RICERCA ITALIANA     

Dependability-oriented design of electric apparatus on board train

Università degli Studi di Padova

Abstract

On board the modern trains there is a lot of electrical apparatus that can be grouped into four systems:
- supply system, composed by a transformer (for ac electrical lines) and by static power converters for voltage regulation on the power line,
- traction drive, composed by ac motors and voltage source inverters for the controlled supply of the motors,
- auxiliary equipment, formed by a variety of devices (illumination circuits, motor-driven compressors, batteries, etc.) and by static power converters for conditioning their supply voltage,
- communication network, which links aboard apparatus and devices for an integrated management of them.
The quality of the service carried out by the train system (and its safety) depends on the correct operation of all the above-mentioned systems. The increasing of the systems complexity, the demand of new functionalities and the more and more wide employment of electronic control units are factors that tend to impair the correctness of the service.
The research program under consideration fits into this scenario of topical relevance and great social and economical interest and intends to consider the design of the electrical apparatus in the light of the increased requirements of safety and quality of service. The theoretical tool by which the topic will be faced is the dependability theory, recently developed in order to set in an organic way the study and the design of safety-critical >>>

Principal Investigator

Giuseppe BUJA Università degli Studi di PADOVA

Research Objectives

In the past, the electric apparatus for railway applications were designed according to simplicity and cost-effectiveness criteria. Many apparatus were used for helping the machine drivers that controlled their operation and, when necessary, directly took care of the possible faults or, generally speaking, of the apparatus malfunctioning. In the last few years, the technological context has radically changed: the electrical apparatus perform an increasing number of complex tasks and often substitute for the operators in doing services critical for the safety and the quality of service. Thus, it has became mandatory to arrange apparatus with prefixed levels of operativeness, commonly obtained by means of a "robust" choice of the components. Such a solution, however, does not make use of the potentialities that an extensive approach to the operativeness of the apparatus could offer, by encompassing their design and by executing the design by help of methods and solutions made available by the recent scientific and technologic advancements. The research program under consideration is aimed at facing this issue, by approaching the design of the apparatus on board train in conformity with criteria based on the dependability theory.
In the railway environment, the dependability theory has been recently used for designing the fixed signalling plants. By the research program under consideration, it will be also applied to the design of the electric apparatus of a train. The >>>

Timescale

24 months

National and international background

In the modern transportation systems with economic and social relevance, such as the railway system, safety, completion of the expected service, availability of the system, reduced number of reserves are mandatory requirements. The achievement of these objectives is made even more difficult because, for technical and historic reasons, national and international railway networks use different levels of voltage and supply of different type (DC or AC). Furthermore, in the last years European Union is pushing towards the interoperability of the railway transportation systems, i.e. toward the introduction of locomotives able to operate with supply networks having different electrical parameters. Therefore, the apparatus on board train are requested -on one side- to be continuously improved in their functional performance to satisfy the market demand and -on the other side- to be able to carry out more and more complex tasks, such as to be robust against events capable of damaging or deteriorating the functionality of the apparatus, to make the on-line diagnosis of the rolling stock, to provide new on-board auxiliary services that, incidentally, are constantly increasing and absorb a power quantity that is no more negligible compared to that for the traction.
It is obvious that the greater-than-before structural and functional complexity of the apparatus is supposed not to go to the detriment of their reliability and availability. On the contrary, today it is necessary to >>>