IEC 62924:2017

Overview

IEC 62924:2017 - "Railway applications – Fixed installations – Stationary energy storage system for DC traction systems" - is an International Electrotechnical Commission (IEC) standard that establishes requirements and test methods for stationary energy storage systems (ESS) installed trackside within DC electrified railway power networks. These systems are designed to store electrical energy drawn from the DC power supply network and return the energy when needed, providing crucial support in managing regenerative braking energy and power quality.

By addressing both configuration and testing aspects, IEC 62924:2017 helps manufacturers, railway operators, and infrastructure managers ensure the reliability, safety, and effectiveness of stationary ESS for railway applications, contributing to energy efficiency and system optimization.

Key Topics

• Scope of Application: Applies to stationary energy storage systems installed trackside for use in DC traction power networks. The standard does not cover onboard storage.
• Energy Management: Outlines the ability of ESS to absorb excess regenerative braking energy, reducing energy waste and supporting efficient power usage.
• System Configurations: Describes systems with and without electronic power converters, allowing adaptation to various technology choices such as batteries, capacitors, and flywheels.
• Service Conditions: Specifies environmental and electrical conditions for ESS operation, referencing other IEC standards.
• Testing & Performance: Details a range of test methods (type, routine, commissioning) to ensure system safety, durability, and effectiveness.
• Control & Protection: Covers requirements for ESS control, including charge/discharge management, and protection functions for safe integration with the DC power supply.
• Terminology: Defines key terms such as charge-discharge efficiency, state of charge (SOC), state of energy (SOE), and duty cycle, ensuring clear communication across the industry.

Applications

Stationary energy storage systems following IEC 62924:2017 play a critical role in modern rail electrification, particularly where regenerative braking is widely used. Key applications include:

• Regenerative Energy Absorption: ESS can capture energy generated during train braking, which might otherwise be wasted, especially where DC substations are not reversible.
  • Enables energy savings and operational cost reduction.
  • Reduces wear and maintenance needs on mechanical braking components, improving rolling stock lifespan.
  • Minimizes heat buildup in tunnels and confined spaces, enhancing safety and passenger comfort.
• Power Compensation and Quality: ESS helps stabilize line voltage and mitigate peak power demands, lessening the load on substations and enabling more reliable service.
• Flexible Energy Use: Allows stored energy to be redistributed within the network or directed to stationary facilities such as stations.
• Reducing Infrastructure Demands: By shaving power peaks, ESS systems can reduce the rating requirements for substations and other power supply equipment.

Related Standards

IEC 62924:2017 references several other IEC standards to ensure harmonized and comprehensive compliance. Related standards include:

• IEC 60146: Semiconductor converters - for power conversion equipment specifications.
• IEC 60529: Degrees of protection provided by enclosures (IP Code) - for ingress protection.
• IEC 60850: Supply voltages of traction systems - for compatibility with traction supply voltages.
• IEC 61936-1: Power installations exceeding 1 kV a.c. - common rules for high voltage installations.
• IEC 61992-7-1: DC switchgear, measurement, control, and protection devices for DC traction systems.
• IEC 62236 series: Electromagnetic compatibility requirements for railway applications.
• IEC 62590: Electronic power converters for railway substations.

Practical Value

Adopting IEC 62924:2017 helps the railway sector move towards more sustainable and efficient electrified railways. It provides:

• Consistent framework for integrating stationary energy storage into DC networks.
• Improved energy utilization and reduced environmental impact.
• Enhanced system resilience and operational flexibility.
• Clear guidelines supporting interoperability and safety, reducing barriers to deployment of innovative energy storage technologies.

By following this internationally recognized standard, stakeholders ensure that energy storage installations for DC traction systems deliver both economic and environmental benefits while complying with best practices in railway infrastructure management.