منابع مشابه
HVDC Feeder Solution for Electric Railways
For AC railway power supply systems with a different frequency than the public grid, high-voltage AC (HVAC) transmission lines are common, connected to the catenary by transformers. This paper suggests an alternative design based on an HVDC (High Voltage DC) feeder, which is connected to the catenary by converters. Such an HVDC line would also be appropriate for DC-fed railways and AC-fed railw...
متن کاملProgress of Electric Railways in Japan
In 2001, railways in Japan carried 21.79 billion passengers (25.1% of all passenger transport) or 384.5 billion passenger-km (27% of all passenger transport). Rail freight totalled 59 million tonnes (1.0% of all freight transport) or 22.2 billion tonnekm (3.8% of total), clearly indicating that Japanese railway operators are almost exclusively passenger companies. Following the 1987 privatizati...
متن کاملOn Generalized Random Railways
We consider a random generalized railway defined as a random 3-regular multigraph where some vertices are regarded as switches not allowing traffic between any pair of attached edges. It is shown that the probability that the generalized railway is functioning is linear in the proportion of switches. Thus there is no threshold phenomenon for this property.
متن کاملHarmonic Elimination of 25 kV AC Electric Railways Utilizing a New Hybrid Filter Structure
Thyristor rectifiers are widely used in electric railways in order to control the speed. As a consequence of their usage in addition to substantial input lead current, an enormous amount of harmonics is injected into the grid. To avoid such harmonics as well as reactive power compensation, reactive power hybrid filters consisting of active and passive filters are utilized. Regarding different p...
متن کاملLethal troubles
The battle for whale conservation is intensifying ahead of a key meeting in June.
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Scientific American
سال: 1914
ISSN: 0036-8733
DOI: 10.1038/scientificamerican01241914-53supp