The incremental design efficiency improvement of commercially manufactured induction motors

The improvement in induction motor efficiency over the years has been incremental in nature. One of the well known methods used to increase the efficiency of induction motors, cost effectively, is by increasing the stack length. There are many motor manufacturers with proprietary designs that are optimized for different parameters, e.g. cost, volume, weight, copper, iron, etc. Therefore, the effectiveness of incrementally improving the efficiency for motors of various designs and from different manufacturers presents an interesting research. This paper seeks to determine the incremental improvement of design efficiency of motors that are already subjected to commercial production. Motors from five manufacturers were tested, torn down and analyzed and their design efficiency improvement is investigated.