Harmonics control of the 20 MVA PWM inverter fed LSM drive system for the Yamanashi Maglev Test Line

This paper deals with harmonics control of a 20 MVA PWM inverter-fed LSM drive system for the Yamanashi Maglev Test Line in Japan. Contents include: (1) maintaining current control performance and compensating the resonant characteristics of the LSM load with a high-power filter; (2) developing a novel PWM control method, in order to reduce the lowest and/or second order carrier harmonics caused by asymmetrical PWM multiplication; and (3) reducing the inductive interference caused by zero sequence harmonics with a common-mode reactor.