Power System design

- Gathering network data (short- circuit levels, load flow, line parameters).

- Determining substitution type (AIS, GIS, VIS, hybrid) and it's impact on protection schemes.

- Identifying applicable standards (IEC 61850, IEEE C37.2, ANCI)

Short- Circuit computing:

   -Calculating all types of fault currents at different busbars.

   -Finding maximum and minimum fault currents for relay settings. 

Load Flow calculations:

  -Computing normal and emergency load currents for transformers and feeders. 

  -Checking equipment thermal limits.

Protection zone definition:

   -Defining primary and backup protection zones. 

   -Ensuring proper overlapping to avoid blind spots. 

Primary relays:

  - Differential relay for transformers and busbars (low & high impedance)

  - Overcurrent (OC) and directional OC (DOC) relays.

  - Earth fault (EF) relay (ground protection).

  - Distance relay for transmission lines. 

Backup protection systems:

  - Backup OC and EF relays.

  - Instantaneous OC relays.

Supporting Equipment:

  - CTs and VTs with appropriate accuracy.

  - Circuit Breakers (CBs) with proper interrupting capacity.

  - Surge Arresters and Earthing Systems.

Relay parameters calculation:

  - Time multiplier setting (TMS [IEC], TDS [IEEE/ANCI]) for OC relays.

  - Pick up current and time delay setting. 

  - Curve Selection (IEC standard inverse, very inverse, extremely inverse) 

  - Coordination with upstream/downstream relays.

Protection coordination studies:

  - Ensuring selective tripping (primary backup hierarchy).

  - Preventing nuisance tripping.

Single line diagrams(SLD) and protection single line diagrams(PSLD):

    *Protection devices and their connections. 

Protection Schematics (SICAM PAS & Microscada Pro sys 600 Softwares)

   # Relay wiring diagrams.

        - Connection of relay to CTs and PTs

        - Protection relay wiring 

        - Trip circuits

        - Signalling and alarm systems 

        - Earthing arrangements

        - Cable and wire specifications (sizing, colour coding)

        - Labelling and identifications

   # Control and interlocking diagrams.

        - Controlled equipment (CBs, DS, ES, CTs/PTs)

        - Control systems (local, remote/SCADA, PLC, Relay-Based Logic)

        - Control and status signals

        - Status indication(LED indicators, SCADA signals)

        - Electrical interlocks(hierarchy in opening and closing equipment)

        - Mechanical interlocks (physical locks between DS & ES)

        - Logical interlocks (programmed interlocks in PLC/Relay, coordination with protection relays)

Layout & Auxiliary Drawings:

   - Panel arrangement drawings. 

   - Cable routine and termination details 

Technical Specifications and Data-sheets:

   - Relay, CT, VT and CB specifications.

   - SCADA and communication protocols (IEC-61850, Modbus, ...)

Verifying relay response under different fault locations and conditions.