42 kV compressor motor for air separation plant in Sweden

A high-voltage synchronous motor has been installed to drive a compressor at an air separation plant in Sweden. It is directly connected to a 42 kV bus, without an intervening transformer. Rated 9 MVA, it has an active power output of 6.5 MW and can produce reactive power continuously, thus supporting the electrical network during the starting of other large motors in the area. The following items are discussed: site requirements; potential benefits of high-voltage motor technology; electrical and mechanical limitations; design and construction of motor; testing and verification of efficiency and capability; installation and commissioning; and operational experience.