Metro Trains Electrical Networks – Understanding our traction system

Summary

This video provides a comprehensive understanding of the MTM traction system, highlighting its components, protocols, and safety measures. It covers the conversion of high voltage AC to DC power, the function of substations, the importance of overhead wiring, and fault protection mechanisms such as spark gaps. The video emphasizes the importance of adhering to safety guidelines, including the use of access permits, safe approach distances (SADs), and proper equipment for working near high voltage assets. Through these safety protocols, MTM ensures the protection of workers and the public around electrical infrastructure.

Takeaways

• 😀 Understanding of the traction system is crucial for safety when working near electrical overhead assets.
• 😀 MTM's electrical control center, Electro, manages all high voltage operations for the electrified system.
• 😀 MTM relies on external power distribution companies for incoming high voltage power, which is converted to 1500 volts DC for trains.
• 😀 Traction substations are placed along the track to minimize voltage drops and maintain train performance.
• 😀 Overhead electrical sections are identified by unique IDs, ensuring precise network management and fault protection.
• 😀 The spark gap is essential for fault protection, providing a path for fault current in case of high voltage failures.
• 😀 Electrical components like isolators, feeders, and overhead structures must be treated as live, with strict safety protocols in place.
• 😀 Site-based risk assessments ensure proper control measures are implemented to maintain safe approach distances (SADs) from high voltage apparatus.
• 😀 Work in the vicinity of high voltage assets is governed by the Victorian Traction Industry Electrical Safety Rules (Orange Book).
• 😀 Access to electrical apparatus is controlled via a permit system, with specific levels of authorization required for different work scenarios.
• 😀 Failure to follow safety procedures and access authority rules could lead to electrical incidents, injury, or death.

Q & A

What is the primary purpose of the video?

The primary purpose of the video is to provide an understanding of the traction system, including its components, switching protocols, and the interaction with the electrical control center. It aims to support the development, training, and awareness of industry participants.

Why is it important to understand the network operator's requirements when working near MTM electrical overhead assets?

It is crucial to understand the network operator's requirements for safety when working around MTM electrical overhead assets to protect both workers and those in the vicinity from potential electrical hazards.

What is Electrol, and what is its role in the MTM electrical system?

Electrol is MTM's electrical systems control center. It manages high voltage power operations across the MTM electrified system and coordinates the supply of power to the network, relying on external power distribution companies.

How do traction substations function in the MTM system?

Traction substations convert incoming 22,000 volts AC power to 1,500 volts DC, which is required to run the trains. They are located at regular intervals along the track to minimize voltage drops and maintain train performance.

What are electrical sections, and how are they identified?

Electrical sections are segments of the overhead system, each with a unique identification number related to the line section, track, and distance from Flinders Street. They are supplied with 1,500 volts DC power from two circuit breakers from two substations.

What role does the spark gap play in the overhead system?

The spark gap is part of the DC fault protection system. It ensures that, in case of insulation failure on an overhead structure, fault current can flow, causing the substation circuit breakers to open and de-energize the section.

What is the function of the electrolysis feeder, and why is it important?

The electrolysis feeder runs along the outside of structures to mitigate the corrosive effects of stray DC current on underground metallic structures like gas and water pipes. It also provides a safe return path to the substation.

What are Safe Approach Distances (SADs), and why are they critical?

Safe Approach Distances (SADs) define the minimum distance that mobile plant or persons must maintain from live electrical apparatus. These distances are vital to ensure safety and prevent electrical incidents, injuries, or death.

What is the role of an Overhead Safety Observer (OSO)?

An Overhead Safety Observer (OSO) monitors the approach to electrical assets when works are being carried out near live overhead lines. They ensure that the agreed safety controls are in place and are responsible for ensuring the safety of the worksite.

How are work permits and access authorities managed when working around high voltage electrical apparatus?

Work permits, such as the Permit to Work Near (PTWN) or the Electrical Access Permit (EAP), are issued to ensure that safety controls are in place before work commences. These permits govern access to electrical apparatus and must be adhered to, including isolating and earthing equipment when necessary.