The failure of an emergency diesel generator could cause a blackout with economic or human losses, especially if it occurs in a hospital. The authors performed an up to date statistic on diesel generators fails has been investigated in a hundred of hospitals. Although standard maintenance operation has been correctly performed, it has been found a 6 % of failures for the genset per year. MTBF of generators and main components have been investigated and updated values are reported in this paper. Components reliability is proved to be at its maximum technological value, consequently an innovative solution is here proposed. Often neighboring buildings or different electrical systems have separated emergency generators. Nowadays, in case of genset failure, most of the electrical installations are not designed to be fed from other generators. Several electrical configurations for diesel generators interconnections have been studied, in order to guarantee the mutual succor between them and therefore improving reliability. Two innovative schemes for emergency generators connection are here proposed for a more reliable electrical design.

The paper presents a preliminary technical-economic comparison between a 3 kV DC railway and the use of trains with on-board storage systems. Numerical simulations have been carried out on a real railway line, which presents an electrified section at 3 kV DC and a non-electrified section, currently covered by diesel-powered trains. Different types of ESS have been analyzed, implementing the models in Matlab/Simulink environment. A preparatory economic investigation has been carried out.

Nowadays there are 3 % of missed start-ups of emergency gensets in Italian hospitals every year. The subject of this work is the analysis of the failure to start an emergency genset due to the failure of the batteries. The work is based on ten years statistics of maintenance on hospital facilities. A real case study is here described; measurements were made on a 1000 kVA genset of a hospital to study the real operating conditions of the system. The whole electrical, mechanical and dynamic model of the starter system of a genset is studied. Computer simulations for this study are based on the Matlab/Simulink model of the considered starter system. An automatic system of parallel between the batteries of different generators is presented as a solution to the problem. This system can also indicate to the maintenance technician the need to replace a partially deteriorated battery in a timely manner. It is also proved that it is possible to succor the failed battery instantly without losing the first part of the starting transient. The work demonstrates that the failure to start, due to a fault in the batteries, can be significantly reduced by using the proposed solution. With this technical proposal the risk of blackouts and relative human losses are largely reduced.