ERACS Introduction

The economic design of power systems is critically dependent on being able to predict the system behavior under both normal and abnormal operating conditions. Hand calculations and estimates are possible but increasingly expensive in engineers' time and run the risk of introducing errors resulting in significant safety and reliability implications.

Benefits

Using ERACS to conduct power system analysis, clients are able to:

	save costs
	reduce risk
	improve quality
	increase reliability and safety

System

The following ERACS program modules and options are available:

	graphical user interface (GUI)
	loadflow
	fault (classical)
	fault IEC909
	harmonic injection
	harmonic impedance
	harmonics G5/4
	transient stability
	protection co-ordination
	universal dynamic modeller (UDM)
	stand-alone and network versions
	10, 50, 100, 150, 300, 500 and 1500 busbar versions.

Quality

ERACS is developed under ERA's ISO 9001 and TickIT certified quality system.

Why ERA?

The ERACS suite of power systems analysis software is in constant use by experienced ERA power engineers for system study purposes. Therefore, they have direct input into the program development to incorporate best practices currently in use within the electrical industry.

ERACS' wide user base (including offshore, marine, mining, utilities, transport and academia) is also encouraged to contribute to the development and direction of the programs. In this way the ERACS programs are constantly moving forward, providing real benefits in terms of reduced study times and improved technical capability to users, and in meeting the specific needs of engineers with practical problems to solve.

The provision of a dedicated ERACS support 'hotline' and user web area further benefits its user base. Staffed by electrical/software engineers with a great depth of understanding of the latest programming techniques and tools, they also have direct access to ERA's own leading power systems engineers for technical support in times of need. ERA prides itself on its fast response time to technical queries from its software users.

ERACS - Features and Facilities

ERACS Graphical User Interface (GUI) options and facilities:

	cad style interface for the creation of a single line diagram of the study network including a wide variety of functionality (move and scale diagram, cut, copy and paste elements etc)
	a network explorer to show and select the networks, data states and studies stored in the database
	models include: series L, C & R elements static VAr compensators power factor controllers wind turbine generators (including DFIGs) gas turbines (LM6000Pa, Pc & LM2500) induction and synchronous machines lines & cables busbars & bus-sections transformers (up to 4 windings) switches & circuit breakers fuses, relays, auto reclosers auto tap changers mechanical loads time variant functions harmonic sources shunt loads (20 types) neutral earthing & fault limiting reactors AVRs and governors reactive power compensator systems (Elspec - Equalizer)
	up to eight windows may be open simultaneously each re-sizeable, images re-scalable, with or without results
	a re-sizeable overview of the complete network is available
	zoom in/zoom out functionality
	advanced mouse & keyboard navigation controls
	single data entry and block copy saves time and improves data integrity
	fully relational database for efficient co-ordination with other applications
	user defined preferences include: voltage colours voltage ranges results/data selection indication of isolated elements overloaded elements cable style
	text annotation on diagram; hide/display of element data/results; memo fields for networks; data states and libraries; reporting etc
	mouse co-ordinates/results given on all graphical displays
	context sensitive help and on-line user and technical manuals
	multi-user databases
	nameplate or per unit data entry
	library import and export facilities
	export of results to other applications including standard Excel Loadflow report
	comprehensive zip archive and transmission facility, including unzip facilities
	selectable snap on grid
	network export & import facility
	copy networks between database option
	database health check and data optimisation facility
	group switching of circuit breakers
	network elements navigation and find facility
	highlight isolated equipment by user selected colour
	user selectable and positioned results and data
	calculators and data converters
	induction machine data calculator
	password and access level controls including supervisor, user and operator modes
	without the dongle in place ERACS operates in viewer mode
	comprehensive library management system
	stand alone and networked versions available (dongle protected)
	time locked leasing option
	remote dongle update facility for leasing and adding additional programs
	upgrades (typically 3 a year) via cd & www downloads
	hard copy user & technical manuals (also in pdf format)
	on screen help system
	plus many more options and facilities

Loadflow

Typical applications for the use of the ERACS loadflow program are:

	selection of transformer tap changer settings
	system voltage profiling
	system loss optimisation
	MW and MVAr power flow analysis
	equipment loading factors
	power factor correction location and optimisation
	system planning
	generator operating procedures
	equipment specification
	impact load studies
	circuit reconfiguration studies
	power generation planning
	training

ERACS Loadflow options and facilities:

	user specified busbar voltage alarms
	user specified global and local MW & MVAr load multipliers
	user specified overload alarms
	user specified seasonal overhead line rating selection
	user specified automatic tap changer operation (off, locked or on)
	user selected on screen element results
	user selected on screen element data
	on screen power flow direction arrows
	radial, meshed or combined networks
	embedded generators
	loadflow control and diagnostic support window
	more than 100 calculated result types available for display per loadflow calculation

Fault (classical)

Typical applications for the use of the ERACS fault program are:

	calculation of data for circuit breaker and switchgear ratings (maximum and minimum 3 phase fault currents)
	calculation of data for relay and fuse selection and setting
	calculation of motor fault contribution
	determination of fault current distribution and busbar-voltage levels during a fault

ERACS Fault options and facilities:

	all classical shunt connected fault types accommodated
	open circuit faults
	fault survey option (multiple fault calculations per study)
	faults applied to the terminals of most system elements
	faults applied anywhere along the length of cables and lines
	on screen arrows indicating positive sequence power flow
	user selected on screen results
	fault summary box
	user specified additional fault impedance for both phase and earth paths
	three user specified reactance options
	induction motor fault contribution option
	more than 90 calculated result types available for display per fault calculation

Fault (IEC909)

Typical applications for the use of the ERACS fault program are:

	calculation of data for circuit breaker and switchgear ratings (maximum and minimum 3 phase fault currents)
	calculation of data for relay and fuse selection and setting
	calculation of motor fault contribution

ERACS Fault (IEC909) options and facilities:

	single fault - fault applied to a single user specified element
	fault survey - fault applied to every busbar in the network
	all classical fault types (single phase to earth, phase to phase, two phase to earth and three phase)
	user specified break times
	user specified additional phase and ground path impedances
	fourteen calculated result types available for display per fault calculation

Harmonic Impedance, Injection & G5/4

Typical applications for the use of the ERACS harmonic injection and impedance programs are:

	filter design
	system resonance identification
	equipment rating/de-rating studies (pfc, cable neutrals, transformers etc.)
	G5/4 compliance checking

ERACS Harmonic Injection options and facilities:

	multiple harmonics injected
	harmonic characteristics stored in the ERACS library
	multiple injection points (at the same or at different voltage levels)
	resistance of lines and cables adjusted for skin effects
	transformer resistance is modified to adjust for skin effects and core eddy current effects
	triple harmonic blocking/bypass option for transformers
	more than 34 calculated result types available for display per fault calculation
	TIF weighting factors (1935, IEEE 519-1992 & CCITT Vol.VI
	transformer de-rating factors: K-Factor (UL), Loss Factor (ANSI/IEEE C57) & Factor K (BS 7844-3:1998 or BS 7821-4:1995)

ERACS Harmonic Impedance options and facilities:

	graphically selected injection and transfer busbars
	up to six transfer busbars may be selected from any location on the network at any voltage level
	results displayed as a graphical output with dynamic cursor indication of values
	resistance of lines and cables adjusted for skin effects
	transformer resistance is modified to adjust for skin effects and core eddy current effects
	triple harmonic blocking/bypass option for transformers and induction machines
	harmonic offset option
	user selected impedance units (pu or ohms)

ERACS Harmonic - Engineering Recommendation G5/4 options and facilities:

	stage 1 assessment for connection to low voltage (LV) systems
	stage 2 assessment for points of common coupling (PCC) above LV and below 33kV
	stage 3 assessment for connections of all non-linear equipment to supply systems with PCCs at 33kV or above
	waveform results display - periodic & phasor
	spectrum results display - magnitude & phase
	tabular results display

Protection Co-ordination

Typical applications for the use of the ERACS Protection Co-ordination program are:

	selection of protection devices
	protection grading studies
	protection stability studies (under steady state conditions)
	protection planning philosophy and performance checking
	protection system safety documentation

ERACS Protection Co-ordination options and facilities:

	discrimination setting and documentation
	stability checking under steady state conditions
	dynamic performance analysis
	protection on mesh, radial and parallel systems
	combined LV, MV and HV protection systems
	large ERACS device library, user updateable
	protection devices defined by time, current data or user specified or international formulas
	user selectable reference voltage
	multi-stage relay device model
	graphical selection of setting data
	show/hide protection links between relays and circuit breakers
	customisable co-ordination plots
	standard protection tables and reports
	replay facility for dynamic analysis
	all classical fault types catered for
	faults applied to the terminals of most system elements
	faults applied anywhere along the length of cables and lines
	on-screen arrows indicating positive sequence power flow
	user selected on-screen results
	induction motor fault contribution option
	more than 90 calculated result types available for display per calculation

Transient Stability

Typical applications for the use of the ERACS Transient Stability program are:

	motor starting studies including starting techniques
	voltage dip profiling
	generator load application and rejection tests
	loss of generation
	system synchronising
	system stability studies
	AVR and governor testing
	wind farm analysis (torque variation studies)
	mixed frequency system analysis

ERACS Transient Stability options and facilities:

	generator synchronising
	AVR and governor switching
	fault application and rejection
	mixed frequency systems
	unlimited number of system events
	graphical display of results
	user selectable study times
	graphically selected system events
	user specified torque variation characteristics (library key)
	six motor starting techniques
	induction wind generator models
	AVR and governor models
	more than 100 result types available for display per transient stability calculation

Universal Dynamic Modeller (UDM)

Typical applications for the use of a UDM program are:

	AVR validation
	governor validation
	controlled shunt models (pfc's, static VAr compensators etc.)

ERACS Universal Dynamic Modeller options and facilities:

	32 control functions
	graphical building and linking of functions
	user selectable display of data or variable names
	user defined text annotation
	models stored in the ERACS library for use by the Transient Stability program

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ERA is pleased to announce the release of their small network version of ERACS - 10Bus. The 10Bus version is aimed at engineers wishing to carry out studies on smaller systems but who still require the assurance, convenience, power and support of a world leading high performance power systems analysis tool at a more affordable price. 

• Fully functioning ERACS Graphical User Interface

• Full ERACS Program Capability

• Full ERACS Support Service

• Full purchase credit available when trading up to larger versions

• No limit to the number of networks that can be modeled 

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minimum hardware requirements

ERACS requires the following:

	a personal computer with an Intel® Pentium® 266 MHz or higher processor
	Microsoft® Windows® 98/NT Workstation 4.0
	64 MB of memory
	120 MB of available hard disk space
	CD-ROM drive
	Parallel Port
	super VGA video adapter that supports a resolution of 800 x 600 and 256 colours or higher
	Microsoft® compatible mouse
	optional compatible printer.

recommended hardware requirements

	a personal computer with an Intel® Pentium® 4 Processor (2.80GHz)
	Microsoft® Windows® XP Professional (SP2)
	512MB RAM
	120MB of available hard disk space
	CD-ROM drive
	Parallel Port
	17" Monitor
	super VGA video adapter that supports a resolution of at least 1024 x 768 and 16 million colours or higher
	Microsoft® compatible mouse
	optional compatible printer.

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operating environment

ERACS has been developed for the Microsoft® Windows® XP, 2000, NT Workstation 4.0, 98 and 95 operating systems running on a personal computer, either standalone or across a network. To achieve this two versions of ERACS are available: single user and multi user.

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ERACS prices - The ERACS software can be fully configured according to the specific user requirements. Multi-user and site licence discounts are available. Full customisation service also available upon request.

For educational and training establishments, we supply the full software and support package at preferential rates on the understanding that the software will not be used for commercial purposes. For prices or a quotation please contact ERA Technology Ltd.

To satisfy a short-term requirement ERACS may also be leased on a monthly basis. Please contact ERA Technology Ltd for details.

programs
	graphical user interface (GUI) (diagram building, display, reproduction, library management, data storage and retrieval).
	loadflow
	fault (classical)
	fault (IEC 909)
	harmonic impedance
	harmonic injection
	G5/4
	transient stability
	protection co-ordination
	universal dynamic modeller
options
	network version
	10, 50, 100, 150, 300, 500 and 1500 busbar versions
	additional manuals
	ERA current rating standards for cables, 69.30
	specialist AVR and governor models
	diagram building/data entry
	training

All purchases are subject to ERA Standard Terms and Conditions of sale and the ERACS Software Licence Agreement.

demo request

A free demo version of ERACS can be requested from the ERACS main page.

The demonstration program is interactive, allowing users to operate the majority of functions of the full suite. Users can display results from previously calculated networks, which have been installed in the software. If you require any further information, would like an engineer to telephone to discuss your requirements or perhaps to demonstrate ERACS please do not hesitate to contact ERA Technology Ltd.

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