AS 7662.1 – 25 kV AC Rail Traction Systems – Part 1: Traction Power Requirements

The objective of this Standard is to provide the Australian rail industry with a set of mandatory and recommended requirements for the traction power system and includes the interface requirements with other rail systems.

The Standard addresses the requirements of a traction power system for the use of designers, contractors and rail infrastructure managers (RIMs).

The use of this Standard allows for a uniform approach to be applied to the design, installation, testing and commissioning, operation and asset management of traction power supply systems.

• AS 7662.1 provides the Australian rail industry with a set of mandatory and recommended requirements for the traction power system, including the interface requirements with other rail systems.
• Aimed at increasing harmonization across existing and proposed 25kV AC rail traction systems.
• Focused on best practice in safety, design, manufacture and operation of 25kV AC systems.

With the Australian Railway industry looking to decarbonization the development of AS 7662.1 is timely. As more railways are being built using 25kV rail traction systems the need to harmonize to reduce costs and improve efficiencies is growing.

AS 7662 provides rail transport operators with clear requirements and recommendations to design harmonized 25kV systems that will take advantage of these efficiencies.

High voltage electrical systems require careful safety management to reduce the risks of serious incidents. AS 7662.1 combines international and national best practice in management of the safety risks associated with 25kV AC using baseline safety requirements. This allows RTOs to build on these requirements where needed to manage risks within their own system.

• Electric shock.
• Too many electric trains on sections causing trains to draw too much current resulting in harm to overhead power systems.
• Neutral sections causing sudden electric traction changes.
• Mechanical / electrical failure of fuses, circuit breakers, RCD’s.

To implement this Standard, the following approach is recommended:

For new railways, specify compliance with AS 7662.1 in design requirements.

For existing railways:

• Review AS 7662.1 against applicable internal standards.
• Identify common areas and variances.
• Where commonality exists, update requirements to reference AS 7662.1 using your organisation’s change management process.
• Where variances occur, assess whether AS 7662.1 provides better safety and/or harmonisation outcomes against your organisation’s risk profile and SFAIRP argument.
• If AS 7662.1 results in improved outcomes, amend organisational standards accordingly.
• If internal standards provide better outcomes, a derogation or deviation statement to AS 7662.1 may be required within your organisation’s standards.