energy Management System

(EMS).

The XA/21 EMS meets these demands with a secure core system built on an open-standard, distributed

architecture and augmented by powerful application suites for generation, transmission and distribution

power grids.

Key Benefits

• Monitors and controls generation, transmission and distribution assests in real-time

• Provides real-time situational awareness coupled with advanced visualization capabilities for faster

user recognition of the overall system status

• Analyzes near-term operating grid contingencies and provides alternative solutions to reduce

potential outages

• Economically provides increased grid capacity while maintaining overall grid reliability and regulatory

requirements

• Reduces overall system support costs through intuitive data and display maintenance support tools

• Meets today’s secure system needs with flexible environments including fully redundant primary and

backup production, quality assurance, training and development systems

Situational Awareness

• Robust generation and transmission grid power

system applications supporting real-time, study

and training environments provide current and

future operator situational awareness

• Built-in advanced visualization capabilities

driven by a secure, platform independent

Graphical User Interface

• World coordinate displays supporting

transmission grid overviews provide support

for graphical backgrounds, weather data,

crew locations, flexible gradients and dynamic

approaching limit symbols for flows and other

real-time data

• Operator configurable dashboards provide

support for displays, charts and graphs,

summaries and graphical contingencies

• Advanced alarm and event summaries with

operator customizable sorting and filtering

Advanced Functionality

• Enhanced grid reliability

• Increased grid capacity

• Advanced contingency awareness

• Decreased system support costs

• Secure system that meets worldwide regulatory

requirements

GEDigitalEnergy.com

XA/21 EMS Overview

The XA/21 EMS is designed to flexibly meet each utility’s needs based on

their asset fleet. The base system provides the XA/21 system platform

infrastructure and three core application suites: EnterNet Suite (ES) (platform

independent GUI), SCADA (DAC, Alarm Events, RT-Calcs, HIS, etc.) and Data

Engineering Tools.

Optional applications can be added depending on each utility’s needs.

Generation applications provide a solution for generation and enterprise

renewable management companies and industrials with onsite generation.

Typical transmission grid operators may only need the advanced

transmission applications. A vertically-integrated electrical utility can

choose the entire suite of applications, including Transmission, Generation,

Hydro and Distribution applications.

The distributed and extensible architecture of XA/21 scales from a single

server to a fully redundant system with many servers supporting hundreds

of operator consoles.

XA/21 systems are typically deployed in a multi-system environment, with

separate systems for the Primary and Emergency Backup Control Centers and

the Program Development, Quality Assurance and Operator Training Systems.

The secure architecture of XA/21 conforms to industry-standard security

practices and is implemented with a layered strategy to ensure cyber

security at the network, system and application levels.

Architecture

XA/21 is a network-based, distributed processing environment consisting of

interconnected processing nodes which can be tailored to specific functions.

XA/21 is a highly eXtensible Architecture based on industry-standards and

designed to meet the needs of the EMS market well into the 21st century.

The XA/21 system is a highly available security-hardened solution that has

the inherent capability to expand as user requirements dictate, both in

terms of applications and architecture. XA/21 can be scaled from a single

processing node to a fully redundant configuration with multiple servers

supporting hundreds of users.

A redundant Local Area Network (LAN) serves as the data highway

connecting the various elements in the XA/21 system. The XA/21 system

uses a broadcast interface for the exchange and propagation of dynamically

changing data required at multiple nodes in the network.

Each node with critical functionality in the XA/21 system connects to both

the primary and backup LANs. Either LAN can be designated as prime

with the other becoming the backup. The system continuously checks the

integrity of both LANs.

The platform independent ES GUI consists of autonomous multi-headed

high-performance graphics workstations connected to the LAN. The ES

architecture supports a three-tiered (client, server, agent) configuration,

allowing support for secure remote users with the server residing in the

Demilitarized Zone (DMZ).

Multi-system Environment

XA/21 control systems are generally deployed in a multiple system

environment to meet the security and redundancy needs of each utility.

Most deployment environments include separate systems for the Primary

and Emergency Backup Control Centers, as well as Development, Quality

Assurance and Training. Three Backup Control System (BCS) options are

natively supported within XA/21:

• Site Isolation BCS

• Standby or Snapshot BCS

• Integrated BCS

Optional Applications

Operating System

XA/21 System Base RDBMS

XA/21 Portable Application Interface

XA/21 EnterNet

Suite GUI

XA/21 SCADA

XA/21 Data

Engineering Tools

Platform and Core Applications

Transmission Applications

• State Estimator

• Scheduling

• Contingency Analysis

• Optimal Power Flow

• Security-constrained Dispatch

• Remedial Action

• Preventative Action

• Network Status Processor

• Fault Level Analysis

• Voltage and Transient Stability

• Operator Training Simulator

• Enterprise Gateway

Generation Applications

• Automatic Generation Control

• Generation Dispatch

• Real-time Production Costs

• Reserve Monitoring

• Energy Scheduling and

Accounting

• GDC Market Interface

Hydro Applications

• Automatic Voltage Control

• Water Monitoring and

Accounting

• Automatic Generation Control

• Power Scheduling

• Spillway Gate Control

Distribution Applications

• Connectivity Analysis

• Load Flow

• Fault Detection, Isolation and

System Restoration

• Contingency Load Transfer

• Integrated Volt-Var Control

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XA/21 System Architecture

EMS LAN

Switches

DAC LAN

DMZ

Operator Consoles

NAS/SAN

Array

EMS LAN

SCADA/TSM

Servers

DAC LAN

DMZ

Switches

FEP/ES

Servers

Web Server/

Proxy Server

Oracle Servers

Corporate

Historian

Primary Control Center

Backup Control Center

Operator Consoles

Switch

Switches

Firewall

Web Server/

Proxy Server

Corporate

Historian

Domain Servers

Firewall

Switches

Switch

NAS/SAN

Array

SCADA/TSM

Servers

FEP/ES

Servers

Oracle Servers

Domain Servers

External

Network

Printers

GPS

DAC Cabinet

Communications to RTUs

GPS

DAC Cabinet

Communications to RTUs

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Site Isolation Backup Control System

The Site Isolation (SISO) BCS provides an independent, isolated system that

is loosely coupled with the primary system. Only one site is “active” (primary)

at any given instance in time and the BCS must be manually prompted. Real-

time updates are buffered and distributed in real-time. This BCS supports

both Dual DAC and Isolated DAC scan options. The SISO BCS provides the

highest overall system availability, with a moderate level of bandwidth

required between the two systems.

Standby or Snapshot Backup Control System

The Standby or Snapshot BCS provides a separate system, with a critical

data snapshot, periodically from the primary to the backup system for

manual backup system initiation.

Integrated Backup Control System

The Integrated BCS extends the primary system across two geographic sites,

allowing for four levels of server redundancy.

Secure Architecture

XA/21 systems are implemented with a defense-in-depth strategy to ensure

the cyber security of the production environment, with processes at the

business level and technical security measures at the network, host and

application layers. The XA/21 system is designed to conform to industry-

standard security practices, including those within the NIST SP 800-53

guidelines and NERC

CIP standard.

Security controls at the network level include:

• An architecture with a strictly defined perimeter.

• A DMZ network designed to eliminate direct communication between the

critical trusted zone and the external networks.

Security controls at the host level include:

• A system built with only the software, accounts and services required for

operational use.

• Malicious software prevention tools to detect, prevent, deter and mitigate

the introduction, exposure and propagation of malware.

• Only the ports and services required for normal and emergency

operations to communicate.

• File integrity monitoring to determine if unauthorized modifications have

been made.

• Centralized user account management.

• Disaster recovery capabilities.

Security controls at the application level include:

• The use of secure coding standards to reduce the risk of software bugs

and flaws creating security vulnerabilities.

• A system that has been independently tested for security vulnerabilities.

• Access controls designed to enforce authentication and accountability, as

well as minimize the risk of unauthorized access.

Logging and auditing capabilities that allow for traceability of access and

actions.

Visualization – EnterNet Suite GUI

The XA/21 system provides a rich, platform-independent user interface.

Features of the ES GUI include basic SCADA visualization as well as many

advanced situational awareness capabilities that enable operators

to proactively monitor and control the power grid. The ES GUI is fully

internationalized for single- and multi-byte languages and will run on

Microsoft

and Linux

based consoles.

ES includes bookmarks displays, filtered and sorted summaries, charts and

graphs, time series forms and dashboards. It allows the operator to link

to URLs (e.g., maintenance records, photos, live camera for door alarm,

outage management, geo-spatial maps, etc.). Displays can be referenced

by external applications on the user console using a URL.

Displays

The ES GUI supports dynamic world-, page-, and list/grid-based displays.

World-based displays are primarily used for large, geographic or

schematic system maps. A single world coordinate display is composed

of one or more layers of information that are automatically decluttered

based on zoom level.

Page-based displays are designed to emulate the pages of a book. All pages

are the same size and only one page can be viewed at a time. Page-based

displays are primarily used for station one-line or schematics. The ES GUI

allows the use of same display definition for multiple data sources (SCADA,

Operator Training Simulator, advanced applications and historical playback)

in real-time and study modes.

SCADA summaries are presented as a list- or grid-based display. Grid-based

displays provide a highly flexible and feature-rich method for displaying tabular

data, in which the total number of entries (rows) in the set varies with current

system or filter conditions, and the tabular information is presented in columns

that can be optionally viewed, sorted, re-sized and re-positioned by the user.

Charts and Graphs

Charts and graphs can be dynamically built using drag and drop into a

wizard from a display. The ES GUI supports many chart and graph types

including real-time and historical trends, kiviat, bar, line, compass, wind rose

and power charts. Charts and graphs can be bookmarked and included in

dashboards.

One-line Diagram

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Advanced Visualization

The ES GUI has many built-in advanced visualization capabilities, including:

• Graphical backgrounds

• Gradients based on display filter criteria

• Support for dynamic network coloring based on prevailing conditions

• Approaching limit symbols and summary colorization to show

measurements approaching limit violations

• Geo-coordinate plotting of events on displays (e.g., lightning strikes, crew

locations)

• Playback of data and events from data historians

• Bitmap weather overlays

Dashboards

A Dashboard is a convenient way of creating an overview display containing

multiple display components that are joined together. A Dashboard

provides the user with many different layout arrangements and can include

displays, charts and graphs, and filtered and sorted summaries. Once built,

each component of the Dashboard is fully functional and the completed

dashboard can be bookmarked.

Access Control and Permissions

User interface features and functions are granted to a user based on each

individual user’s permissions, areas of responsibility (AORs) and other access

control restrictions. Users are authenticated by a centralized domain server

with support for multi-factor authentication.

SCADA Applications

Data Acquisition and Control

The Data Acquisition and Control (DAC) System is responsible for acquiring

and processing data from and issuing controls to the following SCADA

remote devices:

• Remote Terminal Units (RTUs)

• Time and Frequency Receivers

• Mapboards

• Digital Displays

• Strip Chart Recorders

Data acquisition tasks include remote device scanning, communication

failure detection, message encoding and decoding, communication

restoration, error checking and error rate monitoring. Data may be

scanned at multiple different frequencies and may be demanded by either

application programs or by operator request. The number of scan cycles,

the frequency of each and the remote devices scanned is configurable by

the programmer/engineer through the Database Editing System.

RTU Protocol Support

The XA/21 system supports a number of RTU protocols including DNP 3.0,

IEC

870-5-101, IEC 870-5-104 and Modbus

, as well as a large number of

legacy protocols.

The DAC software maintains error statistics on, and the current status

of, communications over the various channels via RTUs. This feature

provides the operators and communications technicians with updated

communications status information, including noisy channel conditions

which result in normally un-noticed communications retries.

Area of Responsibility Administration Display

Geographical Overview with Voltage Gradients

Kiviat Chart

GEDigitalEnergy.com

Sequence of Events (SOE) processing provides the operator with

chronological reports and display(s) showing the change-of-state events for

pre-defined RTU indication (status) points. SOE reports are maintained by

the historical information system for the current and previous day’s events.

Data Link Support

XA/21 Data Links provide the capability for communication with other

control centers via a common protocol. XA/21 supports the following data

link protocols:

• ELCOM™-90 (ELCOMB83 compatibility)

• ICCP for ISO

standard ISO/IEC 870-6

Association-based secure ICCP functionality is available.

OPC Data Access Server and Client Support

XA/21 extends the system architecture to loosely coupled PCs, by

supporting Object Linking and Embedding for Process Control (OPC) Data

Access (DA). The OPC Front-end Processor (FEP) communicates with OPC

DA servers provided by one or more vendors for acquiring data on behalf

of the XA/21 EMS.

Phasor Measurement Unit Device

XA/21 has the capability to acquire synchrophasor measurements directly

from Phasor Measurement Units (PMUs) and/or Primary Domain Controllers

(PDCs) in IEEE

C37.118 format and store them into its real-time database

for visualization and use by other applications such as the State Estimator.

Alarm and Events

The alarm and events reporting mechanism is designed to support up to 16

classes (1-16). For a given class, the handling and attributes (priority, color,

audible) of each are database configurable.

Alarms and events are presented to the user in real-time within SCADA

summaries. In addition, applications are available that allow the user to

extract alarm and event data from the historical database.

Load Shedding/Restoration

Automatic Load Shedding/Restoration (LS/R) provides a rapid method of

opening and (optionally) closing groups of circuit breakers without the need

to individually select and then operate each breaker separately. Groups are

defined in the database and can be one of three types as follows.

Linear LS/R Group

Begins the shed at the breaker stated as the Start Point and proceeds to the

end of the list or until the desired load is shed.

Circular LS/R Group

Begins at the Start Point and processes until the desired load is shed. Upon

reaching the end the start point wraps back to the first breaker.

Rotational LS/R Group

Circular LS/R group that automatically restores the previously shed

breaker(s).

Sequential Control (Automatic Supervisory)

Sequential Control provides the capability to schedule automatic execution

of pre-defined control sequences. A sequence editor is provided to enable

the easy creation and maintenance of sequences and to categorize them

in a sequence library. The sequential control capability allows the user to

perform operations such as:

• Switching sequence related to maintenance , isolation or feeder

reconfiguration.

• De-energizing or energizing network elements such as parallel

transformers.

• Group commands (ganged switching, device isolation, load shed).

• Conditional control of one or more devices at different stations as a result

of detecting a specific system condition.

Transmission Switching Application

The Transmission Switching Applications (TSAs) are a suite of applications

that can be deployed either individually or in combination.

TSA Real-time Switching Validation involves real-time validation of all

requested switching device change of states. With this feature, every control

request, manual state change request or programmatic non-control state

change request associated with a switching device is validated against a

set of configurable validation rules. If the request is invalid, it is rejected and

not performed.

TSA Documents and Permits provides comprehensive management of the

electronic documentation and field permits associated with switching (in

PDF format).

TSA Switching Schedule Jobs provides comprehensive management of the

electronic switching schedules associated with planned switching schedule

jobs, fault switching schedules or unplanned switching schedules.

Given that each utility’s types of switching schedules and operational

procedures vary, TSAs are customizable through data configuration so they

can be easily tailored to meet a given utility’s needs.

Alarm/Event Summary

GEDigitalEnergy.com

Real-time Calculations

Real-time Calculations provides a standard and extensible calculation library

which, in addition to arithmetic and logical operations, contains standard

functions traditionally associated with a power system (e.g., MVA, PF).

Points are associated to the calculations using the database administration

facilities.

Historical Information Systems

XA/21 supports multiple Historical Information Systems including Oracle

’s

RDBMS, Instep’s eDNA, OSIsofts Inc.’s PI Historian and GE’s Proficy data

historian.

Data Engineering Tools

The XA/21 system provides a number of editors that allow users to manage

and administer the database, displays and forms or reports, including the

Database Suite, Commit User Interface, Display Editor, Display Update

Manager, Pseudo Display Editor and Time Series Builder.

For the database and display editing functions, centralized editing controls

changes to the on-line database by allowing editing at only one system (the

Master), and automatically making the data available for commit by job at each

of the other systems (the Slaves) to keep the data synchronized. All database

edits and commits are performed on-line without any system failovers. The

Commit User Interface and the Display Update Manager prepare and execute

the files needed to perform this synchronization, and all configured systems

have access to a centralized data storage repository of proven editing files.

Database Editor Suite

The Database Editor Suite application is a combination of the Database

Browser and the Database Editor functions. It allows for the display of

XA/21 views, attributes and other structures that make up the XA/21 Logical

Database, including allowing editing of these values.

Commit User Interface

The Commit User Interface provides the capability to choose one or more

database modifications to apply to the on-line system. This design allows

users to commit only the portions of data that are complete, while not

interfering with the editing capabilities of other users. A user may select

individual instances, jobs, multiple jobs or selections from several jobs for

application to the operational database.

Display Editor

The XA/21 Display Editor is a set of interactive software tools that can be

used to build and manage all elements of displays within an XA/21 system.

The Display Editor is based on AutoCAD

with linkages back to the real-time

database. In addition to the capabilities supplied by AutoCAD, the Display

Build Facility provides the facilities to meet the requirements for displays in

the XA/21 EMS environment. These facilities include:

• Definition of the static display information using AutoCAD’s graphic

drawing facilities for defining geographical or schematic diagrams.

• Incorporation of real-time or application data within a display.

• The ability to define graphical symbols to represent the current state

of telemetered or calculated devices. These graphical symbols can be

further organized into groups (called a device) and stored in libraries for

future reference.

• The ability to define the characteristics (referred to as attributes) of a

display such as display ID, pan/zoom characteristics, refresh rates, fonts,

application interfaces, etc. These attributes vary depending on the type of

display being constructed.

Display Update Manager

The Display Update Manager allows for the distribution of run-time displays

to all systems. Once distributed, the displays are available to the operator on

the next display call-up.

Pseudo Display Editor

The Pseudo Display Editor allows the engineer to build multiple displays

based on a common template. An example of representative use is a wind

farm. A typical wind farm is made up of many turbines/generators. Drawing

and maintaining individual displays for each turbine would be very time

consuming. As each turbine pseudo display is derived from a common

template, any changes to the template are automatically reflected in the

resultant turbine display.

Time Series Form Builder

The Time Series Form Builder is a development tool used for creating

applications for viewing XA/21 historical data from the Oracle relational

database. The Time Series Form Builder is designed for the non-technical

user, whereby simple point-and-click, drag-and-drop operations are used to

create fully functional applications.

Database Editor

AutoCAD based Display Editor (One-line)

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Transmission Applications

The XA/21 Transmission Security Management (TSM) subsystem delivers a

powerful set of tools for efficiently operating and protecting the integrity

of the power system. The TSM application module delivers rich information

about the real-time system with the added capability of being able to

examine near future states of the system.

With multi-user/multi-case support, the TSM subsystem provides a high

performance environment for network analysis, contingency analysis,

optional optimal power flow and optional fault level analysis functions.

Using the TSM subsystem, control center personnel can identify and analyze

potential operating problems and formulate various preventative strategies.

Base Applications

Real-time and Study State Estimator

The State Estimator (SE) engine estimates and analyzes the accuracy of the

telemetry within the transmission network provides this functionality using

robust algorithms. Estimated values are provided for all input measurement

types as well as for bus phase angles and branch series and shunt

impedances. SE has the ability to use PMU data such as time-aligned bus

voltage and phase angles to improve results.

Study Power Flow

Study Power Flow uses robust algorithm techniques, including Newton and

Fast-decoupled, for analyzing the transmission network within TSM. The

Power Flow engines provide a base case off-line study solution that can be

used for further study.

Network Status Processor

Network Status Processor (NSP) provides a precise determination of

electrical connectivity at the individual bus section level. Rather than relying

on user-defined calculations that must be maintained over time, NSP uses

a detailed connectivity model in conjunction with generalized Boolean logic

to accurately determine electrical connectivity and resulting energization

status for each individual power system component.

Schedules

Schedules provide typical day and absolute schedules for use in determining

the base network solution in Power Flow and in State Estimation where

telemetry is not available or requires further scaling.

Real-time and Study Contingency Analysis/Contingency Selection

Contingency Analysis tools provide capabilities for studying the impacts

of topological or MW generation changes to a base case solution. Each

contingency case can be processed as part of a group of other contingency

cases in a batch mode, providing the user with the ability to study impacts

of many contingencies against known system conditions.

Supplemental Applications

Real-time and Study Optimal Power Flow

To supplement the base transmission applications the following applications

can be optionally included.

• Security-constrained Dispatch Active Power Optimization

Optimization tools allow constraint limit violations to be relieved through

several selectable objective function methodologies using active power

controls. Users can choose to optimize all limits or only active power

limits.

• Voltage/VAR Scheduling Reactive Power Optimization

Constraint violations can be relieved through several selectable objective

function methodologies using reactive power controls. Users can choose

to optimize all limits or only reactive power limits.

• Post-contingency Remedial Action Optimization

The Remedial Action (RA) module provides the capability to obtain

independent optimized corrective rescheduling plans for each of a list

of harmful contingency cases that is identified by Contingency Analysis.

For each harmful case, a set of active and reactive power control moves

is obtained that minimizes the values of the user-specified objectives

while observing all operating limits designated for enforcement when

implemented in the post-contingency time frame.

• Pre-contingency Preventative Action Optimization

The Preventative Action (PA) module provides the capability to obtain

optimized preventative scheduling plans for a list of contingency cases.

PA minimizes the values of the user-specified objectives while observing

all operating limits designated for enforcement in the base case and

contingency cases. A set of active and reactive power control moves

is obtained that results in the system remaining secure due to the

occurrence of any one of the contingency cases when implemented in

the pre-contingency time frame.

Contingency Analysis Case Report

State Estimator Case Comparison

GEDigitalEnergy.com

Real-time and Study Fault Level Analysis

Fault level analysis tools provide real-time and off-line study capability to

simulate three-phase, phase-ground, phase-phase and phase-phase-

ground fault currents. User-defined or pre-defined faults can be used within

any active case.

Voltage and Transient Stability

XA/21 supports an interface to third-party security assessment tools,

including Voltage and Transient Stability.

Operator Training Simulator

Due to the ever-increasing growth and complexity of today’s EMS, the

need for training tools that supplement the traditional on the job training

of system dispatchers is recognized as an important requirement in the

control center environment. The Operator Training Simulator (OTS) provides

simulated conditions through which operators can be trained to control

the transmission grid on an XA/21 EMS, all based on the same engines and

model as the base transmission applications. The OTS creates a realistic

environment for the system operator to become familiarized with XA/21

system operation functions, test new operational approaches and learn to

manage emergencies through simulated conditions.

Enterprise Gateway – IEC 61970 Common Information Model

Exchange

The Enterprise Gateway (EG) allows the transmission model to be exchanged

in Common Information Model (CIM) format. EG supports full and incremental

model import and export into the XA/21. Imported models may be used as

the base network model definition, as incremental changes to the external

model or be imported into the study environment as an independent model.

Generation Applications

The XA/21 Generation Applications provide the functions required for

dispatch and closed loop control of generation in an economical fashion

while considering interchange schedules, generation limits and reserve

requirements. In addition, the Generation Dispatch and Control (GDC)

subsystem provides alarming as required in order to alert the operator to

impending conditions.

Automatic Generation Control

Automatic Generation Control (AGC) provides closed-loop control of

generating units within a control area of an interconnected power system.

AGC provides supplementary control of area generation to maintain area

frequency and/or area net interchange within defined limits. The primary

objective of AGC is to minimize the instantaneous and accumulated Area

Control Error (ACE) subject to specified NERC control performance criteria.

A secondary goal of AGC, in conjunction with the Generation Dispatch

function, is to minimize the area production cost within the bounds of

practical operating constraints.

Generation Dispatch

Generation Dispatch (GD) allocates the required amount of area generation

among available on-line generating units in an economical fashion so as to

minimize control area production cost with consideration of transmission

losses and high/low generator limits.

The GD function supports conventional fossil fuel (i.e., coal, oil and natural

gas) fired units and combustion turbines for which incremental heat rate

(IHR) curves are available.

Real-time Production Costs

Real-time Production Cost (RTPC) processes real-time data for power system

operating cost accounting. Historical Database Reports are prepared on a

periodic basis, which summarize the fuel, operating and maintenance (OM)

and startup/shutdown costs for each unit, plant and area in the power system.

Automatic Generation Control Summary

Fault Level Analysis Fault Detail Display

Operator Training Simulator - Conditional Event

GEDigitalEnergy.com

RTPC also provides real-time production cost performance monitoring. The

actual production cost is periodically compared with the optimal production

cost (based on the Target Pass economic dispatch). An alarm is issued to

the operator if the difference between actual and optimal production costs

exceeds a pre-defined tolerance.

Reserve Monitoring

Reserve Monitoring provides current information on available active (MW)

and reactive (MVAR) reserves in the system. The Reserve Monitor is a

standard software feature of the GDC. However, definitions of the various

Reserve parameters may vary with individual customer requirements.

Energy Scheduling and Accounting

Energy Scheduling and Accounting (ESA) provides the operator with the

capability to schedule future operating plans (for load, generation and

interchange) and review past accounting information through Java-based

energy related forms and reports.

ESA comprises the following functions:

• AGC Performance Monitoring (APM)

• Production Costs and Fuel Accounting (PC)

• Interchange Scheduling (I/S)

• Inadvertent Interchange Accounting (IA)

• Load Forecasting with:

- Similar Day Load Forecasting (SDF), or

- Demand Forecasting (DF)

• Unit Commitment/Transaction Evaluation (UC/TE) or Comprehensive

Operations Planning and Scheduling (COPS)

GDC Market Interface

XA/21 offers interfaces to many different regional market systems. A typical

market system interface consists of the primary data being supplied via

ICCP data links for Base points and Net Scheduled Interchange with XML

files provided as supplementary or as a backup. XA/21 has the option of

running in “Market mode” or independently as a backup for the Regional

Marketing System. As each market interface is different, the XA/21 system

can be customized to meet the needs of each utility.

Hydro Applications

For systems with reservoir-based, hydro-electric generators, XA/21 is

available with several optional hydro applications.

Automatic Voltage Control with MVAR Balancing

Generator Automatic Voltage Control (AVC) and MVAR Balancing provide

simultaneous operation of AGC with AVC to coordinate closed control of MW

and MVAR generation within operational and capability limits.

Water Monitoring and Accounting

Water Monitoring and Accounting provides the operator with a water release

summary and detailed information for current/previous hour conditions

for all reservoirs, plants, generators and gates (spillway, bypass, auxiliary

releases) along with projected releases for the current hour.

Historical forms are available for summarizing water release on a daily,

monthly and yearly basis.

Automatic Generation Control of Hydro Plants

AGC of hydro plants provides closed-loop MW control of hydro generators

to meet the plants hourly base-point schedules or real-time plant set-points,

while remaining within hourly plant operational water and generation limits.

Power Scheduling for Hydro Plants

The Power Scheduling functions support the processing of 24-hour (current/

next days) plant base-point schedules and bus KV or MVAR schedules

originating either locally or remotely (via data link).

Spillway Gate Control

Spillway Gate Control provides open and closed loop control of spillway

gates using either a total discharge or release level control objective.

Turbine Discharge Curve Monitor Display

Production Cost

GEDigitalEnergy.com

Distribution Applications

XA/21 Distribution Management System (DMS) applications provide facilities

for the effective management and operation of the distribution network

from the distribution station and into the feeder network. DMS applications

are based on models and graphics derived from a utility’s GIS.

Distribution Connectivity Analysis

The Distribution Connectivity Analysis (DCA) application automatically

monitors and analyzes the global connectivity network state based on static

or wired connectivity and current open/closed status of switching devices.

In addition, temporary changes to network topology applied by a user in

the real-time operating environment are taken into account. The electrical

status of each device in the network is always up-to-date.

Load Flow

Load Flow (LF) is an event-triggered application that uses network topology

information, as well as the current estimated load demands, to calculate

the three-phase voltage and current values for every device in the network.

LF provides estimated values for those electrical quantities at network

locations where SCADA measurements are not available.

Fault Detection, Isolation and System Restoration

The objective of Fault Detection, Isolation and System Restoration (FDIR) is

to improve customer service by minimizing the duration/extent of forced

outages due to faults in the medium voltage radial network. Whenever a

substation breaker or line recloser trips, and the associated auto-reclosing

relay locks out, FDIR will:

• Automatically attempt to determine the location of the fault based on

telemetered FRTU fault passage detection and breaker over-current relay

trip data.

• Then attempt to identify switching actions to isolate the faulted section

and restore power to un-faulted feeder sections up- and down-stream of

the faulted section.

• Then display the recommended switching actions to the operator for

approval and implementation.

Contingency Load Transfer

The interactive Contingency Load Transfer (CLT) study mode application

provides switching recommendations for a network reconfiguration

transferring load from one feeder to another to reduce overload on a

particular device or re-energize outaged portions of the network.

Integrated Volt-Var Control

The Integrated Volt-Var Control (IVVC) determines desirable capacitor

switching and transformer tap control actions resulting in better network

operations. IVVC has two primary modes of operation: Voltage Control,

concerned with temporarily reducing the total system load below defined

levels at peak load periods; and VAR Control, concerned with maintaining

the power factor at bulk supply points above minimum defined levels.

Distribution Device Select Switch

Distribution Load Flow Results

Distribution Allocated Load and Generator States

imagination at work

Digital Energy

2018 Powers Ferry Road

Atlanta, GA 30339

1-877-605-6777 (toll-free in North America)

678-844-3777 (direct number)

[email protected]

GEDigitalEnergy.com

GE, the GE monogram and XA/21 are trademarks of General Electric Company.

IEC is a registered trademark of Commission Electrotechnique Internationale. ISO is a registered

trademark of the International Organization for Standardization. NERC is a registered trademark

of North American Electric Reliability Corporation. Microsoft is a registered trademark of Microsoft

Corporation in the United States and/or other countries. LINUX is a registered trademark of Linus

Torvalds. Modbus is a registered trademark of Schneider Automation, Inc. ELCOM is a trademark

of ELCOM, Inc. IEEE is a registered trademark of the Institute of Electrical Electronics Engineers,

Inc. OSISoft is a registered trademark of OSI Soft, LLC. Oracle is a registered trademark of Oracle

Corporation and/or its affiliates. AutoCAD and Autodesk are either registered trademarks or

trademarks of Autodesk, Inc., in the USA and/or other countries.

GE reserves the right to make changes to specifications of products described at any time without

notice and without obligation to notify any person of such changes.

GEA-12686A(E)

English

120919