The authors have proposed a new suppression method of the 6th-order torque ripple of permanent magnet synchronous motors (PMSMs). The proposed method can estimate the harmonic components in the flux-linkage which is the cause of 6th-order torque ripple. And, the proposed method does not use a torque meter, and estimate the harmonic components by mainly using current sensors of the inverter. By simulation using two RT models, it was confirmed that the 6th-order torque ripple could be suppressed approximately 48%.Index Terms-Permanent magnet synchronous motor, 6th-order torque ripple, periodic disturbance observer, without Torque Meter.

The authors have proposed and made a hydrogen generation system for fuel cell electric vehicles (FCEVs) and fuel cell hybrid electric vehicles (FCHEVs). The system which is called as STEP (Sodium TEtrahydroborate Power) system generates large amount of hydrogen by hydrolysis of powdery sodium borohydride (NaBH4). In this paper, The authors constructed a prototype FCEV with STEP system, and the effectiveness of the proposed system was verified by comparison with a conventional system in experiment. Two driving patterns, which simulate the driving situations of rapid acceleration, traffic jam and constant low speed, were used in the experiment to verify the effectiveness of a FCEV with STEP system. And, the STEP system used in hydrogen pressure control is still unstable during acceleration; however, the transient characteristics of the FC output power in both system were almost same. As a result, it was understood that the proposed system had ability of hydrogen supply system as well as a conventional system.