03.04.2011
VG Power has together with Trafikverket (previous Banverket), Jernbaneverket and Luleå Generatorservice worked together during several years with improvements in the design of the old rotating converters that supplies the railway power grid with 16.67 Hz electricity.
The old rotating units consists of 2 wagons. The units are mobile and moveable on railroad as ordinary wagons. The first wagon is the apparatus wagon and it includes switch gear, control equipment, relay protections and regulators. The second includes a 12 pole synchronous motor driven from the conventional 50 Hz grid and it is directly connected to a generator which converts the frequency to 16.67 Hz. Via a transformer in the first wagon is than the voltage increased to 16.5 kV and fed in to the railway grid. This converter wagon sets were originally built by ASEA and taken in to operation already in the 1940- and 50: s
As both motor and generator has separate excitations has it originally been slip rings with many carbon brushes that produces a lot of carbon dust inside the wagons. The need for maintenance has been high as well as the needed amount of outages. Already a few years ago did we together develop a solution with brushless exciters of same technology that has been used in hydro generators for many years. With this solution is the carbon dust problem eliminated and the need for maintenance significant reduced. This solution has been implemented in a large numbers of the existing converter wagons owned by Trafikverket.
Now we have moved the development even one step further with improvements in order to make the wagons even more environmental friendly. A new design of the generator has been implemented and with this new technology is 16.5 kV generated directly so the transformer in the apparatus wagon is no longer needed. This gives even more advantages from both maintenance and environmental perspective.
The first wagon was refurbished and modified during autumn 2010 in Luleå Generators workshop and test run was done by Trafikverket in the beginning of 2011 at their test hall in Frövi. It is now in normal operation and it will be located in Falköping from the 6 March.
The combination between the robust old wagons and improved design of the new components will now contribute to a higher utilization and improved environment in Trafikverkets operations.
Photo: A typical converter wagon set model Q48 (not the described)
