Maximum efficiency operation of Synchronous Reluctance Machine using signal injection

This paper introduces a new maximum efficiency operation method of Synchronous Reluctance Machine (SynRM) based on a signal injection. To control SynRM in the maximum efficient operating point, the sum of the copper losses and the iron losses should be minimized. Although many kinds of efficient operating method had been introduced, most of them were dependent upon the machine parameters. The inaccuracy of the machine parameters, especially d-/q-axis inductances which are known to vary extremely according to the operating condition, makes the maximum efficiency operating point be out of the target. In this paper, a new maximum efficiency operating method of SynRM is proposed. Adopting the high frequency signal injection concept, the maximum efficiency operating point can be traced without dependency on the machine parameters. The effectiveness of the method is verified by experimental results.