Counting the losses in very high efficiency machine design: Contemporary computer simulation techniques and results encountered in very high efficiency electric machine design for renewable energy applications

The majority of applications that consume electrical energy use energy from non-renewable, greenhouse gas producing supplies, such as oil and coal. The reality is that the major reduction in greenhouse gas production within the next decade will not come from the increase in renewable energy supply, but the more efficient use of the current electricity generation. This paper illustrates current techniques and advances in machine design that aims to produce machines with efficiencies in the upper 90% region. To achieve such high efficiencies, highly accurate computer based simulations are performed and show the necessity for three dimensional analysis. A case study of a 6-kW axial flux machine is presented and the theoretical and measured loss results analyzed. In conclusion, simulation inaccuracies are summarized and a case for further study is presented.