Freelance Electrical Engineer
Electrical Drives, Traction Systems, and Electromagnetic Compatibility
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Traction System Case Study
From the abstract:
The development of a cost-optimal traction system towards a specific set of customer requirements is a complex, iterative process with many pitfalls. The new European market situation, with business-oriented operators specifying only their basic performance requirements and no technical details, and with a multinational industry where components such as motors, inverters, etc. are supplied not only from different departments but from different countries, increases the complexity of the process even further, and with that the risk of sub optimisation. Even in the simplest case, with the only requirement being a maximum run time between two stations with a certain train weight, several very different solutions are all technically possible.
Among the most important (costly!) trade-offs that must be balanced are:
* The number of traction motors vs. the installed traction power;
* Traction motor size, rated power of the 3-phase inverter, and traction motor cooling system;
* Interference requirements and AC and DC line filters;
* DC link voltage, main transformer layout, and line converter design;
* Step-up choppers or direct supply from the DC line
Ice on the Overhead Line
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Then a short note that describes in general terms the four most
important problems related to AC-AC traction:
This is an OH series that goes through the
problems and countermeasures related to electrical resonances between the
vehicle and the supply system, and the amplification of PWM harmonics.
This is a rather basic note on power control
of AC-AC vehicles, explaining how it is possible to use regenerative braking
even on long supply lines without exceeding the maximum line voltage limits.
This note explains why the low-frequency power
oscillations that are sometimes seen in the rather weak 16.7 Hz railway power
supply network in Scandinavia do not cause interference with DC track circuits.
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