Ipsa 2 Protection Grading

IntroductionThe Ipsa 2 Protection Grading module provides a quick, easy and reliable wayof analysing protection devices and determining protection relay settings.

The Protection Grading module utilises the accurate Ipsa 2 fault levelcalculations to determine device and relay operating times.

FeaturesThe Protection Grading module comprises an extensive catalogue of featuresto simplify and speed up the analysis of protection systems, including:

• Detailed fault current analysis even on meshed systems

• Graphical display of time-current characteristics

• Comparison of different time-current curves

• Tables of operating and discrimination times

• Wide range of relays, fuses and damage curves

• Addition of new devices using the Protection Device Modelling application

Drawing upon an extensive database of modelled devices andprotection relays, Ipsa 2’s optional Protection Grading module isdesigned for comprehensive analysis of protection systems.

All types of protection analyses are supported, ranging fromstraightforward operating times tables to complicated comparisonsof time-current curves.

Ipsa 2’s fully flexible format permits the addition of new devices,upon user request, so that its database continually expands inalignment to industry changes and developments.

Load Flow

Fault Level

Transient Stability

Protection Grading

Harmonics

Reliability

Scripting

DC Networks

Training & Support

AnalysisThe operating times of protection devices are calculated usingthe integrated Ipsa 2 Fault Level module, provided as standardwith the system. This gives the exact operating time of eachdevice based on the fault current that flows through theindividual devices.

User-defined fault currents can also be specified to determinethe operating times at specific fault levels.

Three-phase, single-phase and phase-phase faults are allmodelled including the effects of AC and DC fault current decays.

Operating times are reported at specific fault currents as well asthe margin between devices, according to specific analysisrequirements.

The operation of devices can also be linked to circuit breakers,allowing them to operate in transient and dynamic studies. Thisextends to accurate modelling of the dynamic rotation of the discfor older electro-mechanical relays.

Protection settings dialogue

The devices are created using the following curve typesand characteristics:

• Instantaneous and constant current

• Definite time

• IDMT curves including ANSI, IEC and Areva

• Defined points for fuses

• Pick up and time delay

• Transient disc modelling

• Defined setting ranges and adjustment steps

• User-defined nominal relay currents

Device DatabaseIpsa 2 contains an extensive database of protection relaysand device characteristics to allow protection schemes tobe easily generated. The database covers a selection of LVand HV devices from manufacturers including:

• ABB

• Alstom/GEC/Areva

• Basler

• Beckwith

• Cutler Hammer

• GE

The database also includes:

• Cable damage curves

• Transformer damage curves

• LV fuse links

The range of modelled devices within the Ipsa 2 databaseis regularly updated and new devices added free ofcharge, upon user request.

Ipsa 2 Protection Grading

TNEI Bainbridge House 86-90 London Road Manchester M1 2PW

+44 (0) 161 233 4800 software@ipsa-power.com www.ipsa-power.com

Ipsa Power is developed, maintained and supported by TNEI

ReportingIpsa 2 provides detailed, zoom-able plots of the time-currentcharacteristics for protection devices. These graphs show the devicenames, curves and fault currents.

The graphs can be exported in a variety of image formats for use inother documents and the co-ordinate data can also be exported as atext file for manipulation purposes.

Device operating times and grading margin are displayed alongside thetime-current curves together with a single line diagram of the devicesplotted, for both written and visual representation of statistical results.

Protection Device ModellingThe additional Protection Device Modelling application allowsusers to model new devices to suit their unique requirements.A graphical interface is provided, enabling devices to be quicklycreated.

Simple fuse characteristics or complex multistage relays can bedeveloped which are subsequently available for use in Ipsa 2.

Time-current co-ordination curves

Protection device modelling application

• Ormazabal

• Reyrolle

• Schneider

• SEG Woodward

• Siemens

• Terasaki

• HV fuse links

• Time fuse links

Protection grading results