A map-data distribution method distributes map data from a map-data distribution server to a client and causes the client to draw a map image. In one preferred embodiment, the present invention splits off some of the excess capacity gas flow from a gas concentrator which is then stored via liquefaction. The winding with the smallest number of poles may operate the machine at the lowest bus frequency, while the winding with the largest number of poles may operate the machine at the highest bus frequency.