Our Services

Transmission and Zone Substation Protection Design

We offer expertise in protection design to help you determine the most appropriate protection schemes for substations.

We have designed protection schemes for substations ranging in voltage from 500kV to 11kV and rating of 1200 MVA  to 100 KVA. 

Our goal is to provide the most appropriate protection for the substation to permit the specified operating reliability and technical requirements i.e National Grid Connection Code and Australian Standards where applicable. 

All necessary calculations are undertaken to determine protection sensitivity, reliability and stability.  Relay requirements determined from substation single line diagram or customer specification of protection requirements. 

Indicative protection relay settings are determined to guarantee that the protection relay setting ranges are adequate and there are no surprises at the time of commissioning.  The designs guarantee that no blind spots are left and that every type of fault can be detected by two protection relays.

Circuit breaker failure and substation battery failure are considered and customer is consulted as to the level of backup required for installation.

Protection, metering and SCADA Secondary Design

We can calculate the protection relay settings for:

  • generators
  • motors
  • overhead feeders
  • cables
  • power transformers
  • busbars
  • capacitor banks
  • shunt reactors
  • static var compensators
  • pole mounted reclosers

Protection Relay Settings

We can undertake protection relay coordination studies to determine substation protection relay settings.

Fault levels have to be determined for all possible system operating conditions, these are used to determine the protection relays ability to detect and clear system faults. The protection schemes are set so as to isolate the least amount of the electrical system as possible, thus minimising the disruption caused by the fault.

The protection relay clearance times are determined to meet primary plant short time rating, systems stability requirements and statutory authority requirements. We take care to determine the correct protection relay operating margins, both in current and time so as to effectively eliminate malgrading. When setting distance relays on double circuit high voltage feeders the zero sequence mutual coupling between the circuits is taken into consideration so as to minimise the possibility of over or under reaching occuring.

We have undertaken grading studies for system voltages ranging from 500kV down to 415V.

Fault Level Calculations

We use a proven and comprehensive fault level program to model the electrical system and determine fault currents under all possible system operating conditions.

The fault types considered are three phase, phase-phase, phase-phase-earth and phase-earth. All combinations of neutral earthing devices can be modelled.

The program also calculates the fault currents and impedances seen by distance relay on the primary side of a power transformer for a fault on the secondary side. This eliminates the tedious work of determining if remote backup protection is provided for substation low voltage bus faults.

Relay Setting File Preparation

We have expertise in preparing protection relay software setting files for Alstom, GE-Multilin, Siemens, Reyrolle, ABB, Basler and Schweitzer(SEL) protection relays.

Protection Relay settings can be downloaded into the relays via a serial RS232 communications port. This provides an accurate record of settings installed in relay and eliminates relay setting errors by commissioning technicians.

Specification of Protection CT’s and VT’s

Crucial to any protection scheme are correctly specified and sized current and voltage transformers. 

Incorrectly specified current or voltage transformers can lead to protection failures or protection instability. We can specify your current or voltage transformer requirements to the latest Australian standards.

Specification of Current and Voltage Transformers

We can provide protection relay specifications ready to issue to protection relay suppliers.

We can also analyse quotations and make recommendations for the most appropriate relays to purchase. 

Arc Flash Hazard Assessments

We take pride in finding the most appropriate solution, saving our clients material and labour costs.

We can prepare the refurbishment design of your substation secondary protection schemes.

We work closely with our clients to provide the most practical and economical solution for the refurbishment of the substation's ageing protection schemes.

We also provide a turn key design solution or provide additional design resources to complement those of the client.

We have undertaken refurbishment designs for substations ranging in voltage from 500kV to 11kV.

Fault Incident Investigations

Fortunately, system faults do not occur very often, but when they do they can be very disruptive and costly to your business.

For many faults it is difficult to determine whether the protection relays operated correctly. If you have had a recent network incident and you have any doubts about the protection relay operation, do not ignore the warning signs, it could possibly be incorrect protection relay settings.

We can investigate the network disturbance for you and determine if the protection operated correctly. Where it has not, we will make recommendations to correct any problems.

Secondary Systems Refurbishment

Protection schematics can be produced for any manufacturer's protection relays.

We provide both the drafting services and the engineering expertise that goes to produce protection schematics. Drawings can be produced to Australian Standards using Auto-CAD or Micro-Station.

We are expert in producing:

  • A.C & D.C schematics
  • Panel layouts
  • Wiring diagrams
  • Cable schedules and connection diagrams for protection
  • Control, metering and SCADA schemes

Fault Incident Investigations

We work with our clients to produce strategic network development plans that comply with the requirements of the current regulatory framework.