Minimization of life cycle energy cost of a single-phase induction motor

This article deals with the optimization of a single-phase permanent capacitor induction machine according to the criterion of gross energy requirement. The presented study is applied to roller shutter drives produced by SOMFY. These motors present low ratio between the operating time and the total time of use. Therefore, they are perfect candidates for an optimized eco-design method by minimizing the gross energy requirement. As the studied motors are in roller shutter´s tubes whose diameter is fixed by production and distribution constraints, only two free parameters are available for our optimizations: the active length and number of turns per phase. In this paper, the size of the motors is optimized in a transient thermal regime. The optimizations are based on a typical operating cycle of roller shutter. It is noticed that the part of the energy required for production and recycling is significant in the gross energy requirement. Thus, the usual optimization focused on the only operating losses is inefficient for this typical operating cycle. This conclusion is validated when existing motors specifications are used as parameters for the optimization. The sensitivity of optimization results are evaluated with respect to both the diameter scale and operating cycle. When the solution are optimal, it appears that an increase of the diameter reduce the gross energy requirement. Another main result is that the operating cycle definition is fundamental in the design of the motor. It justifies the principle of on-cycle optimization.