Standards Development

Scope

This document gives the coordination requirements among the subsystems of neutral-section passing (NSP) system for train in the AC electrified railway with overhead contact line system by 2 control categories including:

- without-power-supply: manual-control or auto-control on-board;

- with-power-supply: change-over auto-energizing with mechanical or electronic switchgear, or continuous and flexible auto-energizing with power converters, etc.

This document specifies the functional principles and structures of different NSPs, as well as the main technical requirements for co-ordinations control parameters and key date of the subsystems.

This document also gives the guidelines to test and commissioning requirements, the protection and emergency procedure requirements in case of subsystem failure in NSP.

Note:This document can give the reference to the co-ordination requirements of neutral-zone passing system between DC and AC railway.

This document does not deal with:

- the mechanical contact interaction between pantograph and overhead contact line, which is dealt with in IEC 62486.

- the interface between rolling stock and electrical fixed installations for traction, in the frame of “power supply” qualities, which is dealt with in IEC 62313.

- detail requirements of each equipment itself for single use or other applications , which are dealt with relevant equipment standards.

Purpose

1. Purpose

The purpose of the group documents is to:

- Regulate and improve the co-ordinations in the neutral section passing system,

- Improve the safety, reliability and service quality of the railway operation.

2. Present situation in the electrified railway application Neutral section:

- inherent feature of the 90% electrified railways of the world, when interoperation between different power supply circuit.

Operation accidents:

- train halted on slope, stopping in neutral section, heavily arcing, main circuit breaker overvoltage faults, catenary collapsed by the short-circuit current between phases, etc., occur frequently when train passing through the neutral section.

Risks:

- lower seriously the capacity and the service quality of railway transportation, esp. passenger transportation.

- budgets for the maintenance of the rescue and recovering from the accidents.

Reasons:

- the problem in the co-ordinations in the neutral-section passing system.

- no practical standards to regulate the co-ordinations.

3. Technical benefits

The establishment of the group of standards has many technological advantages for the railway application market. It is helpful to guide the co-ordinations among railway lines, stations, bridges, tunnels, traction power supply and traction substations and posts, catenary, electric power and rolling stock depot in engineering construction, operation and maintenance.

According to the analyses of the present situation of railway applications in the world, the term of the neutral- section passing system for passenger and/or freight train can be defined, which is divided into two categories:

- without power by switching on-board: usually used in electrified railways;

- with power by switching or feeding from fixed installations: utilized in Japan, Switzerland, South-Korea, China, and France, to achieve the train neutral-section passing system with power.

The system covers the technologies of main subsystems of the railway, with the co-ordinations of which the reliable operation of the train passing through the neutral-section could be achieved, mainly including:

- Train subsystem (including pantograph arrangement, main circuit breaker opening and closing, train control equipment, on-board protection equipment, etc.);

- Infrastructure subsystem (including traffic arrangement, line gradient and curve conditions, layout of station or connecting line, etc.);

- Signal subsystem (including ground signal equipment, ground induction equipment, etc.);

- Traction power supply system (including substation location, distribution and layout of phase-break points of traction network, OCS arrangement of neutral section (or change-over section) of phase-break, rail-side sign for passing the neutral section, auto-energizing device for neutral section, etc.)

The subsystems and the equipment interact with each other and need to be regulated by the co-ordinating technical requirements, to determine the working conditions of relevant equipment co-ordination with each other.

This NP will be expected to solve the following practical coordination parameters and values:

- automatic control principles, train speed, transient overvoltage, traction stations distance, processing times in ATP on-board;

- neutral sections with different arrangement;

- distance to adjacent signals, magnet plate or wheel detectors arrangement;

- railway slope, stations arrangement co-ordinations between rolling stocks, fixed signals and installations, etc.

4.Economic benefits

The economic benefits of the group standards application including, 

- optimize engineering and save investment;

- reduce maintenance and rescue budgets caused by the risks of failure.

5.Social benefits

The social benefits of the group standards application including,

- improve interoperability of countries or voltages;

- improve passenger traffic quality and travel comfortability;

- improve transportation capacity of high-speed railway.

6. Quality assurance Then the group of standards will support the quality assurance as to,

- standardize the cooperative work of all participants in the construction phases of railway engineering; - standardize the co-ordinating parameter of sub-systems and equipment;

- coordinate with all interested participants to complete the performance evaluation of the train neutral-section passing system to confirm the function and operation requirements ;

- guide the dynamic acceptance test, to simulate the automatic control of passenger and/or freight train neutral-section passing system with and without power consumption under normal operation state, and to simulate backup manual control and self-rescue procedure under failure cases in train running and organization system;

- guide the operation parties to verify, evaluate and optimize the system function of the passenger and/or freight train neutral-section passing system and to ensure the transportation reliability.

7. Safety aspect Based on the group of standards, the accuracy, safety and reliability of train passing neutral-section during high- speed operation will be improved. Even if the TCS or ATP or the catenary failed, the reasonable setting of breaker open/close signs by the rail side could be signalled to the driver, with the well-developed train organization, it can improve the safety and reliability of the railway operation.

Meanwhile, the advanced neutral-section power supply equipment and devices according to Part 2 series will avoid the failure of the on-board equipment which could arise the damage of catenary, and solves the difficult problem that train could not reliably passing through neutral-section or braking on the long and extreme slope without power. It also amends against the inherent defects of three-phase traction power supply system.

8. Benefit parties The applications of the standards will benefit all interested parties inside the railway transportation: Railway Owner, Engineering Co., Train Manufacturer, Operation Co., Maintenance Co., the passenger service, and the freight logistics 9 SDGs（ Relevant SDGs’ items）

GOAL 9: Industry, Innovation and Infrastructure.

In summary, the establishment of this standard will certainly provide technical co-ordination criteria of neutral- section passing system for train in favour of all interested participants of railway transportation in various countries. And it can standardize and improve the reliability and comfort quality of railway transportation