Connection criteria at the distribution network for distributed generation

CIGRÉ Technical Brochure 31

Impatto ambientale dei veicoli elettrici: approccio LCA

L’articolo mostra come la metodologia LCA (Life Cycle Analysis o analisi del ciclo di vita) possa essere applicata al confronto ambientale tra sistemi veicolari. Mostra inoltre l'importanza di tenere adeguatamente conto, per i veicoli elettrici, delle caratteristiche del Sistema Elettrico per l'Energi

Active shielding of overhead line magnetic field: Design and applications

The paper presents the successful field application of active shielding of the magnetic field of HV overhead lines. Two plants have been deployed and are being operated since some years on a 132-kV and a 400- kV line. The solutions adopted minimize the impact on the line structure. Also the configuration of the control systems has been studied in order to avoid any impact on the normal operation of the line. Two different solutions were used; the first is based on a current sensor and a radio transmitter–receiver system, the second relies on the mutual effect between the line and the shield wires thus not requiring any device installed on the power conductors. Both systems have been continuously operated for some years and have assured to keep the magnetic field at the sensitive targets below the desired limits

Da cogenerazione a trigenerazione: migliorare l'efficienza energetica

All'indubbio beneficio energetico ottenibile dagli impianti di cogenerazione e di trigenerazione non corrispondono attualmente sufficienti opportunità dal punto di vista economico, fiscale e normativo

Benchmark systems for network integration of renewable and distributed energy resources

CIGRE' Technical Brochure 57

Parametric analysis of 2 × 25 kV railway electric supply

The most common system for railway high-speed lines electric supply and the somehow de-facto standard is a special AC industrial frequency system called 2 × 25 kV system. Although several studies exist showing the performance of this system in frequency and time domains, there is a lack of studies analysing how geometric parameters influence the system behaviour, mainly in terms of conductor currents. This study first introduces a simple analytic model able to explain the fundamental feats of 2 × 25 kV systems, then evaluates the effects of critical electrical and geometrical parameters on this behaviour based on mathematical relationships and numerical computations. This simple model allows understanding the main reasons why this system is able to transmit power as a 50 kV system, while trains experience just 25 kV

Hybrid energy systems for static applications

Through a couple of examples this paper describes how hybrid systems can play an important role in today’s energy systems. They are valuable and efficient solutions in both isolated systems and for large interconnected networks. Different technologies for storage and generation as well as different operation techniques are needed for each application, but the benefits which can be achieved with respect to traditional solution are important in easing the transition towards a sustainable energy system